New Adsorption Materials for Deep Desulfurization of Fuel Oil.

In recent years, due to the rapid growth of mankind's demand for energy, harmful gases (SOx) produced by the combustion of sulfur-containing compounds in fuel oil have caused serious problems to the ecological environment and human health. Therefore, in order to solve this hidden danger from the source, countries around the world have created increasingly strict standards for the sulfur content in fuel. Adsorption desulfurization technology has attracted wide attention due to its advantages of energy saving and low operating cost. This paper reviewed the latest research progress on various porous adsorption materials. The future challenges and research directions of adsorption materials to meet the needs of clean fuels are proposed.

Features of Wax Appearance Temperature Determination of Waxy Crude Oil Using Attenuated Total Reflection Fourier Transform Infrared Spectroscopy Under Ambient and High Pressure.

The wax appearance temperature (WAT), being one of the key characteristics of waxy crude oil and other waxy substances, is used for the necessary assessment of the phase stability of materials during various technological processes. However, the determination of this parameter as well as peculiarities of wax formation under high gas pressure suffers from the lack of suitable techniques for this task. To address this issue, an attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR) method has been applied for the first time to measure the WAT of waxy crude oil under high gas pressure. Carbon dioxide (CO2), nitrogen, and natural gas were used in the study due to their widespread applicability as injection gases in enhanced oil recovery methods. The S2/S1 versus temperature method based on changes in the band of rocking vibrations of the CH2 group was applied to determine WAT. It was found that the ATR FT-IR method based on the proposed dependence S2/S1 versus temperature gives lower WAT values compared to those observed by viscometry, magnetic resonance imaging inspection, and cross-polarized microscopy methods for the waxy crude oil studied. A detailed analysis was carried out using variable-temperature ATR FT-IR spectra of waxy crude oil in the temperature region near the WAT. Essentially different dynamics of wax crystal formation in waxy oil sample and model paraffin solution were demonstrated during the cooling process. The results obtained by high-pressure ATR FT-IR showed that CO2 and natural gas reduce the WAT, while nitrogen has virtually no effect. In addition, for the studied oil, it was found that high pressure of CO2 and natural gases leads to a visual decrease in the amount of wax crystals precipitated, but not to the complete disappearance of microcrystals at a certain temperature and pressure. The results obtained proved that ATR FT-IR can be an effective method for proper determinations of WAT under high-pressure conditions similar to those met in practice.

Efficient Diesel Desulfurization by Novel Amphiphilic Polyoxometalate-Based Hybrid Catalyst at Room Temperature.

Amphiphilic hybrid catalysts were prepared by modifying [SMo12O40]2- with tetrabutylammonium bromide (TBAB), 1-butyl-3-methylimidazole bromide (BMIMBr) and octadecyl trimethyl ammonium bromide (ODAB), respectively. The prepared catalysts were characterized by IR, XRD, SEM, TG and XPS. The desulfurization performance of the catalysts was investigated in model oil and actual diesel using hydrogen peroxide (H2O2) as an oxidant and acetonitrile as an extractant. All catalysts exhibited favorable activity for removing sulfur compounds at room temperature. Dibenzothiophene (DBT) can be nearly completely removed using SMo12O402--organic catalysts within a short reaction time. For different sulfur compounds, the [TBA]2SMo12O40 catalyst showed a better removal effect than the [BMIM]2SMo12O40 and [ODA]2SMo12O40 catalyst. The [TBA]2SMo12O40 dissolved in extraction solvent could be reused up to five times in an oxidative desulfurization (ODS) cycle with no significant loss of activity. The [BMIM]2SMo12O40 performed as a heterogeneous catalyst able to be recycled from the ODS system and maintained excellent catalytic activity. The catalysts showed a positive desulfurization effect in real diesel treatment. Finally, we described the ODS desulfurization mechanism of DBT using SMo12O402--organic hybrid catalysts. The amphiphilic hybrid catalyst cation captures DBT, while SMo12O402- reacts with the oxidant H2O2 to produce peroxy-active species. DBT can be oxidized to its sulfone by the action of peroxy-active species to achieve ODS desulfurization.

Ultrasonic Auxiliary Ozone Oxidation-Extraction Desulfurization: A Highly Efficient and Stable Process for Ultra-Deep Desulfurization.

For ultra-deep desulfurization of diesel fuel, this study applied the ultrasound-assisted catalytic ozonation process to the dibenzothiophene (DBT) removal process with four Keggin-type heteropolyacids (HPA) as catalysts and acetonitrile as extractant. Through experimental evaluations, H3PMo12O40 was found to be the most effective catalyst for the oxidative removal of DBT. Under favorable operating conditions with a temperature of 0 °C, H3PMo12O40 dosage of 2.5 wt.% of n-octane, and ultrasonic irradiation, DBT can be effectively removed from simulated diesel. Moreover, the reused catalyst exhibited good catalytic activity in recovery experiments. This desulfurization process has high potential for ultra-deep desulfurization of diesel.

Hydrodeoxygenation of 2,5-dimethyltetrahydrofuran over bifunctional Pt-Cs2.5H0.5PW12O40 catalyst in the gas phase: enhancing effect of gold.

