甲苯甲醇烷基化制对二甲苯催化剂中试反应性能研究
收稿日期: 2020-09-11
网络出版日期: 2021-03-11
基金资助
中国海油石油集团有限公司课题(CNOOC-KJ 135 FZDXM 00 LH 002 YJY-2017)
版权
Study on pilot catalytic performance of the modified catalyst for alkylation of toluene with methanol to p-xylene
Received date: 2020-09-11
Online published: 2021-03-11
Copyright
经过多步改性制备了负载二氧化硅(SiO2)、氧化镁(MgO)、五氧化二磷(P2O5)、贵金属铂(Pt)的纳米ZSM-5分子筛催化剂,并在六段固定床反应器上分段装填该催化剂720 g进行甲苯、甲醇烷基化制对二甲苯反应活性评价。实验结果表明,通过调变甲醇和甲苯物质的量比可以使甲苯转化率在22%~30%可调,烷基化液相产物中二甲苯选择性保持在95%以上,二甲苯中对二甲苯选择性保持在95%以上;催化剂单程寿命达到1 300 h,随着反应时间延长催化剂的活性有所下降。通过X射线衍射(XRD)、热重分析(TG-DTG)和氮气吸附-脱附等手段对参加反应前后的催化剂进行了表征,结果表明反应中生成的积炭堵塞了分子筛的孔道或覆盖了催化剂的活性位;经过在反应器内原位再生,催化剂的反应活性基本恢复到新鲜催化剂水平。
李孝国 , 李永恒 , 侯章贵 , 韩国栋 , 肖家旺 , 郜金平 , 常洋 . 甲苯甲醇烷基化制对二甲苯催化剂中试反应性能研究[J]. 无机盐工业, 2021 , 53(3) : 97 -101 . DOI: 10.11962/1006-4990.2020-0419
A composite-modified nano ZSM-5 zeolite catalyst was prepared through multi-step impregnation with the precur-sor of SiO2,MgO,P2O5 and Pt.The catalytic performance for alkylation of toluene with methanol was investigated in a six-stage fixed bed reactor,which is filled with more than 720 g of the catalyst.The result shows that the conversion rate of toluene was controllably adjusted in the range of 22%~30% by adjusting the amount-of-substance ratio of toluene to methanol,as well as the selectivity to xylene in liquid products of alkylation and selectivity to p-xylene in xylene(o-xylene,m-xylene and p-xylene) both simultaneously stabilized above 95%.The life of the catalyst reaches 1 300 h in alkylation reaction and the catalytic activity decreased after 1 200 h.The fresh and deactivated catalysts were characterized by XRD,TG-DTG and N2 adsorption-desorption.It is indicated that the generated coke blocked the pores of ZSM-5 zeolite or deposited on the active sites of catalyst,leading to the catalytic deactivation.The catalytic activity of deactivated catalyst almost can be restored after in-situ regeneration.
[1] | 华经产业研究院. 2019—2025年中国对二甲苯(PX)行业发展前景预测及投资战略研究报告[EB/OL]. https://www.huaon.com/story/466103,2019-09-12. |
[2] | 洪汉青, 杜玉如, 娄阳, 等. 芳烃生产技术进展及发展趋势[J]. 化学工业, 2018,36(5):40-44. |
[3] | 孔德金, 杨卫民. 芳烃生产技术进展[J]. 化工进展, 2011,30(1):16-25. |
[4] | 杨卫胜, 孔德金, 谢在库. 增产对二甲苯的芳烃组合工艺[J]. 化学反应工程与工艺, 2009,25(3):276-279. |
[5] | 刘永存, 肖寒, 王帅, 等. Ni-Mo-P/Beta-ZSM-5催化剂对四氢萘加氢裂化性能的研究[J]. 无机盐工业, 2018,50(6):81-85. |
[6] | 戴清, 杨玉旺, 高旭东, 等. 分子筛改性γ-Al2O3催化剂对甲醇脱水反应的影响[J]. 无机盐工业, 2014,46(11):69-72. |
[7] | 韩丽华, 刘平, 高俊华, 等. Si、P、Mg改性HZSM-5提高甲苯/甲醇烷基化中对二甲苯的选择性[J]. 天然气化工:C1化学与化工, 2019,44(3):1-6. |
[8] | Li G X, Wu C, Dong P, et al. Core-shell HZSM-5@silicalite-1 co-mposite:Controllable synjournal and catalytic performance in alkyla-tion of toluene with methanol[J]. Catalysis Letters, 2020,150(7):1923-1931. |
[9] | Li G X, Wu C, Ji D, et al. Acidity and catalyst performance of two shape-selective HZSM-5 catalysts for alkylation of toluene with me-thanol[J]. Reaction Kinetics,Mechanisms and Catalysis, 2020,129:963-974. |
[10] | Li J H, Ji W X, Liu M, et al. New insight into the alkylation-effici-ency of methanol with toluene over ZSM-5:Microporous diffusibi-lity significantly affects reacting-pathways[J]. Microporous and Mesoporous Materials, 2019,282:252-259. |
[11] | 范景新, 景卫东, 于海斌, 等. 甲苯甲醇选择性烷基化催化剂研究进展[J]. 无机盐工业, 2013,45(6):62-64. |
[12] | Zhao Y, Wu H Y, Tan W, et al. Effect of metal medication of HZSM-5 on catalyst stability in the shape-selective methylation of tolu-ene[J]. Catalysis Today, 2010,156:69-73. |
[13] | Zhao Y, Tan W, Wu H Y, et al. Effect of Pt on stability of nano-sc-ale ZSM-5 catalyst for toluene alkylation with methanol into para-xylene[J]. Catalysis Today, 2011,160:179-183. |
[14] | Xu S T, Zhi Y C, Han J F, et al. Advances in catalysis for methanol-to-olefins conversion[J]. Advances in Catalysis, 2017,61:37-122. |
[15] | Wang C, Xu J, Qi G D, et al. Methylbenzene hydrocarbon pool in methanol-to-olefins conversion over zeolite H-ZSM-5[J]. Journal of Catalysis, 2015,332:127-137. |
[16] | Janssen T V W, Svelle S, Olsbye U. Kinetic modeling of deactiva-tion profiles in the methanol-to-hydrocarbons(MTH) reaction:A combined autocatalytic-hydrocarbon pool approach[J]. Journal of Catalysis, 2013,308:122-130. |
[17] | 赵建宁, 王峰, 刘素丽. ZSM-5分子筛物化性能的差异对其催化性能的影响[J]. 石油化工应用, 2017,36(10):114-118. |
[18] | 袁苹, 王浩, 薛彦峰, 等. 不同粒径ZSM-5分子筛在苯与甲醇烷基化反应中催化性能及反应条件优化[J]. 物理化学学报, 2016,32(7):1775-1784. |
/
〈 |
|
〉 |