Chemical Engineers design and develop processes that transform the physical and chemical state of a substance, suiting commercial applicability. It ranges from improving food processing to fertilizers to even the clothes we wear. Modern day chemical engineers also work on pioneering concepts like nanotechnology. A specialization in chemical engineering, petroleum engineering, deals with optimizing extraction of oil and gas from the surface of earth. Petroleum engineers implement methods that maximize the extraction of hydrocarbons efficiently with least environmental repercussions.