INSTRUMENTATION ENGINEERING INPLANT TRAINING REPORT OF FACT UDHYOGAMALAM
THE FERTILIZERS AND CHEMICALS TRAVANCORE LIMIT(FACT),Udyogamandal
I underwent an in-plant training to acquaint myself for a period of one month from July 3rd to July 14th, 2017 to get an industrial exposure in a practical aspectof technical implementation. During the course of study I was able to interact freely with the officials and other employees in the plant and fetch maximum relevant information from them. I also got an opportunity to visit the work area and get a ‘hands on’ experience on various industrial devices. The training helped me to get an idea about the various manufacturing processes and the technical instruments which are used in the plant. I also got familiarized with various large scale central distributive controlsystems which play the most crucial role in monitoring and controlling various processes in a chemical industry.
ACKNOWLEDGEMENT
I would like to take this opportunity to express my sincere gratitude to all those who have helped me throughout this in-plant training. It gives me immense pleasure to acknowledge all those who have rendered encouragement and support for the successful completion of work.
First of all ,I would like to thank my institution-Amrita School of Engineering, for allowing me to proceed with the in plant training.
I place my sincere thanks to Mr. Joy Ukkan, Dy.Manager(Trg) of FACT Training department, for permitting me to do the training at FACT.
I would also like to thank Mr.K B Jayaraj Dy.CE(I) UD, Mr.R Raju Amm(I) Sulphate , Mr.Babu Kurian,Amm(I) AC , Mr.Gopal MMI (AC), Mr.Prasad, Dept. Of Instrumentation, PD and Mr.Suneel,Dept. Of Instrumentation PD for giving there valuable time in guiding and sharing their knowledge with me.
I express my hearty thanks to all The Employees of THE FERTILIZERS AND CHEMICALS TRAVANCORE LIMITED for their constant support during the entire training.
Man’s history is replete with revolutions, responsible for molding his system of thought and shaping his modes of living. Revolutions have, more often than not, emerged out of crisis-situations it was one such crisis situation that guided the enlightened perception of a far sighted visionary to form FACT. Yes! The FERTILISER AND CHEMICALS TRAVANCORELIMITED-popularly known as FACT-was indeed a revolution when it was established as the first large scale fertilizer factory in the country. Since then, it has played a major role in creating fertilizer consciousness among our farmers, and giving a positive direction to the modernization of agriculture in India. And that, of course is an interesting story-a story of never ending challenges and constructive responses.
The History
The 1940,s were a time of critical food shortage in our country. The traditional approach to cultivation was not of much help in finding a solution to this problem. And nitrogenous fertilizer had not yet arrived on the agriculture scene in sufficient quantities to make any perceptible impact. A revolution was indeed necessary to change the status quo. And when it came, it did through the vision of Dr. C.P. Ramaswami Aiyar, the Dewan of the former Travancore State, who mooted the idea of increasing food production by the application of fertilizer as a long term solution to food problem. To give concrete shape to his idea, he sought the help of Seshayee Brothers Ltd. Industrialist known for their pioneering work. And India’s first large-scale fertilizer plant was set up in 1944 at Udyogamandal on the banks of the river periyar in Kerala State. The new venture of course had to go through many teething troubles. For instance, the raw materials necessary for the production of ammonium salts were not available in the state. But this deficiency was overcome by adopting a revolutionary method known as the FIREWOOD GASIFICATIONPROCESS.
However, initial difficulties notwithstanding, the plant at Udyogamandal went into commercial production in 1947, with the slated capacity to manufacture 50,000 tonnes of Ammonium Sulphate (10,000 tonnes of N). This was followed by the production of SUPER PHOSPHATE in a new plant with a capacity of 44,000 tones. A sulphuric acid plant of 75 tonnes per day was also installed which was considered large going standard at that time. Meanwhile the inner dynamics of FACT was finding another expression in the formation of new unit with the help of the State Government and Methur Chemical & Industrial Corporation Ltd., for the production of caustic soda which later become today’s Travancore-Cochin Chemical Ltd., a Kerala Government undertaking. This indeed was a big leap forward as it replaced all the imports of that product, saving a considerable amount of foreign exchange. FACT was the first to use its by-product, chlorine, as hydrochloric acid to produce
Ammonium Chloride. These by-products produced by FACT paved the way for setting up of other industrial units around the FACT complex viz. Hindustan Insecticide Ltd., Indian Rare Earth Ltd., etc. Expansion.
In the late 50s, the Udyogamandal Division launched its first expansion with an outlay of Rs. 3 crores. Highlights of the period were the installation of two plants to produce Phosphoric Acid and Ammonium Phosphate(16:20 Grade). The second stage of expansion involving Rs.2 crore saw the replacement of the Firewood Gasification Process and the Electrolytic Process by the Texaco Oil Gasification Process for which a new plant was set up. FACT became a Kerala State Public Sector Enterprise on 15th August1960. On 21st November 1962, the Government of India became the major share holder. The 2nd stage of expansion of FACT was completed in 1962.
The 3rd stage of expansion of FACT was completed in 1965 with setting up of a new Ammonium Sulphate Plant. FACT has been a pace-setter in marketing evolving a continuous and comprehensive package of effective communication with farmers and promotional programs to increase the fertilizer consciousness among our farmers. In fact, FACT was the first fertilizer manufacturer in India to introduce the village adoption conceptsince 1968 to improve agricultural productivity and enhance the overall socio-economic status of farmers. FACT has a well organized marking net work, capable of distribution over a million tones of fertilizers. With the licensing of Cochin Division in 1966 FACT further expanded and by 1976 the production of sulphuric acid, phosphoric acid and Urea was started. In 1979 Production of NPK was commercialized.
FACT Engineering and Design Organization (FEDO) was established in1965 to meet the emerging need for indigenous capabilities in vital areas of engineering, design and consultancy for establishing large and modern fertilizer plants. FEDO has since then diversified into Petrochemicals and other areas also. It offers multifarious services from project identification and evaluation stage to plant design, procurement project management, site supervision, commissioning and operating new plants as well as revamping and modernization of old plants. FEDO received international accreditation ISO 9001 2004 for quality system standards covering areas of consultancy, design & engineering services for construction of large fertilizer, petrochemicals, chemicals and related projects including purchasing, construction, supervisor, inspection and expediting services.
FACT Engineering Works (FEW) was established on 13th April 1966 as a unit to fabricate and install equipment for fertilizer plants. FEW was originally conceived as a unit to fabricate and install equipment for FACT’s own plants. Over the year it developed capabilities in the manufacture of class I pressure vessels, heat exchangers, rail mounted, LPG tank wagons etc. It has a well equipped workshop approved by Lloyds Register of Shipping, further; this division has excelled in laying cross country piping fabrication and installation of large penstocks for hydel units in Kerala. The Cochin Division of FACT, the 2nd production unit was set up at Ambalamedu and the 1st phase was commissioned in 1973.
The 2ndphase of FACT Cochin Division was commissioned in 1976. The project was designed to produce Ammonia which would be converted to Urea and also to produce high analysis, water soluble NP fertilizers. This division comprises of a number of large capacity
plants to produce Ammonia, Urea, Sulphuric Acid, Phosphoric Acid and Fertilizers like FACTAMPHOS 20-20and DAP 18-46.
FACT has also a Research & development Department which carries out research related to fertilizers. This Division is also capable of doing fundamental research in areas of fertilizers and chemicals technology. So far FACT R & D has taken 17 patents in areas like Sodium Fluoride, Sulphuric Acid and Ammonium Phosphate.
PRODUCTS & PRODUCT MIX PRODUCTS
Finished products
Ammonium Sulphate- Udyogamandal Division
Ammonium Phosphate/ Complex fertilizers / Factamfos – Udyogamandal Division & Cochin Division
Caprolactum- Petrochemical Division
Biofertilizers - Research & Development Division
Exported Products
Caprolactum - Petrochemical Division
Ammonium Sulphate – Udyogamandal Division
Byproducts
Nitric Acid & Soda Ash- Petrochemical Division
Gypsum - Udyogamandal Division & Cochin Division
Carbon Dioxide Gas – Udyogamandal
Intermediary Products
Ammonia - Udyogamandal & Cochin Division
Synthesis Gas - Udyogamandal Division
Sulphuric Acid- Udyogamandal & Cochin Division
Oleum - Udyogamandal Division
SO2 Gas - Udyogamandal Division
Phosphoric Acid - Udyogamandal & Cochin Division
Safety is the state of being "safe" ,the condition of being protected against physical, social, occupational, or other types or consequences offailure, damage, error, accidents, harm or any other event which could be considered non- desirable. Safety can also be defined to be the control of recognized hazards to achieve an acceptable level of risk. This can take the form of being protected from the event or from exposure to something that causes health or economical losses. It can include protection of people or of possessions.
The Fertilizers And Chemicals Travancore has been declared as a Major Hazard Accidental Industry –MHAI.
