Chemical engineering is the branch of engineering that deals with chemical production and the manufacture of products through chemical processes, together with applied mathematics and economics to produce, transform, transport, and properly use chemicals, materials and energy. This includes designing equipment, systems and processes for refining raw materials and for mixing, compounding and processing chemicals to make valuable products. Chemical engineers are in great demand because of the large number of industries that depend on the synthesis and processing of chemicals and materials. In addition to traditional careers in the chemical, energy and oil industries, chemical engineers enjoy increasing opportunities in biotechnology, pharmaceuticals, electronic device fabrication and environmental engineering. The unique training of the chemical engineer becomes essential in these areas when processes involve the chemical or physical transformation of matter. For example, chemical engineers working in the chemical industry investigate the creation of new polymeric materials with important electrical, optical or mechanical properties. This requires attention not only to the synthesis of the polymer, but also to the flow and forming processes necessary to create a final product. In biotechnology, chemical engineers help design production facilities that use microorganisms and enzymes to synthesize new drugs. Problems in environmental engineering that engage chemical engineers include the development of processes (catalytic converters, effluent treatment facilities) to minimize the release of or deactivate products that are harmful to the environment. To do these jobs, chemical engineering students must have a complete and quantitative understanding of both the engineering and scientific principles underlying these technological processes.