2,5-Dimethyltetrahydrofuran (DMTHF) is deoxygenated to n-hexane with >99% selectivity at mild conditions (90 °C, 1 bar H2 pressure, fixed-bed reactor) in the presence of the bifunctional metal-acid catalyst Pt-CsPW comprising Pt and Cs2.5H0.5PW12O40 (CsPW), an acidic Cs salt of Keggin-type heteropoly acid H3PW12O40. Addition of gold to the Pt-CsPW catalyst increases the turnover rate at Pt sites more than twofold, whereas the Au alone without Pt is not active. The enhancement of catalyst activity is attributed to PtAu alloying, which is supported by STEM-EDX and XRD analysis.

Diethyl Ether Conversion to Ethene and Ethanol Catalyzed by Heteropoly Acids.

The conversion of diethyl ether (DEE) to ethene and ethanol was studied at a gas-solid interface over bulk and supported Brønsted solid acid catalysts based on tungsten Keggin heteropoly acids (HPAs) at 130-250 °C and ambient pressure. The yield of ethene increased with increasing reaction temperature and reached 98% at 220-250 °C (WHSV = 2.2 h-1). The most active HPA catalysts were silica-supported H3PW12O40 and H4SiW12O40 and the bulk heteropoly salt Cs2.5H0.5PW12O40. The HPA catalysts outperformed zeolites HZSM-5 and USY reported elsewhere. A correlation between catalyst activity and catalyst acid strength was established, which indicates that Brønsted acid sites play an important role in DEE elimination over HPA catalysts. The results point to the reaction occurring through the consecutive reaction pathway: DEE → C2H4 + EtOH followed by EtOH → C2H4 + H2O, where ethene is both a primary product of DEE elimination and a secondary product via dehydration of the primary product EtOH. Evidence is provided that DEE elimination over bulk HPA and high-loaded HPA/SiO2 catalysts proceeds via the surface-type mechanism.

Facile gas-phase hydrodeoxygenation of 2,5-dimethylfuran over bifunctional metal-acid catalyst Pt-Cs2.5H0.5PW12O40.

2,5-Dimethylfuran is deoxygenated to n-hexane with 100% yield on a bifunctional Pt/C-Cs2.5H0.5PW12O40 catalyst under very mild conditions (90 °C, 1 bar H2) in a one-step gas-phase process. A proposed mechanism includes a sequence of hydrogenolysis, hydrogenation and dehydration steps occurring on Pt and proton sites of the bifunctional catalyst.

One-pot synthesis of sorbitol via hydrolysis-hydrogenation of cellulose in the presence of Ru-containing composites.

The aim of this work was to study the one-pot synthesis of sorbitol via hydrolysis-hydrogenation of cellulose in the presence of Ru-containing composites based on H3PW12O40 supported on ZrO2 and Nb2O5 (Ru-PW/ZrO2 and Ru-PW/Nb2O5). The main parameters impacted the reaction rate and yield of sorbitol, i.e. reaction conditions and type of catalyst were investigated. Ru-PW/ZrO2 systems were more active than Ru-PW/Nb2O5. The yield of sorbitol was found to depend on the activation temperature of PW/ZrO2 and PW/Nb2O5 which affected textural properties, the amount of acid sites and size of Ru nanoparticles. The highest 66% sorbitol yield was observed in the presence of 3%Ru-PW/ZrO2 activated at 550 °C and 1/1 of weight ratio of cellulose/catalyst, 180 °C, 7 MPa hydrogen pressure. This catalyst was stable for three cycles of the reaction without lost of it's activity.

Efficient hydrodeoxygenation of biomass-derived ketones over bifunctional Pt-polyoxometalate catalyst.

Acidic heteropoly salt Cs(2.5)H(0.5)PW(12)O(40) doped with Pt nanoparticles is a highly active and selective catalyst for one-step hydrogenation of methyl isobutyl and diisobutyl ketones to the corresponding alkanes in the gas phase at 100 °C with 97-99% yield via metal-acid bifunctional catalysis.

Multifunctional catalysis by Pd-polyoxometalate: one-step conversion of acetone to methyl isobutyl ketone.

Pd metal supported on Cs2.5H0.5PW12O40 is an efficient bifunctional catalyst for the one-step conversion of acetone to methyl isobutyl ketone in gas and liquid phase.

Highly efficient liquid-phase oxidation of primary alcohols to aldehydes with oxygen catalysed by Ru-Co oxide.

RuIV-CoIII (1:1.5) binary oxide, prepared by co-precipitation, is a highly efficient solid catalyst for the oxidation of primary alcohols to aldehydes with O2 (76-95% selectivity at 54-100% conversion) in a liquid phase under atmospheric pressure.

Polyoxometalate-catalysed epoxidation of 1-octene with hydrogen peroxide in microemulsions coupled with ultrafiltration.

Epoxidation of 1-octene with hydrogen peroxide catalysed by amphiphilic salts of peroxo tungstophosphate [PO4[WO(O2)2]4]3- in water-in-oil microemulsions is an efficient and environmentally benign reaction which, coupled with ultrafiltration, shows the potential for continuous production of epoxides.

Heteropoly acid as a novel efficient catalyst for Fries rearrangement.

Heteropoly acid H3PW12O40 is a very efficient and environmentally benign catalyst for the Fries rearrangement of phenyl acetate in homogeneous or heterogeneous liquid-phase systems at 100-150 degrees C.