There are two methods for classifying an industry into MHAI unit-
Process Involved – Fertilizers, petrochemical products, cement, paint, etc.
ii)Quantity of chemical being handled and its commonly specified in tones
Heinrich's Domino Theory
Heinrich's Domino Theory states that accidents result from a chain of sequential events, metaphorically like a line of dominoes falling over. When one of the dominoes falls, it triggers the next one, and the next... - but removing a key factor (such as an unsafe condition or an unsafe act) prevents the start of the chain reaction.
Heinrich posits five metaphorical dominoes labelled with accident causes. They are Social Environment and Ancestry, Fault of Person, Unsafe Act or Mechanical or Physical Hazard (unsafe condition), Accident, and Injury. Heinrich defines each of these "dominoes" explicitly, and gives advice on minimizing or eliminating their presence in the sequence.
Fire and safety
Fire triangle
The fire triangle or combustion triangle is a simple model for understanding the necessary ingredients for most fires. The triangle illustrates the three elements a fire needs to ignite: heat, fuel, and an oxidizing agent (usually oxygen). A fire naturally occurs when the elements are present and combined in the right mixture, meaning that fire is actually an event rather than a thing. A fire can be prevented or extinguished by removing any one of the elements in the fire triangle. Forexample, covering a fire with a fire blanket removes the oxygen part of the triangle and can extinguish a fire.
Classification of fire
( Class A: Ordinary combustibles-Class A fires consist of ordinary combustibles such as wood, paper, fabric, and most kinds of trash.
( Class B/C: Flammable liquid and gas. These are fires whose fuel is flammable or combustible liquid or gas. Flammable liquids are designated "Class B", while burning gases are separately designated "Class C". A solid stream of water should never be used to extinguish this type because it can cause the fuel to scatter, spreading the flames. The most effective way to extinguish a liquid or gas fueled fire is by inhibiting the chemical chain reaction of the fire, which is done by dry chemical extinguishing agents, although smothering with CO2 or, for liquids, foam is also effective.
( Class C or Class E: Electrical fires are fires involving potentially energized electrical equipment. This sort of fire may be caused by short-circuiting machinery or overloaded electrical cables. Electrical fire may be fought in the same way as an ordinary combustible fire, but water, foam, and other conductive agents are not to be used. Carbon dioxide CO2, and dry chemical powder extinguishers such as PKP and even baking sodaare especially suited to extinguishing this sort of fire.
( Class D :Metal - Class D fires consist of combustible metals such as magnesium, potassium, titanium, and zirconium. ( Class K or F - Class K fires involve unsaturated cooking oils in well- insulated cooking appliances located in commercial kitchens.
Ammonium Sulphate
Ammonium sulfate was once the leading form of nitrogen fertilizer, but it now supplies a
relatively small percentage of the world total nitrogen fertilizer because of the rapiud growth in use of urea, ammonium nitrate. The main advantages of ammonium sulfate are its low
hygroscopicity, good physical properties (when properly prepared), chemical stability and good agronomic effectiveness. It reaction in the soil is strongly acid forming, which is an advantage on alkaline soils and for some crops such as tea; in some other situations its acid forming character is a disadvantages. Its main disadvantages is its lower analysis (21%N), which increases packaging, storage and transportation costs. As a result, the delivered cost at the farm level is usually higher per unit of nitrogen than that of urea or ammonium nitrate. However, in some cases, ammonium sulfate may be the most economic source of nitrogen when the transportation at low cost, or when a credit can be taken for its content.
Ammonium sulfate is available as a byproduct from the steel industry (recovered from coke oven gas) and from some metallurgical and from chemical processes.
Commercial form, storage and transportation:
Fertilizer grade ammonium sulfate specifications normally indicate a minimal nitrogen content, which is usually not less than 20.5%. limitations on free acidity and free moisture are also generally demanded; typical figures are 0.2% for free H2SO4 and 0.2% for free H2O.
occasionally, maximal values for certain organic or inorganic impurities may also be specified for byproduct material.
Properties of Pure Ammonium sulfate:
Formula (NH4)2 SO4
Molecular weight 132.14
Nitrogen content 21.2%
Color White
Density of soild, 200 1.769
Specific gravity of saturated solutions
1.2414 at 200C
1.2502 at 930C
Specific heat of solid 0.345 cal/g-0C at 910C
Specific heat of saturated solutions
0.67 cal/g-0C at 200C
0.63 cal/g-0C at 1000C
Heat of crystallization 11.6 kcal/kg from 42%
solution
Heat of dilution 6.35 kcal/kg from 42% to1.8% solutions
Melting point 512.20C
Thermal stability Decomposes above 2800C pH 5.0
Loose-bulk density 962kg/m3
Angle of repose 280
Critical relative humidity
At 200C 81.1%
At 300C 81% Solubility, g/100g of water At 00C 70.6 At 1000C 103.8 Several factors contribute to trouble free storage of ammonium sulfate and other fertilizers. First, the product should be of uniform crystal size and should contain a low percentage of lines. It should be dry and preferably have below 0.1% free moisture. No free acidity should be cooled with dry air under controlled condition after drying, particularly when the ambient temperature and humidity are sufficient high to cause subsequent moisture condensation after cooling in bulk storage pile or in sealed bags. Ammonium sulfate is commonly shipped in polyethylene or paper bags.
The majority of its production is coming from coking of coal as a byproduct. Ammonium
sulphate is produced by the direct reaction of concentrated sulphuric acid and gaseous ammonia and proceeds according to the following steps.
1. Reaction of Ammonia and Sulphuric Acid:
Liquid ammonia is evaporated in an evaporator using 16 bar steam and preheated using
low pressure steam. The stiochiometric quantities of preheated gaseous ammonia and concentrated sulphuri acid (98.5% wt/wt) are introduced to the evaporator – crystalliser (operating under vacuum). These quantities are maintained by a flow recorder controller and properly mixed by a circulating pump (from upper part of the crystalliser to the evaporator)
2. Crystallization
The reaction takes place in the crystallizer where the generated heat of reaction causes
evaporation of water making the solution supersaturated. The supersaturated solution
settles down to the bottom of crystalliser where it is pumped to vacuum metallic filter
where the A. S crystals are separated, while the mother liquor is recycled to the
crystalliser.
3. Drying of the wet Ammonium Sulphate Crystals
The wet A.S crystals are conveyed (by belt conveyors) to the rotary dryer to be dried
against hot air (steam heated) and then conveyed to the storage area where it naturally
cooled and bagged.
The following presents the process block diagram for ammonium sulphate production.
A brief summary of the Contact Process
The Contact Process:
1)makes sulphur dioxide;
2)convers the sulphur dioxide into sulphur trioxide (the reversible reaction at the heart of the process);
3)converts the sulphur trioxide into concentrated sulphuric acid.
Making the sulphur dioxide
This can either be made by burning sulphur in an excess of air:
. . . or by heating sulphide ores like pyrite in an excess of air:
In either case, an excess of air is used so that the sulphur dioxide produced is already mixed with oxygen for the next stage.
Converting the sulphur dioxide into sulphur trioxide
This is a reversible reaction, and the formation of the sulphur trioxide is exothermic.
A flow scheme for this part of the process looks like this:
The reasons for all these conditions will be explored in detail further down the page.
Converting the sulphur trioxide into sulphuric acid
This can't be done by simply adding water to the sulphur trioxide - the reaction is so uncontrollable that it creates a fog of sulphuric acid. Instead, the sulphur trioxide is first dissolved in concentrated sulphuric acid:
The product is known as fuming sulphuric acid or oleum.
This can then be reacted safely with water to produce concentrated sulphuric acid - twice as much as you originally used to make the fuming sulphuric acid.
Explaining the conditions
The proportions of sulphur dioxide and oxygen
The mixture of sulphur dioxide and oxygen going into the reactor is in equal proportions by volume.
Avogadro's Law says that equal volumes of gases at the same temperature and pressure contain equal numbers of molecules. That means that the gases are going into the reactor in the ratio of 1 molecule of sulphur dioxide to 1 of oxygen.
That is an excess of oxygen relative to the proportions demanded by the equation.
According to Le Chatelier's Principle, Increasing the concentration of oxygen in the mixture causes the position of equilibrium to shift towards the right. Since the oxygen comes from the air, this is a very cheap way of increasing the conversion of sulphur dioxide into sulphur trioxide.
Why not use an even higher proportion of oxygen? This is easy to see if you take an extreme case. Suppose you have a million molecules of oxygen to every molecule of sulphur dioxide.
The equilibrium is going to be tipped very strongly towards sulphur trioxide - virtually every molecule of sulphur dioxide will be converted into sulphur trioxide. Great! But you aren't going to produce much sulphur trioxide every day. The vast majority of what you are passing over the catalyst is oxygen which has nothing to react with.
By increasing the proportion of oxygen you can increase the percentage of the sulphur dioxide converted, but at the same time decrease the total amount of sulphur trioxide made each day. The 1 : 1 mixture turns out to give you the best possible overall yield of sulphur trioxide.
