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Title: Technology and economics of close-coupled gasifiers for retrofitting gas/oil combustion units to biomass feedstock

Conference ·
OSTI ID:6567990

Close-coupled air gasifiers can be used to convert existing gas/oil boilers to burn biomass. The gasifiers are relatively simple units operating at 85%-90% thermal efficiency. The gas contains CO, H/sub 2/, hydrocarbon gases and vapors with N/sub 2/, H/sub 2/O, and CO/sub 2/ dilutants, and has a heating value of 140-200 Btu/scf when burned hot without scrubbing. Use of this gas in existing boilers may cause 5%-10% derating. Recent tests of a 14 MBtu/hour gasifier coupled to a power boiler in California over a 158 hour period gave satisfactory results with low emissions and only minor technical difficulties. The economics of two gasifiers reported in the literature are analyzed with respect to fuel cost, as a function of capital and operating costs. The gas is estimated to cost $1.40-$2.70/MBtu for biomass feedstocks costing $10-$20/dry ton. The capital costs of retrofitting existing gas/oil boilers are approximately two-thirds the cost of new installations of package wood-fired boilers. Although gasifiers larger than 100 MBtu/hour are not now available, they could probably be used to convert larger field-erected boilers to biomass more economically than construction of new wood-fired boilers. The cost of construction of a new wood-fired package boiler is estimated to be about the same as the cost of a gasifier plus a conventional gas/oil package boiler.

Research Organization:
Solar Energy Research Inst., Golden, CO (USA)
OSTI ID:
6567990
Report Number(s):
DDS-033
Resource Relation:
Conference: First World Energy Congress, React '78, Atlanta, GA, USA, 31 Oct 1978
Country of Publication:
United States
Language:
English