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A series of ZSM-5@MCM-41 core–shell composite materials prepared via a multi-cycle-sol–gel coating strategy is investigated as the catalyst for benzene alkylation with ethylene, in which both ethylbenzene and para-diethylbenzene (p-DEB) are aimed as the target products. With multi-cycle-sol–gel coating, the external acid sites on the samples are gradually passivated by the inert MCM-41 shell. As a result, the shape selectivity to p-DEB is greatly enhanced. Nevertheless, the coating of mesoporous MCM-41 shell on ZSM-5 accelerates deactivation of the catalyst only due to the dilution effect of ZSM-5 content in the catalyst at the same space velocity, which is a reason that core–shell ZSM-5@MCM-41 will potentially be a practical catalyst in shape selective alkylation of benzene. In order to enhance the yield of p-DEB on ZSM-5@MCM-41, the reaction conditions at the fixed bed reactor including temperature, the molar rate of benzene to ethylene and GHSV, are also optimized.

Hierarchical ZSM-5 zeolite with radial mesopores is controllably synthesized using piperidine in a NaOH solution. The piperidine molecules enter the zeolite micropores and protect the zeolite framework from extensive desilication. The areas containing fewer aluminum atoms contain fewer piperidine protectant molecules and so they dissolve first. Small amounts of mesopores are then gradually generated in areas with more aluminum atoms and more piperidine protectant. In this manner, radial mesopores are formed in the ZSM-5 zeolite with a maximal preservation of the micropores and active sites. The optimal hierarchical ZSM-5 zeolite, prepared with a molar ratio of piperidine to zeolite of 0.03, had a mesopore surface area of 136 m2·g−1 and a solid yield of 80%. The incorporation of the radial mesopores results in micropores that are interconnected which shortened the average diffusion path length. Compared to the parent zeolite, the hierarchical ZSM-5 zeolite possesses more accessible acid sites and has a higher catalytic activity and a longer lifetime for the alkylation of benzene.

A kind of shaped core-shell structured binder-free ZSM-5 catalyst is prepared by re-crystallization method, from a shaped mixture of ZSM-5 zeolite and pure silica source as a binder. According to the characterization results, it is found that the silica shell, surrounding the ZSM-5 core in the shaped mixture, can be converted into ZSM-5 zeolite phase under the hydrothermal conditions with vapor-solid phase method. In this way, the catalyst with core-shell zeolite structure is consequently formed. The prepared binder-free ZSM-5 catalyst has more micro-pores than the ordinary shaped zeolite with a binder. In addition, its acidity is weakened because of the migration of framework aluminum towards the outer shell layer of ZSM-5 crystals. When applied to the vapor-phase benzene alkylation with ethylene, this catalyst shows an enhanced stability and selectivity compared to the ordinary shaped catalyst. Specially, xylene, a critical by-product formed by side reactions, is greatly suppressed over the shaped core-shell structured binder-free catalyst. In view of its good mechanical strength as well as its extended lifetime, the shaped core-shell structured binder-free ZSM-5 catalyst will be valuable in the practical industrial ethylbenzene production.

Almost all the oil and gas reservoirs developed in marine sedimentary strata of China have undergone processes of multi-phase reservoir formation and later modification. The irregular reservoirs are classified into three types as the Naxi, Tahe and Renqiu ones, increasing successively in the development degree of karstificated pores and fissures and the connection degree of independent reservoirs. In these reservoirs, the unity in the fluid feature, pressure and oil-gas-water interface also increases successively from the Naxi to the Renqiu type. The main body of Ordovician reservoirs of the Tahe Oilfield in the Tarim Basin is a network pool rather than a stratified, massive, stratigraphically-unconformed or weathering-crust one. The fluid nature of oil, gas and water, the interface positions and the pressures, as well as the dynamic conditions of fluids within the reservoirs during the production are all different from those in stratified or massive oil and gas reservoirs. Carbonates in the Akekule uplift and the Tahe Oilfield are assemblages of various types of reservoirs, which have an overall oil-bearing potential and obvious uneven distribution. Testing and producing tests are the major means to evaluate this type of reservoirs and acid fracturing improvement is a key link in petroleum exploration and development.

Based on the analytical data of gas components, carbon and helium isotopes from more than fifty samples, three major types of (hot) spring gases in eastern China are identified. Type I is dominated by carbon dioxide with higher δ13CCO2 values ( > − 7‰ PDM ), and originates from volcanic magma or a mixture of magma and carbonate metamorphism. Type II is dominated by nitrogen and is related to meteoric waters. Type III is dominated by methane (CH4) with lower δ13C1 values (−53.1‰ to − 65.1‰ PDB) and is principally a biogenic gas.