 So yesterday's questions I have written there, I think what does a chemical engineer do and below that we have written research and research we have discussed and next one was process development, I think I better write for continuity sake, research, process development, process design and evaluation, then we have plan design, I think I have written plan design, operation, construction and operation, yeah operation, then product, supervision, plant, technical service, product sales. So these are the things we have been discussing, I think quickly I have to go through and research we have told three types, you know this is basic research, exploratory research, I think you have to remember these words, I think you have to make a note of that and third one is process research, in process research what do we do, in exploratory research we will try to find out which catalyst is better and all that, in basic research how the catalyst is working, how the molecules are moving, where they are getting adsorbed, why should they get adsorbed there only, why cannot they go somewhere else, all that basic questions are answered in the basic research and exploratory research particularly in industry when you do not have much time, you try even ammonia, 20,000 catalyst it seems they have tried, I will send you one beautiful, you have to collect ideas of all the, you are doing that, yeah. So I will send you some information, I got one paper today, I think with the title also is which saved the world or something, so it is about ammonia process where there was a chemist who has patiently tried 20,000 catalysts of different combinations, so finally they could come up with this, you know iron with some mixture metals, otherwise originally it is osmium and something else, where Haber actually did it, but that is not practical, so that is why Haber also got Nobel prize for what he did, he proved that you know it is possible to produce at large quantities and the other person, Bosch, Karl Bosch, he also got Nobel prize and how much work he has done in beautifully written in that paper I will show you to you, that you will be proud of, proud to be chemical engineers if you read that, how many things one has to do, even this all these things I have written there you can be lifelong a research chemical engineer, okay that is your profession. So this is what chemical engineers do means you are not going to do all these things, if you are doing all these things you cannot do anything, okay because I think you are not expert in anything, so that is why you can choose that if you are interested in research, if your brain is very sharp and if you want to put your brain always under very sharp conditions then this is the best one, because always it thinks that something new, something new, something new, right and then this process development, process development I told you once you have the process design on a very small scale may be 1 kg in the laboratory and then you can try that various equipment also will be there under process design but whereas in exploratory design, exploratory research you are only concentrating on the one aspect catalyst alone, so like that for example it is not catalyst in some other process may be how the bubbles are moving in a bubble column reactor, okay so all your research is only on the bubbles, what kind of bubbles you have, how do you want normally we would like to all of us enjoy very very spherical bubbles but unfortunately if you look at the aquarium all of them are not spherical bubbles, some will be like this, head shaped, some will be slugs if the diameter is very small, okay some will be very beautiful spherical bubbles, so I mean all chemical engineers should fall in love with only spherical bubbles, why? Easy for what? Easy for measurement, if you are able to measure the diameter then you can find out what is the surface area and we know that in all these processes surface area is very important because all these you know whenever you have a heterogeneous system it is the interfacial area or surface area which is more important, so that is why that is why spherical bubbles are very easy to but unfortunately life is not that easy so that is why you have to live with slug shaped bubbles and also head shaped bubbles and you know some spherical bubbles and also not only that, some large bubbles, some small bubbles, all combinations, that is why we say bubble size distribution and lifelong you can work only on these bubbles, drops, okay particles are not that difficult and you will never get a spherical particle and always in the class we would draw only spherical particles and then write what is entering, what is leaving through this particle and all that but you will never get a very beautiful spherical particles except when you are playing this you know marbles, those particles are beautiful particles, no chemical industry can produce that kind of particles per catalyst, okay that is why most of the time they go for the cylindrical particles, easy to produce, right, so that is why in this process design, process research when you are talking we are talking about small scale getting as much information as possible starting from heat exchangers if there are and small condensers if you want to have distillation and condensation, so all kinds of things you will have then come to this level, process development, in process development you focus on pilot plants, why should we do that I told you already that because I do not know whether straight away from process research is to industrial scale when I go I am not confident whether things will work or not, right, most of the time it will not work, right, the reason is all the chemical engineering processes are all means most of them are only heterogeneous systems, in heterogeneous systems either you have bubbles, drops or particles, in fact if you understand bubbles, drops and particles you understand whole chemical engineering, right, in any system you see you will have either bubbles or particles or drops and all of them behave differently, the way bubble behaves when it is moving is slightly different than the way drop moves and when compared to these two with particles particles behave in a different way, so that is