Chemical engineering largely involves the design and maintenance of chemical processes for large-scale manufacture. Chemical engineers in this branch are usually employed under the title of process engineer. A related term with a wider definition is chemical technology.
Chemical engineers design, construct and operate plants
APPLICATIONS
Chemical engineering is applied in the manufacture of a wide variety of products. The chemical industry proper manufactures inorganic and organic industrial chemicals, ceramics, fuels and petrochemicals, agrochemicals (fertilizers, insecticides, herbicides), plastics and elastomers, oleochemicals, explosives, detergents and detergent products (soap, shampoo, cleaning fluids), fragrances and flavors, additives, dietary supplements and pharmaceuticals. Closely allied or overlapping disciplines include wood processing, food processing, environmental technology, and the engineering of petroleum, glass, paints and other coatings, inks, sealants and adhesives.
MODERN CHEMICAL ENGINEERING
The modern discipline of chemical engineering encompasses much more than just process engineering. Chemical engineers are now engaged in the development and production of a diverse range of products, as well as in commodity and specialty chemicals. These products include high performance materials needed for aerospace, automotive, biomedical, electronic, environmental,space and military applications. Examples include ultra-strong fibers, fabrics, dye-sensitized solar cells, adhesives and composites for vehicles, bio-compatible materials for implants and prosthetics, gels for medical applications, pharmaceuticals, and films with special dielectric, optical or spectroscopic properties for opto-electronic devices. Additionally, chemical engineering is often intertwined with biology and biomedical engineering. Many chemical engineers work on biological projects such as understanding biopolymers (proteins) and mapping the human genome. The line between chemists and chemical engineers is growing ever more thin as more and more chemical engineers begin to start their own innovation using their knowledge of chemistry, physics and mathematics to create, implement and mass produce their ideas.
CONTENTS
1-Micro process engineering
2-Paper engineering
3-Plastics engineering
4-Process engineering
1- MICRO PROCESS ENGINEERING
Micro process engineering is the science of conducting chemical or physical processes (unit operations) inside small volumina, typically inside channels with diameters of less than 1 mm (microchannels) or other structures with sub-millimeter dimensions. These processes are usually carried out in continuous flow mode, as opposed to batch production, allowing a throughput high enough to make micro process engineering a tool for chemical production. Micro process engineering is therefore not to be confused with microchemistry, which deals with very small overall quantities of matter.
The subfield of micro process engineering that deals with chemical reactions, carried out in microstructured reactors or "microreactors", is also known as microreaction technology.
The unique advantages of microstructured reactors or microreactors are enhanced heat transfer due to the large surface area-to-volume ratio, and enhanced mass transfer. For example, the length scale of diffusion processes is comparable to that of microchannels or even shorter, and efficient mixing of reactants can be achieved during very short times (typically milliseconds). The good heat transfer properties allow a precise temperature control of reactions. For example, highly exothermic reactions can be conducted almost isothermally when the microstructured reactor contains a second set of microchannels ("cooling passage"), fluidically separated from the reaction channels ("reaction passage"), through which a flow of cold fluid with sufficiently high heat capacity is maintained. It is also possible to change the temperature of microstructured reactors very rapidly to intentionally achieve a non-isothermal behaviour.
2- PAPER ENGINEERING
Paper Engineering is an interdisciplinary branch of engineering that deals with the application of physical science (e.g. chemistry and physics) with mathematics to the process of converting renewable bio-resources into useful and valuable products. Similar to chemical engineering in many aspects, the field employs the common principles of chemical process engineering to the manufacture of pulp, paper and other biomaterials.
Paper engineering encompasses the design and analysis of the various unit operations employed in the manufacture of paper; addressing the preparation of its raw materials from trees or other natural resources via a pulping process, chemical and mechanical pretreatment of these recovered biopolymer (e.g. principally, although not solely, cellulose-based) fibers in a fluid suspension, the high-speed forming and initial dewatering of a non-woven web, the development of bulk sheet properties via control of energy and mass transfer operations, as well as post-treatment of the sheet with coating, calendering, and other chemical and mechanical processes.
Universities offering a degree in paper engineering include:
USA
Miami University
North Carolina State University
SUNY College of Environmental Science and Forestry
University of Maine
University of Minnesota
University of Washington
University of Wisconsin-Stevens Point
Western Michigan University
Canada
University of New Brunswick
Finland
Helsinki University of Technology
India
Indian Institute of Technology, Roorkee
3- PLASTICS ENGINEERING
Plastics engineering encompasses the processing, design, development, and manufacture of plastics products. A plastic is a polymeric material that is in a semi-liquid state, having the property of plasticity and exhibiting flow. The nature of plastic materials poses unique challenges to an engineer. Mechanical properties of plastics are often difficult to quantify, and the plastics engineer has to design a product that meets certain specifications while keeping costs to a minimum. Other properties that the plastics engineer has to address include; outdoor weatherability, thermal properties such as upper use temperature, electrical properties, barrier properties, and resistance to chemical attack.
In plastics engineering, as in most engineering disciplines, the economics of a product plays an important role. The cost of plastic materials ranges from the cheapest commodity plastics used in mass produced consumer products to the very expensive, so called engineering resins. The cost of a plastic product is measured in different ways, and the absolute cost of a plastic material is difficult to ascertain. Cost is often measured in price per pound of material, or price per unit volume of material. In many cases however, it is important for a product to meet certain specifications, and cost could then be measured in price per unit of a property. Price with respect to processibility is often important, as some materials need to be processed at very high temperatures, increasing the amount of cooling time a part needs. In a large production run cooling time is very expensive.
Some plastics are manufactured from re-cycled materials but their use in engineering tends to be limited because the consistency of formulation and their physical properties tend to be less consistent. Electrical and electronic equipment and motor vehicle markets together accounted for 58 per cent of engineered plastics demand in 2003. Engineered plastics demand in the US was estimated at $9,702 million in 2007.
4- PROCESS ENGINEERING
Process engineering is often a synonym for chemical engineering and focuses on the design, operation and maintenance of chemical and material manufacturing processes. Process engineering and process engineers are found in a vast range of industries, such as the petrochemical, mineral processing, material, Information Technology, food and pharmaceutical and biotechnological industries. Process engineering also involves developing new processes, project engineering and troubleshooting.
BOOKS ON CHEMICAL ENGINEERING
No comments:
Post a Comment