Experimental Program for the Development of Peat Gasification. Single-Stage Fluidized-Bed Gasification Tests. Interim Report No. 12

摘要

This interim report presents the results of work performed by the Institute of Gas Technology (IGT) for the task on Single-Stage Fluidized-Bed Gasification Tests as a part of Experimental Program for the Development of Peat Gasification. A total of 24 tests were conducted to obtain kinetic data for designing a single-stage fluidized-bed gasifier for producing medium-Btu gas or substitute natural gas (SNG). The tests were conducted in a 6-inch-diameter process-develpoment unit that had been modified for feeding peat to the bottom of the fluidized bed. The operating temperatures, pressures, steam/carbon feed ratios, and residence times ranged from about 1435 exp 0 to 1765 exp 0 F, 140 to 540 psia, 0.0 to 3.6 mol/mol, and 13 to 75.9 minutes, respectively. The results show that high conversions of carbon can be achieved at relatively low severity conditions of temperature and pressure. The addition of steam to the oxygen and fluidizing-gas-feed mixture did not significantly affect the kinetics and product distribution. Increasing the moisture content of the feed peat resulted in increased carbon conversions. In general, less than 1% of the feed carbon appeared in the liquid products. The preliminary economic evaluation of IGT's single-stage fluidized-bed gasification process was based on the production of a nominal 250 billion Btu/day of SNG or fuel gas from Minnesota peat. Utility-type financing guidelines were used to determine the product gas cost; the sensitivities of gas cost to changes in major components were also estimated. For a base-case peat cost (50% moisture peat delivered to the plant) of $2.00 per million Btu, the 20-year-average costs (late-1982 dollars) of SNG and fuel gas were $7.71 and $5.97 per million Btu, respectively. The sensitivity of the gas cost to the delivered cost of peat (in the range $1.25 to $3.25 per million Btu) and plant size (in the range 25 to 250 billion Btu/day) has also been estimated. (ERA citation 08:045329)