why that behaviour is very important inside the reactor how they are moving, right, so that is why you have to get that pilot plant level you should have studied already in your process design course I think you should have some process design course, right, where process design and economics are process equipment design is different where you calculate you know the total time required for the complete money recovery once you design the plant and then try to operate plant design and process economics, yeah, so I think you should have, you know different universities you have with different names, so in all that also always we talk about pilot plant, pilot plants are very very costly, if you are able to really predict or nowadays with computers if you are able to simulate the entire pilot plant and able to see that what are the problems you may face at pilot plant scale, that is why CFD will help you, okay, so with the latest softwares you can do that also you know to avoid the actual construction of a pilot plant and collecting data instead of that if you are able to create the entire pilot plant on computer and then try to simulate, simulation means trying various parameters and then every time recording what is happening at the end of the simulation because your target is to produce maximum amount of material with minimum amount of cost, that is what is the whole chemical engineering process, right, so that is why the pilot plant scale we cannot avoid, we have to go through that, unless you I think you know every one of you that is what I told you know some of you would have told that chemical engineering is already saturated, it is not saturated, only his brain is saturated he is not able to see the problems, so if you make your brain sharp you can always try to find out some improvement, in fact in our department now recently the trend changed last 5, 6 years but as always what we have been doing in our department for the last 30, 40 years is that how to improve the performance of a equipment, it may be a heat exchanger, it may be a distillation column, it may be a reactor, okay and in reactors how many kinds of reactors you can see, basically we can divide them only into 3 pots, okay ideal reactors but if you look at the reactors you have fluidizer beds, you have packet beds, we have moving beds and we have bubble columns, right and we have again you know liquid-liquid reactor, what is that, mixture settlers, mixture settlers also are reactors, okay and you have rotary kilns, right but rotary kiln also can be imagined in the one of these perfect, I mean ideal reactors, okay but all these reactors are there that is why life long people will work only on the improvement of rotary kiln, it is not that easy that in very slowly sluggishly move very, very slowly you know the speed is only 5 rpm or less than 5 rpm, you cannot put 100 rpm, okay that is only for fans and all that, right but you cannot so the moment you put 100 rpm you know that would not act as a reactor, okay and life long people can work only on that or only on fluidizer bed or only on packet bed or only on sluggishly reactor, sluggishly reactor has 3 phases, gas, liquid and solid like your production of hydrogen, hydrogenation of vegetable oils, you know Dalda and all that so you have catalyst as ran in nickel catalyst and liquid as oil, unsaturated oil and hydrogen as the gas, you have 3 phases, life long people will work only there, okay so that is why you have to choose one of the steps and then try to find out where your interest is, that is why what does a chemical engineer do means it is not that he is doing all this, you have to choose either that or this or this or the last, I think this is the easiest one, okay because this is what they do in MBA, the management, okay, product sales, okay you can go and talk to them happily in English but you should have good English, okay to convince them, even I think you can say right wrong as right so by convincing them then they will buy something, that is what you know people come and then sell soaps and you know powders and all that and then I pity them most of the time when they come immediately you will say go away, you know in the houses when they come Saturday, Sundays I mean it is very unfortunate but still we do that, it is very bad, so this is what is the easiest one without brain you can do this but only with mouth talking, all other things definitely they need lot of thinking and lot of knowledge from chemical engineering and okay so then process development is pilot plant scale that you can remember that process development means pilot plant scale and at the end of that what you normally have is that lots of data, lots of data on whatever doubts you have for example fluidizer beds are terrible reactors, even now we do not have good procedures to design a fluidizer bed reactor, you know what is the problem you have the solid particles gas will go and the particles will behave in a different way, gas also behaves in a different way and gas creates large bubbles inside the solids and you know the diameter can be 3 meter 4 meter like a big well, 3 meter 4 meter diameter is not small, okay so under those conditions you have tons and tons of solids there and you have to send gas to fluidize, I hope all of you know what is fluidization, all of you have studied this in fluid mechanics, I am sorry for chemistry people but I think chemistry people have to like to work more that is catalyst, particularly I think in catalyst how many people are there chemistry background, how many people are chemical engineering background, 4 are there right, Chaya, you are Chaya, you are chemistry, yeah chemistry, chemical engineering, one more, oh 2, 2, okay I think 2 of you should teach them after the classes over what I have you know talked, so that way you remember as well as they will be also comfortable please help them, okay I think because they may not understand for what is fluidized bed and of course only 2 people will be out of class even though physically they are present here, so that is why I do not know how to take the simple examples, I think they may not know the simple reactors also but slowly we make them understand but I think you can help them, right, yeah