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摘要: 以复合离子液体[Et3NH]Cl-AlCl3-CuCl为催化剂, 在连续搅拌釜式反应器中进行了异丁烷与2-丁烯烷基化反应; 利用氘代异丁烷同位素示踪法研究了催化反应机理。结果表明, 在离子液体中异丁烷烷基化的反应诱导期较短; 三甲基戊烷产物主要源于异丁烷的自烷基化、丁烷/丁烯的直接烷基化以及C12+中间体的裂化反应, 而大部分二甲基己烷是仲丁基碳正离子与丁烯加成的产物。Abstract: The alkylation of isobutane with butene catalyzed by [Et3NH]Cl-AlCl3-CuCl ionic liquid was carried out in a continuous stirred autoclave reactor; deuterated isobutane was used as an isotope tracer to investigate the reaction mechanism of alkylation. The results indicate that the induction period of alkylation catalyzed by Cl-AlCl3-CuCl is less than 30min. Tri-methyl-pentanes are primarily produced from the self-alkylation of isobutane, the alkylation of isobutane with 2-butene and the cracking of C12+ intermediates, whereas the undesired di-methyl-hexane is mainly formed from the addition reaction between sec-C4+ and 2-butene.
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Key words:
- ionic liquids /
- isobutane /
- alkylation /
- reaction mechanism
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表 1 异丁烷/2-丁烯烷基化C8产物分布a
Table 1 Product distribution of isobutane/ 2-butene alkylation a
Component Molecular weight H2SO4 [Et3NH]Cl-AlCl3-CuCl Alkane TMP (C8H8D10) 124 - 0.05 2, 2, 4-TMP (C8H18) 114 9.13 13.63 TMP (C8H5D13) 127 - 0.04 2, 2-DMH (C8H18) 114 - 0.01 2, 4-DMH (C8H18) 114 3.2 2.71 2, 5-DMH (C8H18) 114 4.51 2.28 2, 2, 3-TMP (C8H18) 114 0.92 1.66 TMP (C8H9D9) 123 - 0.12 TMP (C8H16D2) 116 - 0.24 3, 3-DMH (C8H18) 114 - 0.01 2, 3, 4-TMP (C8H18) 114 6.01 13.72 2, 2, 3-TMP (C8H18) 114 8.12 11.43 TMP (C8D18) 132 - 0.02 a the mixture of i-C4D10 (5g), i-C4H10 (50g) was used as the feed and sampling was made after continuous reaction for 30min 表 2 不同催化剂中异丁烷/2-丁烯烷基化副产物的分布
Table 2 Side-product distribution of isobutane/ 2-butene alkylation
Component Molecular weight H2SO4 [Et3NH]Cl-AlCl3-CuCl C4H10 59 5.23 C4H9D 59 0.36 C5H12 72 2.73 0.16 C6H14 86 4.48 0.30 C7H16 100 5.21 1.14 C6D14 100 - 0.04 C8H16 112 17.36 1.01 C12H24D2 172 - 0.16 C12H12D14 184 - 0.08 C12H18D8 178 - 0.02 C12H12D14 184 - 0.05 C12H26 170 11.84 23.62 -
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