The temperature
Equilibrium considerations
You need to shift the position of the equilibrium as far as possible to the right in order to produce the maximum possible amount of sulphur trioxide in the equilibrium mixture.
The forward reaction (the production of sulphur trioxide) is exothermic.
According to Le Chatelier's Principle, this will be favoured if you lower the temperature. The system will respond by moving the position of equilibrium to counteract this - in other words by producing more heat.
In order to get as much sulphur trioxide as possible in the equilibrium mixture, you need as low a temperature as possible. However, 400 - 450°C isn't a low temperature!
Rate considerations
The lower the temperature you use, the slower the reaction becomes. A manufacturer is trying to produce as much sulphur trioxide as possible per day. It makes no sense to try to achieve an equilibrium mixture which contains a very high proportion of sulphur trioxide if it takes several years for the reaction to reach that equilibrium.
You need the gases to reach equilibrium within the very short time that they will be in contact with the catalyst in the reactor.
The compromise
400 - 450°C is a compromise temperature producing a fairly high proportion of sulphur trioxide in the equilibrium mixture, but in a very short time.
The pressure
Equilibrium considerations
Notice that there are 3 molecules on the left-hand side of the equation, but only 2 on the right.
According to Le Chatelier's Principle, if you increase the pressure the system will respond by favouring the reaction which produces fewer molecules. That will cause the pressure to fall again.
In order to get as much sulphur trioxide as possible in the equilibrium mixture, you need as high a pressure as possible. High pressures also increase the rate of the reaction. However, the reaction is done at pressures close to atmospheric pressure!
Economic considerations
Even at these relatively low pressures, there is a 99.5% conversion of sulphur dioxide into sulphur trioxide. The very small improvement that you could achieve by increasing the pressure isn't worth the expense of producing those high pressures.
The catalyst
Equilibrium considerations
The catalyst has no effect whatsoever on the position of the equilibrium. Adding a catalyst doesn't produce any greater percentage of sulphur trioxide in the equilibrium mixture. Its only function is to speed up the reaction.
Ammonium Phosphate Sulphate
This is composed mainly of ammonium sulphate and ammonium phosphate with a nitrogen content of 16 per cent and P2O5 content of 20 per cent in the 16-20-0 grade. In the 20-20-0 grade, some urea is added to increase the nitrogen to 20 per cent.
Production Capacity
Total installed capacity in the country for this fertiliser is about 186,700 tonnes per annum as P2Og. CIL-Ennore and FACT-Alwaye and Cochin produce this product.
Raw Materials
Raw materials required to produce ammonium phosphate sulphate are ammonia, phosphoric acid and sulphuric acid.
Methods of Manufacture
To make ammonium phosphate sulphate (16:20:0), a mixture of 25-30 per cent P2O5 phosphoric acid and sulphuric acid is directly-neutralized with the ammonia. The resulting slurry is granulated in a blunger. This produces a mixture of mono ammonium phosphate and ammonium sulphate which are present in the proportions of about 42 per cent and 58 per cent respectively. Ammonium Phosphate Sulphate has the same good physical property as the other ammonium phosphates, in addition to being a carrier of plant nutrient sulphur. In yet another process, the ammonium sulphate solution is added to phosphoric acid and then the mixture is ammoniated. Urea can be added in the blunger for the 20-20-0 grade.
2NH, + H3PO4 → (NH4)2HPO4
2NH3 + H2SO4 → (NH4)2SO4
A flow sheer for the process is shown in the bellow figure:
FCO Specifications (per cent by weight)
Handling, Storage and Packing
The grades are free flowing and do not normally pose any handling and storage problems.
In FACT , HABER PROCESS is using for manufacturing the Ammonia.
The Haber Process combines nitrogen from the air with hydrogen derived mainly from natural gas (methane) into ammonia. The reaction is reversible and the production of ammonia is exothermic.
A flow scheme for the Haber Process looks like this:
Some notes on the conditions
The catalyst
The catalyst is actually slightly more complicated than pure iron. It has potassium hydroxide added to it as a promoter - a substance that increases its efficiency.
The pressure
The pressure varies from one manufacturing plant to another, but is always high. You can't go far wrong in an exam quoting 200 atmospheres.
Recycling
At each pass of the gases through the reactor, only about 15% of the nitrogen and hydrogen converts to ammonia. (This figure also varies from plant to plant.) By continual recycling of the unreacted nitrogen and hydrogen, the overall conversion is about 98%.
Explaining the conditions
The proportions of nitrogen and hydrogen
The mixture of nitrogen and hydrogen going into the reactor is in the ratio of 1 volume of nitrogen to 3 volumes of hydrogen.
Avogadro's Law says that equal volumes of gases at the same temperature and pressure contain equal numbers of molecules. That means that the gases are going into the reactor in the ratio of 1 molecule of nitrogen to 3 of hydrogen.
That is the proportion demanded by the equation.
In some reactions you might choose to use an excess of one of the reactants. You would do this if it is particularly important to use up as much as possible of the other reactant - if, for example, it was much more expensive. That doesn't apply in this case.
There is always a down-side to using anything other than the equation proportions. If you have an excess of one reactant there will be molecules passing through the reactor which can't possibly react because there isn't anything for them to react with. This wastes reactor space - particularly space on the surface of the catalyst.
The temperature
Equilibrium considerations
You need to shift the position of the equilibrium as far as possible to the right in order to produce the maximum possible amount of ammonia in the equilibrium mixture.
The forward reaction (the production of ammonia) is exothermic.
According to Le Chatelier's Principle, this will be favoured if you lower the temperature. The system will respond by moving the position of equilibrium to counteract this - in other words by producing more heat.
In order to get as much ammonia as possible in the equilibrium mixture, you need as low a temperature as possible. However, 400 - 450°C isn't a low temperature!
Rate considerations
The lower the temperature you use, the slower the reaction becomes. A manufacturer is trying to produce as much ammonia as possible per day. It makes no sense to try to achieve an equilibrium mixture which contains a very high proportion of ammonia if it takes several years for the reaction to reach that equilibrium.
You need the gases to reach equilibrium within the very short time that they will be in contact with the catalyst in the reactor.
The compromise
400 - 450°C is a compromise temperature producing a reasonably high proportion of ammonia in the equilibrium mixture (even if it is only 15%), but in a very short time.
The pressure
Equilibrium considerations
Notice that there are 4 molecules on the left-hand side of the equation, but only 2 on the right.
According to Le Chatelier's Principle, if you increase the pressure the system will respond by favouring the reaction which produces fewer molecules. That will cause the pressure to fall again.
In order to get as much ammonia as possible in the equilibrium mixture, you need as high a pressure as possible. 200 atmospheres is a high pressure, but not amazingly high.
Rate considerations
Increasing the pressure brings the molecules closer together. In this particular instance, it will increase their chances of hitting and sticking to the surface of the catalyst where they can react. The higher the pressure the better in terms of the rate of a gas reaction.
Economic considerations
Very high pressures are very expensive to produce on two counts.
You have to build extremely strong pipes and containment vessels to withstand the very high pressure. That increases your capital costs when the plant is built.
High pressures cost a lot to produce and maintain. That means that the running costs of your plant are very high.
The compromise
200 atmospheres is a compromise pressure chosen on economic grounds. If the pressure used is too high, the cost of generating it exceeds the price you can get for the extra ammonia produced.
The catalyst
Equilibrium considerations
The catalyst has no effect whatsoever on the position of the equilibrium. Adding a catalyst doesn't produce any greater percentage of ammonia in the equilibrium mixture. Its only function is to speed up the reaction.
Rate considerations
In the absence of a catalyst the reaction is so slow that virtually no reaction happens in any sensible time. The catalyst ensures that the reaction is fast enough for a dynamic equilibrium to be set up within the very short time that the gases are actually in the reactor.
Separating the ammonia
When the gases leave the reactor they are hot and at a very high pressure. Ammonia is easily liquefied under pressure as long as it isn't too hot, and so the temperature of the mixture is lowered enough for the ammonia to turn to a liquid. The nitrogen and hydrogen remain as gases even under these high pressures, and can be recycled.
Safety Valve safety Valve is a type of valve that automatically actuates when the pressure of inlet side of the valve increases to a predetermined pressure, to open the valve disc and discharge the fluid ( steam or gas ) ; and when the pressure decreases to the prescribed value, to close the valve disc again. Safety valve is so-called a final safety device which controls the pressure and discharges certain amount of fluid by itself without any electric power support.
Safety Valve is mainly installed in a chemical plant, electric power boiler, gas storage tank, preventing the pressure vessels from exploding or damaging.
When the container pressure exceeds the design requirements, the safety valve automatically opens; the escaping gas reduces internal over pressure, to prevent the container or pipeline damage. And when the internal pressure reduces to normal operating pressure, the container automatically shuts down to avoid over-pressure exhaust all the gas, lead to waste and productionsuspension. It is mainly composedbythe seat, disc (valve core) and the loading mechanism.
