chemical engg seminar

8/9/2019 Chemical Engg Seminar

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CH E 1121:Chemical Engineering Seminar

Lecture 1 Objectives:

What is Chemical Engineering?

Historical Accomplishments

Fundamental Topics

Chemical ProcessesAmmonia Synthesis

Flow Sheets


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Chemical Engineeringinvolves the application of

math, chemistry, physics, and increasingly, biology

to model and understand chemical and physicalprocesses on molecular and macroscopic levels

and

to develop economic processes based on such changesfor the betterment of mankind.


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AIChE Top Ten Achievements of Ch EBased on historical impact and creativity of response to societal need (1983)

Synthetic Rubber: Second largest government project after the Manhattanproject in WWII. Annual production: 325 M tires.

Antiobiotics and Medicines: Millions were killed in epidemics prior to the massproduction of effective medicines. Penicillin was developed in 1929.

Polymers: Predominant materials for consumer products. Annual production in US:115 B lb. Bakelite (phenol/formaldehyde) was developed in 1905.

Synthetic Fibers: Rayon was first extruded in 1910 and nylon in 1939. Currentproduction of fibers is 8 B pounds/year.

Cyrogenic Separation of Air in O 2 and N 2: Nitrogen is used to make fertilizer and as a cryogen; O 2 is used in medicine and metals processing.

Separation of Nuclear Isotopes: Made nuclear energy possible; nuclear isotopes are used in medical research, diagnostics, and treatments.

Catalytic Cracking of Crude Oil: Allowed oil to be transformed into a range of hydrocarbon products, including fuels, plastics, pharmaceuticals.

Pollution Control: Catalytic converters for cars, scrubbers on smokestacks,and other strategies used to protect and restore the environment.

Fertilizers (Ammonia): Improved agriculture productivity and reduced world hunger;35 B pounds produced in US in 1995 - sixth largest of all chemicals.

Biomedical Engineering: Development of artificial organs.


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Fundamental Topics for Ch EMass and Energy Balances: Analysis of ProcessesThermodynamics: Process feasibility; phase behavior - important

for separation of multicomponent mixturesFluid Mechanics: How fluids flow - important in pumpingHeat Transfer: How heat transfers - important for heat exchangers

Mass Transfer:Mixing or separation of chemical species using

distillation, extraction, evaporation, drying, absorption, etc.

Reaction Kinetics and Engineering: Modeling chemicalreactions; design and sizing of chemical reactors

Process Control: Control of the process to optimize economics,including enhancing product quality and decreasing pollutionMaterials and Corrosion: Materials selection and optimizationEconomics: Cost and optimization of design and process options


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Professional Activities and Area

Process Engineering

Process Development

Plant Design

Environmental Engineering

Technical Sales

Technical Management

Research

Fine Chemicals

Pharmaceuticals

Polymers/Plastics

Fuels/Oil Refining

Foods

Biochemical/Biomedical

Materials

Electronics

Pulp and Paper

All require technical proficiencycoupled with effective communication skills!


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Chemical Engineering involves the application of math, chemistry, physics, and increasingly, biology to model andunderstand chemical and physical processes on both the molecular and macroscopic levels and to develop economic processes based onsuch changes for the betterment of mankind.

Chemical Process: Conversion of materials into desired productsusing equipment and conditions which facilitate that conversion.

Laboratory Process: A + B C

Delivery Heat transfer Reaction Separation


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Chemical Process for A + B C:

Tank Pump Heat Exchanger Reactor DistillationColumn

Hot Stream

Hot Stream


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Process TerminologyContinuous Process: Inputs and outputs flow continuouslythrough the process. Example: The chemical process

described on the previous page for making C from A and B.

Batch Process: Feed is charged into the system at thebeginning of the process and products are removed at one

time at the end. Example: The laboratory scheme for making C from A and B shown earlier.

Steady State Process: Process variables do not change

with time (except possibly for minor fluctuations aboutconstant mean values).


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Flow SheetsBlock Diagrams

Process Flow DiagramsStream compositionTotal stream flow

Stream temperatureStream pressure

Piping and Instrumentation DiagramsMost detailed diagram: equipment, process instrumentation,piping, valves, fittings, materials specification, etc.


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Example: Design of a Process toSynthesize Ammonia

N2 + 3 H 2

NH3

Continuous Process: Inputs and outputs flowcontinuously through the process.

But, is the output realistic?

NH3

N2

H2 Reactor


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Ammonia Synthesis: Product Purity

There will be some residual reactant in the effluent.

How do we purify the product?

Compound Boiling Point at 1 atm, in C

NH3 -33

H2 -253

N2 -196

N2H2NH3

N2H2

Reactor


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Ammonia Production: Product Separation

Will the separation be perfect?

What should we do with the N 2 and H 2 exiting thecondenser?

