磷酸对HZSM-5成型及其催化乙醇脱水性能的影响  

Effects of Phosphate Acid on the Forming Strength and Performance of Catalytic Ethanol Dehydration of HZSM-5

作　　者：胡耀池[1] 章文贵[1] 詹妮娜[1] 胡燚[1] 黄和[1] 

机构地区：[1]南京工业大学生物与制药工程学院,江苏南京210009

出　　处：《化学试剂》2014年第6期487-492,512,共7页Chemical Reagents

基　　金：国家杰出青年科学基金资助项目(21225626);国家高技术研究发展计划资助项目("863"计划)(2012AA-022300;2014AA021206)

摘　　要：获得较高活性、高强度的适用于固定床工艺的成型HZSM-5分子筛催化剂对推进乙醇脱水制乙烯工业应用有着积极的意义。采用磷酸、硅溶胶以及羧甲基纤维素钠等作为助剂,制备了系列成型HZSM-5分子筛,研究了磷酸添加量对分子筛抗压强度及催化乙醇脱水活性的影响。结果表明,在无磷酸添加时,成型抗压强度仅为20.5 N/cm;而添加磷酸后,成型HZSM-5的抗压强度明显提高,当P添加量达到3.3 wt%时抗压强度达到最高值为120.9 N/cm;可满足固定床工艺需求;而继续增加磷酸添加量,HZSM-5的抗压强度逐渐减弱,随着磷酸添加量的增加,催化剂的活性逐步下降。当P添加量达到3.3 wt%时,在320℃,乙醇浓度50 wt%以及质量空速2.0 h-1条件下,乙醇转化率为97.9%,乙烯选择性为97.8%,较好地兼顾了工业上对催化剂强度及活性需求。Suitable forming strength is important for efficient HZSM-5 catalysts＇ industrial application in a fixed-bed process of the ethanol dehydration. Phosphoric acid, silica and sodium carboxymethyl cellulose were used as additives to pre- pare a series of HZSM-5 catalysts. The effects of phosphoric acid content on the compressive strength of the catalysts and the dehydration activity were investigated. The results showed that the compressive strength of HZSM-5 was only 20. 5 N/cm without phosphoric acid, while it was improved significantly after the adding of phosphoric acid. Especially, the compressive strength achieved the highest value 120. 9 N/em with 3.3 wt% P, meeting the industrial demand of a fixed-bed process. Then the compressive strength of HZSM-5 gradually showed a decline with the increasing content of phosphoric acid. Meanwhile,the catalyst activity also gradually decreased. When P content reached 3.3 wt% , ethanol conversion and ethylene selectivity reached 97.9% and 97.8% respectively, under the reaction conditions of temperature 320 ℃ ,ethanol concentration 50 wt% and WHSV 2.0 h-l. The HZSM-5 with 3.3 wt% P could meet the industrial requirements for strength and activity of catalyst.

关 键 词：磷酸 HZSM-5 成型 乙醇 脱水 

分 类 号：O611.62[理学—无机化学]