Control valves are valves used to control conditions such as flow, pressure, temperature, and liquid level by fully or partially opening or closing in responseto signals received from controllers that compare a "setpoint" to a "process variable" whose value is provided by sensors that monitor changes in such conditions.
The positioner is a device mounted on a controlvalve that receives control signal from a DCS or any host system. The signal can be a 4- 20mA/HART/Fieldbus, etc. The positioner receives the signal and understands the desired (target) position of the valve.
E.g.,A positioner working on a 4-20mA signal range receives a 12mA means the valve has to be positioned at 50% open. Without a positioner, the valve might not be positioned at 50% due to several factors suchas fluid forces, friction, etc. The positioner sends pressure to the actuator in order to position the valve at 50%. The positioner is also physically connected with the valve stem, so it receives feedback about the current position of the val11. the positioner adjusts the output to the actuator if required. In short, the ultimate function of the positioner is to ensure that the desired opening of the valve is achieved in responseto the control signal received from the host system.
Solenoid valves are used for quick controlling (or to trip a system). Normally they are used when an emergency control in flow is to done. Solenoid valves are much faster than other valves.
A solenoid valve is the combination of a basic solenoid and mechanical valve.So a solenoid valve has two parts namely- Electrical solenoid, mechanical valve.
Solenoid converts electrical energy to mechanical energy and this energy is used to operate a mechanical valve that is to open, close or to adjust in a position. When the coil is energized , the resulting magnetic field pulls the plunger to the middle of the coil. The magnetic force is unidirectional — a spring is required to return the plunger to its un energized position.
Radar Level Transmitters are used to measure the level of a liquid, in a huge tank, mostly a storage tank than a process tank . Radar level instruments measure the distance from the Transmitter/sensor to the surface of a process material located further below. Radar level instruments use radio waves which are electromagnetic in with very high frequency in the microwave frequency range. Radar level instruments use an antenna to broadcastorsend radio signals to the process liquid whose level is to be determined.
To measure the level of a liquid or solid, radar signals are transmitted from the antenna of a radar instrument located at the top of a tank or vessel. The pulse radar sends out a microwave signal that bounces off the produt surface and returns to the gauge. The transmitter measures the time delay between the transmitted and received echo signal and the onboard microprocessorcalculates the distance to the liquid surface. To calculate liquid level, the transmitter is programmed with the reference gauge height of the application usually the bottomof the tank or chamber. The liquid level is then calculated by the microprocessorin the transmitter.
Resistance Temperature Detectors are sensors that measure temperature by correlating the resistance of the RTD element with temperature. Most RTD elements consist of a length of fine coiled wire wrapped around a ceramic or glass core. The RTD element is constructed from a pure material, the resistance of which, at various temperatures, has been documented .The material has a predictable change in resistance as the temperature varies; it is this change that is used to determine temperature. RTDs are generally considered to be among the most accurate temperature sensors available. RTDs also provide high immunity to electrical noise and are, therefore, well suited for applications in process and industrial automation environments, especially around motors, generators and other high voltage equipment. However, they have a small temperature range.
A thermocouple consists of two dissimilar metals, joined together at one end. When the junction of the two metals is cooled or heated a voltage is produced that can be correlated back to the temperature. Since thermocouples measure wide temperature ranges and are relatively rugged, they are very often used demanding industrial automation and process controlapplications. In selecting a thermocouple, the following criteria are key considerations:
( Temperature range
( Chemical resistance of the thermocouple or sheath material
( Abrasion and vibration resistance
( Installation requirements (may need to be compatible with existing equipment;existing holes may determine probediameter)
A pressure transducer, often called a pressure transmitter, is a transducer that converts pressure into an analog electrical signal. Although there are various types of pressure transducers, one of the most common is the strain- gage base transducer.
The conversion of pressure into an electrical signal is achieved by the physical deformation of strain gages which are bonded into the diaphragm of the pressure transducer and wired into a Wheatstone bridge configuration. Pressure applied to the pressure transducer produces a deflection of the diaphragm which introduces strain to the gages. The strain will producean electrical resistance change proportional to the pressure. The converted electrical signal is in the range of 4 -20 ma.
Key Note :
All the instruments are configured to have a 4-20ma current signal or 1-5 v as the output. Since a 4-20mA signal is least affected by electrical noise and resistance in the signal wires, these transducers are best used when the signal must be transmitted long distances. It is not uncommon to use these transducers in applications where the lead wire must be 1000 feet or more.
While the operating voltage is device specific, most of the devices use 24V DC or 110v DC as input voltage.
Distributed controlsystems (DCSs) are dedicated systems used to control manufacturing processes that are continuous or batch-oriented, suchas oil refining, petrochemicals, central station power generation, fertilizers, pharmaceuticals, food and beverage manufacturing, cement production, steelmaking, and papermaking. DCSs are connected to sensors and actuators and use setpoint control to control the flow of material through the plant. Pressure or flow measurements are transmitted to the controller, usually through the aid of a signal conditioning input/output (I/O) device. When the measured variable reaches a certain point, the controller instructs a valve or actuation device to open or close until the fluidic flow process reaches the desired setpoint.
The Fertilizers and Chemicals Travancore-FACT plants have thousands of I/O points and employ very large DCSs. Processesare not limited to fluidic flow through pipes, but also include measuring, monitoring and controlling of various parameters like pressure, flow, temperature, etc
(DCS in Ammonium Sulphate(UD) plant -YOKOGAWA CENTUM CS1000
Since the day it is released ,CENTUM CS 1000 is widely applied in the plants of oil refinery, petrochemical, chemistry, iron and steel, non-ferrous metal, metal, cement, paper pulp, food and pharmaceutical industries, and power, gas and water supply as well as many other public utilities.
The excellent operability and engineering technique, and the high reliability proved by the abundant actual application results, guaranteed that the CENTUM CS 1000 will continue to play an important role in process industries
( System Overview
( Information Command Station (ICS) A station for operating and monitoring the plant process control.
( Console Type ICS
A standard type of ICS with extensive capability and high reliability.
( Desktop ICS
The ICS on the desktop, the main body, CRT and keyboard are separated.
( PICS
A general-purpose PC used as ICS.
( Field Control Station (FCS)
The controlunit for plant process control
( Node
A remote input and output unit that passes the field signals to FCS control unit via remote buses.
( Engineering Work Station (EWS)
A workstation with engineering capabilities used for system configuration and system maintenance.
( Bus Converter(ABC)
Bus converters are required if a system contains multiple domains or contains the legacy CENTUM project.
( Communication Gateway(ACG)
A communication gateway unit is for linking a supervisory computer to control bus.
( V Net
Real time controlbus for linking FCS, ICS and ABC.
( E Net
The information LAN of the system for linking ICSs and EWS.
( Human Machine Interface
There are 4 panels on the human – machine interface -Graphic Panel, Control Panel, Overview Panel and Trend Panel .
Up to ten panels can be tiled or cascaded on display. Since the panels with the required information can be promptly switched, the speedyoperation and monitoring becomes possible. By shrinking the size of panels to one fourth, four panels can be displayed on one screen.
Features of Delta V DCS system :
( Advanced Control
The Delta V system enables you to quickly deploy state-of-the-art intelligent control for improved plant performance, without the implementation and maintenance problems associated with traditional advanced control systems. With embedded intelligent control, such as fuzzy logic, model predictive control, and neural network function blocks, advanced applications can be implemented with minimal effort.
( Device Integration:
The DeltaV system enables your plant and maintenance team to easily monitor field device health status. Based on real-time diagnostics from intelligent field devices, your staff can respond quickly and make informed decisions to prevent unexpected shutdowns. Integrated machinery protection and prediction deliver critical feedback on the health of your plant’s rotating machinery asset.
( Enterprise Integration:
Ready access to continuous and event historical process information is critical to operating, analyzing, and optimizing your plant. This collected information also needs to be available to applications beyond the control system boundaries, such as laboratory information and enterprise resource planning (ERP) systems. The DeltaV system integrates via standard-based open communications – enabling control data to be provided to the experts who need it, anywhere.
( Controllers:
The Delta V controllers provide communication and control between the field devices and the other nodes on the control network. These powerful controllers have embedded intelligent control to optimize your loops – all the time. The S- series controllers have all the features of the M-series controllers with the added support for electronic marshalling and the wireless I/O card.
Delta V Operate gives operators an intuitive view into the process with easy, one click access to alarm summaries, alarm faceplates, trends, display navigation, and online help. Delta V diagnostics extend not only to the system components but beyond – to cyber security and intelligent deice and machinery monitoring – increasing process uptime and reducing unplanned shutdowns.
