Study On The Migration Of Trace Elements In Coal Gasification Process

The three coals named A,D and X used in different kinds of gasifiers were selected.The effects of trace elements on the volatilization rate,enrichment state and gasification temperature of the trace elements during the whole gasification process were studied by ash melting temperature tester,X-ray diffraction(XRD),inductively coupled plasma emission spectrometer(ICP-OES),high temperature tube furnace,respectively.And the thermodynamics simulation software were used to simulate the migration of trace elements in coal,which is the migration of trace elements during coal gasification.And the effect of calcium and magnesium flux on trace elements was studied.The following conclusions were obtained:(1)The enrichment of trace elements in residues collected from different gasifiers are different.The total enrichment rate of trace elements in A coal used in Shell coalifier is higher,and the Mn,Ni,Sn and V are mainly enriched in slag.Pb is mainly enriched in fly ash;The enrichment rate of Sn and Cr in filter is higher;The enrichment rate of most elements in D coal used in fixed gasifier is not high,only the enrichment rate of element Mn,Ni,Cr,Cu is high,mainly concentrated in the cinder and fly ash;The trace elements Co,Mn,Ni,Cr and Cu in the Texaco gasifier are mainly enriched in the cinder,and Pb and Zn are mainly enriched in the filter.(2)The contents of Zn,Pb and Li in the high temperature gasification process decreased as the temperature increased.The evaporation rate of Zn in A,D and X was the highest at 1000℃,which was 91.8%,85%,86%,respectively;The volatilization rate of element Pb is also the highest at 1000℃,and volatilization rate is 97%,98.6%,94%,respectively.(3)The effects of different fluxes on various trace elements are different.The calcium and magnesium complex flux promotes the Co,Cu,Cr and Ni to some extent.MgO promotes the volatilization of Be,Ba and Sr elements to a certain extent.CaO promotes the enrichment of Mn element to a certain extent.(4)Compared with Shell gasifier and Texaco gasifier,the conversion forms of seven kinds of trace elements Ba,Sr,Li,V,Be,Co and Ge in the process of simulation are same,but there are differences in the conversion temperature.The conversion forms of seven kinds of trace elements Cr,Cu,Mn,Ni,Ga,Pb and Sn are different,and the final stable forms are different.Individual elements always maintain a form in the simulation.