Zeolites Y were modified by ion-exchange method, and their structural properties were examined using N2 adsorption, Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and chemical composition analysis. The dynamic adsorption of methyl mercaptan (CH3SH) on different ion-exchanged zeolites Y was conducted on a fixed-bed adsorption column. The effects of gas hourly space velocity, operation temperature, and composition of the feed gas on the performance of CH3SH adsorption on ion-exchanged zeolites Y were studied carefully. Furthermore, the adsorption mechanism for CH3SH and CO2 adsorption on ion-exchanged zeolites was revealed by using density functional theory (DFT) calculation methods. Among all the ion-exchanged samples, Cu–Y holds the highest CH3SH breakthrough adsorption capacity, q, of up to 70 mg/g. When using natural gas containing 4% CO2 as the feed, q of Cu–Y was slightly reduced to 64 mg/g. The DFT calculation results indicate that the S–M bond is formed between CH3SH and Cu2+ during CH3SH adsorption, which benefits the adsorption of CH3SH on Cu–Y zeolite. Moreover, the DFT calculation suggests the weak Cu–O bonding interaction formed in the adsorption of CO2 on Cu–Y, the interaction of which releases much less energy compared with CH3SH adsorption. The CH3SH-saturated Cu–Y sample can be regenerated by thermal treatment under air atmosphere at 350 °C. After six adsorption–regeneration cycles, the regenerated Cu–Y shows q of 55 mg/g, which is 21.4% lower than that of the fresh sample.

Conversion of chloromethane to olefins over SAPO-34 and HZSM-22 catalysts has been investigated at various temperatures. SAPO-34 showed higher activity and better stability than HZSM-22 catalyst. Ethylene and propylene were the main products over SAPO-34, whereas the main products over HZSM-22 were propylene, butylene, and C5+ alkanes in this conversion. Polymethylated benzenes and methylnaphthalene were the main components of coke species confined in the spent SAPO-34 catalyst. However, long-chain alkanes were the main species trapped in the spent HZSM-22 catalyst in the initial period, and many polymethylated benzenes emerged with growing time on stream. The differences in selectivity and coke species from both spent catalysts suggested that the conversion of chloromethane to olefins was greatly influenced by the topology structure of zeolite catalyst and that olefin methylation and cracking might be an important route followed over the HZSM-22 catalyst.

A series of ion-exchanged zeolites Y were prepared by postsynthesis method and characterized using multiple techniques including XRD, N2 adsorption, XPS, FTIR, and chemical composition analysis. The adsorption of carbon disulfide (CS2) on ion-exchanged zeolites Y was investigated by dynamic adsorption tests carried out at a fixed-bed adsorption unit coupled with density functional theory (DFT) computation. The effects of metal ions, gas hourly space velocity (GHSV), and operation temperature on the adsorption capacities of CS2 on ion-exchanged samples were studied carefully. In addition, the mechanism for CS2 adsorption on zeolite Y was discussed. Among all the ion-exchanged samples, Ag–Y zeolite holds the highest CS2 breakthrough adsorption capacity up to 44.8 mg/g. The XPS analysis indicates that Ag+ was introduced into the zeolite Y structure. The DFT study indicates that the S–M (σ) bond involving CS2 and Ag+ was formed, which strengthens the S–Ag interaction and, therefore, benefits the adsorption of CS2 on Ag–Y zeolite. The used Ag–Y zeolite can be regenerated by thermal treatment at 400 °C under an air atmosphere. After seven adsorption–regeneration cycles, the used Ag–Y maintains the adsorption capacity of 37.6 mg/g.

The conversion of chloromethane to light olefins over SAPO-34 modified with metal chloride has been investigated. The results show that the acid and the ratio of the strong acid density to the weak acid density can be regulated through modification with different metal chlorides. SAPO-34 modified with metal chloride showed a higher activity and better stability than SAPO-34, and the sample modified with FeCl3 presented the best stability among all of the investigated metal chlorides. The differences in catalytic behaviors among the samples modified with different metal chlorides suggest that the conversion of chloromethane to olefins is strongly influenced by the total acid density and the ratio of the strong acid density to the weak acid density. Coke formation and hydrogen transfer were alleviated over the samples modified with FeCl3, because of their lower total acid density and ratio of strong acid density to weak acid density compared to SAPO-34.

