Zero emission natural gas power and liquefaction plant

Abstract

A zero-emissions power plant receives natural gas from wells at elevated pressure and temperature. Gas is expanded through one or more turbo-expanders, preferably reformed, and sent to a fuel cell where electricity, heat, carbon-dioxide, and water are generated. The carbon-dioxide is compressed by at least one compressor and piped downhole for sequestration. The turbo-expanders have shafts which preferably share the shafts of the compressors. Thus, energy given up by the natural gas in the turbo-expanders is used to run compressors which compress carbon dioxide for downhole sequestration. In one embodiment, the natural gas is applied to heat exchangers in order to generate a stream of liquid natural gas. The remainder of the gas is expanded through the turbo-expanders and processed in the reformer prior to being sent to the fuel cell. A shifter may be used between the reformer and fuel cell. A solid oxide fuel cell is preferred.

Dependencies are inferred from the claim text.