Catalytic pyrolysis characteristics of simulated seawater in lean coal

In the underground catalytic gasification process of lean coal, the solid catalyst cannot be used and recovered, so it is necessary to develop an inexpensive liquid catalyst.In order to explore the feasibility of seawater as a cheap gasification agent for underground coal gasification, and to understand the catalytic effect of NaCl component on coal pyrolysis and gasification, this paper selects the block size with 3%NaCl solution (simulated seawater) as catalyst.The lean coal of Wangxie Coal Mine of about 6cm was subjected to pyrolysis test.The heating rate inside and outside of the coal block and the composition of the pyrolysis product tar were measured.The influence of the catalyst on the semi-coke structure was studied.The results show that the temperature transfer in the process of pyrolysis of massive lean coal has hysteresis.The activation energy of large-scale coal with addition of NaCl catalyst in the temperature range of 350℃~650℃ is reduced by 39%and 45%, respectively, compared with the raw coal;catalytic pyrolysis The benzene content in tar increased by 7.8%, the hydrocarbon content of coal sample Ⅰ decreased by 14.9%, coal sample Ⅱ decreased by 32.4%;the specific surface area of catalytic pyrolysis coal char was significantly larger than that of non-catalyzed pyrolysis;The content of-OH bond and=C=O health coal Ⅱ coke < coal Ⅰ coke < raw coal.It can be concluded that seawater has a certain catalytic effect on coal pyrolysis and gasification.