CAJ | 학술논문

针对甲基丙烯醛氧化酯化浆态床反应过程中颗粒催化剂易破碎、活性组分易流失等缺点，采用浸渍法在电沉积到泡沫镍合金表面的氧化铝-氧化镁涂层上负载活性组分，制备了PdxPby/Al2O3-MgO/泡沫镍合金整体式催化剂。研究分析了铝溶胶含量、Al2O3含量、沉积电压和沉积时间等条件对涂层负载的影响，并对载体和催化剂进行了 BET、XRD、SEM、ICP 和 TEM 表征和气-液-固固定床反应性能评价。结果表明，当铝溶胶的体积含量为35%～40%，Al2O3含量为25～30 g·L?1，沉积电压为10～12 V，沉积时间为8～12 min，搅拌速度为200～250 r·min?1时可得到稳定的涂层。在温度为80℃、压力为0.3 MPa、醇醛摩尔比为8：1、液相物料进口流量为0.5 ml·min?1、氧气进口流量为35 ml·min?1、反应时间为2 h条件下，整体式催化剂上甲基丙烯醛转化率最高为76.1%，甲基丙烯酸甲酯选择性为81.2%。研究结果可为甲基丙烯醛氧化酯化制甲基丙烯酸甲酯的生产工艺优化提供科学数据。
침대갑기병희철양화지화장태상반응과정중과립최화제역파쇄、활성조분역류실등결점，채용침지법재전침적도포말얼합금표면적양화려-양화미도층상부재활성조분，제비료PdxPby/Al2O3-MgO/포말얼합금정체식최화제。연구분석료려용효함량、Al2O3함량、침적전압화침적시간등조건대도층부재적영향，병대재체화최화제진행료 BET、XRD、SEM、ICP 화 TEM 표정화기-액-고고정상반응성능평개。결과표명，당려용효적체적함량위35%～40%，Al2O3함량위25～30 g·L?1，침적전압위10～12 V，침적시간위8～12 min，교반속도위200～250 r·min?1시가득도은정적도층。재온도위80℃、압력위0.3 MPa、순철마이비위8：1、액상물료진구류량위0.5 ml·min?1、양기진구류량위35 ml·min?1、반응시간위2 h조건하，정체식최화제상갑기병희철전화솔최고위76.1%，갑기병희산갑지선택성위81.2%。연구결과가위갑기병희철양화지화제갑기병희산갑지적생산공예우화제공과학수거。
In order to overcome the shortcomings of particulate catalyst for oxidative esterification of methacrolein in slurry reactor, the monolithic catalyst(PdxPby/Al2O3-MgO/ nickel alloy foam)for direct oxidative esterification of methacrolein (MAL) with methanol to methyl methacrylate (MMA) was prepared using dipping methods. The porous Al2O3-MgO with high surface area on nickel alloy foam support was synthesized using electro-deposition method. The effects of preparation parameters on Al2O3coating were studied, and the optimum coating was achieved when the volume content of aluminum sol was 35%—40%, the Al2O3 content was 25—30 g·L?1, the stirring speed was 200—250 r·min?1, the deposition voltage was 10—12 V, and the deposition time was 8—12 min. Furthermore, the coating and catalyst were characterized using BET, XRD, SEM, ICP as well as TEM and the catalytic performance of Pd5Pb5/Al2O3-MgO/nickel alloy foam was investigated in a fixed bed reactor. The optimal reaction conditions were determined as:T=80℃,p=0.3 MPa, methanol:MAL molar ratio=8:1, liquid materials flux rate =0.5 ml·min?1, oxygen flux rate=35 ml·min?1 and reaction time=2 h. Under these conditions, MAL conversion and MMA selectivity reached 76.1% and 81.2%,respectively. The results can provide scientific basis for the optimization of methacrolein to methyl methacrylate production process.