- Effect of surface silicon modification of H-beta zeolites for alkylation of benzene with 1-dodecene
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H-beta zeolites of 100-200 nm (named BEA-L) and 20-30 nm (named BEA-S) were treated by chemical liquid deposition (CLD) of tetraethyl orthosilicate (TEOS) to improve the selectivity of 2-phenyl linear alkylbenzene (2-LAB) from benzene alkylation with 1-dodecene. The results indicate that H-beta zeolite with a smaller crystal size has a longer lifetime due to shorter channels and less diffusion limitation. The deposited SiO2 layers passivated the external surface acid sites of the zeolite and made the pores narrower. BEA-L lost more external Br?nsted acid sites than BEA-S with the same added amount of TEOS, which was due to the severe aggregation of BEA-S grains. This increased passivation gave BEA-L increased 2-LAB selectivity. And when the added amount of SiO2 was 7.20 wt% of the parent zeolite, the selectivity of 2-LAB over BEA-L significantly increased from 41.9% to 54.7% while that of BEA-S only increased by 2%.
- Han, Minghan,Li, Ruimin,Xing, Shiyong,Zhang, Shuai
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p. 10006 - 10016
(2020/03/23)
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- Organosilane surfactant-directed synthesis of hierarchical mordenite with enhanced catalytic performance in the alkylation of benzene with 1-dodecene
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To improve the stability of mordenite (MOR) in the alkylation of benzene with long chain olefin, hierarchical MOR zeolites were synthesized by using organosilane surfactant [3-(trimethoxysilyl)propyl]octadecyldimethyl-ammonium chloride (TPOAC) as the mesopore structure-directing agent. Our findings reveal that the crystal size, hierarchical structure, and acidic properties of the mesoporous MOR zeolites are significantly influenced by the TPOAC/SiO2 molar ratio in the synthesis gel. Moreover, the hierarchical MOR zeolite synthesized under the optimized synthesis conditions presented the pure phase of the MOR framework and uniform mesoporous distribution. More importantly, the catalytic performance evaluated by the alkylation of benzene with 1-dodecene indicates that the optimal mesoporous MOR zeolite shows improved stability and comparable selectivity of 2-phenyl alkane (2-LAB) around 80% compared to the conventional sole microporous MOR zeolite. The improved stability of the mesoporous MOR zeolite can be attributed to the enhanced diffusivity of long chain linear alkylbenzenes and oligomers due to interconnected meso-/microporosity in the MOR. This journal is
- Liu, Meng-Nan,Li, Yu-Zhao,Xie, Zhi-Xia,Hao, Qing-Qing,Luo, Qun-Xing,Zhang, Jianbo,Chen, Huiyong,Dai, Chengyi,Ma, Xiaoxun
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p. 16638 - 16644
(2020/10/14)
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- A process for preparing long-chain alkyl benzene (by machine translation)
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The invention discloses a process for preparing long-chain alkyl benzene, including: the [...] chain alkyl agent in the metal compound assistants and the presence of the ionic liquid catalyst for carrying out the alkylation reaction, containing the reaction product of the long-chain alkyl benzene; wherein the alkylating agent is C states the long chain10 - C18 Straight-chain olefin or halide; said ionic liquid catalyst comprises a cation and anion, the cation is selected from the isoquinoline kind of positive ion, quinoline kind of positive ion and benzimidazole in at least one of the kind of positive ion, the anion is selected from sulfuric acid hydrogen radical, trifluoromethanesulfonic acid radical, the dihydrogen phosphates, paratoluene sulfonic acid, trifluoroacetic acid radical, four fluorophosphoric acid radical and six fluoboric acid in the root of the at least one. The method of the invention the kind of positive ion cation is isoquinoline, quinoline kind of positive ion or benzimidazole kind of positive ion of the ionic liquid as catalyst, to mix with the additive for preparing long-chain alkylbenzene, mild reaction conditions, the reaction conversion rate of raw materials is high, the product has good choice. (by machine translation)
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Paragraph 0080-0088; 0098-0101
