Saturday, December 27, 2014

Instruments and their use in Chemical engineering field.

Saturday, November 1, 2014

Excel Tutorial - 1 : Mass balance calculation using Microsoft Excel

We know that out there in this free information world, lot of soft-wares are available which ease the complexity of work. What if we can design our own mini super ninja software ( actually Excel files) to reduce our repetitive actions while calculating . Lets get started how to do simple calculations in excel.

In this tutorial neutralization of Sulphuric acid ( H2SO4 )   by Sodium hydroxide ( NaOH )was considered. Go through the problem statement given in the below image. Excel tutorial

At first mention the Chemical reaction in one of the cells (A1 or B5 etc.,). Mention the molecular weights separately in a cell. This is important to put the value in a single cell ( L6 for H2O, L7 for NaOH, L8 for H2SO4, L9 for Na2SO4) it should not contain any alphabets. If you enter alphabets in the molecular weights column it will result in error.

Now we have given the H2SO4 quantity that should be neutralized. Put this value in a separate cell (D11) and convert it in to moles by dividing the mass with molecular weight mentioned in L8 cell. Excel tutorial

Now use this moles and multiply this moles with 2 , as 1 mole of H2SO4 requires 2 moles of NaOH for Neutralization which would result in formation of 1 mole of Na2SO4 and 2 moles of H2O. Excel tutorial Excel tutorial

Multiply the moles by molecular weight in cell E17 to get the mass of NaOH required for neutralization. Excel tutorial

Similarly do it for H2O & Na2SO4 Excel tutorial

Mass used for reaction should be equal to mass produced in the reaction. Excel tutorial

Please feel free to put up your doubts and queries below.

To download the Excel file click the link

Mass Balance

For more information on Excel . Go through the following links.

Sunday, October 12, 2014

Type of valves using in industries

What is a Valve?

Valve is a device which is used to regulate the flow in a pipe line. It may be mechanical thing but the function is very much required for Chemical engineering operations. Based on the requirement, allowed pressure drop, flow rate we can employ different kind of valves. Valves often change the flow pattern in pipe lines. This may be due to the obstruction or restriction offered by the valve body. Here boundary layer separation may occur, which leads to form friction. In order to calculate form friction pertaining to that particular valve we have L/D ratios and K values.

Types of valves

Here are the some of most common valves using in Chemical industries.

Globe Valves
  • Globe valves offer better control of flow but at the expense of large pressure drop. Most of the control valves are globe valves.

Gate valves

  • In Gate valves a Gate facilitate the flow of fluid. It will slide from complete open to close position.In gate valves the sliding stem can be movable or fixed stationary.

Ball Valves

  • Ball valves contain a ball as a flow regulating element. The ball contains a provision to allow the flow. One quarter (1/4) turn of the valve handle can regulate the flow from minimum to maximum.
Plug valves

  • Function of plug valve is similar to Ball valve but the regulating element will be different.
Check valves( Non Returning Valves)

  • Check valves or non returning valves allow flow only in one direction. Opposite direction flow doesn't happen here. This is particularly useful in reactor inlets, where exothermic reactions might happen in pipe lines.
Butterfly valves

  • Butterfly valves contain a disk which can rotate from 0 to 90 degrees for complete close to open state. This valve can be used as a control valve in water service.
Diaphragm valves

  • Similar to Globe valve , a diaphragm valve contains a plate like arrangement which functions as a stem in Globe valve.
Control valves

  • Control valves are a special class of valves which are highly useful in controlling the flow of a fluid in pipe lines from a control room. Control valve contains a stem which can be varied by giving the set points from the distributed control system(DCS). Control valve design also important thing in process industries.
Still a lot of valves are out there , each of which has its own feature. To name a few  Solenoid valves, needle valves etc.,

Wednesday, August 27, 2014

GATE 2015 Chemical Engineering

Gear up for the next biggest challenge in your career, GATE-2015 online application starts from September 1st 2015. GATE (Graduate Aptitude Test in Engineering) is a common way to enter into masters, doctorial programs and public sector undertaking (PSU) companies. This time IIT Kanpur is organizing GATE-2015.

GATE-2015 Chemical Engineering (CH)

GATE 2015 chemical engineering by
It is better to start the preparation 3 to 4 months before the commencement of exam. Practice is the mantra. The more you practice the more you will be benefited. It will be useful to solve the numerical questions. The easiest way to gain more marks is to concentrate on Aptitude, English, and Mathematics. From technical side Process calculations, Chemical technology subjects are easy to gain more marks. Fluid mechanics, Process economics, thermodynamics are easier to solve next. Chemical kinetics, Heat and mass transfer subjects come in next place. The order should be decided by you ultimately based on your preparation. Follow to get updates on GATE-2015 and other Chemical engineering related stuff.

