Chemical Engineering a branch of engineering that
applies the natural (or experimental) sciences (e.g. chemistry and
physics) and
life sciences (e.g. biology, microbiology and biochemistry)
together with mathematics and economics to produce, transform, transport, and
properly use chemicals, materials and energy. It essentially deals with the
engineering of chemicals, energy and the processes that create and/or convert
them. Modern chemical engineers are concerned with processes
that convert raw-materials or (cheap) chemicals into more useful or valuable
forms. In addition, they are also concerned with pioneering valuable materials
and related techniques – which are often essential to related fields such as nanotechnology,
fuel cells
and bioengineering.
Within chemical engineering, two broad subgroups include design, manufacture,
and operation of plants and machinery in industrial chemical and related
processes ("chemical process engineers") and development of new or
adapted substances for products ranging from foods and beverages to cosmetics
to cleaners to pharmaceutical ingredients, among many other products ("chemical
product engineers").
Etymology
A 1996 British
Journal for the History of Science
article cites James F. Donnelly for mentioning an 1839 reference to chemical
engineering in relation to the production of sulfuric acid.
In the same paper however, George E. Davis,
an English consultant, was credited for having coined the term.
The History of Science in United States: An Encyclopedia puts this at
around 1890.
"Chemical engineering", describing the use of mechanical equipment in
the chemical industry, became common vocabulary in England after
1850.
By 1910, the profession, "chemical engineer", was already in common
use in Britain and the United States.
History
Chemical engineering emerged upon
the development of unit operations, a fundamental concept of the discipline chemical
engineering. Most authors agree that Davis invented unit operations if not
substantially developed it.
He gave a series of lectures on unit operations at the Manchester
Technical School (University
of Manchester today) in 1887, considered to be
one of the earliest such about chemical engineering.Three years before Davis' lectures, Henry Edward Armstrong taught a degree course in chemical engineering at the City
and Guilds of London Institute.
Armstrong's course "failed simply because its graduates ... were not
especially attractive to employers." Employers of the time would have
rather hired chemists and mechanical engineers.
Courses in chemical engineering offered by Massachusetts
Institute of Technology (MIT) in
the United States, Owen's College
in Manchester,
England and University
College London suffered under similar
circumstances.
Starting from 1888,
Lewis M. Norton taught at MIT the first chemical engineering course in the
United States. Norton's course was contemporaneous and essentially similar with
Armstrong's course. Both courses, however, simply merged chemistry and
engineering subjects. "Its practitioners had difficulty convincing
engineers that they were engineers and chemists that they were not simply
chemists."
Unit operations was introduced into the course by William Hultz Walker in 1905.By the early 1920s, unit operations became an important aspect of chemical
engineering at MIT and other US universities, as well as at Imperial College London.
New
concepts and innovations
By the 1940s, it became clear that
unit operations alone was insufficient in developing chemical reactors.
While the predominance of unit operations in chemical engineering courses in
Britain and the United States continued until the 1960s, transport
phenomena started to experience greater
focus.
Along with other novel concepts, such process
systems engineering (PSE), a "second
paradigm" was defined.
Transport phenomena gave an analytical
approach to chemical engineering
while PSE focused on its synthetic elements, such as control system
and process
design.
Developments in chemical engineering before and after World War II
were mainly incited by the petrochemical industry,
however, advances in other fields were made as well. Advancements in biochemical engineering in the 1940s, for example, found application in the pharmaceutical industry, and allowed for the mass production
of various antibiotics, including penicillin
and streptomycin.
Meanwhile, progress in polymer science
in the 1950s paved way for the "age of plastics".
Safety
and hazard developments
Concerns regarding the safety and
environmental impact of large-scale chemical manufacturing facilities were also
raised during this period. Silent Spring,
published in 1962, alerted its readers to the harmful effects of DDT, a potent insecticide. The 1974 Flixborough disaster in the United Kingdom resulted in 28 deaths, as well as
damage to a chemical plant and three nearby villages. The 1984 Bhopal disaster
in India resulted
in almost 4,000 deaths. These
incidents, along with other
incidents, affected the reputation of the
trade as industrial safety and environmental
protection were given more focus.
In response, the IChemE required safety to be part of every degree course that
it accredited after 1982. By the 1970s, legislation and monitoring agencies
were instituted in various countries, such as France, Germany, and the United States.
Recent
progress
Advancements in computer science
found applications designing and managing plants, simplifying calculations and
drawings that previously had to be done manually. The completion of the Human Genome Project is also seen as a major development, not only advancing
chemical engineering but genetic engineering and genomics as well.
Chemical engineering principles were used to produce DNA sequences
in large quantities.While the application of chemical engineering principles to these fields only
began in the 1990s, Rice University
researchers see this as a trend towards biotechnology.
The latest book 'Chemical Process Technology and Simulation' gives a very good
comprehensive account of the various products and methods of its production and
also deals with computer based process simulation of complex processes as
practiced in industry.
Chemical
engineering involves the application of several principles. Key concepts are
presented below.
Chemical
reaction engineering
Chemical engineering involves
managing plant processes and conditions to ensure optimal plant operation.
Chemical reaction engineers construct models for reactor analysis and design
using laboratory data and physical parameters, such as chemical thermodynamics, to solve problems and predict reactor performance.
Plant
design
Chemical engineering design concerns
the creation of plans, specification, and economic analyses for new plants or
plant modifications. Design engineers often work in a consulting role,
designing plants to meet clients' needs. Design is limited by a number of
factors, including funding, government regulations and safety standards. These
constraints dictate a plant's choice of process, materials and equipment.
Process
design
A unit operation is a physical step
in an individual chemical engineering process. Unit operations (such as crystallization,
drying and evaporation)
are used to prepare reactants, purifying and separating its products, recycling
unspent reactants, and controlling energy transfer in reactors.
On the other hand, a unit process is the chemical equivalent of a unit operation.
Along with unit operations, unit processes constitute a process operation. Unit
processes (such as nitration and oxidation) involve the conversion of material by biochemical,
thermochemical and other means. Chemical engineers responsible for these
are called process engineers.
Process Design is the most
challenging field of chemical engineering. Overall process simulation is to be
done using various software. The recent book "Chemical Process Technology
and Simulation" by Srikumar Koyikkal gives many classical examples. It is
also a text book of Chemical Process Technology.
Transport
phenomena
Transport phenomena occur frequently
in industrial problems. These include fluid dynamics,
heat transfer and mass transfer,
which mainly concern momentum transfer,
energy transfer and transport of chemical species
respectively. Basic equations for describing the three transport phenomena in
the macroscopic, microscopic
and molecular
levels are very similar. Thus, understanding transport phenomena requires
thorough understanding of mathematics.
Applications
and practice
Chemical engineers "develop economic ways of using materials and
energy".
Chemical engineers use chemistry and engineering to turn raw materials into usable products,
such as medicine, petrochemicals and plastics on a large-scale, industrial
setting. They are also involved in waste management
and research. Both applied and research facets could make extensive use of
computers.
A chemical engineer may be involved
in industry or university research where they are tasked in designing and
performing experiments to create new and better ways of production, controlling
pollution, conserving resources and making these processes safer. They may be
involved in designing and constructing plants as a project engineer.
In this field, the chemical engineer uses their knowledge in selecting plant
equipment and the optimum method of production to minimize costs and increase
profitability. After its construction, they may help in upgrading its
equipment. They may also be involved in its daily operations.
Chemical engineers may be permanently employed at chemical plants to manage
operations. Alternatively, they may serve in a consultant role to troubleshoot
problems, manage process changes and otherwise assist plant operators.
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