Gasoline Range Hydrocarbons Research Articles

Effect of acidic properties of hierarchical HZSM-5 on the product distribution in methanol conversion to gasoline

Hierarchical ZSM-5 zeolites with different SiO2/Al2O3 ratio but similar crystal size were directly synthesized by a single-template hydrothermal method, and the intrinsic effect of acidic properties on their catalytic performance in methanol to gasoline (MTG) reaction was comprehensively investigated. The physicochemical properties of HZSM-5 zeolites were characterized by XRD, N2 adsorption-desorption, SEM, NH3-TPD, FTIR, and TGA techniques. The results show good linear correlations between the yields of gasoline components and the relative content of Bronsted acid sites, and the hierarchical HZSM-5 zeolite with SiO2/Al2O3 molar ratio of 200 was firstly found to exhibit high reactivity, excellent product distribution and superior stability in MTG reaction, which can be attributed to its appropriate acid distribution with moderate Bronsted acid sites and proper B/L ratio, predominantly promoting gasoline range hydrocarbons production and inhibiting side reactions.

Hydrothermal preparation of a platinum-loaded sulphated nanozirconia catalyst for the effective conversion of waste low density polyethylene into gasoline-range hydrocarbons.

A platinum-loaded sulphated nanozirconia (Pt/nano ZrO2–SO4) bifunctional metal–acid catalyst was synthesized using a hydrothermal process. The nano ZrO2–SO4 was initially prepared by dispersing the nano ZrO2 in H2SO4, followed by wet impregnation via heating in an aqueous PtCl4 solution. This material was subsequently calcined and reduced under hydrogen gas to produce the catalyst. The Pt/nano ZrO2–SO4 was found to be a highly active, selective and stable solid acid catalyst for the conversion of waste low density polyethylene (LDPE) to high value hydrocarbons. The catalytic activity and stability of this material were evaluated during the hydrocracking of waste LDPE while optimizing the reaction temperature, time and catalyst-to-feed ratio. The activity of catalyst prepared by hydrothermal was attributed to highly dispersion of Pt species interacting with the support and inhibition of the agglomeration process. The impregnation method of hydrothermal generated highly active and selective catalyst with Pt loads of 1 wt%. The hydrocracking of waste LDPE over Pt/nanoZrO2–SO4 at 250 °C for 60 min with a catalyst-to-feed proportion of 1 wt% gave the largest gasoline fraction.

Stable Production of Gasoline-Ranged Hydrocarbons from Dimethyl Ether over Iron-Modified ZSM-22 Zeolite

In this work, we developed metal-modified ZSM-22 zeolites for the application of converting dimethyl ether (DME) to gasoline-ranged hydrocarbons. ZSM-22 zeolite samples were modified by microwave-a...

Methanol to Gasoline Conversion over CuO/ZSM-5 Catalyst Synthesized Using Sonochemistry Method

AbstractIn this research, the catalytic conversion of methanol to gasoline range hydrocarbons has been studied over CuO (5 %)/ZSM-5 and CuO (7 %)/ZSM-5 catalysts prepared via sonochemistry methods. Conversion of methanol to gasoline (MTG) has been carried out in a fixed bed reactor under atmospheric pressure and 400˚C temperature, over copper oxide on the synthesized ZSM-5 catalyst. The samples were characterized by XRD, SEM, TEM, BET, and FTIR techniques; in which good crystallinity and high specific surface area of synthesized zeolite were proved after impregnation of zeolite with copper. The present investigation suggests that the CuO/ZSM-5 catalyst made by sonochemistry method can increase the yield toward hydrocarbon production. It was concluded that impregnation of zeolite with copper oxide can alter the Brønsted/Lewis acid sites ratio and provide new Lewis acid sites over the surface of the ZSM-5. The main products of methanol to gasoline reaction over the catalyst that prepared via sonochemistry method were toluene, xylene, ethylbenzene, ethyl toluene, tetra methylbenzene, diethyl benzene and butylbenzene. The total amount of aromatics in the products was 80 % by using this catalyst. Our results suggest that catalyst synthesized by using sonochemistry shows better production yield toward hydrocarbons by affecting the distribution of active sites on the surface of the ZSM-5.