(2019/05/16)
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- Synthesis of efficient SBA-15 immobilized ionic liquid catalyst and its performance for Friedel–Crafts reaction
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Friedel–Crafts alkylation of benzene with 1-dodecene, which is an important reaction of synthetic detergent, was studied via ionic liquid [bmim][TFSI]/AlCl3 (1-butyl-3-methylimidazolium bis((trifluoromethyl)sulfonyl)imide/AlCl3) immobilized on SBA-15 catalysts. XRD, BET, TEM, TG, ammonia TPD investigations were used to search insight into catalyst characteristic. The immobilized catalysts preserved ordered structure and presented high specific surface areas. The utilization of active sites was significantly improved by immobilization. Based on ammonia TPD, immobilized catalysts exhibited higher Lewis acidity than aluminum chloride grafted SBA-15. TG indicated that thermal stability of ionic liquid has been improved by immobilization. The influences of various reaction conditions including reaction time, benzene/1-dodecene ratio were studied. Immobilized ionic liquids have better performance of no matter 1-dodecene conversion or 2-linear alkyl benzene (2-LAB) selectivity, than bulk ionic liquid catalysts or aluminum chloride grafted mesoporous materials. 2-LAB selectivity can be increased from about 35% with bulk ionic liquid to more than 60% with immobilized catalysts. Under optimal condition, 2-LAB selectivity reached as high as 80%. The immobilized catalysts could be reused. And at 3th cycle of catalysts, 1-dodecene conversion could still reach more than 50%. The role of deactivation was proposed based on TEM, BET and TG investigations. By-products as oligomer, produced by oligomerization of olefin, blocked or covered the pores, led to deactivation of catalysts.
- He, Yibo,Zhang, Qinghua,Zhan, Xiaoli,Cheng, Dang-guo,Chen, Fengqiu
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p. 112 - 120
(2016/11/23)
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- Selective synthesis of linear alkylbenzene by alkylation of benzene with 1-dodecene over desilicated zeolites
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The alkylation of benzene with 1-dodecene to linear alkylbenzenes (LAB) was investigated over 12-ring zeolites MOR, BEA, and FAU with varying framework topologies and Si/Al ratios. The reaction was carried out under a high-pressure, 20 bar, in a fixed-bed flow reactor at 140 C, using WHSV 4 h-1, benzene/1-dodecene molar ratio of 6.0 and time-on-stream of 6.0 h. In contrast to MOR and BEA zeolites, FAU exhibited the lowest selectivity (24%) to the desired 2-phenyl dodecane (2-LAB) due to its large cavities. The MOR and BEA with different Si/Al ratios were further desilicated using alkali-metal treatments (0.2 M and 0.05 M NaOH) to create hierarchical porous structure. The desilication of both zeolites improved the conversion of 1-dodecene and the selectivity to 2-LAB. The excellent stability resulting from desilication is attributed to a better diffusivity of the LAB isomers, shortening of real contact time, due to the enhanced mesporous structure in both zeolites and the higher Lewis acidity. The selectivity to 2-LAB increased to 70% over desilicated MOR (Si/Al ratio = 20) compared with a selectivity of 35% over desilicated BEA (Si/Al ratio = 24).
- Aslam, Waqas,Siddiqui, M. Abdul Bari,Rabindran Jermy,Aitani, Abdullah,?ejka, Ji?í,Al-Khattaf, Sulaiman
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p. 187 - 197
(2014/03/21)
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- Process for the production of phenylalkanes using a hydrocarbon fraction that is obtained from the Fischer-Tropsch process
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A process for the production of phenylalkanes comprising a reaction for alkylation of at least one aromatic compound by at least one hydrocarbon fraction that is directly obtained from the Fischer-Tropsch process comprising linear olefins that have 9 to 16 carbon atoms per molecule and oxygenated compounds is described. Said alkylation reaction is carried out in a catalytic reactor that contains at least one reaction zone that comprises at least one acidic solid catalyst, and said hydrocarbon fraction does not undergo any purification treatment prior to its introduction into said reaction zone.
