The Effect of Catalyst Content on Supercritical Water Gasification Process with Shochu (Japanese Popular Distilled Liquor) Residue and the Result of Long-time Continuous Operation

Abstract

The operation of a 1 t-wet/d supercritical water gasification plant was evaluated for the gasification of barley shochu residues with activated carbon charges ranging from 0 to 0.05 kg/kg-slurry. Activated carbon concentrations greater than 0.025 kg/kg-slurry were found to prevent plugging by tarry residues. The pressure loss for the effluent that flowed in the annulus of the double-tube heat exchanger did not exceed 0.2 MPa. Long continuous operation times of 17 h 48 min were possible with an activated carbon charge of 0.025 kg/kg-slurry. Activated carbon is not only effective for prevention of plugging, but also effective for reduction in total organic carbon and enhancement of carbon gasification efficiency. An economic evaluation showed that the process can be viable when operated for more than 200 d per year.