Changing World Technologies (CWT), a privately held synthetic fuel company, was founded in August 1997 by Brian S. Appel, who also served as chief executive officer of CWT and its subsidiaries. Through Mr. Appel's technology company, CWT was granted a license to operate. CWT was started primarily to develop and commercialize the thermal depolymerization technology, now referred to by the company as "thermal conversion process" or TCP. The process produces renewable diesel fuel oil (RDO) from agricultural wastes including fats, oils, and greases (FOG); dissolved air flotations (DAF); waste greases; offal; animal carcasses; and other organic-rich wastes.