Effects Of Ca&b As Additives On Catalytic Performace For Hydrogenation Of Sec-butyl Acetate

With the increasing demand of sec-Butanol and its downstream products methyl ethyl ketone,the synthesis process of sec-Butanol is more and more noticed by chemical enterprises.Compared with the tradition al n-Butene hydration process,the hydrogenation of sec-Butyl Acetate to produce the sec-Butanol process has the advantages of high conversion rate and high selectivity.Based on the previous research,the effects of CaO and B₂O₃ as additives on catalystic performance for hydrogenation of sec-Butyl Acetate were investigated.At the same time,the catalytic transfer hydrogenation process of sec-Butanol to sec-Butyl Acetate was preliminary studied.The evaluation and characterization results of catalyst with differern CaO contents showed that the introduction of CaO mainly increased the catalyst pore size and the loading of active component CuO,but also led to the uneven distribution of pore size,the decrease of specific surface area and CuO dispersion.The activity of the catalyst increased with the increase of CaO contents.When the CaO contents were higher than 25 wt%,the activity was basically unchanged.TPD characterization results showed that on the surface of CaO modified catalyst existed acid and alkali active sites at the same time,of which the majority were basic sites.With the increase of CaO contents,the number of acid sites decreased greatly,and the basic sites increased gradually.After catalyst was modified with K₂O instead of CaO,The evaluation and characterization results showed that the effect of K20 was similar to CaO.However,under the same conditions,the conversion of K₂O modified catalyst was lower,mainly because that CaO modification increased the adsorption of CuO on the catalyst surface.The evaluation and characterization results of different B₂O₃ contents catalysts showed that the introduction of B₂O₃ mainly improved the dispersion degree of CuO,and reduced the specific surface area,pore volume and CuO loading.With the increase of B₂O₃ contents,the activity of the catalyst was increasing,and when the contents of B₂O₃ were higher than 12 wt%,the activity was basically unchanged.TPD characterization results showed that with the increase of B₂O₃ contents,the number of basic sites on the catalyst surface was decreasing and the acid centers was increasing preferably.The evaluation and characterization results of the catalytic transfer hydrogenation process of sec-Butanol to sec-Butyl Acetate showed that the active components selected Cu was more appropriate,Supplemented by B₂O₃ modified at the same time,and the y-Al₂O₃ support was better after modified by 30 wt%CaO.Improve the contents of sec-Butanol in raw materials were more beneficial to improve the conversion of sec-Butyl Acetate and the selectivity of methyl ethyl ketone,but the conversion of sec-Butanol was decreased.After the introduction of H₂ in the reaction system,the conversion of sec-Butyl Acetate increased significantly.In addition,the increase of reaction temperature increased the activity of the catalyst,but the selectivity decreased.The increase of weight hourly space velocity increased the conversion of sec-Butanol while the conversion of sec-Butyl Acetate was reducing.Low pressure conditions was beneficial to the dehydrogenation of sec-Butanol,and high pressure was conducive to hydrogenation of sec-Butyl acetate.