it is very very difficult to have direct scale up for the fluidized beds, so that is the reason why you have various scales of fluidized beds, finally to design the final one, large scale one, okay so that is why you have lots of data how the bubbles are moving if it is fluidized bed, even bubble columns are that is not easy because when you take a small nice yeah this size reactor and then bubble you will get very nice bubbles, now in the industry this kind of size reactors no one will use, okay there will be again 2 meters, 3 meters diameters bubble columns and height may be again 4, 5 meters, right so you do not even know that how much gas you have to push through to keep that you know the bubbles move that is why pressure drop and all that we calculate compressors and all that we use, right even blowers will not be sufficient only compressors will be sufficient will be required, so then the bubbles will move will be moving but here maximum size it can go may be let us say 5 mm or 6 mm or 10 mm bubbles but there this to start with itself you may have 1 feet diameter bubbles, 1 foot diameter bubbles, so then how do you tackle that, that is why the scale of problems come in chemical engineering and in other engineering it is not it is not there, for example in cars automobile design of mechanical engineers so whatever car size outside you know body and you know backside, dicky, front side, engine all those things only will change but the engine size will not change much depending on the capacity they may have you know slight variation so that is why they have control over combustion there, right that droplets combustion when they spray and spark plug will start and then it will burn and that volume increases so it moves the pistons all that, so that is very easy to imagine and there is nothing more to that except what kind of fuel you will use if you change the fuel what will happen, nowadays we want to use alcohol as fuel or you know oil some oils as fuel all that, that is what is the research what they do but the basic shape of the engine is not changing but in chemical engineering every equipment changes, every equipment in that flow chart so that is why in the process research here you will have approximate idea of what are the equipment that are coming there, okay in the process research that means very very small scale then you go to this scale and then you just a little bit magnify all those equipment then you have to collect the data how the bubbles are moving if it is bubble column or even heat exchangers in large scale diameter generally heat exchangers behave properly, right but in spite of that how do you distribute uniformly you know through the tube side and also at that shell side all that information you have to collect and if it is reactor you have to collect lots of information temperature wise and also the kinetics all that you have to see that what you get in the laboratory also happening in the pilot plant scale so that means you have lots of data there and with that data go to process design evaluation what you do there is everything on the paper you should now draw the flow chart in the process design and development you know process design is different and equipment design is different in equipment design actually you produce you know the equipment size, right volume and whereas in process design you cannot say that you know the volume of process is so much but there what you have to do in process design is the steps like flow chart is exactly like flow chart development the real flow chart the final flow chart which you which you see in Sri one Dryden most of you used that those flow charts are developed here probably you may be thinking that why the hell I have joined chemical engineering, okay I think it is so much difficult it is not that easy job that is why we are we must be proud of that how much information is required for one process to develop that is why if I collect all your email IDs I will send you that paper it is only two pages but how beautifully it is explained and how much work is involved in that, right and Karl Bosch how much work I think he is a chemical engineer but I thought he was a mechanical engineer converted but they straight away said he is a chemical engineer but I said that because at that time there was no chemical engineering in Germany, okay as far as I remember may be technical chemist or something may be there but I think how much work he has done how many things I think you know for everything is a big problem for him, okay that is at filed plant scale because the pressure is around 300 atmospheres and the temperature is around 500 to 550 centigrade temperature is okay to maintain but the pressure to go to that level is not possible that is why that is the simplest reactor what they have and I think this is the reactor and all other things are to you know pressurize the system that is in the laboratory what they have used and you know that one must be the compressor where it keeps the pressure high and with that too the next one to this level he has gone that is the reactor dimensions are not given but I think I will show you next one this is what I told you I have seen in the in the university of Karlsruhe, right there is a guy also standing here that is me, okay yeah you can now imagine my height is only 5 1 half now you can measure how many 5 1 half, okay how many 6 1 yeah so may be 30 40 feet right at that time and they have produced this that is what is the information that was there I think if this is in 1913 and 1908 what is the first one 1908 yeah 1908 he just proved the concept that it can be done and then they handed over to Karlsruhe in that BAS of company from then onwards day and night they worked in 1913 they have designed the whole thing and then finally they have produced I think 7200 tons per metric tons I think must be per annum then afterwards also I had some other information I think by 1921 it has gone to 72000 I think and then afterwards it went to 450000 that is almost half a million tons that is in 1991 okay using the same technology even now people use only iron catalyst right okay so that is what and this is what yeah and this one that is in German language this is means I mean I know little