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Pure benzene is an important chemical feedstock, and coking benzene is one of its sources. However, the industrialized coking benzene refining processes are not green and sustainable. To solve this problem, a green two-step process for the desulfurization of coking benzene with the advantages of easy operation, low environmental pollution and solid waste (sorbent/thiophene) recyclability was evaluated. The thiophene in coking benzene was first alkylated by the olefins present in it using a suitable AlCl3/silica gel catalyst to produce alkylthiophenes, which can be easily separated by distillation. The AlCl3/silica gel catalyst obtained by a novel green process was effective in catalyzing the alkylation of thiophene by 1-hexene with an efficiency of removing thiophene up to 94.2%. AlCl3 was grafted onto silica gel by reacting with hydroxyls on its surface, which could prevent the dissolution problem of AlCl3 in benzene. The residual thiophene with its concentration range of 100–1000 mg L−1 in benzene was then almost completely removed by adsorption using an ion-exchanged zeolite. The CeY zeolite sorbent showed excellent performance in deeply removing the residual thiophene in the benzene, in which the adsorption desulfurization over the CeY sorbent fits a Langmuir isotherm. The product met the requirements for a chemical feedstock, in that no thiophene was measured in the purified benzene by gas chromatography with a flame photometric detector. The CeY zeolite with adsorbed thiophene was used to prepare polythiophene–CeY composites by chemical oxidative polymerization using anhydrous FeCl3 as an oxidant at 0 °C. The decomposition temperature of the polythiophene–CeY composites is 480 °C, which is 60 °C higher than that of polythiophene. [ABSTRACT FROM AUTHOR]

Abstract: AlCl3/silica gel catalysts were prepared by inclosed grafting method in the autoclave and their catalytic activities for alkylation reaction of thiophene with olefins in benzene were studied. The gas chromatograph and chromatography–mass spectroscopy were used to quantitatively determine the thiophene in benzene and qualitatively measure the reaction products, respectively. XPS, SEM, EDX and N2 adsorption techniques were used to characterize the physical and chemical properties of catalyst samples. The results show that AlCl3 can be effectively anchored by reacting with the silanol groups on silica gel surface to form the Si x (OH) y − a O a AlCl(3− a) species and the prepared AlCl3/silica gel catalyst possesses the significant activity for the alkylation reaction of thiophene and olefin. The preparation conditions, such as mass ratio of AlCl3/silica gel support, grafting temperature and time, and thermal treatment temperature of silica gel, have an important role on the content and distribution of active component over silica gel support, and thus affect the catalytic activity. The optimum preparation conditions of AlCl3/silica gel catalyst are that AlCl3 is grafted on silica gel support, which has been thermally treated at 400°C for 3h, and at 180°C for 4h with the mass ratio of 0.20 for AlCl3/silica gel support. The loading ratio of AlCl3 on silica gel can reach about 64wt.% and the optimal conversion rate of thiophene in benzene is 94.23% when the ratio of liquid to catalyst is 20mL/g. [Copyright &y& Elsevier]

The commercial NaY zeolite with the Si/Al ratio of 5:1 was selected and modified for researching the adsorptive removal of thiophene from benzene. The zeolite was ion-exchanged in Ce(NO3)3 solution and then calcined in muffle to prepare the CeY sorbent. The results show that it is a suitable method to prepare the sorbent removing thiophene from benzene that NaY zeolite is ion-exchanged by cerium in Ce(NO3)3 solution. The desulfurization efficiency of CeY sorbent increases obviously comparing with NaY zeolite. The effects of the calcination temperature, calcination time, concentration of Ce(NO3)3 solution, ion-exchange time, and ion-exchange times on the desulfurization capacity of CeY sorbent were also studied. The results show that the optimal CeY sorbent can be obtained when NaY zeolite is ion-exchanged in 0.5 mol/L Ce(NO3)3 solution at 100°C for 4 h, calcined at 700°C for 2 h, and repeated the above steps two times. The results of XRD and BET characterization indicate that those preparation conditions mainly influence on the crystallinity, specific surface area of CeY sorbent. The best CeY sorbent can remove thiophene to 136.8 mg/L from 550.0 mg/L in thiophene-benzene solution at ambient temperature and pressure with the agent-liquid ratio of 1:16 (g/mL). [ABSTRACT FROM AUTHOR]

• The texture properties of hierarchical TS-1 zeolites can be precisely modulated by the TritonX homologues with different amounts of ethoxide. • The mesoporosity and Ti content of hierarchical Ti-rich determine the conversion of benzene. • Introducing additional mesoporosity into the hierarchical TS-1 facilitates the direct the oxidation of benzene. The hydrothermal approach was used to effectively synthesis hierarchical TS-1 utilizing the green and inexpensive surfactant TritonX homologues with varying amounts of ethylene oxide groups. The textural property of obtained materials can be modulated by varying the number of ethylene oxide groups of the TritonX homologues. The mesoporous size of hierarchical TS-1 depends on the micelles size of TritonX homologues. The synthesized samples have significant intracrystalline mesopores with a pore size range of 3.5–4.5 nm. The impact of various ethylene oxide group counts of TritonX homologous on the structure, texture properties, and titanium species was investigated using a variety of characterization methods. The hydroxylation of benzene with the H 2 O 2 as oxidizer was used to investigate the catalytic properties of hierarchical TS-1. The catalytic properties and stability of the resulting materials were noticeably improved in the hydroxylation of benzene in comparison with the traditional TS-1. [Display omitted] [ABSTRACT FROM AUTHOR]