Development of NKK coal gasification process -- A status report

Nippon Kokan is developing a new coal gasification process which produces medium BTU gas using bituminous coal. The NKK coal gasification process is fed with crushed coal and is expected to be one of high coal conversion and low oxygen consumption. The gasifier is constructed with two parts; the top part is an ash agglomerating coal gasifier of spouted bed reactor and the bottom part is a slagging gasifier of recycled char fines. Initially the ash agglomerating gasifier (100 kg/h) and the char gasifier (40 kg/h) were constructed separately and have been operated independently. Test programs of both gasifiers were conducted from mid 1981 to the first part of 1983. High ash bearing agglomerates containing less than 4% carbon fell through the throat of the spouted bed without any accompanying coal particles. The slags blown out from the char gasifier contained traces of carbon. These corresponded to an overall carbon utilization of up to 99+% (assuming no other losses) for the NKK coal gasification process.