chemical engineering plant design (1)

Chemical Engineering Plant Design

Course Code:Ch.E-403

Prof. Dr. A.K Salariya

chemical engineering plant design2

Chemical Engineering plant design

Total Credit Hours 3+1=4

Three Credit hour for theory:-

Mid term + Final term + Assignments + Quizzes = 75% marks

One Credit hour for lab:-

(Covered mini projects assigned to group of three student.)

=25 %Marks

chemical engineering plant design 3

Course outlineIntroductionProcess design developmentGeneral design considerationOptimum designMaterials of construction and fabrication.Material transfer handling and equipment designHeat transfer equipment designMass transfer equipment designApplication of computer aided design software.


Books Recommended

Following are recommended course books.1-Peter Max S., Timmerhaus Klamus D. “plant Design and

economics for Chemical Engineers” 5th Ed. McGraw hill Inc.2-Ludwig Ernest E. “Applied Process Design for Chemical

and Petrochemical plants” Voll 1,2 &3, 3rd Ed.2002 Gulf publishing company.

3-Walas Stanley M. “Chemical Process Equipment- Selection and Design Butterworth Heinemann” 1999

4-Coulson and Richardson, “Chemical Engineering ”, Vol VI “Butterworth Heinemann”1999.

5-Wells G.l Rose L.M “The art of Chemical Design”1986 Elsevier.

6-Smith Robin “Chemical Process Design”1995. McGraw Hill Inc,

7-Bakhurst & Harker,, “Chemical Process Design ”John Willey.8-Evans, “Handbook of Chemical Equipment Design”9-E.L.Cussler and G.D Moggridge, “ Chemical Product Design”,

2001, Cambridge University press.


Recommended Books Following is the list of Reference books that are very

useful for students during study the chemical engineering plant design and their final year Design projects.

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Some useful links from webFollowing are the useful links for students for chemical engineering plant

design projects.

o McGraw Hill Collections

http//www.digitallibarary.edu.pk/megraw.htmlo McGraw Hill’s Access Science

http//www.accessscience.como McGraw –Hill’s Digital Engineering library

http//accessengineeringlibrary.como Project muse

http//muse.jhu.eduo Springer link.

http//www.springerlink.com o Chemical engineering -Wikipedia, the free encyclopedia

en.wikipedia.org/wiki/Chemical_engineeringo Cost estimating for chemical engineering plant design

people.clarkson.edu/~wwilcox/Design/refcosts.htm


Some useful links from webo http://www.chemsof.com/exch/exchsam1.htmo http://processflowsheets.blogspot.com o http://www.cheresources.com

o These are only few of thousands link, Remaining links will be discuss during the course study.

o Except of Web help WEC library also have digital library of about 2000 books and journals related to Engineering Sciences. Which are also very helpful in learning the Chemical engineering plant design.

IntroductionA successful chemical engineer must also have the ability to apply knowledge and understanding of the fundamental sciences and the related engineering subjects such as thermodynamics, reaction kinetics, heat transfer, mass transfer, and computer technology to practical situations for the purpose of accomplishing something that will be beneficial to society.Chemical engineer must recognize the economic, environmental, and ethical implications that are involves in such developments and proceed accordingly


CHEMICAL ENGINEERING PLANT DESIGN

Plant Design:-

It includes all engineering aspects involved in the development of either a new, modified, or expanded industrial plant.

In this development, the chemical engineer will be making economic evaluations of new processes, designing individual pieces of equipment for the proposed new venture, or developing a plant layout for coordination of the overall operation.


Design engineer:Because of these many design duties, the chemical engineer is many times referred as a design engineer.

Cost engineer:a chemical engineer specializing in the economic aspects of the design is often referred to as a cost engineer. In many instances, the term process engineering is used in connection with economic evaluation and general economic analyses of industrial processes, while process design refers to the actual design of the equipment and facilities necessary for carrying out the process

chemical engineering plant design


Contd...The process engineer may not be connected directly with

the final detailed design of the equipment, and the design of the equipment may have little influence on a decision by management as to whether a given return on investment inadequate to justify construction of proposed process.

the most effective teamwork and coordination of efforts are obtained when each of the engineers in the specialized groups is aware of the many functions in the overall design project

General overall Design Considerations

Various aspects of environmental protection, as well as the safety and health needs of plant personnel and the public.