Production of gasoline range hydrocarbons from catalytic cracking of linoleic acid over various acidic zeolite catalysts.

Employment of edible oils as alternative green fuel for vehicles had raised debates on the sustainability of food supply especially in the third-world countries. The non-edible oil obtained from the abundantly available rubber seeds could mitigate this issue and at the same time reduce the environmental impact. Therefore, this paper investigates the catalytic cracking reaction of a model compound named linoleic acid that is enormously present in the rubber seed oil. Batch-scale experiments were conducted using 8.8mL Inconel batch reactor having a cyclic horizontal swing span of 2cm with a frequency of 60cycles per minute at 450°C under atmospheric condition for 90min. The performance of HZSM-5, HBeta, HFerrierite, HMordenite and HY catalysts was tested for their efficiency in favouring gasoline range hydrocarbons. The compounds present in the organic liquid product were then analysed using GC-MS and classified based on PIONA which stands for paraffin, isoparaffin, olefin, naphthenes and aromatics respectively. The results obtained show that HZSM-5 catalyst favoured gasoline range hydrocarbons that were rich in aromatics compounds and promoted the production of desired isoparaffin. It also gave a higher cracking activity; however, large gaseous as by-products were produced at the same time.

Production of high-octane gasoline via hydrodeoxygenation of sorbitol over palladium-based bimetallic catalysts

A methodology for the synthesis of gasoline-range fuels from carbon neutral resources is introduced. Sorbitol, a sugar-based compound, was employed as a raw material because the compound is readily obtained from cellulose. Gasoline-range hydrocarbons were produced via hydrodeoxygenation (HDO) on zirconium phosphate-supported Pd-bimetallic (Pt−Pd, Ru−Pd, Ni−Pd, Fe−Pd, Co−Pd, W−Pd) catalysts. Among the tested catalysts, the bimetallic W−Pd/ZrP catalyst exhibited the highest yield of gasoline products, peaking at ∼70%. However, with the bimetallic Fe−Pd and Co−Pd catalysts, high-octane gasoline products were made (research octane number (RON) of the products was higher than 100). The Fe−Pd catalyst also showed the highest initial activity for the HDO of sorbitol. This study demonstrates that HDO in the Pd-system is a promising option to produce high-quality gasoline-range hydrocarbons from lignocellulosic biomass.

Cobalt hybrid catalysts in Fischer-Tropsch synthesis

AbstractCurrently, cobalt and zeolites are used in Fischer-Tropsch synthesis (FTS) to produce gasoline-range hydrocarbons (GRHs) that constitute clean and environmentally friendly fuels. This technology has earned a great deal of attention from researchers across the world, as it provides a substitute for fuel derived from fossil crudes, which have hitherto been the sole source of the petrol and diesel required by the industry. However, owing to the depletion of the earth’s oil and coal reserves and the unfavourable environmental impact of conventional fuel production, an alternative source of fuel is needed. This article provides a critical review of the technological challenges involved in producing middle isoparaffins and olefins (gasoline hydrocarbons) by FTS. These involve combining cobalt-based catalysts and zeolites to form hybrid catalysts. In this review, we address most of these by setting out each method of creating cobalt and zeolite hybrid catalysts in turn, so that researchers can identify which applications are most effective for producing GRHs.

Study on the Catalytic Effect of Nitric Acid Activated Myanmar Natural Clay for the Degradation of Plastic Wastes

In this study, the performance of different acid treated Myanmar Natural Clay (Mabisian) was conducted the pyrolysis of mixed plastic wastes, 40% high density polyethylene, 30% polypropylene, 25% low density polyethylene and 5% polystyrene. Mabisian clay was refluxed with different concentration of nitric acid (2M, 4M, 6M, 8M, 10M, 12M and 14M) at 100ºC for 3hrs followed by calcination at 500ºC for 1hr. The physico-chemical characteristics of resulted leached clay were studied by X-Ray Fluoresence spectroscopy (XRF), X-Ray Diffraction (XRD) and Fourier Transformed Infrared Spectroscopy (FTIR). The pyrolytic oil was characterized by Gas Chromatography – mass spectopy (GC-MS). XRF and FTIR studies indicated that acid treatment under reflux condition lead to the removal of octahedral Al3+ cations along with other impurities. The chemical treatment increased the Si/Al ratio. The maximum liquid yield (75%) was obtained at 12 M nitric acid, 3hr reaction time and 100 º C reaction temperatures. In addition, the percent peak area of gasoline range hydrocarbon was obtained 55.6% at optimum condition. Thus, the treated clay can be used as promising as catalyst support.