high pressure reactor for ammonia synthesis means after Haber and Bosch Haber is the scientist and Bosch is the chemical engineer then this is end to end means developed developed at the university technician Karlsruhe Karlsruhe they call means high school technical high school Karlsruhe that is what that is developed there and this is from 1990, 1923 to 1982 this reactor at 500 degrees Celsius and 300 bar produced 1 million tons of ammonia how many years there from 1923 to 1982 right after that they have removed that reactor and then again put another reactor everything was a problem for him because you know the hydrogen being the lightest molecule then it used to diffuse through the reactor that means through the interstices of you know the metal parts in the wall so it used to come and it is diffuse and come out so what happens it seems after sometime the strength of the wall will go it will burst okay so many problems all these problems beautifully he has solved and that is what is happening in each and every process I tell you in each and every chemical if you take we are talking about ammonia you talk sulphuric acid you have the same stories okay you take for example you know sodium chloride sodium chloride is solved from sea we can easily get no sodium bicarbonate what is washing soda production of that and chloro alkalis you know many compounds all this everything will have a story how to produce benzene you will have a story how to produce tolvine you will have a story right so if you take chemical technology it is everything is you know stories only because we do not tell the stories there but we just give you only the final flow chart with all the conditions and all that so for every condition to be fixed either in distillation column or in heat exchanger or in reactor people would have struggled there so so much sweat and flesh has gone to produce each and every process that is why I am proud of chemical engineering I really enjoy I think whenever someone talks about chemical engineering my volume will become double mentally so because I think you know so happy so because I think we are the people who are dealing with very very very complicated processes and we do not have a one rule for example like that you know one rule in the sense okay we have now developed a process for sulfuric acid can I use the same process same same information for producing nitric acid this is also acid that is also acid no you cannot that is the problem not only that in organic synthesis only one molecule will change you know in that ring benzene ring for example only one molecule will change so one molecule change okay it is almost like benzene only so let me do the same process here means you cannot do that totally you have to think differently kinetics will change and your temperatures will change pressures will change in the reactor everything will change and everything starts with reaction everything starts with reaction so that is why I think really start loving chemical engineering and then try to learn at least now more interesting subjects and every subject is interesting in chemical engineering including chemical technology is very interesting if the normally we do not know how to teach so that is why you are getting bored but if the way I mean Russians have developed I think the Russians chemical engineering chemical technology books I do not know whether you have seen or not you would have not born I think at that time so there was one publication called Meere publication M I R Meere publication there was a lot of translations from Russian to English but there every process they start with reaction thermodynamics and you know other steps and everything together one by one they do that tried and tried that I think in some of the flow charts but she want all that directly statistics they give then process they give and process also so much details you get fed up because we are only reading that as only for our examination but industry people love that why because in industry every step is important every information given there is important for you know if they open the Shriv book I hope you I am talking only English no Shriv okay Shriv book yeah so Shriv book has also lot of information for industries right so that is why I think every process has this kind of problems which have come through all the steps the step one step two this is pilot plant level step three is the actual flow chart development level and economics also will come after drawing the flow chart now calculate in each step what is the cost what is the what should be the even sizing of the reactors everything you have done there in the flow chart all the information is there that means just before constructing house they will have the blueprint right for plan and all that that everything is there with you for the process right so at that point of time you know what is the size of the reactor what how much material is used for the reactor what is the material cost and what will be the temperature you know for 200 degree centigrade how much energy has to put you know energy cost everything you have to calculate and then evaluate whether the process is economically viable or not that is what is process design and evaluation and unfortunately it is not economically viable what do you do start again from here again exploratory research or basic research or process research and then onwards again pilot plant all that so that is why even though you are doing that it is not guaranteed that you will be successful in your time that only gives us kick you know if you are not successful again with more vigor you have to come and try to solve the problem not run away or not take the bottles okay no use of taking bottles I think you are not deceiving anyone you are only deceiving yourself because whenever we are depressed we go for bottles okay and these bottles also I will tell you later what kind of process is that it is a horrible process yeah I mean if you know the actual process you don't even drink that okay anyway so process design and evaluation okay we know that only microorganism is doing I think it is different okay process design and evaluation that is the one then we have the plant design once you it is