A biorefinery is a center that melds biomass conversion processes and equipment to manufacture fuels, power, heat, and chemicals from biomass. The biorefinery concept is parallel to today's petroleum refinery, which makes various fuels and products from petroleum. Biorefining is the sustainable conversion of biomass into a spectrum of bio-based products and bioenergy. By producing various products, a biorefinery takes advantage of the various parts in biomass and their intermediates therefore maximizing the value acquired from the biomass feedstock. A biorefinery could, for instance, manufacture one or several low-volume, but high-value, chemical or nutraceutical products and a low-value, but high-volume liquid transportation fuel such as biodiesel. At the same time generating electricity and process heat, by combined heat and power (CHP) technology, for its own use and perhaps adequate for sale of electricity to the local utility. The high-value products boost profitability, the high-volume fuel helps meet energy needs, and the power production aids to lower energy costs and minimize greenhouse gas emissions from conventional power plant facilities. Although some facilities prevail that can be called bio-refineries, the bio-refinery has yet to be fully accomplished. Future biorefineries may play a vital role in yielding chemicals and materials that are traditionally extracted from petroleum.