 నీనోలిసా నీన్రోలింద్మాస్సినెరోనోసి. నికామా  hairstrippal ధతిని నిచినదా నిండిందా మఎరిరాతారం నికిరం. ప౰ంచి నిని ంచినింని ఎదిసిమి భటంద౿సంలరి తిసింపక౿సిసిమం. class, okay. Yeah, in the girls hostel and boys hostel if you start telling, then you do not forget, once or twice you tell, you will not forget, right. And also we have taken another example that brick technology, okay. But I did not ask, but how do you make, you know, scientific code also we discussed, right? When it is taking 10 hours or 8 hours, then you have to go to science level of manipulating the genes of the microorganisms, then I think you can make really scientific how do you make scientific bricks because what we have discussed was simple technology how much water you have to add you know what should be approximately the stones in the mud although if you put mud it may you know melt and it may not have sufficient strength so that is why how do you make scientific bricks in fact there is tremendous amount of science is required tremendous amount of science is required if you want to make scientific bricks that means using science designing perfect bricks okay how do you do that do not go to some other thing we are talking about only mud and sand not fly ash will not give you scientific bricks what is science in fly ash it is waste that is why it is science so what is the science in fly ash tell me if you have some other ideas please tell me it is a substitute for mud and sand that is all but I am asking how do you now make scientific bricks the technology we know the steps we know how do you make that so you have to think know you have to always extend your brain what you know beyond what teacher told then only you have that you know research mind teacher tells something then you have to also expand on your own from your brain a little bit you know some other steps okay some other projections there okay so whatever you believe the teacher tells then you are a good listener we will accept that but you are not using your brain to sharpen and also your brain to do something new this is what is in fact unfortunately that is the problem with all our I mean with the society our society because that is why we are not able to make good researchers the reason is that we always believe elders mother and father whatever they say they may show bull and then they may say this is elephant you will say yes yes yes it is elephant okay then you do not question them at all similarly you do not question the teachers you do not question yourself so that is why we have a stable society but again you know normal society it cannot innovate or it cannot do something new that is why even though our culture is one of the oldest we could not produce anything at international level producing technology producing materials producing some theories all that because we simply believe God and afterwards we believe our parents and afterwards we believe our teachers you should not believe any one of these people which I told even you should not believe God okay ya now if you want to break away from science otherwise you know you always say that okay God gives something we only use that and even if you do not get food okay today only God gave me only one meal so the remaining tool means anyway tomorrow he may give at that time we will see that is why you know because where is the because you are trying to compromise and in research you should be more aggressive you cannot be compromising for each and everything okay so that is why you have to also think you know when I told how do you make card scientifically you should have two examples only I gave the other example you should have thought on your own that how do I make now okay he told me how to make scientific card but now how do you make scientific bricks so at least at this point of time that is why I think in schools also we are killing the innovation and we are killing the enthusiasm what do we give in the schools 10 kgs of books behind that fellow okay he is already only one foot above the ground and by putting this weight again you know anti gravity it will pull down okay pull down so I think that he also cannot grow faster okay always gravity is acting on him you know another additional 10 kgs or 5 kgs load okay that is all what we give him we never you know allow them to to think on their own even if they want I think you know there are two ice creams and if I one ice cream is black and another ice cream is white and this fellow wants to take that black that chocolate ice cream so then mother father no that is not good you only eat this you have to allow him to eat and if it is bad then he will come back anyway to this if he does not like the taste but we try to dictate no that is good that is not good you only do this or you only eat this that is why we are not allowing I mean we are doing a wonderful job as parents to all of you okay but when you become parents do not do that you allow your child to go anywhere jump up and down I think ask any question okay you have to patiently answer then only I think do not give them book do not give him books do not give him even computer okay and do not allow him to see the TV right ask him to think that is all because TV that is all what else I say no really that is what is most important no so what does he get by seeing the TV that fellow sits and then always looks at that cartoons right I mean cartoons are really innovative if he makes the cartoons not seeing the cartoons if he is able to draw on his own cartoons and then make the new cartoons then fantastic and what happens at the age of you know maybe third year or fourth year he will get the specs all of us got around 45-50 years but most of the young children know because of the contribution from TV they are getting only third year and fourth year it is this thick and by the time he