•DMDS adsorption isotherm onto ZSM-5 can be interpreted by Langmuir model.•DMDS adsorption onto ZSM-5 zeolite takes place through physical interaction and degree of freedom decrease.•The DMDS adsorption kinetic can be modeled by pseudo-first-order equation.•ZSM-5 can remove all the sulfur component in MTBE efficiently in the dynamic adsorption experiment until breakthrough at 35 min.The adsorption of dimethyl disulfide (DMDS) onto ZSM-5 zeolite from methyl tert-butyl ether (MTBE) solution was investigated in the aspects of adsorption equilibrium and kinetics. Factors that influence adsorption process including time, temperature and initial concentration have been investigated carefully. The adsorption kinetics data could be described by pseudo-first-order very well. The Langmuir equation could be used to interpret the adsorption isotherm and the thermodynamic parameters were derived from the Langmuir constant (kL). The minus values of enthalpy and Gibbs free energy of adsorption indicate that the adsorption of DMDS on ZSM-5 is exothermic and spontaneous. Adsorption breakthrough curve was found to be typically S-shape.

A series of ZSM-5 zeolites were prepared through a chemical liquid deposition (CLD) method and used for adsorption removal of dimethyl disulfide (DMDS) from methyl tert-butyl ether (MTBE). The structural properties and acidity were characterized, and the proper deposition amount and calcination temperature have been accessed. N2 adsorption test and X-ray photoelectron spectroscopy (XPS) results show that methylsilicone oil is deposited on the external surface and narrows the pore size of the zeolite. NH3-temperature-programmed desorption (NH3-TPD) and modified Hammett indicator titration results indicate that the acid sites on the external surface are eliminated while acid sites in the channel are not influenced significantly. Both the pore structure and acidity play important roles in determining the sulfide adsorption process. The optimal modification condition was found as a deposition amount of 30% and a calcination temperature of 500 °C. Adsorption isotherms were also conducted in both parent and CLD-modified ZSM-5 adsorbents. The DMDS adsorption capacity of CLD-modified adsorbent is 8.24 mg/g, which is almost 6 times higher than that of the parent ZSM-5 sample.

Based on the investigation on nonbonded interactions between solvent and organosulfur molecules, the reaction kinetics of carbonyl sulfide (COS) with chemical solvents in aqueous solutions, and experimental validation, a hybrid solvent (named UDS-2) was designed to simultaneously remove H2S and organosulfurs from sour natural gas at high removal efficiency. The solvent components, which could enhance physical and chemical absorption of methyl mercaptan and COS, were screened using quantum chemistry method coupled with kinetics analysis. The results show that the five-membered sulfur heterocyclic compound (SUL) exhibits significant advantage of physical solubility of methyl mercaptan and COS. Meanwhile, the cyclic amine (CA) with weak steric hindrance effect as well as moderate basicity could enhance chemical removal of COS. UDS-2 solvent was obtained by blending SUL and CA with N-methyldiethanolamine (MDEA) at optimal proportion, and the removal efficiencies for methyl mercaptan, COS, and total organosulfur of UDS-2 were 53.1, 23.9, and 42.4 percentage points higher than those of MDEA. UDS-2 was successfully applied in a natural gas purification plant. Under the operation conditions of absorption pressure of 5.5 MPa, gas flow rate of 8.48 × 103 N m3/h, gas–liquid ratios of 240 in absorber-I and 471 in absorber-II, the removal efficiencies for methyl mercaptan, COS, and total organosulfur are 77.6%, 74.5% and 75.6%, respectively. The contents of H2S, CO2, and total sulfur in purified gas can be reduced below 0.7 mg/(N m3), 0.16 vol % and 43.5 mg/(N m3), respectively, which all met the corresponding specification for Chinese first-grade commercial natural gas. Additionally, the low hydrocarbon loss of 1.34 N m3/(N m3 solution) indicates UDS-2 solvent has good selectivity for sulfur compounds over hydrocarbons.