economically viable then go to plant design so give may be here mechanical engineers are more they can help us right construction wise so we know very clearly that this is what you have to fabricate this is the size of the reactor that is the diameter that is the height this is the thickness of the wall you should have okay and the nuts and bolts everything that part I think some of you who worked in industry you should have known all these there are now companies analyzing only in this step right once you know this step process design on the paper you have all the information what is step one, step two, step three what are the equipment all that then afterwards they will convert everything into plant design where they will go and then nut and bolt they start constructing after construction and they have to operate that is what is what is that first time you call commissioning and also call is erection and procurement procurement pre commissioning procurement start up actual starting up is really problems in chemical industry right because that is the first time you are starting the entire process so that means it starts with reactants and then the reactants have to flow from they have to get heated up and then go to the reactor and then react come to next one and then if it is a distillation process what you are using this operation then you will have it has to go to distillation column and all that because first time you do not know where it is blocked or it may be blocking somewhere and you do not know whether we have opened or closed even though you have taken sufficient care so that is why people are really worried at the time of this start up okay so that is what it operation then once of course smoothly everything happening then we have the product supervision this is what I think most of us prefer to be you know as chemical engineers because here the work is not that much except just looking at the reactor whether there is something going on suddenly something may go wrong and in this at this level you should be more you should have very good personal relationship with the workers with the operators otherwise I am an engineer you are an operator you do means you will say go to hell or go to the reactor go inside the reactor okay so that is what they may tell that is why you know that human relations also are very very important in chemical engineering because after all these steps are over next is only human relations and then the next one is plant technical service so that means this man will be operating and then looking at the reactor or heat exchanger or distillation column if there is suddenly something wrong then he will call you I have a problem come here he won't solve okay he is only problem recorder problem solvers are here plant technical service or steam is not coming at the required pressure or water is not flowing or the reactants are not flowing at the required pressure that means they cannot enter the reactor so all that problems will be solved by this technical service then without any problems if you are able to produce then the product comes and that product how beautifully you can pack all that you know imagination I think there is also here also there is of course sales people I am not talking but other than that how do you pack these products nowadays I think most of the products we are alarmed with the packing inside there may not be anything but still I think you see the packing and then take it okay including I think chocolate how what a kind of packing because simply they throw it out and we eat correct no I think what do you do with that paper you don't do anything with that paper so beautiful paper very costly that also we have to be proud that we are only producing that paper very nice paper it can be paper sometimes it can be plastic sometimes and what kind of packing is coming nowadays tremendous amount of varieties of packing right so all that so this is what is the one the answer for overall all the answers for the second step what is the second question what is the second question what does a chemical engineer do please remember these things atleast you know that is why I tell you when you go to your room catch one computer science guy innocent guy so then take him for coffee and then explain all this then only you remember otherwise you don't remember how do you think I remember because I am telling you all the time like that if you tell someone you remember let us postpone that the first quiz is on next month june july sometime or august august or september so then we will postpone till that means all the files are deleted you don't know what is happening at that time so that is why okay good so this is what is about the second question what does a chemical engineer do you can choose this simplest one okay or you can choose this one which is the very very complicated step both extremes but you know this is really thrilling I tell you really thrilling nowadays you have GE this is closed already GM GM is closed general motor circuits chemical engineering section which section is closed research section development is there development also you know these steps these are very important steps lot of thinking is required in fact these two steps only in that paper you will read that Karl Bosch steps how much work he has really done so that is why this is I think at this point of time at least you know some people would have definitely explained to you all this when you are in VTEC okay I don't know maybe some teachers would have exposed you to this information but at that point of time probably now you will enjoy more if you come to PhD again after MTEC again if I tell you the same thing you will enjoy much more it is not simply repetition don't feel that it is simply repetition but I think it is only the memory where you are going to have more and more if it is exposed if we explain this many times and this is what is required if someone asks you now what do you do as a chemical engineer you can give him a big lecture now because you are getting so much information but earlier I don't know how much you know what is the definition of chemical engineering definitions we don't have to tell we don't have to mug up and reproduce but if you are