Engineering Support Services for the DOE/GRI Coal Gasification Research Program. Evaluation of One Method of Peat Harvesting and Dewatering

摘要

This study assumes that the harvesting and dewatering facilities are self-sufficient in generation of the steam and electric power requirements of the operations, fueled by peat product at 50 percent moisture. Dredges and their associated pumps use diesel fuel. Consequently, about 52 percent of the peat removed from the bog is either used for fuel or lost in dewatering. The study is confined to wet harvesting of peat by dredging and transport of the peat as a low-solids slurry over significant distances, which in turn leads to major capital costs for transport equipment and, at least for slurry handling, high operating costs for transportation fuel. Only commercially available equipment was considered in the design of the harvesting and dewatering operations; as a consequence, the equipment is poorly matched for the scale of this operation. Economics developed for the peat gasification plant producing 250 billion Btu per day of SNG indicate that for an average gas cost of $5.00 per million Btu the cost of the peat feed at 50 percent moisture must not exceed $1.57 per million Btu. If the total plant investment for the gasification plant ranges +-30 percent, the peat feed cost must be in the range of $1.18 to 1.91 per million Btu. This contrasts most unfavorably with the estimated peat costs of $3.76 to $4.58 per million Btu developed in the present study. (ERA citation 09:000098)