Chemical Engineering

Summer@Brown2011

August 28, 1859 - Titusville, Pennsylvania

Edwin Drake

Lubbock, Texas= Jet Fuel

Haifa, Israel9 million tons (66 million barrels) of crude oil/ year

What is Chemical Engineering?

Basic sciences PLUS engineering fundamentals:

• Convert raw materials into valuable products• Design and manufacture devices

This is accomplished by:• Chemical reactions (making and breaking of bonds)• Catalysis (accelerating chemical reactions)• Separation, purification of complex chemical mixtures

Famous Chemical Engineers

• Linus Pauling – Nobel Prize in Chemistry, 1954, Nobel Peace Prize, 1962

• Jack Welch – Former CEO of General Electric• Lee Raymond – ExxonMobile chairman and CEO• Victor Mills – Invented first disposable diaper• Robert Gore – Inventor of Gore-Tex• Samuel Bodeman – Former United States

Secretary of Energy (2005-2009)

Convert Raw Materials into Valuable Products

• Crude Oil Gasoline, Jet Fuel, Monomers• Monomers Polymers (ethylene

polyethylene)• Silicon crystals Semiconductors, integrated

circuits• Inorganic Precursors Ceramics• Corn Starch High Fructose Corn Syrup

Design and Manufacture Devices

• Chemical plants (paper, plastics, fertilizers)• Electronics• Biomedical devices (artificial kidney, hearts)• Diagnostic/Drug delivery devices• Novel materials (polymers, fibers, ceramic)• Energy devices (batteries, fuel cells)• Waste treatment solutions• Specialty chemicals (foods, flavors, fragrances)

Chemist vs. Chemical Engineer

• Chemists: Design new molecules and synthesizes new formulas– Work in grams of materials

• Chemical Engineers: Design equipment and processes for large-scale chemical manufacturing– Work in tonnes of materials

Bhopal Gas Tragedy• Union Carbide India Limited pesticide plant,

Bhopal, India - December 2-3, 1984

1-naphthol chloroformate carbaryl

Factors leading to the Bhopal disasterCaused >15,000 deaths

• Use of hazardous chemicals (MIC) instead of less dangerous ones

• Storing these chemicals in large tanks instead of over 200 steel drums.

• Possible corroding material in pipelines• Poor maintenance after the plant ceased production in the early

1980s• Failure of several safety systems (due to poor maintenance and

regulations).• Safety systems being switched off to save money—including the

MIC tank refrigeration system

A Chemical Engineer’s Curriculum

• Lots of Math, Chemistry and Physics• Fundamental Classes– Heat and Mass Transfer– Chemical Thermodynamics– Chemical Kinetics– Fluid Mechanics– Units of Chemical Processes: chemical reactors,

bioreactors, distillation columns, heat exchangers– Design Chemical Process – integrate process units with

regard to economics, safety and environmental impact

Job Opportunities

The Fundamentals

Black Box Theory• Device, system or object which can be viewed solely in

terms of its input, output and transfer characteristics without any knowledge of its inner workings

• Examples:– Computer programming; software testing– Finance: market prediction– Climate change- weather prediction– Physics: Particle physics Hadron Collider– Human mind: fMRI Biological systems…

• Black box theory has been used in many fields of science and engineering

Refinery Operations

EvaporatorConverts Liquid -> Gas

Heat ExchangerA(75C) A(30C)

Distillation ColumnAB A + B

Process Unit

Input/Feed Output

Distillation AB A + B

Heat ExchangerA(75C) A(30C)

Blackbox

Unit Operations

Process streams

• Mass flow rate, m, (kg/h)

• Volumetric flow rate, V (L/min)

€

.

.

€

m =mass

time

.

€

V =volume

time

.

€

m = ρV. .

Process Unit

Input/Feed Output

Distillation AB A + B

Heat ExchangerA(75C) A(30C)

Blackbox

Unit Operations

m1, v1

. .m2, v2

. .

The volumetric flow rate of CCl4 ( = 1.595 g/cm3) in a pipe is 100.0 cm3/min. What is the mass flow rate of the CCl4?

Question 1

Process Unit

Input/Feed Output

Min (kg CH4/h).

Mout (kg CH4/h).

Min != Mout

. .

Why?

1. Incorrect measurement2. Leakage3. Adsorption onto the walls4. Reacted away? Or generated as a product?

Conservation of Mass

What goes in must come out!!

At steady state, accumulation in system = 0:

No reaction:

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Input + Generation - Output - Consumption = Accumulation

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Input - Output = 0€

Input + Generation - Output - Consumption = 0

Each year 50,000 people move into a city, 75,000 people move out, 22,000 are born and 19,000 die. Write a balance on the population of the city.

Question 2

A feed stream of pure liquid water enters an evaporator at a rate of 0.5 kg/s. Three streams come from the evaporator: a vapor stream and two liquid streams. The flow-rate of the vapor stream was measured to be 4 X 106 L/min and its density was 0.004 kg/m3. The vapor stream enters a turbine, where it loses enough energy to condense fully and leave as a single stream. One of the liquid streams is discharged as waste, the other is fed into a heat exchanger, where it is cooled. This stream leaves the heat exchanger at a rate of 0.1893 kg/s. Calculate the flow rate of the discharge and the efficiency of the evaporator.