able to tell what is the meaning of this chemical engineering what do you do as a chemical engineer and how are you helping this society as a chemical engineer that is enough I hope now you have more confidence on that what is the next question how does a chemical process come on what is the interesting question how does a chemical process start I mean what is the starting point or I think you know you can also say how does a chemical flow chart start what is the starting point for any chemical process raw materials I think this is what is the answer all of us give which is wrong it is not raw materials what do you do with raw materials I say I give you two raw materials please tell don't be afraid tell what did you say knowledge is required for a particular process you want to produce design a particular process what is the starting point this is what you know last 15-20 years also no one is answering immediately I think 3-4 years back one person told that sir correct answer I will tell you so then how do you know you only told me sir you came to Tirupati and gave this lecture you joined here after you was in third year second year I think he was remembering and then he told that no it is the product which is the starting point really it is the product I think that we don't know maybe it is obvious you may think that it is quite obvious I think I tell you with my world experience now I am 65 years old not 65-64 only 65 means I cannot be here they will throw me out so my experience is that obvious is not obvious common sense is not common these two I really learnt so that is why even 1 plus 1 equal to 2 I repeat many times it is not obvious and many teachers think that it is obvious and then they ignore that step that step may be the crucial step that is why all my teaching is based on really very very basic person starting person in any course I start only like that because that is important otherwise at high level I start and then most of them they are not able to connect there then what is the use whom I am talking to I am talking to benches and then walls because students are there dead space because they are there lie one dead because that is the reason why I tell very very simple things also so that is why it is the product which is the starting point so what do you do I think I give you an example now let us imagine that now we have on this planet one of the biggest diseases is AIDS for example AIDS cancer we do not have still good medicine for that suddenly you think that you have to produce some medicine okay you can recruit number of chemists and then start doing research try to find out which medicine may be the best for cancer okay now what is the starting point now cancer drug is the starting point that is what I told you that is the starting point for any process so now suppose you are now successful in identifying out a particular drug you are successful I think your chemist did or chemical engineers you join with them and then try to do together and then finally identify this is the drug which will be useful for cancer how do you produce this drug how do you produce that drug that means how the chemist would have come to that understanding of okay this is the product they would have conducted some reactions that reaction will have a stoichiometric equation you are only putting you know reactant here reactant B giving you the product that definitely all the steps are required for us so that means once you identify a drug and if you are able to produce that drug in a very very small scale that means you have a stoichiometric equation ready with you okay so then what is the next point after producing the drug now you take the statistics how many people have cancer and what is the amount of drug you have to give per patient let us say I think over 1 year 1 kg he has to take a total amount may be 1 year he has to be treated with this drug so now you know that how many patients and per patient how much quantity required very simple know process calculations that is why we teach that subject as the first subject so now you will calculate all this okay so much you have to produce that automatically determines your plant in the design expression of reactor that fa not is this right this drug how much you know I think it is simple know to understand we know per patient how much we have to give how many patients are there so that we will say that okay now you have to produce 100 tons per day to produce 100 tons per day now we have the stoichiometric equation because we already identified the drug you know one stoichiometric equation or more than one stoichiometric equation more than one step required so then from that you will back calculate and then find out that okay if it is 90% conversion already in the lab when you are identifying drug when you are conducting that small reaction with small quantities you know that what is the conversion possible 100% conversion is excellent right so based on that conversion now you calculate what will be the reactants you have to produce not in the beginning right I think you told no reactants so that reactants will come only after that and that much reactants you have to produce I mean you have to send to the reactor where you have that fa not I think when you write that equation I will again remain you there that fa not starts okay good now you have only one I think in that reactor design expression because you already done 2 reaction engineering courses most of you there are 4 parameters one is fa not other one is minus r a other one is x a x a x a only other one is volume I hate tau because tau is not required at all in the design expression you will never get tau you will get only v by fa not okay if you want to convert that v into tau by dividing something else you do it but not required directly volume first one is volume conversion reaction rate and fa not these are the 4 out of these 4 you know fa not how do you get fa not the reactant how much you have to send to the reactor you get only from market survey there you can employ MBAs you can ask them to go to the market and then try to find out how many people are patients and how much they require all that information so one parameter you have already decided but in the