The Study On Sulfur Release Behavior During Co-Pyrolysis Of Coal And Corncob

In this study,Py-GC and Py-MS were used to investigate the effects of sulfur transformation during the co-pyrolysis of Eerduosi?ED?/Changzhi?CZ?coals and corncob?COB?at different mixed ratios under Ar and CO₂ atmospheres;Py-GC and Py-MS were also carried out to investigate the effect of minerals in CZ coal on sulfur release and transformation during co-pyrolysis,and the effect of co-pyrolysis method of CZ coal and corncob on sulfur release under these two atmospheres.The main conclusions are obtained as following:?1?Under Ar and CO₂ atmospheres,there is a clear difference in the desulfurization ratios during the co-pyrolysis of coal samples and corncob.During the co-pyrolysis of ED and COB,the release of H₂S is promoted at 7:1 and 3:1,while inhibited at 1:1 under these two atmospheres;and the release of COS was promoted at only 7:1 under Ar atmosphere,while at all ratios under CO₂ atmosphere.During the co-pyrolysis of CZ and COB,the release of H₂S and COS shows obviously promoted effect under both atmospheres.?2?Under Ar and CO₂ atmospheres,some minerals in CZ coal have a certain role in sulfur fixation,and can also catalyze the decomposition of sulfur-containing compounds in the liquid phase during the co-pyrolysis process.Meanwhile,during the co-pyrolysis,these minerals inhibit the release of H₂S,but promote the formation of COS under Ar atmosphere;they inhibit H₂S and COS release at 7:1and promote their release at 3:1 and 1:1 under CO₂ atmosphere.?3?Under Ar atmosphere,the addition of calcium oxide/kaolin can promote the migration of sulfurs to liquid products during the co-pyrolysis process.For sulfur-containing gases,calcium oxide inhibits the release of H₂S and COS,but the inhibitory effect on COS is obvious after 550?;kaolin can inhibit the release of H₂S and COS except for promoting the release of H₂S at 0.80:1.?4?Under Ar and CO₂ atmospheres,CZ and COB also have the obvious synergy in the segmental pyrolysis process.And this process can intrigue the migration of sulfurs to liquid and gas phases.Under Ar atmosphere,it promotes the release of sulfur-containing gases except for no obvious effect on H₂S at 7:1;under CO₂ atmosphere,it also promotes the release of sulfur-containing gases except for the inhibition of COS release at 7:1.Compared with the direct mixed co-pyrolysis process of CZ and COB,desulfurization ratios are higher and the promoting effect is more obvious under these two atmospheres during the segmental pyrolysis.At the same time,the segmental pyrolysis is conducive to the migration of sulfur into liquid phase products.