Investigations on catalyzed steam gasification of biomass. Appendix A. Feasibility study of methane production via catalytic gasification of 2000 tons of wood per day

Abstract

A study has been made of the economic feasibility of producing substitute natural gas (SNG) from wood via catalytic gasification with steam. The plant design in this study was developed from information on gasifier operation supplied by the Pacific Northwest Laboratory (PNL). The plant is designed to process 2000 tons per day of dry wood to SNG. Plant production is 21.6 MM scfd of SNG with a HHV of 956 Btu per scf. All process and support facilities necessary to convert wood to SNG are included. The plant location is Newport, Oregon. The capital cost for the plant is $95,115,000 - September, 1980 basis. Gas production costs which allow for return on capital have been calculated for various wood prices for both utility and private investor financing. For utility financing, the gas production costs are respectively $5.09, $5.56, $6.50, and $8.34 per MM Btu for wood costs of $5, $10, $20, and $40 per dry ton delivered to the plant at a moisture content of 49.50 wt %. For private investor financing, the corresponding product costs are $6.62, $7.11, $8.10, and $10.06 per MM Btu. The cost calculated by the utility financing method includes a return on equity of 15% and an interest rate of 10% on the debt. The private investor financing method, which is 100% equity financing, incorporates a discounted cash flow (DCF) return on equity of 12%. The thermal efficiency without taking an energy credit for by-product char is 58.3%.