Chemical Engineering 131 Discussion

October 27, 2004

• Engineering

The art of directing great resources of power in nature for the usefulness and the convenience of people.

In its modern form, engineering involves mankind, money, materials, machinery, and energy.

Engineering is concerned about systems, processes, and devices useful to, and sought by, society.

Engineering requires more then the creative imagination to innovate useful applications of natural phenomena. It seeks out newer, less expensive, and better means of using natural or man-made resources of energy and materials for their safe application to society.

From the McGraw – Hill Encyclopedia of Science and technology

• Engineers Career Development

- Formal education –> broad and deep in sciences, math, and humanities

- Specialization (internships or co-ops) in the intricacies of a particular engineering discipline.

- The beginnings of post graduate studies and work experience.

- Promotion within the work group to a supervisor which allows oversight of a variety of people and specialties.

- Promotion into a managerial function whereby the daily coordination / blending of people, money, materials, machinery, and energy sources into complicated processes occurs.

• Engineering career track selection usually is:

- Technical (scientist, process, project, design, or manager)

- Operations (day to day operations of a facility, supervisor, superintendent, manager)

- Business (usually requires an MBA or a large amount of market understanding)

• Chemical Engineering

The branch of Engineering that services those industries that chemically convert basic raw materials (e.g., money, materials, machinery, and energy) into a variety of products.

• Chemical Engineering Application - Phase 1 / 2

Usually involves four or more components or phases. These phases include:

I. Concept / II.Research

• By starting with basic scientific data on chemical reactions, usually discovered by research scientists, a Chemical Engineering begins the conversion of raw materials by starting on a bench scale set-up. The engineer develops sound data for various steps in process.

Then the engineer proceeds to scale up the experiments to pilot plant of prototype set-up simulating what may (or may not) happen in a commercial environment.

• Chemical Engineering Application - Phase 3

III. Development

• In the Development section, the engineer relies on previous training in scientific or other engineering fundamentals, first hand or acquired knowledge of process equipment, or extensive research to determine if this experiment has been conducted previously.

If it has, where and what were its outcomes?

In many cases, a mathematical model will be developed.

Evaluations and simulations will be carried out to provide the necessary design details for design of a commercial unit or process.

• Chemical Engineering Application - Phase 4

IV. Commercialization

• After commercialization, chemical engineering plays a role in process start-up and day to day operation of the facility.

Once in operation, the facility becomes a continual problem of: - optimization, - maximizing rates,- keeping accidents and injuries at their lowest possible levels, - balancing inventories of raw material with financial impacts,- always adjusting to the continual changing needs of the market place.

• Tools for the Engineer’s Tool Box

• Know your boss“The customer is the boss because he can always fire anybody by taking his money and spending it somewhere else” – Sam Walton. Then comes your immediate supervisor.

• Communication Writing know-how! You will do it often.Public Speaking - Know your audience.

• Clarity of adviceEngineers are ultimately the brain trusts of an organization and are therefore looked upon as people (or teams) who can solve problems.

• Tools for the Engineer’s Tool Box continued

• EconomicsNothing gets accomplished without economics. How much? Why should I invest in your idea?

• Data Always, Always, Always have data. Chemical Engineering is ruthless without data.

• Manage RiskConduct risk evaluations to understand the risks involved. IMAGINE what could happen if …. “Well, the fire occurred in the capsule because we failed to imagine it could happen.” – Col. Frank Boreman, answering to the US Senate Investigation Committee regarding the Apollo 1 fire.

• Tools for the Engineer’s Tool Box continued

• Manage variability Processing raw materials -- nothing is as pure or clean or as it appears.

• IntegrityAbove all else, an engineer’s role is to search for the truth. When it is all over, the content of your character will be judged by your integrity.

• Time Management / PlanningPlanning is key to a successful career as a engineer.

• Catalyst Summary

• Catalysis is one of the most important technologies we have. Most people are unaware of its wide-ranging significance.

• It plays a crucial role in many aspects of human progress- efficient manufacture of many kinds of materials - fuels to plastics

- in creating new energy sources

- protecting the environment

- in developing effective, safer medicines

• Catalyst Summary

• Catalysis is the phenomenon by which certain chemicals (catalysts) increase a chemical reaction without undergoing any permanent chemical change themselves.

• They can be recovered after a reaction and used again (regeneration).

• Without the correct catalyst, many reactions hardly work.

• The chemical nature of a catalyst can have a real (sometimes radical) effect on the reaction pathways that occur, leading to different chemical products.

• Catalyst Summary

• Over recent decades, there has been enormous progress in understanding the underlying molecular mechanisms which in turn has had an dramatic effects on the development of new catalyst systems.

• About 80% of all processes in the chemical industry now depend on catalysts.

• Since the chemical industry is one of the most important and competitive sectors of all developed economies, it is not surprising that catalysis is an extremely active research area.

• Catalyst Summary

• New catalysts and new catalytic processes are being devised that aim to produce cleaner chemical processes.

• These use less energy, and environmentally acceptable agents (for example, air or oxygen as an oxidant instead of hydrogen peroxide) and perhaps water as a solvent, resulting in less waste.

• Catalyst Summary

• Catalysts are used in three ways.

(1) The first is to change cheap and plentiful starting materials into chemicals that may serve as fuel or starting materials for other processes. In oil refining, 350 million gallons / day of oil worldwide are converted using 1000 tons of catalysts.

Catalytic agents include metals such as platinum, or metal oxides, acids or certain modified minerals.

(2) Catalysts are also used to convert the resulting petrochemicals into so-called 'higher added-value' products such as polymers and fine chemicals.

• Catalyst Summary

• Catalysts are used in three ways continued ...

(3) In the pharmaceutical industry, numerous drugs are made via a series of chemical steps.

These involve a range of fine chemicals which increasingly involve imaginative, highly selective reactions using catalytic agents with complex structures.

• Catalyst Requirements

• Despite the nature of the catalyst, it must have certain properties to be economic.

• First, it must be highly active. Catalysts work by virtue of possessing certain 'active sites' in their structures.

Adsorption or transient bonding at the active site allows the reacting molecules to undergo a particular chemical transformation at much lower energy than would normally be the case in the absence of such sites.

The number of active sites and ease of access controls the rate of turnover of reacting molecules.

• Catalyst Requirements

• The enzyme catalyzes destroys hydrogen peroxide generated in our bodies at a rate of a million-million molecules per second at each active site.

Iron catalysts, the foundation of the Haber process for making Ammonia for the fertilizer industry, turns over only one molecule per active site per second.

Such catalysts need to be manufactured so as to contain a large number of active sites per unit surface area.

Another important requirement is long lifetime. For instance, the iron catalyst in the ammonia process could last 15 years.

• Catalyst Requirements

• A third and crucial characteristic is selectivity. Catalysts actually direct the course of the reaction as well as increase it.

For example, a copper-based catalyst converts 'syngas' (a mixture of carbon monoxide and hydrogen produced by the controlled burning of natural gas) into Methanol.

• However, other metal catalysts yield mixtures of hydrocarbons suitable for various fuels.

• Enzymes are incredibly selective. They are able to recognize a reacting molecule by its shape and transform it in a geometrically specific way.