SNG from peat by the PEATGAS Process

The total energy content of U.S. peat resources is estimated to be equivalent to 1440 quads or over 2400 billion barrels of oil. Generally, peat deposits are located in areas with no other fossil fuel resources. Therefore, for those areas, it represents a very important energy resource. The areas with large peat deposits also have plentiful water supplies, so the local water resources can easily afford conversion of peat to substitute natural gas. Under the joint sponsorship of the U.S. Department of Energy and the Minnesota Gas Company, the Institute of Gas Technology has developed the PEATGAS process for the conversion of peat to substitute natural gas having a heating value of about 960 Btu per SCF. The heart of the process consists of a two-stage PEATGAS reactor incorporating a cocurrent, dilute-phase entrained-flow hydrogasification stage followed by a fluidized-bed char gasification stage using ateam and oxygen. The overall thermal efficiency of the process is calculated to be 67% for a 250 billion Btu per day SNG plant using a 50% moisture content Minnesota peat. About 78% of the total methane produced in the plant is made in the gasifier itself. Therefore, only about 22% of the methane is made by catalytic methanation. The by-products yield on a daily basis from a 250 billion Btu per day SNG plant is estimated to be 136,030 gallons benzene, 6,680 barrels fuel oil, 565 tons anhydrous ammonia, and 52 long tons sulfur. The total fuel output of such a plant is about 309 billion Btu per day.