7 replies to this topic

[ashishg]

Hello,
I am doing my diploma in chemical engineering and have a question regarding mass balance calculations.
Given the production capacity of a chemical plant how does one calculate
the amounts of the feed components?

Thank you,
Ashish

[Art Montemayor]

ashishg:

I am conceding that this is a student forum and we members all take that into consideration in trying to help a Chemical Engineering student through a problem solution. However, the way that you have worded your question leads one to conclude that an astounding educational void or gap is present in your training background.

You say you are "doing my diploma in chemical engineering"; however you don't explain what doing a diploma means with regards to what university level you find yourself in at present: 1st year?, 2nd year?, etc.. I make note of this because in your case it seems important if we are to respond with some valuable advice or help.

I speak with a background in USA grade and high school academics prior to entering a USA university. And we all know the relative academic standings of USA high schools compared with the rest of the world: the USA is not very competitive in overall results. However, I distinctly remember balancing chemical equations in high school, calculating the quantities of reactants from given products' quantities. And this was in a USA high school! How is it that you, at a university level, are unable to understand how to calculate the amount of raw materials entering a given (and known) chemical process?

The answer to your basic question is that Stoichiometry is normally employed in arriving at the required raw materials' quantities in a chemical process. That is, of course, if you have a chemical reaction taking place (Unit Process). Otherwise, if you are talking about a Unit Operation, the answer is arrived at in an even simpler manner: mass in = mass out.

Going back to my first impression, I am concerned that we may not be able to help you because you may lack pre-requisite, necessary training that leads up to the ability of applying Stoichiometry. I hope that is not the case - but then, why would you ask your question if you knew about it?

Give us more background, information and your level of training and perhaps we might be able to help. This is an easy type of problem, but we don't want to start talking over your head or your abilities.

Art Montemayor
Spring, TX

[akshatpathak]

Hello,
I am doing my diploma in chemical engineering and have a question regarding mass balance calculations.
Given the production capacity of a chemical plant how does one calculate
the amounts of the feed components?

Thank you,
Ashish

hey ashish thats pretty easy job as art montemayor says,
wat u have to do is just apply basic stoichiometry to the problem,
eg.assume certain variables for amount of feed introduced and then balance each reactant (considering the chemical reactions taking place) with the products and u'll find ur answer to ur problem,
i'll say that u refer a book CHEMICAL REACTION CALCULATIONS by G.K.ROY,
it contains a large no. of problems involving mass balance.
akshat

[Art Montemayor]

To All:

I received a personal email response from Ashish on the subject post that he originated and, I presume, as a response to my questions:

"Hello Mr.Montemayor

"I am into my first year of my diploma in chemical engineering. Here in India we can join a three year full time diploma course after school, (10th std. I guess that would be 10th grade in the U.S) after which we can either join a company as plant operators or go on to join UG course at the university, the Bachelor of Chemical Engineering(UG).

"I am a novice as far as the mass balance calculations are concerned , hence my question regarding calculating the raw material amounts , knowing the the total production capacity of a plant. There is a chemical reaction taking place.

"I hope this information helps in answering my question.

"Regards,
Ashish"


I am very grateful to Ashish for his response; however, I firmly believe the information belongs to the Forum and to all it's readers and contributors. Therefore, I am taking the liberty of posting it here. I enjoy receiving email from avid and dedicated Chemical Engineering students. Nevertheless, I would appreciate anyone responding to a Forum request or question to post his/her remarks directly in the respective Forum thread in order to have ALL forum members informed and up-to-date on the thread.

Note that my initial observations proved to be essentially correct. No one on this forum (in my opinion) should apply prejudice, bias, or "professional ranking" to student questions. We all strive to help ALL students, regardless of where they originate, study, or level of academic standing. However, even students should appreciate the fact that they can't tolerate engineering responses that result above their learning level. This has no positive help towards students, but rather confuses them and muddles the issue. It therefore is very important for the student to identify his level of preparation so that professional engineers responding to the request can better arrange and organize their response so that it is understandable by the interested student poster. This is not an ego-based Forum for professional engineers to show off their skills and experience. It was organized and intended for needy, curious, and ambitious students who strive to improve their personal engineering talents and who want to rise above the medium, average status. To help these students, we need for them to identify their level of training in a candid and frank manner without fear of being ridiculed or held as academically inferior.

Students: The more you help us understand you and your situation, the more we can help you in your needs.

Art Montemayor
Spring, TX

[siretb]

Akshatpathak:
We would all appreciate that you use a professional language. We engineers think that "wat u have ...." and the like is not suitable. Thank you in advance.

