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摘要: 用NaOH溶液对高硅ZSM-5分子筛进行处理，考察其应用于苯-甲醇烷基化反应过程的最佳处理条件，并用XRD、SEM、XRF、NH3-TPD、TPO、BET等手段对试样进行表征。结果表明，NaOH在脱除分子筛硅物种的同时，也会脱出晶粒表面附着物，暴露出更多的酸性位，形成一定量的介孔，进而影响苯-甲醇烷基化性能。当NaOH处理量为2.4 mmol/gcat时，在液体积空速为85 h-1下，烷基化反应中苯的转化率达到38%，相比处理前提高了近16%，且积炭量低，稳定性好。Abstract: High-silicon ZSM-5 zeolite was treated with NaOH solution to investigate the effect of modification on benzene-methanol alkylation. The physicochemical properties of the samples were characterized by XRD, SEM, XRF, NH3-TPD, TPO, and BET. The results showed that NaOH treatmeng removed the molecular sieve silicon species and the surface deposits, revealed more acid sites, formed certain amount of mesopores, which affected the alkylation performance of benzene-methanol. When the NaOH treatment amount was 2.4 mmol/gcat, the conversion rate of benzene in the alkylation reaction reached 38% at a liquid volume space velocity of 85 h-1, which was nearly 16% higher than that before treatment, and the modified catalyst had low carbon deposition and better stability.
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Key words:
- benzene /
- methanol /
- alkylation /
- ZSM-5 catalyst /
- alkali modification
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图 1 NaOH处理后ZSM-5催化剂的XRD谱图
Figure 1 XRD patterns of the ZSM-5 catalysts treated with NaOH
图 2 NaOH处理后ZSM-5催化剂的结晶度
Figure 2 Crystallinity of the ZSM-5 catalysts treated with NaOH
图 3 NaOH处理后ZSM-5催化剂的SEM照片
Figure 3 SEM images of the ZSM-5 catalysts treated with NaOH
(a): HZSM-5; (b): 1.6N-Z-5; (c): 2.0N-Z-5; (d): 2.4N-Z-5; (e): 2.8N-Z-5; (f): 3.2N-Z-5
图 4 NaOH处理ZSM-5催化剂的氮气吸附-脱附曲线和孔分布
Figure 4 N2 adsorption-desorption isotherms and pore diameter distribution of the ZSM-5 catalysts treated by NaOH
图 5 NaOH处理后ZSM-5催化剂的NH3-TPD谱图
Figure 5 NH3-TPD patterns of the ZSM-5 catalysts treated with NaOH
图 6 NaOH处理后ZSM-5催化剂的烷基化性能
Figure 6 Alkylation performance of the ZSM-5 catalysts treated with NaOH
图 7 NaOH处理后ZSM-5催化剂的O2-TPO谱图
Figure 7 O2-TPO patterns of the ZSM-5 catalysts treated with NaOH
表 1 NaOH处理后ZSM-5催化剂的XRF表征
Table 1 XRF data of ZSM-5 catalysts treated with NaOH
Catalyst Content w/% n(Si)/n(Al) SiO2 Al2O3 HZSM-5 99.4 0.364 231.7 1.6N-Z-5 99.2 0.470 179.1 2.4N-Z-5 99.2 0.545 154.4 2.8N-Z-5 99.1 0.598 140.6 
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表 2 NaOH处理ZSM-5催化剂的N2-BET分析
Table 2 N2-BET results of the ZSM-5 catalysts treated by alkali
Catalyst Surface area A/(m2·g-1) Volume v/(cm3·g-1) ABET AMic AExt vTotal vMic vMes HZSM-5 352.85 206.25 146.60 0.19 0.10 0.09 2.4N-Z-5 339.05 176.00 163.04 0.21 0.09 0.12
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表 3 NaOH处理后ZSM-5催化剂的NH3-TPD表征
Table 3 NH3-TPD results of the ZSM-5 catalysts treated with NaOH
Catalyst Weak acid Strong acid peak temperature t/ ℃ relative peak area peak temperature t/ ℃ relative peak area HZSM-5 198 1.00 400 1.00 1.6N-Z-5 192 0.96 382 1.00 2.0N-Z-5 192 1.02 362 1.01 2.4N-Z-5 194 1.07 367 1.07 2.8N-Z-5 195 1.09 369 1.13 3.2N-Z-5 195 1.16 354 1.22
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表 4 NaOH处理后ZSM-5催化剂的积炭量分析
Table 4 Carbon content data of the ZSM-5 catalysts treated with NaOH
Catalyst Peak area Relative carbon deposit CO2 CO HZSM-5 3.62×10-8 1.87×10-8 1.00 1.6N-Z-5 2.85×10-8 3.47×10-9 0.48 2.0N-Z-5 1.95×10-8 1.07×10-8 0.55 2.4N-Z-5 1.80×10-8 1.76×10-8 0.71 2.8N-Z-5 2.77×10-8 2.17×10-8 0.97 3.2N-Z-5 2.54×10-8 1.03×10-8 0.61