laboratory you just proved on a very small scale whether it is whether reaction is feasible or not but you do not know exactly what are the temperatures because I told you some temperature use and then shake it and then try to produce and one small wait for some time and then take that product out analyze if you get the product you jump up and down that you got the product you never really bothered about what is the exact temperature you have to use or what is the range of temperature you have to use because in any reactor you cannot exactly maintain only 100 degree centigrade either it goes to 105 or it may go to 95 some range you require how do you get this information you have this stoichiometric equation and from stoichiometric equation you can get lots of information I think most of you may not think about this what is the information you can get from stoichiometric Ghani the raw materials required that you cannot calculate it apart from that what you get see these are again obvious things if I tell you but I think you do not think that the first thing that can tell you is that whether the reaction is heterogeneous or homogeneous how do you know because reactant A reactant B what is the physical status okay so that can give you whether the reaction is heterogeneous or homogeneous so stoichiometric can give you hetero or homogeneous reaction so what else it can give excellent exothermic or endothermic exothermic or endothermic so still what information it can give how does that give you temperature condition yeah merit you are telling excellent reversible or irreversible it will give you an idea that means by looking at that you cannot say but by conducting again some reactions only you can find out whether it is reversible or irreversible but you can also do that using thermodynamics because here stoichiometric when you are using stoichiometric equation how do you calculate delta F you need stoichiometric equation right so free energy also you can calculate from stoichiometric equation how do you calculate enthalpy that will give you in fact here heterogeneous or homogeneous exothermic or endothermic delta H when you calculate that will tell you whether it is positive endothermic negative exothermic so that is the information what you get and free energy what information you can get from free energy whether the reaction is possible or not so then that delta free energy delta G you will equate with minus RT and RT ln K what is that K you understand if K is very very large what is your prediction irreversible irreversible that gives you whether you have yeah I think someone was telling you know reversible or irreversible yeah reversible or irreversible okay so you see how much information you can get that simple stoichiometric equation all from thermodynamics right and because free energy thermodynamic data you need to calculate and delta HR again thermodynamic data you need to calculate and that will give you whether the system is exothermic endothermic and all that and even this equation free energy will give you reversible and irreversible and not only that it will also fix temperature and pressure that is what I think someone was telling there at this point of time when you have delta G equal to minus RT ln K so this K and RT is there so for every T and for temperature I mean pressure also if you change then you will know what will be the equilibrium conversions XAE right so maximum conversion that is possible is dictated by this equation and that is connected with temperatures that is what I asked one of the questions in your the first test you know conversion versus temperature for exothermic reaction endothermic reaction okay that we will do later we will do that so all this information you will get from stoichiometric equation this is stoichiometric equation from that you see how much information but now you see we have used thermodynamics data or thermodynamic subject we have to understand and process calculations we have to also understand and these two subjects automatically come here so then what is the next step you have started with your product and it was feasible on very small scale but you do not know what will be the temperature conditions whether there is a variation in that variation what will be the changes in equilibrium conversion all that you do not know all the data now you got what is the next step what information you get still from this stoichiometric equation can you tell me going to R what is the order of reaction this is stoichiometric you cannot because so how do you know whether the equation is first order, second order if it is elementary I know how do you know it is elementary by looking at that how do you know that I am good guy or bad guy when you look at me impossible I can be a dangerous fellow okay or I can be very good fellow okay so that is why by looking at the reactions like people we cannot find out whether this is you know what is the order of reaction so that is why experiment is a must you do not have any other choice you have to do even kinetic theory of gases will beautifully tell me if it is gas phase reaction this is A g, A gas, B gas giving you R gas then our imagination goes one molecule of A and one molecule of B they come together, they collide all energetic collisions will provide will produce R all that beautiful theory is there it is only beautiful theory because at molecular level we cannot imagine molecules are so small I think you know you cannot imagine that but still you do the calculations from theory and then find out from the experiment whether your theory is right or wrong if the theory is not correct change the theory and again measure and then try to find out okay so next step is after finding out all these next step is kinetics kinetics only will give you whether you have order of reaction or whether you know whether there is no order of reaction that is also possible it is not that always I should have order of reaction for this I may have a very very complicated equation where you cannot talk about order now you see we have come to the kinetics part so I am just trying to tell you the sequence of subjects also first one is process calculations second subject normally you taught is thermodynamics thermodynamics