Study On The Co-pyrolysis Behavior Of Corncob,Coal Gangue And Plastic With Various Additives

This paper chooses corncob,coal gangue and plastic as raw materials for experiment,and the co-pyrolysis behavior of corncob,coal gangue and plastic with various additives was studied.The effects of blend ratio of material,temperature and various additives on the yelid and quality of production were investegaed.Furthermore,Scanning electron microscope(SEM)analysis,the infrared spectroscopic(FTIR),1HNMR and 13 CNMR,GC/MS and GC were carried out for analysing the characterizations of the products,and the mechanism also was revealed.The main conclusions are as follows:1.Pyrolysis behavior of corncob and coal gangue individuallyCorncob began to crack at 200? during the process of pyrolysis,and the liquid oil yield increased firstly and then decreased,and the maximum value of oil yield is 49.9% at 500?.Coal gangue begins to crack at 500?,and the liquid oil yield of coal gangue increases with temperature increasing and the maximum value of the oil yield is 8.30% at 900?.The liquid oil yield obtained form corncob is higher than that of the oil yield from coal gangue at the same temperature.For coal gangue,the temperature at which CO begins to emit is higher than that for corncob;and CH4 is generated only at 500? and 600? for coal gangue.Whether for coal gangue or corncob,higher content of CO2 is produced at lower temperature(300-400?),while higher content of H2 is produced at higher temperature(600-900?).2.Co-pyrolysis behavior of corncob and coal gangueDuring the co-pyrolysis of corncob and coal gangue,there exist interactions between coal gangue and corncob when the blend of coal gangue is 20% and 40% and the temperature is above 200 ?.Co-pyrolysis was good for the production of H2,and it is also good for theemission reduction of CO2.The liquid oil gets the maximum value at 500 ?(40.8%).Adding MS and HZSM-5 can enhanc the yield of liquid oil at 500? and 900?,but adding the ?-Al2O3 has no obvious change.PW12/MS and CaCl2/HZSM-5 have better catalytic effect and adding them could obtain higher liquid oil.The release trend of gas has not changed when adding additives,and adding them only change the relative contents at the same temperature.The relative content of H2 at 700 ? and 900 ? is up to 91% and 95.27% when adding KCl/MS and adding Co/HZSM-5,MS,ZnCl2/MS,CaCl2/MS,Co/MS,HZSM-5,Co/HZSM-5and PW12/HZSM-5 all could decrease the content of CO2.Co-pyrolysis of corncob and coal gangue could reduce the oxygen compound content in liquid oil,and the content of aliphatic hydrogen and aliphatic carbon increases,while the content of hydrogen atoms in aromatic ether and carbohydrate decreases.The carbon percentages in organic acid,ester,aldehyde and ketone in liquid oil also decrease,and the quality of liquid oilisimproved.During co-pyrolysis of corncob and coal gangue at high temperature,adding some additives can further increase the content of aliphatic hydrogen and aliphatic carbon and decrease the content of oxygen compound.Among the additives,MS and Co/MS have better catalytic effect on liquid oil properties than other additives.3.Co-pyrolysis behavior of corncob,coal gangue and plasticDuring the co-pyrolysis of corncob,coal gangue and plastic,with the blending ratio of coal gangue decreasing and the blending ratio of plastic increasing,the yield of liquid oil increases.With the temperature increasing,the liquid oil yield increased firstly and then decreased,and the maximum value of liquid oil yield is 53.9% at 500?.The release trend of gas is the same as that during co-pyrolysis of corncob and coal gangue.Adding SnCl2/MS canget the highest liquid oil during the co-pyrolysis at 500? and 900?.The relative content of H2 at 700?,800? and 900? is up to 82.06%,81.19% and 80.17% when adding Co/MS?BaCl2/MS and MS respectively,and adding MS and Co/HZSM-5 could decrease the relative content of CO2 at a series of temperature.The organic compounds in liquid oil obtained from co-pyrolysis of corncob,coal gangue and plastic is the same as that obtained from co-pyrolysis of corncob and coal gangue,but the content is different,especially for the oxygen compound.The contens of organic acid,aldehydes and ketones are further reduced at high temperature,and the conten of olefin is increased.Among all the additives,MS,Co/MS,CaCl2/HZSM-5,CaCl2/?-Al2O3 and Co/?-Al2O3 are better to increase the content of aliphatic hydrogen and aliphatic carbon in liquid oil,and decrease the content of hydrogen atoms in aromatic ether,metoxyphenol,alcohol and carbohydrate;and they are also better to decrease the carbon percentages in organic acid,ester,aldehyde and ketone in liquid oil,and improve the quality of liquid oil.