Study on the Catalytic Effect of Nitric Acid Activated Myanmar Natural Clay for the Degradation of Plastic Wastes

In this study, the performance of different acid treated Myanmar Natural Clay (Mabisian) was conducted the pyrolysis of mixed plastic wastes, 40% high density polyethylene, 30% polypropylene, 25% low density polyethylene and 5% polystyrene. Mabisian clay was refluxed with different concentration of nitric acid (2M, 4M, 6M, 8M, 10M, 12M and 14M) at 100ºC for 3hrs followed by calcination at 500ºC for 1hr. The physico-chemical characteristics of resulted leached clay were studied by X-Ray Fluoresence spectroscopy (XRF), X-Ray Diffraction (XRD) and Fourier Transformed Infrared Spectroscopy (FTIR). The pyrolytic oil was characterized by Gas Chromatography – mass spectopy (GC-MS). XRF and FTIR studies indicated that acid treatment under reflux condition lead to the removal of octahedral Al3+ cations along with other impurities. The chemical treatment increased the Si/Al ratio. The maximum liquid yield (75%) was obtained at 12 M nitric acid, 3hr reaction time and 100 º C reaction temperatures. In addition, the percent peak area of gasoline range hydrocarbon was obtained 55.6% at optimum condition. Thus, the treated clay can be used as promising as catalyst support.

From hydrophilic to hydrophobic: A promising approach to tackle high CO2 selectivity of Fe-based Fischer-Tropsch microcapsule catalysts

Zeolite supported Fischer-Tropsch (FT) catalysis has attracted extensive attentions in past few years. Capsule catalysts have unique characteristics of tuning product selectivity more precisely and enhancing stability of catalysts during reaction, which makes them to stand out of the crowed. Fe-based FT catalysts have been facing limitations for syngas conversion to hydrocarbons with their associated problems of high CO2 selectivity and rapid catalyst deactivation. A series of ZSM-5 supported Fe-based microcapsule catalysts, composed of Fe/ZSM-5 core and silicalite-1 shell, was prepared and employed for direct synthesis of gasoline range hydrocarbons from syngas. Tuning silicalite-1 shell thickness significantly affected water-gas shift reaction with increasing hydrophobicity of catalyst surface, and greatly decreased CO2 selectivity. The microcapsule catalysts significantly suppressed the CO2 selectivity as compared with supported Fe-based catalyst. Moreover, all zeolite supported Fe-based catalysts, showed significantly high gasoline range hydrocarbons selectivity (about 60%). The proposed catalyst design suggests a promising approach to overcome high CO2 selectivity challenge associated with Fe-based FT catalysts.

Confined small-sized cobalt catalysts stimulate carbon-chain growth reversely by modifying ASF law of Fischer\u2013Tropsch synthesis

Fischer–Tropsch synthesis (FTS) is a promising technology to convert syngas derived from non-petroleum-based resources to valuable chemicals or fuels. Selectively producing target products will bring great economic benefits, but unfortunately it is theoretically limited by Anderson–Schulz–Flory (ASF) law. Herein, we synthesize size-uniformed cobalt nanocrystals embedded into mesoporous SiO2 supports, which is likely the structure of water-melon seeds inside pulps. We successfully tune the selectivity of products from diesel-range hydrocarbons (66.2%) to gasoline-range hydrocarbons (62.4%) by controlling the crystallite sizes of confined cobalt from 7.2 to 11.4 nm, and modify the ASF law. Generally, larger Co crystallites increase carbon-chain growth, producing heavier hydrocarbons. But here, we interestingly observe a reverse phenomenon: the uniformly small-sized cobalt crystallites can strongly adsorb active C* species, and the confined structure will inhibit aggregation of cobalt crystallites and escape of reaction intermediates in FTS, inducing the higher selectivity towards heavier hydrocarbons.