ABSTRACT
I underwent an in-plant training to acquaint myself for a period of one month from July 3rd to July 14th, 2017 to get an industrial exposure in a practical aspectof technical implementation. During the course of study I was able to interact freely with the officials and other employees in the plant and fetch maximum relevant information from them. I also got an opportunity to visit the work area and get a ‘hands on’ experience on various industrial devices. The training helped me to get an idea about the various manufacturing processes and the technical instruments which are used in the plant. I also got familiarized with various large scale central distributive controlsystems which play the most crucial role in monitoring and controlling various processes in a chemical industry.
ACKNOWLEDGEMENT
I would like to take this opportunity to express my sincere gratitude to all those who have helped me throughout this in-plant training. It gives me immense pleasure to acknowledge all those who have rendered encouragement and support for the successful completion of work.
First of all ,I would like to thank my institution-Amrita School of Engineering, for allowing me to proceed with the in plant training.
I place my sincere thanks to Mr. Joy Ukkan, Dy.Manager(Trg) of FACT Training department, for permitting me to do the training at FACT.
I would also like to thank Mr.K B Jayaraj Dy.CE(I) UD, Mr.R Raju Amm(I) Sulphate , Mr.Babu Kurian,Amm(I) AC , Mr.Gopal MMI (AC), Mr.Prasad, Dept. Of Instrumentation, PD and Mr.Suneel,Dept. Of Instrumentation PD for giving there valuable time in guiding and sharing their knowledge with me.
I express my hearty thanks to all The Employees of THE FERTILIZERS AND CHEMICALS TRAVANCORE LIMITED for their constant support during the entire training.
FACT-An introduction
Man’s history is replete with revolutions, responsible for molding his system of thought and shaping his modes of living. Revolutions have, more often than not, emerged out of crisis-situations it was one such crisis situation that guided the enlightened perception of a far sighted visionary to form FACT. Yes! The FERTILISER AND CHEMICALS TRAVANCORELIMITED-popularly known as FACT-was indeed a revolution when it was established as the first large scale fertilizer factory in the country. Since then, it has played a major role in creating fertilizer consciousness among our farmers, and giving a positive direction to the modernization of agriculture in India. And that, of course is an interesting story-a story of never ending challenges and constructive responses.
The History
The 1940,s were a time of critical food shortage in our country. The traditional approach to cultivation was not of much help in finding a solution to this problem. And nitrogenous fertilizer had not yet arrived on the agriculture scene in sufficient quantities to make any perceptible impact. A revolution was indeed necessary to change the status quo. And when it came, it did through the vision of Dr. C.P. Ramaswami Aiyar, the Dewan of the former Travancore State, who mooted the idea of increasing food production by the application of fertilizer as a long term solution to food problem. To give concrete shape to his idea, he sought the help of Seshayee Brothers Ltd. Industrialist known for their pioneering work. And India’s first large-scale fertilizer plant was set up in 1944 at Udyogamandal on the banks of the river periyar in Kerala State. The new venture of course had to go through many teething troubles. For instance, the raw materials necessary for the production of ammonium salts were not available in the state. But this deficiency was overcome by adopting a revolutionary method known as the FIREWOOD GASIFICATIONPROCESS.
However, initial difficulties notwithstanding, the plant at Udyogamandal went into commercial production in 1947, with the slated capacity to manufacture 50,000 tonnes of Ammonium Sulphate (10,000 tonnes of N). This was followed by the production of SUPER PHOSPHATE in a new plant with a capacity of 44,000 tones. A sulphuric acid plant of 75 tonnes per day was also installed which was considered large going standard at that time. Meanwhile the inner dynamics of FACT was finding another expression in the formation of new unit with the help of the State Government and Methur Chemical & Industrial Corporation Ltd., for the production of caustic soda which later become today’s Travancore-Cochin Chemical Ltd., a Kerala Government undertaking. This indeed was a big leap forward as it replaced all the imports of that product, saving a considerable amount of foreign exchange. FACT was the first to use its by-product, chlorine, as hydrochloric acid to produce
Ammonium Chloride. These by-products produced by FACT paved the way for setting up of other industrial units around the FACT complex viz. Hindustan Insecticide Ltd., Indian Rare Earth Ltd., etc. Expansion.
In the late 50s, the Udyogamandal Division launched its first expansion with an outlay of Rs. 3 crores. Highlights of the period were the installation of two plants to produce Phosphoric Acid and Ammonium Phosphate(16:20 Grade). The second stage of expansion involving Rs.2 crore saw the replacement of the Firewood Gasification Process and the Electrolytic Process by the Texaco Oil Gasification Process for which a new plant was set up. FACT became a Kerala State Public Sector Enterprise on 15th August1960. On 21st November 1962, the Government of India became the major share holder. The 2nd stage of expansion of FACT was completed in 1962.
The 3rd stage of expansion of FACT was completed in 1965 with setting up of a new Ammonium Sulphate Plant. FACT has been a pace-setter in marketing evolving a continuous and comprehensive package of effective communication with farmers and promotional programs to increase the fertilizer consciousness among our farmers. In fact, FACT was the first fertilizer manufacturer in India to introduce the village adoption conceptsince 1968 to improve agricultural productivity and enhance the overall socio-economic status of farmers. FACT has a well organized marking net work, capable of distribution over a million tones of fertilizers. With the licensing of Cochin Division in 1966 FACT further expanded and by 1976 the production of sulphuric acid, phosphoric acid and Urea was started. In 1979 Production of NPK was commercialized.
Technical Divisions
FACT Engineering and Design Organization (FEDO) was established in1965 to meet the emerging need for indigenous capabilities in vital areas of engineering, design and consultancy for establishing large and modern fertilizer plants. FEDO has since then diversified into Petrochemicals and other areas also. It offers multifarious services from project identification and evaluation stage to plant design, procurement project management, site supervision, commissioning and operating new plants as well as revamping and modernization of old plants. FEDO received international accreditation ISO 9001 2004 for quality system standards covering areas of consultancy, design & engineering services for construction of large fertilizer, petrochemicals, chemicals and related projects including purchasing, construction, supervisor, inspection and expediting services.
FACT Engineering Works (FEW) was established on 13th April 1966 as a unit to fabricate and install equipment for fertilizer plants. FEW was originally conceived as a unit to fabricate and install equipment for FACT’s own plants. Over the year it developed capabilities in the manufacture of class I pressure vessels, heat exchangers, rail mounted, LPG tank wagons etc. It has a well equipped workshop approved by Lloyds Register of Shipping, further; this division has excelled in laying cross country piping fabrication and installation of large penstocks for hydel units in Kerala. The Cochin Division of FACT, the 2nd production unit was set up at Ambalamedu and the 1st phase was commissioned in 1973.
The 2ndphase of FACT Cochin Division was commissioned in 1976. The project was designed to produce Ammonia which would be converted to Urea and also to produce high analysis, water soluble NP fertilizers. This division comprises of a number of large capacity
plants to produce Ammonia, Urea, Sulphuric Acid, Phosphoric Acid and Fertilizers like FACTAMPHOS 20-20and DAP 18-46.
FACT has also a Research & development Department which carries out research related to fertilizers. This Division is also capable of doing fundamental research in areas of fertilizers and chemicals technology. So far FACT R & D has taken 17 patents in areas like Sodium Fluoride, Sulphuric Acid and Ammonium Phosphate.
PRODUCTS & PRODUCT MIX PRODUCTS
Finished products
Ammonium Sulphate- Udyogamandal Division
Ammonium Phosphate/ Complex fertilizers / Factamfos – Udyogamandal Division & Cochin Division
Caprolactum- Petrochemical Division
Biofertilizers - Research & Development Division
Exported Products
Caprolactum - Petrochemical Division
Ammonium Sulphate – Udyogamandal Division
Byproducts
Nitric Acid & Soda Ash- Petrochemical Division
Gypsum - Udyogamandal Division & Cochin Division
Carbon Dioxide Gas – Udyogamandal
Intermediary Products
Ammonia - Udyogamandal & Cochin Division
Synthesis Gas - Udyogamandal Division
Sulphuric Acid- Udyogamandal & Cochin Division
Oleum - Udyogamandal Division
SO2 Gas - Udyogamandal Division
Phosphoric Acid - Udyogamandal & Cochin Division
DAY 1 :SAFETY
GENERAL SAFETY
Safety is the state of being "safe" ,the condition of being protected against physical, social, occupational, or other types or consequences offailure, damage, error, accidents, harm or any other event which could be considered non- desirable. Safety can also be defined to be the control of recognized hazards to achieve an acceptable level of risk. This can take the form of being protected from the event or from exposure to something that causes health or economical losses. It can include protection of people or of possessions.
The Fertilizers And Chemicals Travancore has been declared as a Major Hazard Accidental Industry –MHAI.
There are two methods for classifying an industry into MHAI unit-
Process Involved – Fertilizers, petrochemical products, cement, paint, etc.
ii)Quantity of chemical being handled and its commonly specified in tones
Heinrich's Domino Theory
Heinrich's Domino Theory states that accidents result from a chain of sequential events, metaphorically like a line of dominoes falling over. When one of the dominoes falls, it triggers the next one, and the next... - but removing a key factor (such as an unsafe condition or an unsafe act) prevents the start of the chain reaction.