#Chemieering recommends the following books for GATE-2015 preparation in Chemical engineering stream.

GATE-2015 Highlights

  • GATE-2015 application fees is Rs 1500/- for male candidates in General/OBC category and Rs 750/- for female candidates. For SC, ST, PwD candidates the fees is Rs 750/-.
  • Payments have to be made through debit/ATM cards, credit cards or internet banking and e-challan only
  •  All Supporting documents should be sent online only. No hard copy will be accepted
  • Examinations for all the 22 papers will be conducted by an ONLINE Computer Based Test (CBT). The online examination paper will contain some questions for which numerical answers must be keyed in by the candidate using the virtual keypad. Rest of the questions shall be of Multiple Choice Question (MCQ) type.
  • GATE 2015 examinations will be held during forenoon and afternoon sessions on alternate weekends (Saturday and Sunday) between 31st January 2015 and 14th February 2015. Examination for some of the papers in GATE 2015 will be held in multiple sessions. Exact details regarding complete examination schedule will be notified at a later date.
  • The payment of application fees would be online through different modes like net banking, debit/credit card, e-challan, etc.
  • GATE 2015 score is valid for THREE YEARS from the date of announcement of the results.
  • During the online GATE 2015 examination, all candidates will be provided with an online scientific calculator which has to be used to answer the questions.

Tuesday, August 19, 2014

Types of Chemical engineering drawings - BFD, PFD, P&ID

The terms flow sheet and flow diagrams are often used in engineering and design applications. But this is not the accurate way to describe the process drawings. This post will give a glimpse about the types of process drawings.

Basically there are three types of process diagrams in chemical engineering context.

  1. BFD      - Block Flow Diagrams.
  2. PFD      - Process Flow Diagrams.
  3. P&ID    - Piping and Instrumentation Diagrams.
In a brief BFD represents entire process in a single sheet, where as in PFD you can find some detailed information like plant operating conditions, process flow. It uses symbols to represent the equipment. P&IDs provide detail information when compared to above two drawings. They use standard nomenclature, symbols, and tag numbers to fully describe the process.
These drawings are very useful as they convey the right amount of process information as needed during various stages of bidding, engineering design, procurement, construction, operating & decommissioning phases of the process.

BFD-Block Flow Diagram

Block Flow diagram by

A BFD has the ability to represent the complete process on a little more than a single sheet. It contains mainly text enclosed by boxes, interconnecting lines with flow arrows. In some BFDs mass flow rates may be mentioned so as to describe the material balance over the entire plant.

PFD-Process Flow Diagram

Process Flow diagram by

PFDs contain more information than the block flow diagrams from which they are derived. They show more detail about major equipment, subsystems and the flow of product between them. A typical PFD contains equipment symbols connected by process lines where temperature and pressure information are shown on the line itself. You can easily refer the properties of a particular stream through stream number. For designing a P&ID, equipment layout PFD is mandatory.

P&ID-Piping and Instrumentation Diagram

Piping and instrumentation diagram by

P&IDs carry a lot of information to define the process. Derived from PFD it is the best way of accurately documenting the operation of a process. P&ID takes the conceptual aspects of PFD and expand them by adding

1.      Detailed symbols.
2.      Detailed equipment information.
3.      Equipment order and process sequence.
4.      Process and utility piping.
5.      Process flow direction.
6.      Major and minor bypass lines.
7.      Line numbers, Pipe spec, Pipe size.
8.      Isolation and shut off valves.
9.      Instrumentation controls.
10.  Types of process component connections. 

A P&ID can be best understood with the help of a legend sheet given by the P&ID developer. Legend sheet contains information regarding the nomenclature, tag philosophy, symbols, a lot more. Download the PDF files to know more about drawings and legend sheet.

For detail information on BFD, PFD and P&IDs download the following PDF files.

Saturday, July 12, 2014

Top 10 books for Chemical Engineering beginners.

Whether you are a student or a engineering professional,some books will have lot of impact in your real life. Following books will give wide knowledge in the Chemical Engineering field.

1. Unit operations of Chemical engineering.

Unit Operations of Chemical Engineering By Chemineering.blogspot.comOne of the oldest books from McGraw Hill book house, Unit operations of Chemical engineering can be considered as a bible for Chemical Engineers. This book is widely using in universities as a basic text for Chemical engineering. If you want to learn basics then this book is for you.
Each section has been framed in a perfect manner for learning step by step. At the end of each chapter you can find lot of problems which will be useful for practice.