Hydrocracking of algae oil to aviation fuel-ranged hydrocarbons over NiMo-supported catalysts

An algae oil from Botryococcus braunii (CnH2n–10, n = 29–34) and its model compound (squalene, C30H50) were hydrocracked to light hydrocarbons over NiMo-supported catalysts in batch reactors. Polyoxocation [AlO4Al12(OH)24(H2O)12]7+-pillared montmorillonite (denoted by Al13-Mont) was prepared as a support for NiMo catalyst in the hydrocracking reaction. Al13-Mont had large micropores, large BET surface area, high temperature stability, and properly weak solid acidity. For the hydrocracking of squalene at 300 °C for 6 h under 4 MPa H2, NiMo/SiO2 formed squalane (C30H62) as a main product; NiMo/H-ZSM-5 formed C1−C4 gas hydrocarbons as main products; NiMo/H-Y and NiMo/SiO2-Al2O3 formed C5−C9 gasoline-ranged hydrocarbons as main products; NiMo/Al13-Mont formed C10−C15 aviation fuel-ranged hydrocarbons as main products. The catalysts containing NiMo and solid acids acted as bifunctional catalysts in the squalene hydrocracking reaction: squalene (C30H50) was firstly hydrogenated to squalane (C30H62) on the NiMo sites, and then the formed squalane was cracked to light hydrocarbons on the solid acids. The NiMo/Al13-Mont catalyst achieved a C10−C15 aviation fuel-ranged hydrocarbons yield of 52% for the hydrocracking of Botryococcus braunii oil at 300 °C for 6 h.

Pyrolysis behaviors of oilfield sludge based on Py-GC/MS and DAEM kinetics analysis

In this work, the effect of heating rate (10, 20, 50 and 100 K min−1) on oilfield sludge pyrolysis was studied on thermogravimetric analyzer (TG) and the pyrolysis kinetics was investigated by means of the distributed activation energy model (DAEM). The TG/DTG curves of oilfield sludge pyrolysis are shifted to higher temperatures evidently as the heating rates increase and the intensity of DTG peak is increased with the increase of heating rate. The pyrolysis process of oilfield sludge could be divided into two stage. Kinetics analysis by DAEM revealed that the activation energy (E) decreased from 99.54 to 44.19 kJ mol−1 in the conversion ratio range of 0.1–0.2, and then E raised up to 184.63 kJ mol−1 with increase of the conversion ratio. In addition, Py-GC/MS experiments were performed to investigated the types of products and their proportions in pyrolysis process of oilfield sludge at different pyrolysis temperature (758, 943 and 1193 K) and the corresponding mechanism for oilfield sludge pyrolysis was briefly discussed. Cracking depth of oilfield sludge can be significantly improved by increasing pyrolysis temperature, and the light molecule weight of hydrocarbons (C4C10) increased with the increase of pyrolysis temperatures. Moreover, the increase of pyrolysis temperature was also conducive to the decrease of the polycyclic compounds. However, there is an abrupt increase of aromatics yields (14.69%) when temperature is up to 1193 K. The change of content of gasoline and diesel range hydrocarbons in pyrolysis products of oilfield sludge with pyrolysis temperature was also discussed.

Effect of the promoter presence in catalysts on the compositions of Fischer–Tropsch synthesis products