comes to engineering it does not know where to go because the thickness of this thing is so much light cannot enter everything is black for him in the mind black world is black everything is only black darkness only so that is why you should have thought no okay now scientific bricks how do you make scientific bricks just think sorry with plastic okay why plastic that means you throw away mud and then only start with plastic or what I am talking about given only mud and you know some amount of solids how do you make scientific bricks earlier what we do the technologist has a feel how much sand should be there how much mud should be there he mixes and then puts right some amount of water and all that so now I am asking you on large scale produce like a chemical engineer you produce like any other chemical produce bricks how do you do that mixture is required for long time before that straight away you start with mixture yeah how do you find out that either Thailand error or from theory where what sense of the particle is good what is the particle size so normally they may use 1 mm particle okay 0.5 mm particle why 0.5 mm particle is better than 1 mm or why not 2 mm or why not 0.1 mm sorry yeah all that is the science right I think that way then even if you can go to okay can I use nano technology to make bricks that means where nano powder where I will bring all the powder together and then put them you know like your puzzle form where children play and all the puzzles together and then you will have the brick that is pure science which you cannot realize at this point of time you may do it I told you know that example where that girl told me how do you make sulfuric acid means hydrogen bring sulfur bring O4 bring and then put together and then give it wonderful really if you are able to do the same thing for even brick for any chemical that is what is the pure science but you are not able to realize that so that is why when you are now going for with scientific scientific knowledge is how to find out what is the particle size and how this particle should be orientation of particles inside the mud how do you arrange them like crystal structures right you know from the basic crystals if you go how beautifully those molecules are arranged using in the crystal structure where you have sufficient strength also for those structures for you know some structures have lot of strength some structures have weak strength all that so using that science can you also now design your brick you see for every technology like for example bollocards bollocards we think that it is lowest technology because no sciences no equation is used for making bollocards right so then if you want to really design a scientific bollocard you need tremendous amount of theory tremendous of amount of engineering okay in this brick technology once you find out what is the orientation of solids and what is the right amount of mud right amount of water and also particle size all that scientifically when you see and how do you see scientifically you have to arrange all that and try to find out which gives you the best toughness strength that is what is science then afterwards you have to convert that into product so then you have to use engineering principles as I said I want to have this continuous brick making so you mix at one point actually you know now need one bin with mud another bin with particles then both of them will fall into the mixer and also another bin with water right amount of water all three you know you should have flow rates okay how do you measure flow rate of solids because I know B Tech and M Tech lab you are a B Tech lab you should have done how do you measure flow liquid okay but I think solids definitely you do not know how do you measure because continuously very changing way yeah so that means the entire bin must be on a balance where yeah load cells and all that you know you see all that is the one word what we have to use I know most of you have not been exposed to this information and all of us have been exposed how to measure water flow in the labs that is why I asked that question so that you can think again so load cells are there I mean big flat forms are there now entire lawyers are weighed okay so that kind of thing you have to think now and then say that yes how do I measure now solids flow rates because you have to send may be 10 kgs per hour or may be 15 kgs per hour continuously then mix them after mixing what it has to go through like extruder right and then after that okay so at the end you know paste will not flow that is why you have to put extruder and now after extruder it goes to the mould and this mould must be automatic that mould right so that automatic means you design that mould and then the moment the paste falls there it mould is filled up and another thing will come and then yeah and apply also sufficient pressure and then mould will go this will be thrown out to the directly to for centering or drying drying and afterwards centering okay drying now you see because it is a continuous system you cannot wait now for 8 hours or solar drying means 4 days 5 days so now you have to design a dryer where all this operation must be done very quickly so then it has to go to centre centering also generally centering may take time but even then you have to design that one faster that is what is engineering principles you are using for brick making with the help of science now you define chemical reaction engineering with these examples now you define because I have given sufficient examples when do when engineering comes when science comes and when technology comes forget about technology now I am asking chemical reaction engineering definition it is engineering of chemical reactions okay so now whatever we have discussed that engineering principles we have to use now