Name     - Unit operations of Chemical engineering.
Author  - Warren Lee McCabeJulian SmithPeter Harriot.

2. Introduction to Chemical engineering thermodynamics.

Introduction to chemical engineering thermodynamics by Smith, van ness, abottAnother productive book from McGraw Hill, Introduction to Chemical Thermodynamics is a comprehensive book that starts from basic concepts and end up with a detail description of real gas behavior, solution thermodynamics. Generally solution thermodynamics, real gas behavior is much useful in Chemical and Process industry. Some of the equations from this book found their place in famous simulators which will give the real time values for a given temperature, pressure data. Problems at the end of each chapter will enhance your thermodynamics knowledge.

Name     - Introduction to Chemical Engineering thermodynamics.
Author  - Joseph Mauk Smith, Hendrick C. Van Ness, Michael M. Abbott 

3. Chemical Process Principles Part-1

Chemical process principles by Hougen ,watson and ragatzIn every industry, material and energy balance across a given operation is of immense value. So if you want to ace the material and energy balance this is must book. It will give a glimpse about vapor pressure,humidity, saturation, excess air problems, limiting reagent, crystallization etc.,These principles are much useful to solve mass and momentum transfer problems.

Name     - Chemical Process Principles Part - 1.
Author  - Joseph Mauk Smith, Hendrick C. Van Ness, Michael M. Abbott 

4. Mass transfer operations 

Mass transfer operations by Robert treybal
Mass transfer in general involves transfer of material from one phase to another phase.And the mass transfer operations include Absorption, Distillation, Extraction, Leaching ,Stripping etc.,These operations are explained in a precise manner in this book.Also you can find the mass transfer equipment design fundamentals. You can gain stringent experience by calculating mass transfer problems as you will encounter lot of practical problems at the end of every chapter.

Name     - Mass Transfer Operations.
Author  -  Robert E. Treybal

    5. Heat Transfer

    Heat transfer by J.P. Holman
    Heat transfer is a important operation in every industry (Chemical, Process etc.,) because if you save energy you save money. As a beginner or a engineering professional if you have this book,then you can excel in heat balance calculations, heat exchangers, heat exchanger designs. The data present in this book is of immense value in chemical industry. Every chapter has been explained with clear illustrations. Even it is useful for Mechanical engineers.

    Name   - Heat Transfer.
    Author  - J.P Holman

    6. Chemical reaction engineering

    Chemical reaction engineering by Octave levenspiel
    Chemical reaction engineering is important for determining the reactor size, reactor type, temperatures and pressures required for the reaction. Reactions kinetics plays a major role in chemical industry, particularly in fertilizer and pharma sector. In this particular book you can learn about half time, conversion rates, first order reactions,second order reactions,batch reactors, continuous stirred tank reactors (CSTR), plug flow reactors (PFR), activation energies, catalyst effect etc.,

    Name   -  Chemical reaction engineering.
    Author  -  Octave Levenspiel.

    7. Process system analysis and Control

    Process system analysis and control by Donald
    Now a days every industry is automated, automated in the sense you can monitor the chemical plant from a distributed control system in a control room. In the Process system analysis and control book the author has described how a signal (pressure, temperature, flow etc.,) can be sent to the controller and how the controller functions. This book will give a glimpse about Laplace transforms, first order systems, second order systems, open loop ,closed loop transfer functions, control systems, control valves etc., Check out the book for more!

    Name   - Process system analysis and control.
    Author  - Donald R.  Coughanowr.

    8. Plant Design and Economics for Chemical Engineers

    Plant design and process economics for chemical engineers by Peters, TimmerhausPlant design and economics for a chemical engineers is a very good book on process economics, HAZOP, SWOT analysis, interest calculator, loan repayment, income tax deductions etc., in short it is a non technical book with equal technical importance. You can learn management basics from this book.

    Name  -  Plant design and economics for Chemical engineers.
    Authors  - Max S. Peters, Klaus D. Timmerhaus

    9. Shreve's Chemical process industries

    Shreves chemical process industries by George .T. Austin
    Knowing about Chemical process principles and operations is one part, but knowing about several prominent Chemical process is required. For this Shreve's chemical process industries is a good book. This book is a collection of several chemical process, fertilizer industries, paints oil refineries, sugar industries,ceramic industries, glass industries, etc.,It hilights the major operations involving in that particular process.