[akshatpathak]

SiretB,
thank you for correcting me,like most of you i am an engineering student too but i do not think that our views match when it comes on explaining or problem solving.I belive by going through the simplest method available, by using the simplest language so that the task is completed in minmum time.
Once again thanking u for giving me ur advice,
akshatpathak

[Art Montemayor]

akshatpathak:

I am taking this opportunity to complement siretb's generous advice to you on improving your communications skills. siretb was indeed generous and kind in not taking you to task because, as we all now know, you are not deficient in the use of the English language. In fact, you are more articulate than the average student that we communicate with on these forums. This indicates to me that you are above-average and certainly intelligent and well-educated. I am going to list (for simplicity purposes, as you would say) the various reasons why I - and the greatest majority of experienced, professional engineers - give ultimate importance to concise, clear, accurate, and understandable engineering communications:

1) As professional engineers we spend the greatest amount of our time listening to neophytes, ignorant persons, engineering "wannabes", or other lay-persons who spent most of their time sleeping through chemistry, physics, calculus, and English classes. This is a costly experience for us - not because we have to put up with this common situation, but because it produces a wrong idea or conception of the problems to be solved - due primarily to the inability of the other person to describe the problems at hand correctly and accurately. But yet, we are the ones that solve the problems - not them. How do you think that we can obtain the necessary data and details in order to correctly (and SAFELY) resolve their problem? This embarrassing situation could quickly convert itself into a pathetic and inept communications fiasco, with the problems remaining unresolved - or worse still, in an unsafe and ignorant manner if we don't demand correct communications. This has happened countless times in the past and, unfortunately continues to be the demise of many engineers today. There is presently a demolished and totally wasted spacecraft on the surface of Mars that resulted that way due to the lack of engineers communicating among themselves with respect to the type of units to be used in their calculations. This is a $$Billion mistake - due to a stupid, simple communications mistake, not due to complex astrophysics, thermodynamics, mathematics, etc. etc.

2) Correct and detailed communications are the primary and vital skill required of all engineers. We are prepared in a very tough, competitive, and complex environment involving the hardest subjects in academia. We are put through this obstacle course, not to become mechanics or "fixer-uppers". We are not trained to work with our hands or our backs. We are expected to develop into the leaders of the technical world and industries - designing and planning for the production and efficiency of our societies in a safe, efficient and productive manner. For this we are paid relatively handsome sums for our services and, as such, are expected to issue reports and other communications regarding our successes or failures. We are expected to be at the forefront of all legal contracts and documentation that our clients or employers require to have as written documents of their business operations. How do you believe that your client will respond when he receives a draft of a Scope of Work or Contract for a multi-million $ plant from you and it is written in gibberish?

3) You are being trained to be a leader, not a follower. That is why so much time and expense is being invested on your education and it also explains the level of complex and hard studies you have to overcome. How do you think you are going to succeed when you appear before a board of directors dressed in cut-off, oversized, "Bozo" pants holding a "Boom-box" to your ears, with pierced nose, ears, tongue, and speaking in gibberish? This is typical of followers who immitate others because they can point to no achievements of their own - a lowly, usual characteristic of non-leaders. Leaders are expected to do just the opposite: they innovate and communicate to others what they know with authority and credibility. Nobody in his right mind is going to listen to a serious engineer who persists in speaking gibberish. They simply won't take him as a serious, knowledgeable leader. They'll take him as a serious imitator of others and, as a result, prone to the mistakes and ignorance of others .

4) All languages are instituted as a tool for the common good of society. This is true of all languages - without exception. When you abuse or mis-use a language, you are abusing communication for the common good - something that all professional engineers are devoted to defending and protecting. Let me give you an example:

- A doctor has the free services of society to bury his mistakes;
- A lawyer has the free services of society to incarcerate his mistakes;
- However, if an engineer makes a mistake and causes human casualties or suffering, he is either incarcerated for man-slaughter or loses his license permanently. We, obviously, are held to higher standards and expectations.

It simply doesn't make sense for any engineer to allow for bad or erroneous communications. We have too much to lose in trying to achieve our goals of resolving problems safely and efficiently. To condone gibberish or bad communications is to foment your failure as an engineer. And engineers are supposed to be renowned for their intelligence - not their stupidity!

5) I hope that you don't take all the above as an attempt to try to insult you or to demean you. I have tried to give you clear evidence and examples of why it is critical and very important for you and all engineers to employ the language of your environment to its highest degree of accuracy and correctness as it relates to the society in which you practice. Language is not a religion to defend; rather it is a valuable tool to cultivate and maintain. Without its correct use we engineers cannot communicate effectively - and we will ultimately be graded (whether we like it or not) by how we communicate with others. That is the only practical way that others can obtain an impression of our abilities and our skills.

So, contrary to what you believe, you are not being effective (much less an engineer) when you rely on gibberish to communicate your thoughts to others. You are being confusing and creating the proverbial "Tower of Babel". I don't believe that you want to go through all the hell and suffering that you are going through in your engineering studies just to use them in a very ineffective and confusing manner in the future by not communicating well. When you succeed as a graduate engineer and are assigned to command and lead a team of workers who were not as lucky or advantaged as you were in achieving a degree, it will be your responsibility to train and lead them through difficult, trying and taxing operations that may involve hazards to you and them. It is your professional and moral responsibility to see that they are trained and capable of carrying out your orders without harm to themselves or others. To achieve this goal, you must learn to communicate correctly and accurately. Regardless of any other reason, this last one should suffice to make my point.

Best Regards
Art Montemayor
Spring, TX

[akshatpathak]

Mr ArtMontemayor,
i take this opppurtunity to rectify all the mistakes i have made so far.
You are undoubtedly correct about the fact that correct and detailed communication are the primary and vital skill required of all engineers.
i am glad to join this group as i know that by the time i complete my engineering and enter the real world, i will be ready to tackle and handle all what is required,may one day develop into a successful leader as you say.
Hence,i would like to sincerely thank you for giving me a valuable advice
which may mould me into a better engineer.
akshat