Combination Of OCNG With Aromatization Of Light Hydrocarbons

Ⅰ .An excellent catalyst for OCM to produce ethylene wassuccessfully prepared and characterized. Optimal reactions conditionare suggested .Among more than 40 catalysts of several series,(MnO2-LiCl, MnO2-LiCl-H3BO3, MnO2-Li2SO4, etc) Li-Mn-Ti catalyst isthe best . The author has investigated preparation methods and reactionconditions of this catalyst on the catalysis properties for OCM process.Based upon the experimental results test technological conditions areprovided : Lithium content :0.8%mol:GVSH:1800ml/g.h; reactiontemperature :750℃ .Under the above conditions a methane conversionof 50.7%,C2 selectivity of 40.7%,and a yield of 20.6% were obtained .Inaddition, ethylene/C2 ratio is higher than 90% ,after 7 hours of reactionno obvious change of activity was found .XRD,TGA-DTA and FTIRmeasurements revealed that this catalyst possesses good thermalstability. Ⅱ .Catalysts for aromatization of light hydrocarbons such asmethane ,o-ethane ,ethylene and propane were prepared ,and thecorresponding catalysis reactions were carried out as well. Considering - 54 -吉林大学硕士学位论文that 90% predominant component of the OCM product is ethylene ,theauthor studied the consecutive reaction of the produced ethylene toform aromatic compounds and the needed optimal technologicalconditions. At his point ,a series of Zn-HZSM-5 catalysts wereinvestigated in more detail.Optimal conditions for the ethylenearomatization are :Zinc catalyst:5.8%;reaction temperature :350℃ .VGSH:1800ml/g.h. Si/Al ratio in the HZSM-5 is 25.The author alsostudied the effect of CO and CO2 on the aromatization of the lowhydrocarbons. The experimental data indicate the influence of carbonoxides may be negligible. Ⅲ.A technological study was conducted for the combination of theOCM with the ethylene aromatization: ① Separation of aromatic products : a water trap was installed at the exit of the aromatization reactor to separate the aromatic compounds from aliphatic ones. The efficiency of the separation is satisfactory, which is proved by the experiment. ② In order to maintain pressure balance in the reaction system ,a past of carbon oxides was separated by using soda solution absorption ; a good efficiency of the absorption method was also revealed . ③ Cyclic consecutive reaction of aromatization indicates : a cyclic yield of the aromatic product was 48.3%,which was prolonged for 7 hours of the reaction .