Heinrich posits five metaphorical dominoes labelled with accident causes. They are Social Environment and Ancestry, Fault of Person, Unsafe Act or Mechanical or Physical Hazard (unsafe condition), Accident, and Injury. Heinrich defines each of these "dominoes" explicitly, and gives advice on minimizing or eliminating their presence in the sequence.
Fire and safety
Fire triangle
The fire triangle or combustion triangle is a simple model for understanding the necessary ingredients for most fires. The triangle illustrates the three elements a fire needs to ignite: heat, fuel, and an oxidizing agent (usually oxygen). A fire naturally occurs when the elements are present and combined in the right mixture, meaning that fire is actually an event rather than a thing. A fire can be prevented or extinguished by removing any one of the elements in the fire triangle. Forexample, covering a fire with a fire blanket removes the oxygen part of the triangle and can extinguish a fire.
Classification of fire
( Class A: Ordinary combustibles-Class A fires consist of ordinary combustibles such as wood, paper, fabric, and most kinds of trash.
( Class B/C: Flammable liquid and gas. These are fires whose fuel is flammable or combustible liquid or gas. Flammable liquids are designated "Class B", while burning gases are separately designated "Class C". A solid stream of water should never be used to extinguish this type because it can cause the fuel to scatter, spreading the flames. The most effective way to extinguish a liquid or gas fueled fire is by inhibiting the chemical chain reaction of the fire, which is done by dry chemical extinguishing agents, although smothering with CO2 or, for liquids, foam is also effective.
( Class C or Class E: Electrical fires are fires involving potentially energized electrical equipment. This sort of fire may be caused by short-circuiting machinery or overloaded electrical cables. Electrical fire may be fought in the same way as an ordinary combustible fire, but water, foam, and other conductive agents are not to be used. Carbon dioxide CO2, and dry chemical powder extinguishers such as PKP and even baking sodaare especially suited to extinguishing this sort of fire.
( Class D :Metal - Class D fires consist of combustible metals such as magnesium, potassium, titanium, and zirconium. ( Class K or F - Class K fires involve unsaturated cooking oils in well- insulated cooking appliances located in commercial kitchens.
DAY 2-3 :AMMONIUM SUPHATE PLANT
Ammonium Sulphate
Ammonium sulfate was once the leading form of nitrogen fertilizer, but it now supplies a
relatively small percentage of the world total nitrogen fertilizer because of the rapiud growth in use of urea, ammonium nitrate. The main advantages of ammonium sulfate are its low
hygroscopicity, good physical properties (when properly prepared), chemical stability and good agronomic effectiveness. It reaction in the soil is strongly acid forming, which is an advantage on alkaline soils and for some crops such as tea; in some other situations its acid forming character is a disadvantages. Its main disadvantages is its lower analysis (21%N), which increases packaging, storage and transportation costs. As a result, the delivered cost at the farm level is usually higher per unit of nitrogen than that of urea or ammonium nitrate. However, in some cases, ammonium sulfate may be the most economic source of nitrogen when the transportation at low cost, or when a credit can be taken for its content.
Ammonium sulfate is available as a byproduct from the steel industry (recovered from coke oven gas) and from some metallurgical and from chemical processes.
Commercial form, storage and transportation:
Fertilizer grade ammonium sulfate specifications normally indicate a minimal nitrogen content, which is usually not less than 20.5%. limitations on free acidity and free moisture are also generally demanded; typical figures are 0.2% for free H2SO4 and 0.2% for free H2O.
occasionally, maximal values for certain organic or inorganic impurities may also be specified for byproduct material.
Properties of Pure Ammonium sulfate:
Formula (NH4)2 SO4
Molecular weight 132.14
Nitrogen content 21.2%
Color White
Density of soild, 200 1.769
Specific gravity of saturated solutions
1.2414 at 200C
1.2502 at 930C
Specific heat of solid 0.345 cal/g-0C at 910C
Specific heat of saturated solutions
0.67 cal/g-0C at 200C
0.63 cal/g-0C at 1000C
Heat of crystallization 11.6 kcal/kg from 42%
solution
Heat of dilution 6.35 kcal/kg from 42% to1.8% solutions
Melting point 512.20C
Thermal stability Decomposes above 2800C pH 5.0
Loose-bulk density 962kg/m3
Angle of repose 280
Critical relative humidity
At 200C 81.1%
At 300C 81% Solubility, g/100g of water At 00C 70.6 At 1000C 103.8 Several factors contribute to trouble free storage of ammonium sulfate and other fertilizers. First, the product should be of uniform crystal size and should contain a low percentage of lines. It should be dry and preferably have below 0.1% free moisture. No free acidity should be cooled with dry air under controlled condition after drying, particularly when the ambient temperature and humidity are sufficient high to cause subsequent moisture condensation after cooling in bulk storage pile or in sealed bags. Ammonium sulfate is commonly shipped in polyethylene or paper bags.
The majority of its production is coming from coking of coal as a byproduct. Ammonium
sulphate is produced by the direct reaction of concentrated sulphuric acid and gaseous ammonia and proceeds according to the following steps.
1. Reaction of Ammonia and Sulphuric Acid:
Liquid ammonia is evaporated in an evaporator using 16 bar steam and preheated using
low pressure steam. The stiochiometric quantities of preheated gaseous ammonia and concentrated sulphuri acid (98.5% wt/wt) are introduced to the evaporator – crystalliser (operating under vacuum). These quantities are maintained by a flow recorder controller and properly mixed by a circulating pump (from upper part of the crystalliser to the evaporator)
2. Crystallization
The reaction takes place in the crystallizer where the generated heat of reaction causes
evaporation of water making the solution supersaturated. The supersaturated solution
settles down to the bottom of crystalliser where it is pumped to vacuum metallic filter
where the A. S crystals are separated, while the mother liquor is recycled to the
crystalliser.
3. Drying of the wet Ammonium Sulphate Crystals
The wet A.S crystals are conveyed (by belt conveyors) to the rotary dryer to be dried
against hot air (steam heated) and then conveyed to the storage area where it naturally
cooled and bagged.
The following presents the process block diagram for ammonium sulphate production.
DAY 4,5,8,10 :SULPHURIC PLANT
A brief summary of the Contact Process
The Contact Process:
1)makes sulphur dioxide;
2)convers the sulphur dioxide into sulphur trioxide (the reversible reaction at the heart of the process);
3)converts the sulphur trioxide into concentrated sulphuric acid.
Making the sulphur dioxide
This can either be made by burning sulphur in an excess of air:
. . . or by heating sulphide ores like pyrite in an excess of air:
In either case, an excess of air is used so that the sulphur dioxide produced is already mixed with oxygen for the next stage.
Converting the sulphur dioxide into sulphur trioxide
This is a reversible reaction, and the formation of the sulphur trioxide is exothermic.
A flow scheme for this part of the process looks like this:
The reasons for all these conditions will be explored in detail further down the page.
Converting the sulphur trioxide into sulphuric acid
This can't be done by simply adding water to the sulphur trioxide - the reaction is so uncontrollable that it creates a fog of sulphuric acid. Instead, the sulphur trioxide is first dissolved in concentrated sulphuric acid:
The product is known as fuming sulphuric acid or oleum.
This can then be reacted safely with water to produce concentrated sulphuric acid - twice as much as you originally used to make the fuming sulphuric acid.
Explaining the conditions
The proportions of sulphur dioxide and oxygen
The mixture of sulphur dioxide and oxygen going into the reactor is in equal proportions by volume.
Avogadro's Law says that equal volumes of gases at the same temperature and pressure contain equal numbers of molecules. That means that the gases are going into the reactor in the ratio of 1 molecule of sulphur dioxide to 1 of oxygen.
That is an excess of oxygen relative to the proportions demanded by the equation.
According to Le Chatelier's Principle, Increasing the concentration of oxygen in the mixture causes the position of equilibrium to shift towards the right. Since the oxygen comes from the air, this is a very cheap way of increasing the conversion of sulphur dioxide into sulphur trioxide.
Why not use an even higher proportion of oxygen? This is easy to see if you take an extreme case. Suppose you have a million molecules of oxygen to every molecule of sulphur dioxide.
The equilibrium is going to be tipped very strongly towards sulphur trioxide - virtually every molecule of sulphur dioxide will be converted into sulphur trioxide. Great! But you aren't going to produce much sulphur trioxide every day. The vast majority of what you are passing over the catalyst is oxygen which has nothing to react with.
By increasing the proportion of oxygen you can increase the percentage of the sulphur dioxide converted, but at the same time decrease the total amount of sulphur trioxide made each day. The 1 : 1 mixture turns out to give you the best possible overall yield of sulphur trioxide.
The temperature
Equilibrium considerations
You need to shift the position of the equilibrium as far as possible to the right in order to produce the maximum possible amount of sulphur trioxide in the equilibrium mixture.
The forward reaction (the production of sulphur trioxide) is exothermic.