    Name   - Shreve's Chemical process industries.
    Author -  George T.Austin

    10. Transport Phenomena

    Transport Phenomena by Bird
    Some of the complex problems in chemical engineering are derived from the basic equations mentioned in the above books. This book provides insight into practical problems that occur in every chemical industry, this includes velocity distributions for newtonian and non newtonian fluids, mass tansfer , heat transfer problems etc.,After reading this book you can solve almost every problem by using the shell balance concepts.

    Name  -  Transport Phenomena.
    Authors Warren E Stewart, R. Byron Bird, and Edwin N. Lightfoot 

    Saturday, June 14, 2014

    What is the difference between Chemistry and Chemical Engineering ?

    Have you ever came across this question, what is the difference between Chemistry and Chemical engineering ? To put in simple words Chemistry mainly deals with the chemical aspects (like pH, electromotive force, reaction with water etc.,) of the chemicals, where as if you pick Chemical Engineering it deals mainly with physical aspects (like density, viscosity, diffusivity, boiling point etc., ). But you can find some properties commonly using in both streams.

    Chemist work:

    In general chemists take care of chemical reaction rates, properties of matter, research involved in the production of new chemicals. They use wide variety of equipment in laboratory to analyze the chemical behavior,composition, conductivity, pH, polarity, surface tension etc.,For example the reaction between a polar molecule and a organic compound depends on the affinity between those two chemicals. also the composition, pH of the products after the reaction will be given by the chemists.

    Chemical engineer work:

    Chemical engineers use the data provide by chemists to design a chemical industry. They much involve in designing the distillation columns, extractors, pressure vessels, reactors, by using the physical properties of chemicals. For example in a distillation column, temperature at the top and bottom of the column have predominant effect on the purity of chemicals.Chemical engineers used to work on simulators to solve complex problems related to process in a chemical industry.

    Job profiles:

    Chemists with post graduation and Ph.D have bright opportunities in the field of research. Also they can opt to work as chemists and R&D technicians with graduation.
    Chemical engineers on the other hand have wide opportunities in the field of process engineering, design of chemical plants, chemical plant operation etc.,

    Tuesday, April 29, 2014

    First law of thermodynamics and sign convention of heat, work.

    First law of thermodynamics

    First law of thermodynamics states that
    "Energy can be neither created nor destroyed but one form of energy can be converted to another form."
    For example consider a ball is placed on the top of a table initially. It will have certain potential energy ( Energy possessed by virtue of its height ) as it is at a height from the ground. When it is allowed to fall from the table this potential energy will be converted into kinetic energy ( Energy possessed by virtue of its motion ). This kinetic energy will be converted to heat , sound etc., when it touches the ground.
    In application of the first law to a given process, the sphere of influence of the process is divided into two parts namely system and surroundings. The region in which process occurs is the System and everything which the system interacts is the surroundings. First law of thermodynamics applies to both system and surroundings. In general,
    Δ Energy of system  +  Δ Energy of surrounding  = 0
     For the above example if you consider ball as a system  initial energy is potential and final energy is kinetic,but the energy is gained by surroundings as heat and sound.

    Systems are of two types.

    • Open = System which exchange both mass and energy with surroundings.
    • Closed = System which exchange only energy with surroundings.
    For simplification here we are considering closed systems only. In general system contains some internal energy ( in the form of attractions and vibrations ) and this tend to change when the heat is added or removed, when work is done on the system or delivered by the system.For closed systems energy transfer between system and surroundings takes place in the form of work and heat. ( where as in open systems internal energy will be associated in transit also i.e., at entry and exit of the system ). For closed systems energy changes mostly occur in internal energy. So,
    Δ Energy of system = Change in internal energy  = ± Q ± W 
    Only change in internal energies can be found as it is hard to know the energy associated with  attractions and vibrations. Q is heat and W is work.

    Sign Convention for heat and work.

    Q and W always refer to system. 

    • Heat given by the system, Heat produced by the system = -Q
    • Heat given to the system, Heat supplied to the system = +Q

    • Work done by the system, work produced by the system = -W
    • Work done on the system, work given to the system = +W
    Example :

    Δ Internal energy  =  Q - W 

    Heat is given to the system and work is done by the system.

    Tuesday, April 15, 2014

    How to solve excess air problems in Chemical Engineering?

