Cleaner Fuel Production via Co-Processing of Vacuum Gas Oil with Rapeseed Oil Using a Novel NiW/Acid-Modified Phonolite Catalyst

Clean biofuels are a helpful tool to comply with strict emission standards. The co-processing approach seems to be a compromise solution, allowing the processing of partially bio-based feedstock by utilizing existing units, overcoming the need for high investment in new infrastructures. We performed a model co-processing experiment using vacuum gas oil (VGO) mixed with different contents (0%, 30%, 50%, 70%, 90%, and 100%) of rapeseed oil (RSO), utilizing a nickel–tungsten sulfide catalyst supported on acid-modified phonolite. The experiments were performed using a fixed-bed flow reactor at 420 °C, a hydrogen pressure of 18 MPa, and a weight hourly space velocity (WHSV) of 3 h−1. Surprisingly, the catalyst stayed active despite rising oxygen levels in the feedstock. In the liquid products, the raw diesel (180–360 °C) and jet fuel (120–290 °C) fraction concentrations increased together with increasing RSO share in the feedstock. The sulfur content was lower than 200 ppm for all the products collected using feedstocks with an RSO share of up to 50%. However, for all the products gained from the feedstock with an RSO share of ≥50%, the sulfur level was above the threshold of 200 ppm. The catalyst shifted its functionality from hydrodesulfurization to (hydro)decarboxylation when there was a higher ratio of RSO than VGO content in the feedstock, which seems to be confirmed by gas analysis where increased CO2 content was found after the change to feedstocks containing 50% or more RSO. According to the results, NiW/acid-modified phonolite is a suitable catalyst for the processing of feedstocks with high triglyceride content.

The effect of process parameters on catalytic direct CO2 hydrogenation to methanol

The direct CO2 hydrogenation to methanol is an attractive route to actively remove CO2 and to promote sustainable development. Herein, the performance of Cu-Zn-Mn catalyst supported on mesoporous silica KIT-6 (hereafter, CZM/KIT-6) for methanol synthesis by direct CO2 hydrogenation reaction was investigated by varying the process parameters, which included the weight-hourly space velocity, reaction temperature and reaction pressure. The CO2 conversion was found to decrease with the increase of WHSV. On the other hand, CO2 conversion increased with reaction temperature and pressure. Meanwhile, the methanol selectivity increased with WHSV and reaction pressure but decreased with the increase of reaction temperature. The apparent activation energy of methanol production at low reaction temperature (160 - 220 °C) was 10 kcal/mol. Non-Arrhenius behaviour of methanol formation was observed at high reaction temperature (220 - 260 °C). The performance of CZM/KIT-6 was maintained at high level, with the average methanol yield of 24.4 %, throughout the stability experiment (120-hour time-on-stream). In post-reaction XRD analysis, the copper crystallite growth was found to be 53.5 %, thus, resulting in 35.3 % loss of copper surface area.

A Study into the γ-Al2O3 Binder Influence on Nano-H-ZSM-5 via Scaled-Up Laboratory Methanol-To-Hydrocarbon Reaction

Development of a laboratory selected zeolite into an industrial zeolite-based catalyst faces many challenges due to the scaling-up of reaction which requires many upgrades of the as-prepared catalyst such as an enhanced physical strength. To meet this requirement zeolite powders are normally mixed with various binders and then shaped into bulky bodies. Despite the fact there are a lot of reports on the positive features brought by the shaping treatment, there is still a great need to further explore the zeolite properties after the binder introduction. In this case, a lot of studies have been continuously conducted, however, many results were limited due to the usage of much smaller laboratory samples rather than a real factory plant, and more importantly, the maximal/minimal proportion of zeolites in the shaped catalyst. In this research, our shaped catalysts are based on nano-H-ZSM-5 zeolites and alumina (γ–Al2O3) binder while keeping the zeolite content to a maximum. H-ZSM-5 samples and Al-H-ZSM-5 samples are compared in the designed methanol-to-hydrocarbons reaction. With a reduced weight-hourly-space-velocity (WHSV = 1.5 h−1) and a higher reaction pressure (6 bar) favorable for aromatization, together with the tailored instruments for catalyst volume scale-up (20 g samples are tested each time), our tests focus on the early period catalytic performance (during the first 5 h). Unlike a normal laboratory test, the results from the scaled-up experiments provide important guidance for a potential industrial application. The role of the γ–Al2O3 introduced, not only as binder, but also performing as co-catalyst, on tailoring the early time product distribution, and the corresponding coke deposition is systematically investigated and discussed in details. Notably, the Si/Al ratio of H-ZSM-5 still has a decisive influence on the reaction performance of the Al-H-ZSM-5 samples.