and fluid mechanics simultaneously they come and then of course heat transfer and all that will come all exothermic reaction means now you have to imagine it is highly exothermic the reactor will get heated up now I have to remove and now after the reaction is over it is liquid phase let us imagine for easy imagination and this liquid phase has now reactants and also products so then we have to separate them the easiest process we can imagine is distillation so that fixes even downstream operation so once you fix that distillation is possible and now you use distillation column design mass transfer you have come to mass transfer under what condition distillation is not possible I have the liquid phase ajeotrap also we have now become experts no I think in the simplest language if the boiling points are very close then your distillation column will reach moon height it has to touch moon so moon will feel you know traffic jam and all that so that kind of long long tall reactors we do not have to really design so that is the reason why you go to the next operation what is the next operation but extraction again you cannot avoid distillation ya ya you again separate into some other component and again you have to separate those two right so that is how all downstream processing is designed now mass transfer automatically came right so like that in now if you want to start from the heat exchanger because the temperature 100 degree centigrade you have to heat them and the reactants have to flow through heat exchanger then go to reactor from reactor to distillation column from distillation column to may be storage tank all everywhere you have the flow involved that is why we teach fluid mechanics now you see fluid mechanics have come fluid mechanics process calculations heat transfer mass transfer and reaction engineering will come without talking any reactor we have talked all this we said only it goes to reactor so in actually what reactor you take okay and what process you take whether it is continuous process or batch process all that will come in chemical reaction engineering and for all this we need control 100 degrees means you need 100 degrees centigrade how do you control or even concentration of the in a distillation column okay those concentrations can be again controlled by temperature control inside the distillation column right so that is why control automatically comes and the chemical technology will give you the real information about what is chemical engineering all subjects called and afterwards of course you have plan design and equipment design all that only to supplement this the entire chemical engineering is only based on 5 or 6 subjects any plant you bring that is the greatest of chemical engineering any product you think only these 5 subjects are enough okay if you put everything in transport phenomena mass mass mass heat and momentum then CRE thermodynamics process calculations that is all these are the subjects and of course control control should be okay so how does a chemical process start means with a product and now with all this information you have a flow chart with you I do not know whether you notice it that almost I told you how do you develop a flow chart how do you develop a flow chart we have first told that you identify the product and then you try to find out through the stoichiometric equation what is the total amount of material right ya now from thermodynamics you will find out the temperature and pressure so that means now we have the reactants reactants are available for you that is A plus B is available now temperature is 200 degree centigrade so that means and these A and B are available only at room temperature now you have to heat them to 200 degree centigrade and send it to reactor or you can also heat that inside the reactor itself that becomes a batch system but when you have the continuous system so you have to then the reactants continuously through the heat exchanger that is one of the equipment in the flow chart the first is storage tank pumps then heat exchanger 200 degree centigrade right so that means it is entering at 30 degree or 40 degree centigrade and leaving at 200 degree centigrade now you have heat exchanger in between then that goes to reactor and reactor you have the liquid product as an example then you will have if it is a gas product again you can imagine what is the downstream operation then in the reactor you have the liquid boiling points are very far then you know distillation is the operation what you have to use then distillation column now you draw the flow chart it is very simple for you that is how I feel we have to teach chemical technology you explain the process clearly and then automatically the equipment will fall there we do not teach that we first draw that and this is a heat exchanger this is the reactor this is distillation column this is finally storage tank that is what we explain without telling the real process and most of the teachers we do not know how to teach chemical technology nicely that is what I told you know the Russians have only teach like that their books are all focused on that every step so if you understand every step there and the conditions are given from thermodynamics in fact they in chemical technology book they also calculate from thermodynamics what is free energy what are the temperatures possible what are the pressures what are the conversions everything they calculate that gives the overall picture but problem is why we do not teach in that way is entire semester you can teach only one flow chart and there are how many flow charts you have rubber you have cement I am just telling inorganic things how many things are there paper plastics yes so many so many things are coming so that is the reason why everything mug up quickly and then say that these are the things but that gives you the real feeling for chemical technology chemical technology gives you the real feeling for chemical engineering so this is what I wanted to tell you in the third question how does a chemical process start means it is almost development of a flow chart equipment automatically falls into that this is the overall picture what you get now from that question I think we will stop here