Integrated Process Of Coal Pyrolysis With CO-shift Reaction

The main purpose of this thesis was to research the effect of CO-shift reaction oncoal pyrolysis behavior. Pyrolysis behavior of Nantaizi coal in one consist of CO-shiftatmosphere were investigated. And then we investigated the effect of coal propertieson pyrolysis behavior. The main research works and results are as follows:The effects of CO-shift atmosphere on the coal pyrolysis behavior wereinvestigated in a fixed-bed reactor containing upper B113catalyst layer and lowerNantazi coal layer. The produced char was characterized using TG, elemental analysisand FT-IR, character of tar was measured with FT-IR and gas with GC. The resultsshown that increasing pyrolysis temperature from450℃to650℃, the tar and gasyields have an increase trend, and the char yield decreases in CO-shift atmosphere.The product yields vary slowly after temperature above650℃.Compared withpyrolysis behavior of Nantaizi coal in N2and H2atmosphere, CO-shift reaction isbenefit to produce tar and gas. The tar yield is6.66%and4.49%higher in CO-shiftreaction than those in N2and H2atmosphere. Combustion TG of chars showed thatthe biggest combustion weight loss is H2>N2>CO-shift.The intensities of stretchingvibration peaks of organic functional groups under CO-shift increase compared withthose chars from pyrolysis under N2and H2.The intensities of stretching vibrationpeaks of aliphatic and aromatic hydrocarbon group in tar from pyrolysis underCO-shift increase compared with those under N2and H2.The content ofH2,CO,CO2,CH4and C2-C4is higher in CO-shift than N2and H2atmosphere.The effects of CO, CO2and water vapor atmosphere on the pyrolysis behaviorwere investigated in the fixed-bed reactor containing upper B113catalyst layer andlower Nantazi coal layer. The produced char was characterized using TG and gas withGC. The results showed that the higher tar and gas yields can be obtained in COatmosphere than those in N2atmosphere. Compared with N2atmosphere, the charyield decreases, the gas yield increases and the tar yield has no obvious change in CO2 atmosphere. The tar and gas yields from pyrolysis decrease, and the char yieldincreases in water vapor than those in N2atmosphere. The combustion behaviors ofchars from those in CO, CO2, water vapor and CO-shift reaction atmosphere by TGshowed that the ignition temperature of char combustion is in order ofH2O>CO-shift>CO>CO2. Compared with CO-shift atmosphere, the content of H2、CH4、C2-C4decrease in CO atmosphere, the content of CO and C2-C4increase but H2and CH4decrease in CO2atmosphere, the content of H2increases in water vapor.Tiechanggou coal and Naomaohu coal were used to investigate the effect of coalproperities on pyrolysis behavior in the fixed-bed reactor containing upper B113catalyst layer and lower coal layer. The produced char was characterized using TGand gas with GC. The results showed that tar and gas yields increase with the increaseof vitrinite in the coal. The maximum weight loss rate of chars is in order ofNaomaohu coal>Tichanggou coal>Nantaizi coal. GC analysis of gas from pyrolysisshowed that compared with Nantaizi coal. The content of CO, CO2and C2-C4increasebut H2decreases, CH4has no change from Tiechanggou coal pyrolysis.