Migration Of The Sulfur During The Co-pyrolysis Of Coal And Rubber

SO2 from coal combustion can directly cause serious environmental pollution, and coal pyrolysis is an important initial stage of coal combustion, which is also the main part of the formation of sulfur pollutants. Therefore, studying of sulfur changes in coal during pyrolysis can not only understand sulfur forms of distribution, but also it is important for development and evaluation of new desulfuration technology and coal conversion processes to achieve the clean coal transformation and using. In this paper, using Xiaolongtan lignite, ShenMu bituminous coal, vulcanized rubber and unvulcanized SBR as raw materials, the pyrolysis and co-pyrolysis on the fixed-bed pyrolysis devices were discussed. Sulfur changes in the coal alone pyrolysis and co-pyrolysis were investigated and the main results are as follows.In fixed bed pyrolysis of Xiaolongtan lignite, with the pyrolysis temperature increasing, the distribution of the sulfur in the pyrolysis gas first increased and then decreased, but the sulfur distributed to the char was a trend of first decrease and then increase, and distribution of sulfur into the tar was trend to decrease. In fixed-bed pyrolysis of ShenMu bituminous coal, with the pyrolysis temperature increasing, the sulfur in the pyrolysis gas and tar increased, while the sulfur distributed to the char decreased.In co-pyrolysis of Xiaolongtan lignite and vulcanized SBR, with pyrolysis temperature rising, the sulfur distributed to the pyrolysis gas trended to increase, but the sulfur distributed to in the char decreased, while the distribution of sulfur into the tar first decreased and then increased. At the temperature of 520℃, the distribution of sulfur into the tar reached the minimum value of 33.32wt%. In Xiaolongtan lignite co-pyrolysis with unvulcanized SBR, as the pyrolysis temperature increases, the distribution of the sulfur into the pyrolysis gas and char first decreased and then increased, while the distribution of sulfur into the tar first increased and then decreased. Compared to the sulfur distribution in Xiaolongtan lignite and vulcanized SBR co-pyrolysis products, it can be obtained when the pyrolysis temperature is low, the sulfur of vulcanized SBR is mainly transferred to char. When pyrolysis temperature is high, the sulfur of vulcanized SBR is mainly transferred to the gas phase.In co-pyrolysis of ShenMu coal and vulcanized rubber, with pyrolysis temperature rising, the sulfur distributed to pyrolysis gas increased from 5.25wt% to 14.20wt%, but the sulfur distributed to the coke decreased from 42.00wt% to 29.94wt%, while the distribution of sulfur into the tar first decreased and then increased. At the pyrolysis temperature of 500℃, the distribution of the sulfur into the tar reached the lowest value of 48.44wt%. In co-pyrolysis of ShenMu coal and unvulcanized SBR, with the pyrolysis temperature rising, the distribution of the sulfur into the pyrolysis gas and the tar showed a trend of increasing, but the sulfur distributed to the semi-coke decreased. From the distribution of sulfur in co-prolysis products, it can be seen that more sulfur in the vulcanized SBR is transferred into prolysis gas. Comparing with co-prolysis of Shenmu coal and vulcanized SBR, when the pyrolysis temperature is less than 540℃, the sulfur of vulcanized SBR partly transferred to the tar. In the pyrolysis temperature range, the sulfur content in co-pyrolysis semi-coke of vulcanized SBR and ShenMu coal is lower than that of unvulcanized SBR and ShenMu coal.