Pyrolysis Of Naomaohu Coal And The Mixture Of Coal And Iron Oxide

Coal occupies a dominant position in China’s energy structure in a long term period. With China’s emphasis on environmental protection, as well as the increase in carbon emissions and international pressure, clean coal utilization and transformation in China’s energy strategy is particularly important and urgent. The technology of coal pyrolysis of low rank coal under relatively mild reaction conditions, into gas, tar and char, so as to realize the classification quality and conversion of coal, which is an advanced clean coal utilization technology.In this paper, the pyrolysis process of Naomaohu coal, respectively using the fixed bed reactor and fluidized bed reactor were studied. The influences of different reactor on the effect of coal pyrolysis products rate and composition were studied as well. Results showed that, under nitrogen atmosphere, the optimum temperature of pyrolysis in fixed bed was 500 ℃, residence temperature time was 15min, the tar yield was 14.07%, the pyrolysis gas yield was 11.03%. At 500℃ in the fluidized bed pyrolysis, the tar yield was 13.78%. Compared with fixed bed using fluidized bed, pyrolysis tar group single molecule average aromatic cluster in pyrolysis tar group was more than the number of fixed bed pyrolysis tar, and aliphatic hydrocarbon yield increased, the proportion accounted for aliphatic olefin had improved.Addionally, adding Fe3O4 and Fe2O3 in the process of the Naomaohu coal pyrolysis. When mixing ratio of coal and Fe3O4 was 1,the optimum pyrolysis temperature was 500℃, the tar yield was 11.31%, the pyrolysis gas yield was 16.76%; when mixing ratio of coal and Fe2O3 was 1, the optimum pyrolysis temperature was 500℃, the tar yield was 11.78%, the pyrolysis gas was 14.87%. Coal-Fe2O3 and coal-Fe3O4 pyrolysis tar acid content were 20.70% and 25.54%, higher than the 16.69% of coal pyrolysis; coal-Fe2O3 and coal-Fe3O4 pyrolysis tar fat content were 26.52% and 19.35%, lower than the 29.28% of coal pyrolysis; coal-Fe2O3 and coal-Fe3O4 pyrolysis aromatics content were 27.66% and 28.40%, higher than the 23.63% of coal pyrolysis; coal-Fe2O3 and coal-Fe304 pyrolysis polar content were 24.15% and 23.65%, lower than the 28.49% of coal pyrolysis; coal-Fe2O3 and coal-Fe3O4 pyrolysis alkaline content were 0.97% and 3.06%, while the alkaline tar pyrolysis of coal was 1.90%. Except of alkaline, the influence of the addition of Fe2O3 and Fe3O4 to the content of tar components were basically the same.Adding different proportion of Fe2O3 and Fe3O4, had little effect on the optimum pyrolysis temperature and residence time, and increased the yield of pyrolysis gas, but to some extent reduced the tar yield, and had a great influence on the tar components.