Pilot test of low-rank crushed coal gasification in two-stage fluidized bed reactor

To verify the feasibility and technical features of the fluidized bed two-stage gasification technology for the production of clean fuel gas,a pilot autothermal platform with a capacity of 100 kg / h has been designed and built to test the gasification characteristics of Inner Mongolia Shengli lignite. The running state and the product quality were compared systematically under different typical operational conditions. Keeping the reaction temperatures of pyrolyzer and gasifier at around 840 ℃ and 1 000 ℃ respectively,the corresponding tar content in the generated gases at the outlets of pyrolyzer and gasifier were 1 127 mg / Nm3 and 365 mg / Nm3 . Under a stable operation state,the volume frac- tions of CO,H2 ,CH4 and CO2 in the produced fuel gas were 13. 9% ,7. 9% ,3. 9% and 10. 9% respectively,and the heating value of product gas was close to 4 605 kJ / Nm3 . Compared with the tar from pyrolyzer,the heavy oil fraction of tar from gasifier reduced significantly,while the light oil components increased sharply simultaneously,showing an ef- fective tar thermal cracking and catalytic reforming in the high-temperature char bed of gasifier.