Question 3

One thousand kilograms per hour of a mixture of benzene (B) and toluene (T) containing 50% benzene by mass is separated by distillation into two fractions. The mass flow rate of benzene in the top stream is 450 kg B/h and that of toluene in the bottom stream is 475 kg T/h. The operation is at steady state. Write balances on benzene and toluene to calculate the unknown component flow rates in the output streams.

Question 4

Question 5

Two methanol-water mixtures are contained in separate flasks. The first mixture contains 40.0 wt% methanol, and the second contains 70.0 wt% methanol. If 200 g of the first mixture is combined with 150 g of the second, what are the mass (m) and composition of the product?

Case Study: High Fructose Corn Syrup

High Fructose Corn Syrup• Milestones– 1957 – Process developed by Richard O. Marshall

and Earl R. Kooi– Up until 1970: sucrose used as a main sweetener– 1975 – 1985 – HFCS introduced to processed

foods and soft drinks– Common forms: HFCS 42 and HFCS 55

Soft Drinks 95%Baked Goods 25%Diary 30%Processed Foods 45%

Sold in a bushel: 56 pounds of wet corn(48.1 lb of dry corn + 7.9 lb of water)

Milling Process

Corn Oil 1.6 lb

Cornmeal 2.5 lb

Animal Feed 12.5 lb

Starch 31.5 lb

Water 7.9 lb

Extract Weight/Bushel Cost/Pound Cost/Bushel

Corn Oil 1.6 lb $0.27/lb $0.43/bushel

Cornmeal 2.5 lb $0.132/lb $0.33/bushel

Animal Feed 12.5 lb $0.044/lb $0.55/bushel

Starch 31.5 lb ? ?

Water 7.9 lb --- ----

$1.31/bushel

Raw Material Weight/Bushel Cost/Pound Cost/Bushel

Wet Corn 56 lb $0.047/lb $2.63/bushel

Cost Analysis of Harvesting Corn

Corn Starch High Fructose Corn Syrup

• Liquefication– G-G-G-G-G-G G, G-

G, G-G-G• Saccharification– G-G, G-G-G G, G,

G, G, G• Isomerization– Glucose

Fructose

α-amylase

Glucoamylase

Glucose isomerase

Corn Starch

Other ExtractsStarch Purification

Liquefaction

Saccharification

Isomerization

Separator

55% HFCS42% HFCS

α-amylaseplant

glucoamylaseplant

glucoisomeraseplant

3 hrs, pH 6-7, Initial: 300F, 30 min, Heat: 185F, 30 min, Cool: 140F, 30 min

40-90 hours, pH 4, 140F

30 min process, pH 7, 140-150F

Composition % Fructose % Glucose % Solid

HFCS 42 42 58 70

HFCS 55 55 45 70

Raw Material Weight/Bushel Cost/lb Cost/Bushel

HFCS 42 31.5 lb $0.18/lb $5.67

HFCS 55 31.5 lb $0.20/ lb $6.30

Extract Weight/Bushel Cost/Pound Cost/Bushel

Corn Oil 1.6 lb $0.27/lb $0.43/bushel

Cornmeal 2.5 lb $0.132/lb $0.33/bushel

Animal Feed 12.5 lb $0.044/lb $0.55/bushel

Starch 31.5 lb $0.18/lb $5.67/bushel

Water 7.9 lb --- ----

$7.42/bushel

Raw Material Weight/Bushel Cost/Pound Cost/Bushel

Wet Corn 56 lb $0.047/lb $2.63/bushel

Cost Analysis of Harvesting Corn

Operation Research and Industrial Engineering

ORIE, IEOR, OR-SE-IE

• Originated in military efforts in WWII• Evaluates efficacy of the use of technology• “Decision science”: OR finds optimal solutions to

complex decision making process

Examples

1. Routing: Routes of buses so few buses are needed2. Floor-planning: layout of equipment of factory or

computer chip to reduce manufacturing time/ costs3. Network optimization: set-up of telecommunications

network to maintain quality of service during outages

4. Healthcare: How effective are various disease treatments

Courses?

• Statistics• Optimization• Probability theory• Decision analysis• Queuing/Game/Graph theories• Computer science/analytics

Financial Engineering

NOT a real engineering discipline!

• Applies engineering methodologies to problems in finance

• Combines:

to predict

• Design new financial instruments• Models to help minimize financial risk

€

Math + Finance + Computer Modelling

€

Pricing + Hedging + Trading

Jobs?

• Investment banks• Securities industry• Consulting firms (quantitative analysts)• Corporate finance/risk management roles in

other general manufacturing and service firms

• Prerequisite: Bachelor’s in computer science, operation research economics or math

• Master of Financial Engineering

• Master of Quantitative Finance

• PhDs in computer science or applied mathematics

Face of a Financial Engineer?

Courses to consider in college:

• Financial economics (some colleges offer engineering economics)

• Probability and statistics• Differential equations• Software engineering

Chartered Financial Analyst (CFA)

• International professional designation to financial analyst who complete three (6 hr) exams

• Level 1: Asset valuation, financial reporting/analysis, portfolio management

• Level 2: Asset valuation and quantitative methods• Level 3: Portfolio management and strategies for

managing equity, derivative investments for individuals and institutions