for chemical reactions to make them work what are the engineering principles which you use in chemical reactions yeah mixing is one because I think when you take a large quantities and then you have to mix them for really yeah that is one yeah flow anyway if it is a continuous reactor flow must be used there is also an engineering principle fluid mechanics heat transfer how do you remove heat so that means all engineering principles when you are applying to chemical reactions that is called chemical reaction engineering see now you do not have to even remember that you know because automatically when you know all these sequences you know the definition already correct no if you remember that card if you remember this brick technology because those things we told because you know them already okay how to make them you know but now applying those same things here also applying that engineering principles for chemical reactions like for example flow if it is a continuous reactor even if it is batch also of course you know how to feed and all that so then temperature how do you control how do you supply heat how do you remove heat and before that you also should know kinetics okay what is the type of reaction what you have it may be having order of reaction or it may not be having order of reaction that means you need a rate expression how do you get this rate expression from experiments kinetics you know that is kinetic studies and thermodynamics will not give you rate expression and thermodynamics will not help you in actual reaction engineering in the sense that for the design for the design what you use only rate expression not equilibrium data right equilibrium data will come if it is a reversible reaction in the equation automatically you know what is equilibrium equilibrium constant capital K also will be present in the rate expression but that rate is important how do you get the rate by doing experiments or if it is already given that this is first order you simply write minus r A equal to K into C A so all the engineering principles you are using that and what is the difference between chemical engineer and chemist now chemist will not bother about the flow even if he does continuous but it is only very small quantity where you will put a jar there and then from there drop by drop it will fall and drop by drop if you make in industry you can make you can never make that kind of large quantities that is the difference between chemist and chemical engineer and we do not have to blame him or you need not blame us because that is his duty or her duty as chemist what is that to find out how the molecules are moving to find out how the molecules are reacting and how do you get finally whether this reaction is happening or not that information but his scale is always very very small so now you see with these examples you can even draw the flow chart if I ask you now card making flow chart canít you make now easily you can draw the flow chart for example brick you know that initially you should have the bins and then both have to fall and then you have the mixer from the mixer it has to go to again extruder from extruder it has to go to mold and all that and now you can imagine any process if that is why process is important mind is important mind means you know thinking is important if you think about the process step by step what is really happening where the heat transfer is coming where the mass transfer is coming where the reaction is coming where the fluid flow fluid flow is throughout if it is a continuous system even if it is batch system it is continued I mean all the time you have to pump the liquid after the reaction is over to store or you know from the reactant storage to the reactor so all these things are happening already so now that is why even chemical technology very easy you know by listening by answering these questions what we have that five questions will give you the entire knowledge okay five or six questions right what is the first question chemical engineer what is chemical engineering then what does a chemical engineer do yeah I think you have forgotten already yeah what is the third question how does a process flow chart start and then what is the next question what is the information what is the information required for reactor okay I think this is very clear now I think you can see I don't have to even now define you know how to define now chemical reaction right that is using chemical I mean using engineering principles to conduct chemical reactions that's all I think you know the first person who cashed that name after this after the seminar is over can you guess who huh who cashed that name excellent Levenspiel immediately he got that name and then put the name of the name of his book as chemical reaction engineering fantastic Levenspiel is really great the way he makes things simple okay before that also there are two more books val valas there was a book W W A L A S valas okay I think chemical kinetics for you know kinetics for chemical engineers also that is the title but no not easily readable that is a good book but not easily readable then at the same time even James Smith book yeah chemical engineering kinetics yeah so that book also was there but those books are not that famous when compared to Levenspiel why because the presentation the way he explained things presentation is really beautiful in Levenspiel so he immediately took the name and then put you for his book as chemical reaction engineering because he has already used that book yeah I know the Schmidt recently maybe I think 5-10 years back only that one engineering of chemical reactions again what a wonderful name engineering of chemical reaction that means only he just changed this you know words engineering of chemical reactions instead of chemical reaction engineering okay