CO_2与CH_4催化反应合成气研究

Catalytic CO_2 Reaction of with CH_4 to Produce Synthesis Gas

CO_2与液化天然气(98%为C_3-C_4烃)催化重整制合成气,八十年代初期在当时的西德已建立了工业生装置.近年来,由于石油资源日趋短缺,促进世界各国重视探讨和研究天然气资源利用的新途径.除甲烷氧化偶联制乙烯,甲烷氧化制甲醇和甲醛等直接转化过程已引起广泛的重视外,研究和开发由甲烷制取合成气的新过程也正日益受到人们的关注,其中利用CO_2与甲烷催化重整制合成气,可将造成温室效应,破坏人类生存环境的CO_2气体转化为宝贵的化工原料,所制得的合成气中CO/H_2=1,特别适合做羰基合成和合成有机含氧化合物的原料,近年来对该反应的研究已引起人们的重视.其反应表示如下:

CO2 reforming liquid natural gas (98% C3-C4 hydrocarbons) to produce synthesis gas has been commercialized by Germany in early 1980s. Recently increasing conern about world dependence on petroleum oil has generted interest in the more efficient use of natural gas. Great attention is being paid to CO2 reforming of CH4 to produce synthesis gas. CO2, which leads to the Greenhouse Effect and air-polluted gas, can be converted into a highly valuable feedstock(i. e. synthesis gas) during the process. Pd-bimetal and Ni supported on alumina are effective catalysts for this reaction. The two catalysts show significant activity at 500℃ loadings of 0. 3% Pd-bimetal catalyst was highly effective and showed maximum conversion in excess of 90% with respect to both CO2 and CH4 at 750℃, and no significant carbon deposit after twenty- hour test was found Ni catalyst showed maximum conversions in excess of 91% with respect to CO2 and 88% with respect to CH4 at 750℃, and kept conversions of about 87% with respect to CO2 and 83% with respect to CH4 in ten h during twenty ?four h continuous run at the same temperature. Elemental analysis indicates 16 wt% carbon deposit on Ni catalyst. TPD studies show both CO and CO2 desorption from the Ni catalyst. Two of the CO2 desportion peaks at 300℃ and 600℃ respectively are probably produced by CO disproportionation, this may be one of the reasons for carbon deposition.