N2H2N2H2

NH3Reactor

N2

H2 Condenser - 35 C

NH3


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Ammonia Production Process: Recycle Stream

Gases such as N 2 and H 2 are expensive, bulky, and mustbe compressed for efficient transport. H 2 has the addedrisk of explosion.

How can we modify the process to reduce risk andincrease profits?

What are possible sources of N 2? Sources of H 2?

N2H2

N2H2

N2H2N2H2

NH3Reactor

N2H2

Condenser - 35 C

NH3

Combiner


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Ammonia Production: Sources for N 2 and H 2

N2 from Air: Separation of N 2 and O 2 using a Condenser

Compound Boiling Point at 1 atm, in C

N2 - 196

O2

- 183

A possible H 2 Source is Water:

H2O (gas) + 242 kJ H2 + 1/2 O 2

How might we provide the energy for this reaction?


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Ammonia Production Process: H 2 Source

CH 4 + 2 O 2 CO 2 + 2 H 2O (gas) + 803 kJ

3.3 H 2O (gas) + 3.3 (242 kJ) 3.3 H 2 + 3.3/2 O 2

CH 4 + 0.35 O 2 + 1.3 H 2O CO 2 + 3.3 H 2 (gas) + 0 kJ .

Compound T bN (C)H2 - 253CO 2 - 79CH 4 - 164

O 2 - 183H2O 100

What are the major gases we need to remove from the effluent stream?

Will this depend on the feed stoichiometry?Do we need to remove all of the methane from the effluent?

H2CO 2CH 4O 2H2OCH 4 Reactor

(Burner)

CH 4O 2H2O


16/23


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Ammonia Production Process

CH 4O 2H2O

H2CH 4

N2

(Air)N2O 2

O 2

N2H2CH 4

N2H2CH 4

N2H2

CH 4

N2

H2NH3CH 4

Reactor

N2H2CH 4

NH3

H2CO 2CH 4H2OCH 4 Reactor

(Burner)

CH 4H2

Condenser - 85 C

CO 2H2O

Condenser - 35 C

Condenser - 190 C

CH 4H2O


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Ammonia Process with Purge

CH 4O 2H2O

CO 2H2O

H2

CH 4

N2

(Air)N2O 2

O 2

N2H2CH 4

N2H2CH 4

N2H2

CH 4

N2

H2NH3CH 4

Reactor

N2H2CH 4

NH3

H2CO 2CH 4H2OCH 4 Reactor

(Burner)

CH 4H2

Condenser - 85 C

Condenser - 35 C

Condenser - 190 C

CH 4H2O

N2H2CH 4


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Ammonia Production Process:Heat Integration and Heat Exchange

Are we wasting heat in our process?

CoolStreamB

WarmStreamA

HotStreamA

HeatExchanger

ColdStreamB

FLUIDHANDLING +


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FLUID HANDLING

CentrifugalPumpor blower

Centrifugalcompressor

Turbine

Centrifugalcompressor,alternate symbol a

Valve +control &Valve

HEAT TRANSFER

Shell-and-tubeheat exchanger

Fired heater

Tray dryer

-e ubeside

streamFuel 4

Air cooler

with finnedtubes

Water

Spray condenser

aCoil in tankRotary Waterdryer stream Cooling tower,

or kiln forced draft Air

MASS TRANSFER

Filter -(.- fi


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Ch E 1121 This TermExamine a problem related to disposal of an acidicbyproduct: design a process and investigate how thevarious topics in Ch E apply.

Discuss ethics and professionalism.

Discuss co-operative education and researchopportunities.


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HOMEWORK 1 DUE 9/9

Three-page double-spaced essay:What is Chemical Engineering? and Why am I majoring in ChemicalEngineering?

FORMAT:12-point Times or Times New Roman font1" marginsFive space (1/4") paragraph indentionsNo extra carriage returns between paragraphs

Two carriage returns after the titleName in upper right hand corner Number pages at bottom rightStaple in upper left hand corner Staple your outline to the back of your paper

GRADING (out of 100):Content/Organization 50Format 20Grammar/Spelling 20 (Five points off for every spelling error)Outline 10


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Writing Guidelines

1. Make an outline and use it.2. Use a topic sentence for every paragraph and be sure all

sentences in a paragraph relate to one another or to the topicsentence.

3. Be sure the topic sentences are related logically. Read the firstsentence of every paragraph in the essay - does the organizationmake sense?

4. Be sure that the first six words of each sentence (ignoring short

introductory phrases) include: a short specific subject (not "this", "that", "there", "it", etc.) a verb expressing a key action old information that sets a context for the rest of the sentence

5. Be precise and concise.6. Do not use contractions or jargon. Do not use first person unless

necessary.7. Make sure to include only relevant information! Do not include

parenthetical information - if it's important work it in; if not, omit!

chemical engg seminar

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