so the next question was yeah what is that what is the information what information is required what information is necessary for reactor design okay can you tell me what is that information rate of reaction performance equation conducting that performance equation volume of the reaction volume of the reactor contact flow rate yeah see you know the volume of the reactor you know the rate and you know initial concentration yeah you also know conversion conducting also no conversion then where is the design all the questions you know everything you are telling that you know you need volume you know already conversion you have to give again if I give volume if I give conversion if I give CA not if I give rate expression there is no design everything is not and you are not told there a tau okay you should also know tau okay yeah if everything is known where is the design equation amount of the product yeah that is correct because I think flow rate indirectly that gives the flow rate yield will not come in the design because where are using yield to design the reactor it is always conversion because the basic expression is written in terms of only reactants that is why reactants only get converted okay yeah but still you have not answered my question what is necessary what is the information that is necessary for reactor design okay I will give you another I mean some data you just tell me whether this is just sufficient for reactor design so I give you K as let us say 1 minutes per inverse okay and then okay see I will give also give you someone is asking initial concentration CA not as 1 kilo mole per meter cube yeah and I will give you V as yeah 1 meter cube per second I will also give you FNR as 1 kilo mole per second okay I will also give you XA XA equal to let us say 90 percent conversion do you have all the data for reactor design type of reacting contact the which reactor we have to mention that yes performance equation is not a performance equation you want to find out there is something element rate expression is not given rate expression is first order okay okay which is totally wrong okay it need not be first order for many cases because our mind is still in LKG that is why all of you say that it is first order this is truly valid only for homogeneous reaction the moment you go for heterogeneous reactions it may not be valid because rate can be expressed based on various things because homogeneous reactions we base normally on moles converted per unit time per unit volume if you base only on unit volume then this you know this indication is right that this is first order that is why it is only strictly for homogeneous reactions where rate is based on that rate can be based on surface area rate can be based on weight of the catalyst this can be based on mass in surface area volume of the catalyst volume of the catalyst volume of packet bed so there are so many things which you can have that also we will discuss later so that is why yeah the most important thing it is missing from here is I have not mentioned what kind of reactor okay then Levenspiel has put all this information that is necessary for reactor design in this wonderful diagram I think some of you may be knowing because she is telling already performance equation and all that I do not know how many of you used Levenspiel book all of you then you must know whether you know really the meaning of this diagram yeah what is here reactor this is input this is output yeah then we have here what is called kinetics and here we have contacting yeah some more things are there here in kinetics we will say here chemical and physical physical and in contacting you have batch and you have continuous and in continuous again you have yeah not semi continuous I think you know yeah yes we have here to maintain the same thing okay here I have I hope you understand this P f is plug flow I think first time I have to write because others also are there plug flow and mixed flow mixed flow so now this entire thing also we can imagine as a performance equation performance equation it is an equation indirectly is output is a function of input kinetics and contacting this is a function and this is the performance equation this bracket okay yeah this output means what do you get from this equation I mean this output means what parameter you are expected to calculate if that is an equation volume of the reactor yeah which one is right or both are right both are both you have to calculate given one you can calculate always the problem in chemical reaction engineering is that given the volume find the conversion given the conversion find the volume whenever you are designing a new reactor because reactor volume you do not know that is why you have to always assume that what is the conversion no one tells you what is the right amount of conversion okay and ambitiously speaking all of us want 100 percent conversion but if you go to 100 percent conversion the volume of the reactor will be infinity it occupies the whole universe you do not have space to go and operate you should be inside the reactor okay yeah so that is the reason why you have to assume some conversion economically viable conversion otherwise you know from 90 percent conversion 95 percent conversion 99 percent conversion the value will value of volume will tremendously change when you derive the equations when you calculate you will know so from 0.99 to 0.995 tremendously exponential increase okay very steep increase so volume will become infinity when you go to 0.999999 like that so that is the reason why economically viable conversion which only you know as engineer you have to have that feeling that okay beyond this now it is of course with computers you can simulate with 0.999999 and then 0.999999 like that okay so then you will have what will be the total volumes