According to Le Chatelier's Principle, this will be favoured if you lower the temperature. The system will respond by moving the position of equilibrium to counteract this - in other words by producing more heat.
In order to get as much sulphur trioxide as possible in the equilibrium mixture, you need as low a temperature as possible. However, 400 - 450°C isn't a low temperature!
Rate considerations
The lower the temperature you use, the slower the reaction becomes. A manufacturer is trying to produce as much sulphur trioxide as possible per day. It makes no sense to try to achieve an equilibrium mixture which contains a very high proportion of sulphur trioxide if it takes several years for the reaction to reach that equilibrium.
You need the gases to reach equilibrium within the very short time that they will be in contact with the catalyst in the reactor.
The compromise
400 - 450°C is a compromise temperature producing a fairly high proportion of sulphur trioxide in the equilibrium mixture, but in a very short time.
The pressure
Equilibrium considerations
Notice that there are 3 molecules on the left-hand side of the equation, but only 2 on the right.
According to Le Chatelier's Principle, if you increase the pressure the system will respond by favouring the reaction which produces fewer molecules. That will cause the pressure to fall again.
In order to get as much sulphur trioxide as possible in the equilibrium mixture, you need as high a pressure as possible. High pressures also increase the rate of the reaction. However, the reaction is done at pressures close to atmospheric pressure!
Economic considerations
Even at these relatively low pressures, there is a 99.5% conversion of sulphur dioxide into sulphur trioxide. The very small improvement that you could achieve by increasing the pressure isn't worth the expense of producing those high pressures.
The catalyst
Equilibrium considerations
The catalyst has no effect whatsoever on the position of the equilibrium. Adding a catalyst doesn't produce any greater percentage of sulphur trioxide in the equilibrium mixture. Its only function is to speed up the reaction.
DAY 6-7 :AMMONIUM PHOSPHATE SULPHATE PLANT
Ammonium Phosphate Sulphate
This is composed mainly of ammonium sulphate and ammonium phosphate with a nitrogen content of 16 per cent and P2O5 content of 20 per cent in the 16-20-0 grade. In the 20-20-0 grade, some urea is added to increase the nitrogen to 20 per cent.
Production Capacity
Total installed capacity in the country for this fertiliser is about 186,700 tonnes per annum as P2Og. CIL-Ennore and FACT-Alwaye and Cochin produce this product.
Raw Materials
Raw materials required to produce ammonium phosphate sulphate are ammonia, phosphoric acid and sulphuric acid.
Methods of Manufacture
To make ammonium phosphate sulphate (16:20:0), a mixture of 25-30 per cent P2O5 phosphoric acid and sulphuric acid is directly-neutralized with the ammonia. The resulting slurry is granulated in a blunger. This produces a mixture of mono ammonium phosphate and ammonium sulphate which are present in the proportions of about 42 per cent and 58 per cent respectively. Ammonium Phosphate Sulphate has the same good physical property as the other ammonium phosphates, in addition to being a carrier of plant nutrient sulphur. In yet another process, the ammonium sulphate solution is added to phosphoric acid and then the mixture is ammoniated. Urea can be added in the blunger for the 20-20-0 grade.
2NH, + H3PO4 → (NH4)2HPO4
2NH3 + H2SO4 → (NH4)2SO4
A flow sheer for the process is shown in the bellow figure:
FCO Specifications (per cent by weight)
Handling, Storage and Packing
The grades are free flowing and do not normally pose any handling and storage problems.
DAY 9 : AMMONIA PLANT
In FACT , HABER PROCESS is using for manufacturing the Ammonia.
The Haber Process combines nitrogen from the air with hydrogen derived mainly from natural gas (methane) into ammonia. The reaction is reversible and the production of ammonia is exothermic.
A flow scheme for the Haber Process looks like this:
Some notes on the conditions
The catalyst
The catalyst is actually slightly more complicated than pure iron. It has potassium hydroxide added to it as a promoter - a substance that increases its efficiency.
The pressure
The pressure varies from one manufacturing plant to another, but is always high. You can't go far wrong in an exam quoting 200 atmospheres.
Recycling
At each pass of the gases through the reactor, only about 15% of the nitrogen and hydrogen converts to ammonia. (This figure also varies from plant to plant.) By continual recycling of the unreacted nitrogen and hydrogen, the overall conversion is about 98%.
Explaining the conditions
The proportions of nitrogen and hydrogen
The mixture of nitrogen and hydrogen going into the reactor is in the ratio of 1 volume of nitrogen to 3 volumes of hydrogen.
Avogadro's Law says that equal volumes of gases at the same temperature and pressure contain equal numbers of molecules. That means that the gases are going into the reactor in the ratio of 1 molecule of nitrogen to 3 of hydrogen.
That is the proportion demanded by the equation.
In some reactions you might choose to use an excess of one of the reactants. You would do this if it is particularly important to use up as much as possible of the other reactant - if, for example, it was much more expensive. That doesn't apply in this case.
There is always a down-side to using anything other than the equation proportions. If you have an excess of one reactant there will be molecules passing through the reactor which can't possibly react because there isn't anything for them to react with. This wastes reactor space - particularly space on the surface of the catalyst.
The temperature
Equilibrium considerations
You need to shift the position of the equilibrium as far as possible to the right in order to produce the maximum possible amount of ammonia in the equilibrium mixture.
The forward reaction (the production of ammonia) is exothermic.
According to Le Chatelier's Principle, this will be favoured if you lower the temperature. The system will respond by moving the position of equilibrium to counteract this - in other words by producing more heat.
In order to get as much ammonia as possible in the equilibrium mixture, you need as low a temperature as possible. However, 400 - 450°C isn't a low temperature!
Rate considerations
The lower the temperature you use, the slower the reaction becomes. A manufacturer is trying to produce as much ammonia as possible per day. It makes no sense to try to achieve an equilibrium mixture which contains a very high proportion of ammonia if it takes several years for the reaction to reach that equilibrium.
You need the gases to reach equilibrium within the very short time that they will be in contact with the catalyst in the reactor.
The compromise
400 - 450°C is a compromise temperature producing a reasonably high proportion of ammonia in the equilibrium mixture (even if it is only 15%), but in a very short time.
The pressure
Equilibrium considerations
Notice that there are 4 molecules on the left-hand side of the equation, but only 2 on the right.
According to Le Chatelier's Principle, if you increase the pressure the system will respond by favouring the reaction which produces fewer molecules. That will cause the pressure to fall again.
In order to get as much ammonia as possible in the equilibrium mixture, you need as high a pressure as possible. 200 atmospheres is a high pressure, but not amazingly high.
Rate considerations
Increasing the pressure brings the molecules closer together. In this particular instance, it will increase their chances of hitting and sticking to the surface of the catalyst where they can react. The higher the pressure the better in terms of the rate of a gas reaction.
Economic considerations
Very high pressures are very expensive to produce on two counts.
You have to build extremely strong pipes and containment vessels to withstand the very high pressure. That increases your capital costs when the plant is built.
High pressures cost a lot to produce and maintain. That means that the running costs of your plant are very high.
The compromise
200 atmospheres is a compromise pressure chosen on economic grounds. If the pressure used is too high, the cost of generating it exceeds the price you can get for the extra ammonia produced.
The catalyst
Equilibrium considerations
The catalyst has no effect whatsoever on the position of the equilibrium. Adding a catalyst doesn't produce any greater percentage of ammonia in the equilibrium mixture. Its only function is to speed up the reaction.
Rate considerations
In the absence of a catalyst the reaction is so slow that virtually no reaction happens in any sensible time. The catalyst ensures that the reaction is fast enough for a dynamic equilibrium to be set up within the very short time that the gases are actually in the reactor.
Separating the ammonia
When the gases leave the reactor they are hot and at a very high pressure. Ammonia is easily liquefied under pressure as long as it isn't too hot, and so the temperature of the mixture is lowered enough for the ammonia to turn to a liquid. The nitrogen and hydrogen remain as gases even under these high pressures, and can be recycled.
INSTRUMENTS
VALVES
Safety Valves
Safety Valve safety Valve is a type of valve that automatically actuates when the pressure of inlet side of the valve increases to a predetermined pressure, to open the valve disc and discharge the fluid ( steam or gas ) ; and when the pressure decreases to the prescribed value, to close the valve disc again. Safety valve is so-called a final safety device which controls the pressure and discharges certain amount of fluid by itself without any electric power support.
Safety Valve is mainly installed in a chemical plant, electric power boiler, gas storage tank, preventing the pressure vessels from exploding or damaging.
When the container pressure exceeds the design requirements, the safety valve automatically opens; the escaping gas reduces internal over pressure, to prevent the container or pipeline damage. And when the internal pressure reduces to normal operating pressure, the container automatically shuts down to avoid over-pressure exhaust all the gas, lead to waste and productionsuspension. It is mainly composedbythe seat, disc (valve core) and the loading mechanism.