Plant locationPlant operation and controlUtility requirementsStructural designStorage and buildingsMaterial handlingAnd patent considerations.


A plant-design project moves to completion through a series of stages such as is shown in the following:

1. Inception

2. Preliminary evaluation of economics and market

3. Development of data necessary for final design

4. Final economic evaluation

5. Detailed engineering design

6. Procurement

7. Erection

8. Startup and trial runs

9. Production


Process Plant design developmentStep 1 (Inception of the basic idea):This idea may originate in the sales department, as a result of a

customer request, or to meet a competing product. For the aims and needs of a particular companyIt may be the result of an orderly research program or an offshoot of

such a program.The operating division of the company may develop a new or

modified chemical, generally as an intermediate in the final product.In all these possibilities, if the initial analysis

indicates that the idea may have possibilities of developing into a worthwhile project, a preliminary research or investigation program is initiated.chemical engineering plant design

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Step 2 (Process Research Phase):It includes preliminary market surveys, laboratory-scale experiments, and production of research samples of the final product. When the potentialities of the process are fairly well established to meet the economic goals of the company, the project is ready for the development phase.


Step 3(Development Phase):At this point, a pilot plant or a commercial development plant may be constructed. A pilot plant is a small-scale replica of the full-scale final plant, while a commercial-development plant is usually made from odd pieces of equipment which are already available and is not meant to duplicate the exact setup to be used in the full-scale plant.


Step 4 (cost-and-profit analysis):

A complete market analysis is made, and samples of the final product are sent to prospective customers to determine if the product is satisfactory and if there is a reasonable sales potential.

Capital-cost estimates for the proposed plant are made. Probable returns on the required investment are determined, and a complete cost-and-profit analysis of the process is developed.


Step 5 (Availability of capital funds):Before the final process design starts, company management normally becomes involved to decide if significant capital funds will be committed to the project. It is at this point that the engineers’ preliminary design work along with the oral and written reports which are presented become particularly important because they will provide the primary basis on which management will decide if further funds should be provided for the project. When management has made a firm decision to proceed with provision of significant capital funds for a project, the engineering then involved in further work on the project is known as capitalized engineering while that which has gone on before while the consideration of the project was in the development stage is often referred to as expensed engineering. This distinction is used for tax purposes to allow capitalized engineering costs to be amortized over a period of several years.


Step 6 (Final process design):All the design details are worked out in this phase including

controls, services; piping layouts, firm price quotations, specifications and designs for individual pieces of equipment, and all the other design information necessary for the construction of the final plant.

A complete construction design is then made with elevation drawings, plant-layout arrangements, and other information required for the actual construction of the plant.

The final stage consists of procurement of the equipment, construction of the plant, startup of the plant, overall improvements in the operation, and development of standard

operating procedures to give the best possible results.chemical engineering plant design 19

Typical design steps for chemical processes table 1-1

1. Recognize a societal or engineering need.

a. Make a market analysis if a new product will result.

2. Create one or more potential solutions to meet this need.

a. Make a literature survey and patent search.

b. Identify the preliminary data required.

3. Undertake preliminary process synthesis of these solutions.

a. Determine reactions, separations, and possible operating conditions,

b. Recognize environmental, safety, and health concerns.

4. Assess profitability of preliminary process or processes (if negative, reject

process and create new alternatives).



Contd...5. Refine required design data.

a. Establish property data with appropriate software.

b. Verify experimentally, if necessary, key unknowns in the process.

6. Prepare detailed engineering design.

a. Develop base case (if economic comparison is required).

b. Prepare process flow sheet.

c. Integrate and optimize process.

d. Check process controllability.

e. Size equipment./. Estimate capital cost.

7. Reassess the economic viability of process (if negative, either modify

process or investigate other process alternatives).


Contd...8. Review the process again for environmental, safety, and health effects.

9. Provide a written process design report.

10. Complete the final engineering design.

a. Determine equipment layout and specifications.

b. Develop piping and instrumentation diagrams.

c. Prepare bids for the equipment or the process plant.