you are getting so depending on those volumes you can choose what is economically viable why economically viable means if the volume is infinity and you have to bring the material which is already available in the whole universe and then try to design volume itself is infinity okay so materials of construction is required and how do you supply heat how do you remove heat all these things is a problem so that is why economically viable in all these definitions always that economics is coming for engineering okay that is why another simple example I will tell you to make you remember that as a scientist I do not have to worry about economics right one example is let me say this that I have invented a small pill okay tablet and if I take that tablet life long I do not have to take any food because that gives you sufficient amount of nutrition energy to the body nutrition energy everything to the body but only problem is the cost of this tablet may be 1 billion dollars okay scientist can say that cost of my tablet is only 1 billion dollars okay you cannot find out any fault with him but as an engineer if you are able to produce that one for one paisa then there is no chemical engineering there is no electrical engineering because who will after all we are all working only for our food and life the moment you have that food very happy that one paisa somehow you get it and lifelong you do not have to eat and then you can always happily jump and dance and all that you know this this place will become really paradise you know paradise what they do most of the time in paradise that is the story is tell us that there are four beautiful girls that is what they do in paradise so our place also will become paradise okay so we will have many rambas here they have only one ramba we have many many beautiful people on this planet okay so that is why you know that is the difference between a scientist and an engineer always when engineer is making products it should be as economically viable and also it should be affordable by the people who have to buy those products otherwise what is the point in you know making this wonderful pen with nice plastic and all that and then say that again this is 1 billion dollar who will buy 1 billion dollar I think even ambanese do not have tataas do not have 1 billion they have oh they have I am a old generation where I think our dosa used to cost only 10 paisa or 15 paisa okay dosa or maybe only 5 paisa so that is the generation which we belong so the moment you put more zeros I think our mind will not work the billion has many zeros if you ask me sir billion how many zeros I do not I do not know I know how many zeros 10 has only one that is all okay anyway so this is the information and you know yeah this is economically viable thing is very very important and in all engineering it irrespective of chemical engineering every engineer should feel that yes he has to produce anything whatever is producing if he is constructing a house as civil engineer then again it cannot be costing you know millions or billions of dollars if he is able to make small houses for everyone excellent engineer and for that again civil engineers alone cannot live because chemical engineering should be there why they have to supply cement correct no yeah and inside the furniture also I mean wood we are not making but I think that beautiful paintings for wood a varnish for wood and carpets all this material yeah they do not have fake all they can use in nail size earlier they were using only nails nicely because I think on this planet even iron is not available so that is why we have gone for we will call yeah are you telling something for nails also we need blast furnace we need blast furnace again the technology there is again chemical engineering because that is gas solid non catalytic reaction okay this iron is converted iron ore is converted to iron right yeah that also we will discuss in the next class and yeah I mean next course yeah so that is why this yeah even electronics engineer if you produce TV for may be again billions of dollars who will buy okay but that is why now the TVs and all I think this is electronics which where the cost of electronic components are every time decreasing decreasing that is only thing all other costs are increasing increasing increasing okay you can see earlier what is the pen drive and now what is the cost earlier what is the cost of CD now what is the cost of CD I think I was surprised I think sometime back my students were telling that even for 7 rupees 3 rupees 7 rupees you get a CD and I was remembering that is 120 rupees when I purchased long time back okay now I only take from others okay yeah so that is the kind of thing and like that in every engineering if you are able to produce goods cheaper and cheaper this planet will be really paradise okay and even producing not only materialistic things even for food even now we do not have much food many people are there without food if you are able to produce that food you know excellent fertilizers where immediately before putting the fertilizers itself the crop should come if it smells okay the moment you show the smell for the plants if they are growing so happily you know why not just I think you know have lots of smell and then just breeze over the you know the fields then automatically you will get very beautiful fruits and then all wheat rice all that then the entire planet will be so beautiful but you know for human mind nothing is impossible that is why I like science fiction movies I was telling you know because there their mind you know how beautiful it has imagined particularly that author movie the entire planet was in the mind of James Cameron he is the director he was the director he is the director entire planet right and also how he imagined the people what should be their