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[1] 凡文.中国甲苯市场分析及前景展望[J].中国石油和化工经济分析, 2017, 239(11):52-54. https://www.ixueshu.com/document/affa20823d9fbb0414a4dc030e7d94c3.htmlFAN Wen. China toluene market analysis and prospects[J]. China Pet Chem Econ Anal, 2017, 239(11):52-54. https://www.ixueshu.com/document/affa20823d9fbb0414a4dc030e7d94c3.html [2] 刘玉明, 赵娟, 马运兰.芳烃的市场分析与预测[J].塑料制造, 2012, 212(5):30-34. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=QK201202100594LIU Yu-ming, ZHAO Juan, MA Yun-lan. The analysis arid forecast of aromatics market[J]. Plast Manu, 2012, 212(5):30-3. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=QK201202100594 [3] 赵博.改性纳米HZSM-5催化剂上苯和甲醇的烷基化[D].大连: 大连理工大学, 2013. http://cdmd.cnki.com.cn/Article/CDMD-10141-1013199919.htmZHAO Bo. The alkylation of benzene with methanol over modifiednanoscale HZSM-5[D]. Dalian: Dalian University of Technology, 2013. http://cdmd.cnki.com.cn/Article/CDMD-10141-1013199919.htm [4] 胡慧敏. ZSM-5系列分子筛催化剂上苯与甲醇的烷基化反应研究[D].长沙: 湖南师范大学, 2007. http://cdmd.cnki.com.cn/Article/CDMD-10542-2007174983.htmHU Hui-min. Methylation of benzene with methanol overa series of ZSM-5 catalysts[D]. Changsha: Hunan Normal University, 2007. http://cdmd.cnki.com.cn/Article/CDMD-10542-2007174983.htm [5] 张超.苯、甲醇烷基化催化剂改性及反应特性的研究[D].上海: 华东理工大学, 2013. http://cdmd.cnki.com.cn/Article/CDMD-10251-1013154726.htmZHANG Chao. The study of catalyst modified and reaction characteristics for benzene-methanol alkylation[D]. Shanghai: East Chaina University of Science Technology, 2013. http://cdmd.cnki.com.cn/Article/CDMD-10251-1013154726.htm [6] 陈艳红.多级孔ZSM-5沸石分子筛的制备研究进展[J].无机盐工业, 2017, 49(7):3-6. http://d.old.wanfangdata.com.cn/Periodical/wjygy201707001CHEN Yan-hong. Research advance in synthesis of hierarchical ZSM-5 zeolite[J]. Inorg Chem Ind, 2017, 49(7):3-6. http://d.old.wanfangdata.com.cn/Periodical/wjygy201707001 [7] 魏民, 孔飞飞, 丁越野.碱处理法制备微介孔ZSM-5及其加氢脱硫性能的研究[J].石油炼制与化工, 2015, 46(10):61-66. doi: 10.3969/j.issn.1005-2399.2015.10.012WEI Min, Kong Fei-fei, DING Yue-ye. Study on preparation of micro-mesoporous ZSM-5 zeolite by alkali treatment and proformance in hydrodesulfurization of FCC gasoline[J]. Pet Process Petrochem, 2015, 46(10):61-66. doi: 10.3969/j.issn.1005-2399.2015.10.012 [8] OGURA M, SHINOMIYA SY, TATENO J. Alkali-treatment technique-new method for modification of structural and acid-catalytic properties of ZSM-5 zeolites[J]. Appl Catal A:Gen, 2001, 219(1/2):33-43. https://www.sciencedirect.com/science/article/abs/pii/S0926860X01006457 [9] 宋月芹, 刘锋, 康承琳.碱处理法改善Pt/ZSM-5异构化性能[J].催化学报, 2009, 30(2):159-164. doi: 10.3321/j.issn:0253-9837.2009.02.015SONG Yue-qin, LIU Feng, KANG Cheng-lin. Alkalitreatment for improving isomerization performance of Pt/ZSM-5[J]. Chin J Catal, 2009, 30(2):159-164. doi: 10.3321/j.issn:0253-9837.2009.02.015 [10] 吕江江, 黄星亮, 赵蕾蕾.酸碱处理对ZSM-5分子筛物化性质和反应性能的影响[J].燃料化学学报, 2016, 44(6):732-737. doi: 10.3969/j.issn.0253-2409.2016.06.014LÜ Jiang-jiang, HUANG Xing-liang, ZHAO Lei-lei. Effects of acid-alkali treatment on properties and reactivity of ZSM-5 catalyst[J]. J Fuel Chem Technol, 2016, 44(6):732-737. doi: 10.3969/j.issn.0253-2409.2016.06.014 [11] 李建军, 甘玉花, 王伟明.碱处理法改性ZSM-5分子筛催化苯与乙醇烷基化制乙苯[J].厦门大学学报(自然版), 2012, 51(5):882-887. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=xmdxxb201205015LI Jian-jun, GAN Yu-hua, WANG Wei-ming. Study on surface acidity and morphology of alkaline treated ZSM-5zeolite for alkylation ofbenzene with ethanol to ethylbenzene[J]. J Xiamen Univ (Nat Sci), 2012, 51(5):882-887. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=xmdxxb201205015 [12] 赵蕾蕾.苯甲醇烷基化分子筛催化剂的研究[D].北京: 中国石油大学, 2016. http://cdmd.cnki.com.cn/Article/CDMD-11414-1018700746.htmZhao Lei-lei. The study of catalysts in the alkylation of benzene with methanol[D]. Beijing: China University of Petroleum, 2016. http://cdmd.cnki.com.cn/Article/CDMD-11414-1018700746.htm [13] 孙仁山.苯-甲醇烷基化改性HZSM-5催化剂的研究[D].北京: 中国石油大学, 2017: 67-68.SUN Ren-shan. The study of alkylation of benzene with methanol over modified HZSM-5[D]. Beijing: China University of Petroleum, 2017: 67-68. -
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