| Sec-butyl alcohol is an important organic raw chemical widely used as the raw material for the production of methyl ethyl ketone?MEK?.As the increasing consumption of MEK,demand for sec-butyl alcohol has risen sharply in the past few years.Though copper-based catalysts show both high activity and selectity in ester hydrogenation reaction,the rapid deactivation limits their industrial application.Based on our previous work,Cu/B/Ca/Al2O3 catalyst was prepared and examined in the hydrogenation of sec-butyl acetate?SBA?to2-butanol in terms of catalyst durability,reaction macrokinetics and process parameters.Cu/B/Ca/Al2O3 catalyst exhibited high initial SBA conversion of99.5%,and declined to 88.4%after reaction for 1100 h.Doubling the molar ratio of H2/SBA or reducing the space velocity of SBA could improve the SBA conversion to 96.1%and 99.1%,respectively,for the deactivated catalyst,whereas the selectivity for 2-butanol changed little.Characterization results such as XRD,XRF,BET,FT-IR,TPD-MS,TG-DTA etc,suggested that catalyst structure did not change obviously except for the partial transformation of calcium oxide into calcium acetate.After regeneration by calcination,the deactivated catalyst showed an initial SBA conversion of 99.1%,comparable to the fresh catalyst.Activity of Cu/B/Ca/Al2O3 catalyst was very sensitive to the steam in the reaction,which was probably caused by the deposition of organic species on the catalyst suface induced by the reaction of CaO with H2O and the consequent loss in catalyst acidity.The macrokinetics of the reaction was also analyzed,in tems of the effect reaction temperature and WHSV,with the increasing of temperature and decreasing of WHSV,the SBA conversion rate rose gradually?The apparent activation energy,the pre-exponential factor and reaction order for SBA were estimated to be 72.79 kJ?mol?1,1.405 and1,respectively.Introducing n-pentane as a co-solvent reduced both the hydrogen and energy consumption,significantly. |
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