A Mg-rich Mg–Al spinel modified with CuO and CeO2 via a cogelling method was used to remove SO2 from fluid catalytic cracking (FCC) flue gas. It was found that the generation of a MgO–CuO solid solution was prevented in the presence of CeO2. So CuO had a better dispersion on the adsorbent surface and showed a better catalytic oxidation activity. At the same time, when CuO was added, oxygen defects were found increased greatly in the lattice of CeO2 by Raman spectra and in situ FTIR spectra analyses. This improved the oxygen adsorption capacity of the catalyst. High catalytic oxidation activity and oxygen adsorption capacity of the catalyst enormously promote oxidation of SO2 to SO3, which is much easier to adsorbed by spinel. The SO2 breakthrough time was doubled when the Mg–Al spinel was modified with both CuO and CeO2.

Hierarchical SAPO-34 molecular sieve was successfully synthesized by hydrothermal crystallization method with cetyltrimethyl ammonium bromide as mesoporous generating agent. The influence of different addition amounts of CTAB on the crystalline structures, morphology features, textural properties and acidity of hierarchical SAPO-34 catalysts were characterized by XRD, SEM, BET and NH3-TPD techniques. The results exhibit that the crystal size, mesoporous structure and the total acid amounts of hierarchical SAPO-34 are affected greatly by the molar ratio of CTAB/Al2O3. The selectivity of light olefins (ethane and propylene) can achieve 80 % for all SAPO-34 samples tested in the conversion of chloromethane to light olefins. Compared with the conventional SAPO-34, the hierarchical SAPO-34 samples show better catalytic stability and less carbon deposit in this conversion due to the reduction in total acid sites and the increasing mesopore volume.

To optimize the ratio of vacuum residua/coal tar (VR/CT) in VR solvent deasphalting processing and catalytic cracking processing, their compatibility and properties are investigated in the present work. The investigation reveals two competitive processes of dissolution and adsorption during the blend process. At low CT blending ratio, the molecule interactions in the VR colloidal system are unchanged. The dissolution is nearly balanced with flocculation, and VR is almost compatible with CT. At high CT blending ratio, the flocculation predominates over dissolution and VR is incompatible with CT. Solvent deasphalting experiments revealed that the supercritical fluid extraction and fractionation process of VR has been improved by blending with CT. Fluid catalytic cracking (FCC) results of this deasphalted oil (DAO) indicated that more light oil can be produced with no obvious increase in the diesel/gasoline ratio. The VR can be upgraded by blending with an appropriate amount of CT (<20%) in the solvent deasphalting–fluid catalytic cracking processes.

A structure-oriented lumping (SOL) model to predict the product distribution of delayed coking was built. The effects of feedstock properties and operational conditions on product distribution were analyzed with the proposed model. It was known from model calculation results that for the feedstock residue of this paper, the liquid yield increased 2.5% on average with a temperature increase of 10 °C, that mainly was equal to a 0.15 increase H/C of feedstock; the liquid yield increased 3.5% on average with a recycle ratio decrease of 0.15, that was mainly equal to a 5% carbon residue decrease of feedstock; and liquid yield increased 0.6% on average with a pressure decrease of 0.03 MPa.

A total of 7004 types of molecular lumps and 92 types of reaction rules were proposed to characterize the feedstock and describe the reaction behaviors of delayed coking. The reaction rate constants were estimated as equations of structure vectors. A reaction kinetic model has been built to predict the products distribution of delayed coking. The good prediction accuracy of the model has been proven by the comparison of calculation results and experimental results of delayed coking.

The effect of the solvent deasphalting (SDA) process of vacuum residue (VR) blending with coal tar (CT) was studied, and the experimental conditions were optimized. The results revealed that the SDA process was improved by blending with coal tar. The yield of deasphalted oil (DAO) from VR blended with 10% CT was 2.02 wt % higher than that obtained from VR alone. The contents of nickel and vanadium decreased by 5%, and the sulfur content also decreased, whereas the contents of carbon residue and nitrogen remained unchanged. Components such as alkanes and low-condensation aromatics were easily extracted into DAO, leading to an increase of its yield and quality. The viscosity and colloid stability of VR declined after being blended with CT. Furthermore, the structures of VR and CT were characterized, and their structural models were proposed. Thus, their solubility parameters were calculated. According to dissolved balance theory, the mechanism of how the blended CT improved the SDA process was analyzed based on the test results of the surface tension of the extraction and the analysis of the average molecular structure parameters of DAO.