11. Procure equipment (if work is done in-house).

12. Provide assistance (if requested) in the construction phase.

13. Assist with start-up and shakedown runs.

14. Initiate production.


Contd...Table 1-1 indicates that the design process

involves a wide variety of skills. Among these are research, market analysis, computer simulation, software programming, equipment design, cost estimation profitability analysis and technical communication.

Flow sheet developmentEstablishment of separate flow sheets or road maps for

each solution ( designer creating flow sheets involving just the reaction, separation, and temperature change and pressure change operations and selecting process equipment in task integration step).

A favorable gross profit providing flow sheets are retained the others are rejected.

A base-case design development

The design engineer develops it by creating a detailed process flow sheet with a listing of steady state material balance and energy balances and a designation of major equipment items .


Computer-Aided Design

Rapid calculationsLarge storageLogical decisionsTechnical and mathematical software (study effects of

various design variables on the process or plant design)Process simulatorsSpread sheet software (especially for mass and energy

balances, approximate sizing of equipment, cost estimation, economic analysis steps of process design)


Cost EstimationDirect price quotations based on detailed specifications is

obtained from various equipment venders.Evaluation of costs in the preliminary design phases is

referred as predesign cost estimation.The chemical engineer (or cost engineer) must be certain to consider all possible factors when making a cost analysis. Fixed costs, direct production costs for raw materials, labor, maintenance, power, and utilities must all be included along with costs for plant and administrative overhead, distribution of the final products, and other miscellaneous items.


FACTORS AFFECTING PROFITABILITY

OF INVESTMENTS

A major function of the directors of a manufacturing firm is to maximize the long-term profit to the owners or the stockholders

Time value of money has been integrated into investment-evaluation systems by means of compound-interest relationships.


Optimum designOptimum Economic Design If there are two or more methods for obtaining exactly

equivalent final results, the preferred method would be the one involving the least total cost.

A graphical representation showing the meaning of an optimum economic pipe diameter is presented in Fig. l-l. As shown in this figure, the pumping cost increases with decreased size of pipe diameter because of frictional effects, while the fixed charges for the pipeline become lower when smaller pipe diameters are used because of the reduced capital investment. The optimum economic diameter is located where the sum of the pumping costs and fixed costs for the pipeline becomes a minimum, since this represents the point of least total cost. In Fig. l-l, this point is represented by E.


1-Optimum economic pipe diameter


Optimum Operation Design

Many processes require definite conditions of temperature, pressure, contact time, or other variables if the best results are to be obtained. It is often possible to make a partial separation of these optimum conditions from direct economic considerations.

In cases of this type, the best design is designated as the optimum operation design


2-Determination Of Optimum Operation Temperature In Sulfur Dioxide Converter


PRACTICAL CONSIDERATIONS IN DESIGN

The chemical engineer must never lose sight of the practical limitations involved in a design. It may be possible to determine an exact pipe diameter for an optimum economic design, but this does not mean that this exact size must be used in the final design.

The practical engineer understands the physical problems which are involved in the final operation and maintenance of the designed equipment.


THE DESIGN APPROACH

The optimization of the design as the use of high-speed computers and accompanying software.

At no time, however, should the engineer be led to believe that plants are designed around computers.

The general approach in any plant design involves a carefully balanced combination of theory, practice, originality and plain common sense

In the engineer’s approach to any design problem, it is necessary to be prepared to make many assumptions.



Contd...The good chemical engineer recognize the need for making

certain assumptions but also knows that this type of approach introduces some uncertainties into the final results.

Assumptions are made only when they are necessary and reasonably correct and will not adversely effect the overall design and its economic conclusions.

It is almost always better to sell many units of a product at a low profit per unit than a few units at high profit per unit


Contd...Engineer must take into account the unit production rate

when determining costs and total profits for various types of designs.

Another important factor in the approach to any design problem involves economic conditions and limitations

chemical engineering plant design (1)

Documents

chemical engineeringwikipedia

chemical product design

forchemical engineering

engineering sciences

related engineering

design butterworth heinemann

final year design projects

useful links