Influence of pressure on the release of nitrogen during pressurized gasification of coal

A comprehensive knowledge of the release characteristics of inorganic compounds is required by the designing of gas scrubbing and hot gas cleaning technology. The principal objective of this work was to examine the influence of pressure on the release of nitrogen during pressurized coal gasification in a pilot-scale pressurized ash agglomerating fluidized bed facility with 800 mm i.d.. Jincheng anthracite was gasified at gage pressures of 0.6, 1.0, 1.5 and 2.0 MPa with steam/O₂ (3/1, volume ratio) at 1 000℃. The analysis of nitrogen content and form in hot gas and solid by-product was carried out. The quantitative analysis results show that most of nitrogen is transferred into gas phase, which is slightly changed after 1.0 MPa coupled with an enrichment of nitrogen in solid phase with the increase in pressure. The discussion on the mechanism of nitrogen release at pressure was carried out by contrast analysis of nitrogen form in the coal and bottom ash at microcosmic level.