Research On Characteristics Of Co-gasification Of Alkaline Organic Wastewater And Coal Based On Aspen Plus

In order to solve the coking problem of alkaline organic wastewater during incineration treatment,a process of low temperature gasification combined with high temperature oxidation is proposed.It is expected that the process can not only remove the alkali ash with low melting point,but also make full use of catalytic effect of it to produce valuable syngas.In the disposal of wastes and at the same time play its effective role is of great significance.Under the background of this process,key problems has been briefly discussed.The effect of catalytic components in wastewater on coal gasification in the low temperature zone was studied.Using Aspen Plus software as a tool to simulate catalytic gasification.Firstly,the fluidized bed gasification model of user-defined subroutine was established and the accuracy was verified.Secondly,the catalytic effect is introduced to this model.The catalytic effect added to the subroutine by modifying the reaction rate,and finally formed a model with catalytic effect of waste alkali.The gasification characteristics of coal were studied basing on the verified model.Effects of gasification temperature,water-fuel ratio and air equivalence ratio on gasification performance were discussed.In the relative low temperature range(650?800?),low heating value of syngas is higher than 6MJ/Nm3,while the carbon conversion efficiency almost above 70%.Based on the model,two kinds of system with heat distribution,namely self-sufficient model and combustion-supplied model were constructed.Sensitivity analysis was used to study the influence of important parameters on system heat output.Under the condition of low temperature and water-fuel ratio,the overall heat output is favorable,while the quality of syngas is relatively poor.And furthermore enlarge the treatment of wastewater is contradict with it.Comprehensively considered,the optimum parameters of self-sufficient and combustion-supplied system are determined,which are gasification temperature=750?,water-fuel ratio=1.0,ER=0.4 and gasification temperature=700?,water-fuel ratio=1.5 and ER=0.4.