height what should be their color and you know everything sorry floating mountains that is a new concept floating mountains I do not know that floating mountains are really floating because density difference and all that is there I mean anything which is floating having more than density of air it should fall so that air should be very very thick I think very dense air otherwise you know if they cannot float no otherwise the mountain should be like cotton you know mountain I mean there are big trees also on those mountains right and all that imagination and I think of the best imagination in that movie which are like it is putting that picture to yeah for the you know when they are riding the birds or horse that concept is so beautiful concept because that we can also use okay you have to go today and then put your pigtail to CRE book Levenspiel book then everything you will be part of that you know concept is so beautiful and in our world scriptures this is there already whatever you do you have to be part of that whatever you do so that means that is now physically showing you how to become part of that that is all the difference we have already you know whatever you do you have to completely immerse in that when you do that I think Dhaneshwar is one of the wonderful names the moment you close your eyes and meditate you will be automatically dissolving in whatever you do in whatever you do the moment you are preparing for a CRE exam close your eyes the entire CRE book should be before you each page page by page then automatically you are part of you because you are seeing by closing your eyes that book in your mind you know I told you we have all of us as mental screens not mental mental screens all of us are one way or other mental that is different but all of us have mental screens so those screens will automatically project whatever we would like to have if you have the familiarity with that I gave I don't know whether I asked in this class or somewhere else so the moment I tell Delhi what do you remember immediately only I asked you so that means immediately depending on your exposure someone may imagine you know in his brain or in the mental screen kuthubminar someone may see that gateway of India someone may see the parliament bowen someone may see the palika bazar where they are interested in shopping and all that okay so that is the kind of mental screen I am talking and that mental screen can be beautifully used for our yeah either CRE or any subject for our chemical engineering that is why I think you know I have some exercises for the student you know just go and sit down in your room and then just imagine a heat exchanger and then try to plot the temperature profile you never forget the subject if you do that imagine a distillation column and then just imagine where is the feed how the temperatures are varying from bottom to the top or how the concentrations are varying that means indirectly what I am asking you is to plot temperature profile and concentration profile right and now you can go to extraction column in the extraction columns it is a column there may be mixer settlers also you know one mixer settler where it mixes and then settles in some other one all that so there what kind of concentration and temperature profiles you will have you just sit down and imagine and try to plot all that in your mind you will never forget the subject it is not the marks which are important which may be you may be getting sorry yes in IIT Madras we have yes 10 out of 10 in some other places it may be a may be 10 out of 10 or may be 100 out of 100 you know some many universities also are giving still the actual marks right absolute mark so when you have 100 out of 100 on the paper does not mean that you have 100 out of 100 knowledge in that subject but when you do the way I am telling you just imagine and then try to plot in that subject whatever things what you have gone through you will never forget the subject and all the way subject is with you and marks are in your cupboard correct no you take mark sheet and then you cannot carry every day so you will just put somewhere else but whereas this brain you cannot keep anywhere okay it has to come with you wherever you go so then I think you will beautifully understand whatever is happening in the subject that is what is the interest you have to develop I say everything is interest that is all and most of us are skeptical chemical engineering so what distillation so what reaction engineering so what so the so what is very bad word like cracking the exam okay we have either so what or cracking the exam that is why simply we are indifferent for the subjects and every subject is a wonderful subject I tell you I have shown you what is the beautiful amount of science that is there even in brick technology bullock cards anything you see in nature what is made by us by made by nature also is wonderful so that is why we try to understand nature first and then try to mimic in our things most of the things what we produce like flying aeroplanes only birds you know our gods used you know that gharut mantha it goes and then and we also had what is called Pushpaka Viman right Pushpaka yeah so all that were there in the mythology may be they were imagining I do not know whether at that time they were really existing or is may be their imagination because when people write the stories beautifully they can write again science fiction at that time if there was science fiction at that time you would have created in the mind that this is Pushpaka where people can travel at that time we did not know that right because no way to go back and only science fiction it is possible to go back into the past and also to go back into the future but right now we are not able to do that may be it may come up sometime we do not know if you are able