Influence of Pressure on Product Composition and Hydrogen Consumption in Hydrotreating of Gas Oil and Rapeseed Oil Blends over a NiMo Catalyst

This study describes the co-hydrotreating of mixtures of rapeseed oil (0–20 wt%) with a petroleum feedstock consisting of 90 wt% of straight run gas oil and 10 wt% of light cycle oil. The hydrotreating was carried out in a laboratory flow reactor using a sulfided NiMo/Al2O3 catalyst at a temperature of 345 °C, the pressure of 4.0 and 8.0 MPa, a weight hourly space velocity of 1.0 h−1 and hydrogen to feedstock ratio of 230 m3∙m−3. All the liquid products met the EU diesel fuel specifications for the sulfur content (<10 mg∙kg−1). The content of aromatics in the products was very low due to the high hydrogenation activity of the catalyst and the total conversion of the rapeseed oil into saturated hydrocarbons. The addition of a depressant did not affect the cold filter plugging point of the products. The larger content of n-C17 than n-C18 alkanes suggested that the hydrodecarboxylation and hydrodecarbonylation reactions were preferred over the hydrodeoxygenation of the rapeseed oil. The hydrogen consumption increased with increasing pressure and the hydrogen consumption for the rapeseed oil conversion was higher when compared to the hydrotreating of the petroleum feedstock.

The Effect of the Reaction Conditions on the Properties of Products from Co-hydrotreating of Rapeseed Oil and Petroleum Middle Distillates

This study compares the hydrotreating of the mixture of petroleum middle distillates and the same mixture containing 20 wt % of rapeseed oil. We also study the effect of the temperature and the weight hourly space velocity (WHSV) on the co-hydrotreating of gas oil and rapeseed oil mixture. The hydrotreating is performed over a commercial hydrotreating Ni-Mo/Al2O3 catalyst at temperatures of ca. 320, 330, 340, and 350 °C with a WHSV of 0.5, 1.0, 1.5, and 2.0 h−1 under a pressure of 4 MPa and at a constant hydrogen flow of 28 dm3·h−1. The total conversion of the rapeseed oil is achieved under all the tested reaction conditions. The content of the aromatic hydrocarbons in the products reached a minimum at the lowest reaction temperature and WHSV. The content of sulphur in the products did not exceed 10 mg∙kg−1 at the reaction temperature of 350 °C and a WHSV of 1.0 h−1 and WHSV of 0.5 h−1 regardless of the reaction temperature. Our results show that in the hydrotreating of the feedstock containing rapeseed oil, a large amount of hydrogen is consumed for the dearomatisation of the fossil part and the saturation of the double bonds in the rapeseed oil and its hydrodeoxygenation.

Effects of operating parameters for dry reforming of methane: A short review

Dry reforming of methane (DRM) which also known as CO2 reforming of methane is a well-investigated reaction to serve as an alternative technique to attenuate the abundance of greenhouse gases (CO2 and CH4). The syngas yielded is the main component for the liquid fuels and chemicals production in parallel with the fluctuating price of oil. Major researches were executed to seek for the well-suited catalysts before the commercialization of DRM can be realized. However, severe deactivation due to the carbon formation restricted the usage of promising Ni-based catalysts for DRM. Meanwhile, the deactivation on these catalysts can be associated with the operating conditions of DRM, which subsequently promoted the secondary reactions at different operating conditions. In fact, the parametric study could provide a benchmark for better understanding of the fundamental steps embodied in the CH4 and CO2 activation as well as their conversions. This review explores on the influences of the reaction operating parameters in term of the reaction temperatures, reactant partial pressures, feed ratios, and weight hourly space velocity (WHSV) on catalytic performance and carbon accumulation for the DRM.