Control Valves
Control valves are valves used to control conditions such as flow, pressure, temperature, and liquid level by fully or partially opening or closing in responseto signals received from controllers that compare a "setpoint" to a "process variable" whose value is provided by sensors that monitor changes in such conditions.
The positioner is a device mounted on a controlvalve that receives control signal from a DCS or any host system. The signal can be a 4- 20mA/HART/Fieldbus, etc. The positioner receives the signal and understands the desired (target) position of the valve.
E.g.,A positioner working on a 4-20mA signal range receives a 12mA means the valve has to be positioned at 50% open. Without a positioner, the valve might not be positioned at 50% due to several factors suchas fluid forces, friction, etc. The positioner sends pressure to the actuator in order to position the valve at 50%. The positioner is also physically connected with the valve stem, so it receives feedback about the current position of the val11. the positioner adjusts the output to the actuator if required. In short, the ultimate function of the positioner is to ensure that the desired opening of the valve is achieved in responseto the control signal received from the host system.
Solenoid Valves
Solenoid valves are used for quick controlling (or to trip a system). Normally they are used when an emergency control in flow is to done. Solenoid valves are much faster than other valves.
A solenoid valve is the combination of a basic solenoid and mechanical valve.So a solenoid valve has two parts namely- Electrical solenoid, mechanical valve.
Solenoid converts electrical energy to mechanical energy and this energy is used to operate a mechanical valve that is to open, close or to adjust in a position. When the coil is energized , the resulting magnetic field pulls the plunger to the middle of the coil. The magnetic force is unidirectional — a spring is required to return the plunger to its un energized position.
Radar Level Transmitters
Radar Level Transmitters are used to measure the level of a liquid, in a huge tank, mostly a storage tank than a process tank . Radar level instruments measure the distance from the Transmitter/sensor to the surface of a process material located further below. Radar level instruments use radio waves which are electromagnetic in with very high frequency in the microwave frequency range. Radar level instruments use an antenna to broadcastorsend radio signals to the process liquid whose level is to be determined.
To measure the level of a liquid or solid, radar signals are transmitted from the antenna of a radar instrument located at the top of a tank or vessel. The pulse radar sends out a microwave signal that bounces off the produt surface and returns to the gauge. The transmitter measures the time delay between the transmitted and received echo signal and the onboard microprocessorcalculates the distance to the liquid surface. To calculate liquid level, the transmitter is programmed with the reference gauge height of the application usually the bottomof the tank or chamber. The liquid level is then calculated by the microprocessorin the transmitter.
Temperature Measuring Instruments’
Resistance Temperature Detectors (RTDs)
Resistance Temperature Detectors are sensors that measure temperature by correlating the resistance of the RTD element with temperature. Most RTD elements consist of a length of fine coiled wire wrapped around a ceramic or glass core. The RTD element is constructed from a pure material, the resistance of which, at various temperatures, has been documented .The material has a predictable change in resistance as the temperature varies; it is this change that is used to determine temperature. RTDs are generally considered to be among the most accurate temperature sensors available. RTDs also provide high immunity to electrical noise and are, therefore, well suited for applications in process and industrial automation environments, especially around motors, generators and other high voltage equipment. However, they have a small temperature range.
Thermocouple Based Temperature Detectors
A thermocouple consists of two dissimilar metals, joined together at one end. When the junction of the two metals is cooled or heated a voltage is produced that can be correlated back to the temperature. Since thermocouples measure wide temperature ranges and are relatively rugged, they are very often used demanding industrial automation and process controlapplications. In selecting a thermocouple, the following criteria are key considerations:
( Temperature range
( Chemical resistance of the thermocouple or sheath material
( Abrasion and vibration resistance
( Installation requirements (may need to be compatible with existing equipment;existing holes may determine probediameter)
Pressure Transmitters
A pressure transducer, often called a pressure transmitter, is a transducer that converts pressure into an analog electrical signal. Although there are various types of pressure transducers, one of the most common is the strain- gage base transducer.
The conversion of pressure into an electrical signal is achieved by the physical deformation of strain gages which are bonded into the diaphragm of the pressure transducer and wired into a Wheatstone bridge configuration. Pressure applied to the pressure transducer produces a deflection of the diaphragm which introduces strain to the gages. The strain will producean electrical resistance change proportional to the pressure. The converted electrical signal is in the range of 4 -20 ma.
Key Note :
All the instruments are configured to have a 4-20ma current signal or 1-5 v as the output. Since a 4-20mA signal is least affected by electrical noise and resistance in the signal wires, these transducers are best used when the signal must be transmitted long distances. It is not uncommon to use these transducers in applications where the lead wire must be 1000 feet or more.
While the operating voltage is device specific, most of the devices use 24V DC or 110v DC as input voltage.
DISTRIBUTED CONTROL SYSYTEM –DCS
Distributed controlsystems (DCSs) are dedicated systems used to control manufacturing processes that are continuous or batch-oriented, suchas oil refining, petrochemicals, central station power generation, fertilizers, pharmaceuticals, food and beverage manufacturing, cement production, steelmaking, and papermaking. DCSs are connected to sensors and actuators and use setpoint control to control the flow of material through the plant. Pressure or flow measurements are transmitted to the controller, usually through the aid of a signal conditioning input/output (I/O) device. When the measured variable reaches a certain point, the controller instructs a valve or actuation device to open or close until the fluidic flow process reaches the desired setpoint.
The Fertilizers and Chemicals Travancore-FACT plants have thousands of I/O points and employ very large DCSs. Processesare not limited to fluidic flow through pipes, but also include measuring, monitoring and controlling of various parameters like pressure, flow, temperature, etc
(DCS in Ammonium Sulphate(UD) plant -YOKOGAWA CENTUM CS1000
Since the day it is released ,CENTUM CS 1000 is widely applied in the plants of oil refinery, petrochemical, chemistry, iron and steel, non-ferrous metal, metal, cement, paper pulp, food and pharmaceutical industries, and power, gas and water supply as well as many other public utilities.
The excellent operability and engineering technique, and the high reliability proved by the abundant actual application results, guaranteed that the CENTUM CS 1000 will continue to play an important role in process industries
( System Overview
( Information Command Station (ICS) A station for operating and monitoring the plant process control.
( Console Type ICS
A standard type of ICS with extensive capability and high reliability.
( Desktop ICS
The ICS on the desktop, the main body, CRT and keyboard are separated.
( PICS
A general-purpose PC used as ICS.
( Field Control Station (FCS)
The controlunit for plant process control
( Node
A remote input and output unit that passes the field signals to FCS control unit via remote buses.
( Engineering Work Station (EWS)
A workstation with engineering capabilities used for system configuration and system maintenance.
( Bus Converter(ABC)
Bus converters are required if a system contains multiple domains or contains the legacy CENTUM project.
( Communication Gateway(ACG)
A communication gateway unit is for linking a supervisory computer to control bus.
( V Net
Real time controlbus for linking FCS, ICS and ABC.
( E Net
The information LAN of the system for linking ICSs and EWS.
( Human Machine Interface
There are 4 panels on the human – machine interface -Graphic Panel, Control Panel, Overview Panel and Trend Panel .
Up to ten panels can be tiled or cascaded on display. Since the panels with the required information can be promptly switched, the speedyoperation and monitoring becomes possible. By shrinking the size of panels to one fourth, four panels can be displayed on one screen.
DCS in Caprolactum (PD)plant- EMERSONDELTAV
Features of Delta V DCS system :
( Advanced Control
The Delta V system enables you to quickly deploy state-of-the-art intelligent control for improved plant performance, without the implementation and maintenance problems associated with traditional advanced control systems. With embedded intelligent control, such as fuzzy logic, model predictive control, and neural network function blocks, advanced applications can be implemented with minimal effort.
( Device Integration:
The DeltaV system enables your plant and maintenance team to easily monitor field device health status. Based on real-time diagnostics from intelligent field devices, your staff can respond quickly and make informed decisions to prevent unexpected shutdowns. Integrated machinery protection and prediction deliver critical feedback on the health of your plant’s rotating machinery asset.
( Enterprise Integration:
Ready access to continuous and event historical process information is critical to operating, analyzing, and optimizing your plant. This collected information also needs to be available to applications beyond the control system boundaries, such as laboratory information and enterprise resource planning (ERP) systems. The DeltaV system integrates via standard-based open communications – enabling control data to be provided to the experts who need it, anywhere.
( Controllers:
The Delta V controllers provide communication and control between the field devices and the other nodes on the control network. These powerful controllers have embedded intelligent control to optimize your loops – all the time. The S- series controllers have all the features of the M-series controllers with the added support for electronic marshalling and the wireless I/O card.
Delta V Operate gives operators an intuitive view into the process with easy, one click access to alarm summaries, alarm faceplates, trends, display navigation, and online help. Delta V diagnostics extend not only to the system components but beyond – to cyber security and intelligent deice and machinery monitoring – increasing process uptime and reducing unplanned shutdowns.
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