to do that then probably you will get so that is why I think you know this chemical reaction engineering definition on your own you can now create provided you do all that what I have told you that imagination thinking about these examples then afterwards when you ask this question this is the one for the entire I mean I may teach you ten reaction engineering courses I can never come out of this diagram and if you also understand the meaning of this diagram what do you mean by physical kinetics what do you mean by chemical kinetics what do you mean by contacting okay and what do you mean by batch continuous in continuous again you have two types of ideal reactors actually that is ideal contacting because you can have non-ideal contacting but you will have lot of varieties but ideal contacting this is a wonderful information for the reactor design I thank really Levenspiel for this you know everything whatever you may have heterogeneous reactions homogeneous reactions everything you may have but still you cannot go out of this reaction I mean out of this diagram out of this performance equation who gives input to us I have already told you what do you mean by input input is not given by how do you get raw material how much is required from product you have to back calculate and then say that some she was telling me that I think we need the flow rates right how much you have to produce okay that how much you have to produce is input that is in Levenspiel language F A not F A not moles per second not volumetric flow rate molar flow rate that is what this one F A not F A not already you have with you because someone went to market because you know that this product has demand someone went to market and then they found that this is the total demand in a year so that is your plant capacity that is your F A not when you convert that product into reactant through stoichiometric equation that is one parameter this already we know okay then next one is kinetics from kinetics what do you get simply minus R A right order of reaction all that I think you know every reaction need not have order first of all so kinetics will tell you what is rate minus R A as an expression it may be K into C A if it is first order simple expression or it may be very complicated with so many terms in the numerator in the denominator everywhere okay so that means we we have to now understand for my reaction where may have the stoichiometry what kind of kinetic expression I get that is what this there I have to work here I do not have to work much why because it is market survey simply I will go to market and then take the statistics and then say so much demand we do not have much work there and here I have tremendous amount of work in fact this is the most difficult step in chemical engineering in chemical engineering itself I can tell you then what is this one next one next one is what type of reactor you are going to use that is all what you have if you know what type of reactor let me say batch reactor you have batch system right and then I know kinetics I know the input how much I have to put there right then what is that I have to calculate now if I want to design reactor then I should assume also conversion and then forth the volume can be calculated or if I am already having a reactor and I put all this because I have a batch reactor I know kinetics I know how much I have to dump into that because contacting is batch reactor so then this this will be conversion because volume I know already that will be conversion okay so that is why either you have to assume conversion or you have to assume a volume and always for a new process for a new process it is only volume I have to calculate for an existing reactor already old process there is already a reactor now I can only calculate what is the maximum conversion I can get from the from that volume that is all throughout not only in chemical you know in reaction engineering everywhere it is same okay what are you doing in distillation you are first assuming a 99% purity then calculating number of stages if you know number of stage what do you calculate that problem you never thought normally if I give you I have ten plates and if you also give you a composition there is no problem you do not have to do anything but always what we give is that either give number of plates and then ask you to calculate what is the composition you get and also flow rates and all that you know you get by material balance or give you the extreme compositions and ask you to find out how many stages required for that heat exchange if I give you the temperatures you calculate area if I give area you have to calculate temperatures and if I give area plus temperatures you do not have any problem but I think even if I give in the examination you may try to calculate because your idea is oh there must be some trick so let me calculate you never write simply that everything is given I do not have to do anything in fact that kind of questions I will give okay because you should know I say you should know what is wrong what is right it is not that every problem you have to solve so that is why be careful in my question papers so that is the kind of everything may be there you do not have to do anything if you write that nothing to be done you will get marks for that because I think that is a great information for me because you are able to identify everything is there that itself is a very good happy answer for me because you know that subject you know that problem that is the reason so that is why in next classes what we discuss is only about this we will start from kinetics and then we also go to contacting and we see how do we combine them and then after combining what kind of things we can do with that combining expressions many things we can do okay we will close here thank you