    In learning Chemical process calculations you might have encountered with the excess air or excess oxygen problems. This is more common in combustion type of problems, where oxygen is used as a aid to combustion. One can easily solve this kind of problems by simply noting down the four points. they are,
    1. How many compounds are there which can be combustible ?
    2. How much of oxygen is already there ?
    3. How much actual oxygen is to be supplied ?
    4. What is the percentage excess given ?
    Consider a example where methane ( CH4 ) undergoes combustion with air, according to the reaction,

    CH4     +         2O2      =         CO2     +          2H2O

    CH4     +          Air (O2 + N2)                        =         CO2  +          2H2O  +          N2

    One mole of methane burns in the presence of two moles of oxygen giving one mole carbon dioxide and two moles water. If the above combustion occurs at 100% conversion rate the output stream contains only Carbon dioxide and water, if the conversion rate is less than 100%  then the output contains unreacted methane ( CH), unreacted oxygen, carbon dioxide and water. ( If we are considering air as the source for oxygen then output contains nitrogen also, because air contains 21% Oxygen and 79% Nitrogen and this 21% oxygen should be sufficient to achieve the given case ).

    Let us consider the case where 2 Lb mole methane is burnt with 20% excess air in order to ensure complete combustion of methane. then what is the output gas composition ?
     Now apply the four steps.
    1. Methane is the only compound which undergoes combustion.
    2. Along with methane there is no oxygen , so oxygen already present is zero.
    3. For 2 Lb mole methane 4 Lb mole oxygen is to be supplies as per stoichiometry.
    4. But 20% excess air is supplied so indirectly it means that 20% excess oxygen is considered, so total oxygen moles = 4 Lb moles + 4*20/100  Lb moles = 4 *1.2 Lb moles.
    Output gas composition :
    Methane ( CH) is completely burnt so for 2 Lb moles methane 2 Lb moles carbon dioxide will form along with 4 Lb moles water as per stoichiometry. But the unreacted oxygen = 4*1.2 - 4 Lb moles = 0.8 Lb moles. Nitrogen in output is calculated by
    Total air in = total oxygen/0.21 = 4*1.2/.21 = 22.857 Lb moles
    Total nitrogen in inlet air  =  total air * 0.79 =22.857*.79 = 18.057 Lb Moles.

    ( If there is oxygen along with methane then net oxygen required for combustion = oxygen required for combustion as per stoichiometry - oxygen already present . Now apply percent excess to this quantity and proceed further )

    Now start your own calculation. All the best.

    Saturday, March 8, 2014

    Pressure measurement calculations in U - Tube and Inclined tube manometers using Microsoft Office Excel.

    Pressure is defined as the force exerted per unit area. In Chemical, Mechanical and Civil Engineering works pressure measurement is important in determining the frictional losses, velocity ( Using Hagen Poiseuille equation), pipe line size, etc., Also the pressure difference will indicate the type of pump, compressor to be used in liquids and gases. In order to measure the pressure difference existing in a pipe, we can use a U -Tube manometer. The two ends of the U - Tube manometer are connected to pipe in such a way that one end will be at upstream and the other in stream. Due to the pressure difference in pipe the level in the manometer limbs will differ, we will use this difference for pressure drop calculation. For this type manometer , density of manometer liquid should be higher than the density of liquid in pipe.U- tube manometer is used for normal pressure difference calculation in pipelines.
    Inclined Tube Manometer calculation using Microsoft excelU Tube Manometer calculation using Microsoft excel

    Where as inclined tube manometer is used for measuring small differences in pressure, here enlargement is provided in the vertical leg so that the movement of meniscus in the enlargement is negligible within the operating range of the instrument.
    You can Download the pressure difference calculation Excel sheet here. It includes pressure conversion feature.

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    Excel file for pressure calculation in manometer.

    Tuesday, March 4, 2014

    Use of Microsoft Office Excel in Chemical engineering calculations.

    In Chemical engineering, people need to solve lot of problems in the process calculations. If done by manual method these calculations consume more time and often creates confusion. On the other hand we can use simulation software to solve small material balance  to mighty design calculations, but they are too expensive to install for personal use. Even though some free simulation software are available, they are restricted to some calculations only. Then what is the solution? Here comes Microsoft Office Excel. In Microsoft Excel you can perform small arithmetic operations like addition, subtraction, multiplication, blah blah . to complex problems like iterations for a required case.

    Use of Excel in Chemical Engineering Calculations.
    Microsoft Excel is equipped with some predefined functions along with charts (includes line,bar,pie charts,etc.,) which are very helpful to solve the process calculations. For example cost of production can be compared between different process by using charts for a given compound. You can also define your own function in Excel if you know VBA (Visual Basic Application) programming, which can reduce your hectic work considerably. Microsoft Excel can handle lot of information which can be compiled for the given instructions. This is particularly useful in doing the material balance calculations in stream wise across different sections like reactor, columns, strippers, etc.,
    A lot of predefined and calculated excel sheets are available in internet. Here are some useful websites.


    Invest your time in learning excel and  you can easily solve complex problems in Microsoft Office Excel.
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