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Page/Page column 4
(2008/06/13)
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- Method for formulation of synthetic gas oils or additives for gas oil
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The invention relates to a method for formulation of a synthetic gas oil or an additive for gas oil in which an alkyl-aromatic compound or a mixture of alkyl-aromatic compounds is selected based on at least one parameter that is selected from the group that consists of the number of cycles of the aromatic core, the number of alkyl chains that are grafted to the aromatic cycle, the length of the alkyl chain or chains, the position of the aromatic cycle or cycles on the alkyl chain or chains of said alkyl-aromatic compound or compounds such that the cetane number of the synthetic gas oil or the additive for gas oil is greater than 30. The invention also relates to a process for the production of alkyl-aromatic compounds for use as a gas oil or additive.
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Page/Page column 2-3
(2008/06/13)
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- Use of methanesulfonic acid as catalyst for the production of linear alkylbenzenes
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Methanesulfonic acid (MSA) was used as catalyst for the electrophilic addition of long-chain olefins such as 1-dodecene to benzene. The effect of the temperature, the ratios of the reactants, the amount of MSA, and the stirring of the reaction mixture were studied. After a 3 hr reaction time at 80°C, a selectivity to the phenyldodecanes of > 90% was obtained at 98% dodecene conversion. The presence of water in the reaction mixture was detrimental for the activity of MSA. There was a strong decrease in the activity when the MSA contained > 0.25 wt % of water. With increasing amounts of MSA the reaction proceeded faster; for a complete conversion at least 1 M eq of MSA was needed.
- Luong,Petre,Hoelderich,Commarieu,Laffitte,Espeillac,Souchet
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p. 301 - 307
(2007/10/03)
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- Encapsulated AlCl3: A convenient catalyst for the alkylation of benzene with dodecene
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A novel method for the encapsulation of AlCl3 was successfully carried out using an insoluble polymer wall. The polymer wall was formed by the reaction of poly(styrene-co-dimethylaminoethyl methacrylate) and hydrogenated telechelic polybutadiene containing -COOH groups. The encapsulated AlCl3 was used to catalyze the Friedel-Crafts alkylation of benzene with dodecene. The alkylbenzenes were obtained in excellent yields and the encapsulated AlCl3 catalyst was separated by simple filtration.
- Srirattnai, Kusoomjin,Damronglerd, Somsak,Omi, Shinzo,Roengsumran, Sophon,Petsom, Amorn,Ma, Guang-Hui
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p. 4555 - 4557
(2007/10/03)
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- Relationship of structure to properties of some anionic surfactants as collectors in the flotation process. 1. Effect of chain length
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The surface and thermodynamic properties of some synthetic surfactants, as well as their efficiency as collectors in the flotation of petroleum coke, are studied. These surfactants are monoisomeric alkylbenzenesulfonate of different alkyl chains (C12 to C14). The results show that the length of the hydrocarbon chain of these surfactants plays a major role in determining their surface and thermodynamic properties. The values of surface excess concentration (Γmax) and Gibbs energy of micellization (ΔG°mic) are found to increase with increasing number of carbon atoms in the chain while the values of critical micelle concentration (cmc) are decreased. The results indicate, also, that there is a good relationship between effectiveness of adsorption of a surfactant and its efficiency as a collector. A surfactant of higher Γmax produces a concentrate of lower ash content and higher flotation yield. Thus, the surfactant with longer alkyl chain (C14) and highest Γmax value is more selective, as a collector, than others of shorter carbon chain.
- Abdel-Khalek,Omar,Barakat
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p. 133 - 137
(2007/10/03)
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