Vapor-Phase Furfural Decarbonylation over a High-Performance Catalyst of 1%Pt/SBA-15

A high-performance Pt catalyst supported on SBA-15 was developed for furfural decarbonylation. Compared to Pt catalysts loaded on microporous DeAl-Hbeta zeolite and hierarchical micro-mesoporous MFI nanosheet (NS) materials, the 1%Pt/SBA-15 catalyst afforded notably higher activity, furan selectivity and stability owing to the negligible acid sites and proper mesopores on the SBA-15 support. Among a set of 1%Pt/SBA-15 catalysts bearing Pt nanoparticles (NPs) with sizes of 2.4–4.3 nm, the catalyst with 3.7 nm Pt NPs afforded the highest furan selectivity. Over the optimal catalyst, 88.6% furan selectivity and ca. 90% furfural conversion were obtained at 573 K and a high weight hourly space velocity (WHSV) of 16.5 h−1. Moreover, the reaction temperatures at 440–573 K and the ratios of H2 to furfural at 0.79–9.44 did not affect the reaction selectivity notably, showing that the reaction over 1%Pt/SBA-15 can be conducted over a wide range of conditions. The catalyst was stable under the harsh reaction conditions and lasted for 90 h without significant deactivation, demonstrating the superior property of SBA-15 as a catalyst support for furfural decarbonylation.

Noble Metals-Based Catalysts for Hydrogen Production via Bioethanol Reforming in a Fluidized Bed Reactor

In this work, Pt-Ni/CeO2-SiO2, as well as Ru-Ni/CeO2-SiO2 catalysts, were obtained at different loadings of the noble metal (in the interval 0–3 wt%) and tested for oxidative steam reforming of ethanol. Stability performance was evaluated at 500 °C for 25 h under a steam to ethanol ratio of 4 and an oxygen to ethanol ratio of 0.5. The weight hourly space velocity was fixed to 60 h−1, which is considerably higher than the typical values selected for such processes. All the catalysts deactivated with time-on-stream, due to the severe operative conditions selected. However, the highest ethanol conversion (above 95%) and hydrogen yield (30%) at the end of the test were recorded over the 2 wt%Pt-10 wt%Ni/CeO2-SiO2 catalyst, which also displayed a limited carbon formation rate (1.5 × 10−6 gcoke·gcatalyst−1·gcarbon,fed−1·h−1, reduced almost 5 times compared to the samples that had a Pt or Ru content of 0.5 wt%). Thus, the latter catalyst was identified as a promising candidate for future tests under real bioethanol mixture.

Total Oxidation of Toluene and Propane over Co3O4 Catalysts: Influence of Precipitating pH and Washing

A series of Co3O4 catalysts were synthesized by an ammonia precipitation method at various precipitating pH values (8.0, 8.5, 9.0, 9.5, and 10.0) and with different numbers of washings. Their performance in the total oxidation of two selected hydrocarbons, toluene and propane, was evaluated at a reactant/oxygen molar ratio of 1/210 and a Weight Hourly Space Velocity (WHSV) of 40,000 mL g−1 h−1. The physicochemical properties of the catalysts were characterized by thermogravimetric and differential thermal analysis (TG/DTA), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and N2 absorption–desorption. The results show that the catalysts are in the cubic spinel phase (Fd-3m (227), a = 8.0840 Å) with average crystalline sizes of 29−40 nm and specific surface areas of 12–20 m2 g−1. All catalysts allowed 100% conversion of both toluene and propane at temperatures below 350 °C. The precipitating pH and the number of washings were observed to significantly affect the catalytic performance. The optimal synthesis condition was established to be pH 8.5 with two washings. The best catalyst gave 100% conversion of toluene and propane at 306 °C and 268 °C, respectively.

Synthesis of Highly Selective and Stable Co-Cr/SAPO-34 Catalyst for the Catalytic Dehydration of Ethanol to Ethylene

In this study, silicoaluminophosphate (SAPO)-34 and Me (Me = Cr, Co)-modified SAPO-34 were synthesized and used as catalysts to investigate the catalytic performance by means of a probe reaction from ethanol to ethylene. The metal oxides were loaded on the SAPO-34 support via an impregnation method. The synthesized catalysts were characterized using XRD, SEM, EDX, FT-IR, NH3-TPD, BET, and TGA techniques. Compared to SAPO-34, SAPO-34 doped with metal oxides showed the same chabazite (CHA) topology. The structure and properties of the catalyst were further optimized by varying the amount of Me. The experimental results showed that Co-Cr/SAPO-34 exhibited the best catalytic performance when the reaction temperature reached 400 °C at a weight hourly space velocity (WHSV) of 3.5 h−1, for which the single-pass conversion of ethanol was determined as 99.15%, and the selectivity of ethylene was 99.4% at an optimum catalytic performance in the reaction of up to 600 min. In addition, Co-Cr/SAPO-34 exhibited better catalytic activity and anti-coking ability than pure SAPO-34, which was attributed to its enhanced pore structure and moderate acidity. It can also be concluded from the results of this experiment that the performance of the Co-Cr bimetal-supported catalyst is better than that of the Cr mono-metal catalyst.