Pd catalysts supported on activated carbon, Al2O3 and MgO were prepared, characterized and evaluated in cumene hydroperoxide (CHP) hydrogenation reaction. Pd catalyst supported on Al2O3 showed a better performance both on catalytic activity (CHP conversion, 99.5%; α-cumyl alcohol selectivity, 107.3%) and stability as compared to Pd catalysts supported on activated carbon and MgO. This is attributed to the high surface acidity and fair hydrothermal stability of Al2O3. Changes in support structure and Pd sintering during CHP hydrogenation resulted in the drop of catalytic activity.

More and more acidic crude oil has been exploited in the world. The presence of naphthenic acids in crude oil has a great influence on petroleum refiners. A new method was introduced to separate naphthenic acids from Beijiang highly acidic crude oil in this paper. The 2-methylimidazole solution in ethanol was used as the acid-removal reagent by mixing with the crude oil and then allowing the two phases to separate, with the naphthenic acids being extracted from the crude oil. Data indicated that the optimal content of 2-methylimidazole in ethanol was 20% (w/w) and the optimal extraction time was 10 min, with the reagent/oil ratio being 0.4:1 (w/w). The suitable reaction temperature could be room temperature. The total acid number of the crude oil was lowered from 4.18 to 1.38 mg of KOH/g, and the acid-removal rate could reach up to 67.0%.

A gas oil fraction of a deasphalted vacuum residue, after hydrotreatment, was hydroisomerized in a flow fixed-bed reactor over a commercial catalyst. Liquid products were distilled, on separate occasions, by a simple method for preliminary study and by true boiling point distillation for detailed investigation. Carbon number distributions and hydrocarbon types for various cuts were performed by high temperature GC-MS. It was found that for the light fractions, isoparaffins increased while monocycloalkanes decreased as the boiling point increased. As for the heavy fractions, with the rise in boiling point, each cut had a wider carbon number distribution. Concentrations of monocycloalkanes and isoparaffins in the lube base oil cut had a significant impact on its viscosity index and pour point.

The effect of ferrum-based flux on the melting characteristics of coal ash in coal blends from the Liu-qiao No.2 Coal Mine in Wan-bei (AQ) was investigated. The change of the compositions of mineral under various temperatures before and after adding ferrum-based flux into AQ was studied by XRD and FT-IR. Results show that the presence of mullite formed over 1000°C increases the melting point of coal-ash, leading to high melting temperature of AQ coal-ash. The coal ash fusion temperature will be decreased by adding ferrum-based flux. The eutectic mixtures such as fayalite and hercynite are easily formed between ferrum compounds under high temperature, which remarkably decreases the coal ash fusion temperature.

The deactivation of binderless 5A molecular sieves for the adsorption–separation of normal hydrocarbons was investigated on a fixed-bed adsorber. The deactivated molecular sieves were regenerated by removing the coke deposited through oxidation under various conditions. They showed lower surface area, smaller pore volume, and larger pore diameter than the fresh sample because certain passages of small pore in the molecular sieves were blocked by the coke deposited. With the increase of the coke content in the molecular sieves, the deactivation rate decreased gradually. With the increase of oxidation temperature from 582 K to 787 K, the coke removal efficiency was elevated from 64% to 100%. At 787 K, the coke deposited in the molecular sieves was completely removed and the adsorption activity of the molecular sieves was recovered; however, the surface area and pore volume of the regenerated molecular sieves could not be restored to the original values of the fresh samples. Under 685–884 K, the removal of coke from the binderless 5A molecular sieves by the oxidative treatment could be expressed with a macrokinetic formula: ln(C0/C) = 0.013exp(−28122.1/T) (po2)0.32t.