The effects of alkali promoters namely potassium, copper, and manganese, on the performance of the bi-functional iron–low acidity ZSM-5 catalysts in the Fischer–Tropsch (FT) synthesis were studied. ZSM-5 with very high silica alumina ratio (SAR) of 280 was used to take advantage of its shape selectivity and suppressing the effect of alkali migration on zeolite cation exchange sites. One bi-functional iron base catalyst (FeZ), three single promoted (KFeZ, CuFeZ, MnFeZ) and four multiple promoted (CuKFeZ, CuMnFeZ, KMnFeZ, CuKMnFeZ) catalysts were synthesized by the incipient to wetness impregnation method. They were characterized by XRD, BET, TPR, TEM and TPD analyses methods and tested for their FT synthesis activities.Promoters had considerable impacts on the compositions and the hydrocarbon distributions of the FT synthesis products. Addition of promoters resulted in an increase of up to 8.5–56% and 20–743% in the synthesis of gasoline and diesel range hydrocarbons, respectively. Consequently, the production of the total liquid fuel (gasoline+diesel) also increased from 48% (base catalyst) to 64–79% (promoted catalysts). The highest gasoline range hydrocarbon production was obtained from MnFeZ and CuKMnFeZ (≈70%) while CuKMnFeZ produced a FT product having the highest total liquid fuel (≈79%).

Production of diesel fractions by catalytic cracking of vacuum gas oil and its mixture with cottonseed oil under the influence of a magnetic field

The influence of the 0.4 T magnetic field on catalytic cracking of the vacuum gasoil and its mixture with 5% cottonseed oil was evaluated. Magnetic field intensity excites aromatic resins existing in the vacuum gasoil and causes more effective cracking. Catalytic cracking was conducted using commercial X-zeolite fluid catalytic cracking catalyst and reaction products, especially gasoline and diesel fractions were analyzed in detail. Magnetic field increased the yield of the diesel fraction from 7 to 33% and enriched its composition with aromatic hydrocarbons while opposite effect was observed in gasoline. Cracking mechanisms in formation of gasoline and diesel range hydrocarbons were briefly discussed.

Direct conversion of simulated propene-rich bio-syngas to liquid iso-hydrocarbons via FT-oligomerization integrated catalytic process

The bio-syngas formed from the catalytic cracking of bio-oil include two types of useful components which are light olefin and H2, CO. The integration of FTS and olefinic polymerization seems potential way for the production of hydrocarbon bio-fuels while fully utilizing the olefin-rich bio-syngas. This work aimed to develop an integrated process for the production of liquid hydrocarbons directly from the olefin-rich bio-syngas through a one-stage process, which included the synthesis of liquid hydrocarbons via the oligomerization of light olefin over HZSM-5 along with the FT (Fischer-Tropsch) synthesis of H2, CO over FeMn catalyst. A series of integration configuration composed of Fe-based catalyst (FeMn) and acidic zeolite (HZSM-5) were investigated, it was found that the undesired hydrogenation of lower olefin on the nearby metal active site seems greatly affected the yield of C5+ . More significantly, the proximity of the two active components plays a crucial role in suppressing the undesired hydrogenation reaction and contributing to the high selectivity of liquid hydrocarbons. The optimal catalytic performance yields a high selectivity to gasoline-range hydrocarbons (87.3%) with excellent low olefin hydrogenation selectivity (7.4%). Meanwhile, the obtained gasoline-range hydrocarbon showed high degree of isomerization. The integrated transformation process potentially provides an alternative way for the production of gasoline range isomerized hydrocarbon fuels using olefin-rich bio-syngas.

Gasoline selective Fischer-Tropsch synthesis in structured bifunctional catalysts

The need for energy independence and security has refocused research on Fischer-Tropsch Synthesis (FTS) and its capability to selectively produce short and branched hydrocarbons. In this work, FTS selectivity to gasoline-range products was explored as a catalysis and process engineering problem. Novel structured catalysts for in situ upgrading of FTS products to gasoline-range hydrocarbons were successfully synthesized by coating controlled-thickness ZSM-5 films on the surface of Co-Al2O3/monolith substrates. These catalysts were synthesized on the premise that the monolith serves as an efficient mass and heat transfer structure, while the ZSM-5 layer functions as a hydrocarbon cracking and isomerization agent. Compared to traditional diesel-selective FTS, considerably higher quantity and quality of gasoline-range products were achieved with these bi-layered/bifunctional catalysts. Oil products with gasoline yield higher than 65 wt.% and selectivity to isomers and olefins greater than 70 wt.% were formed at relatively high temperature (230 °C) and intermediate pressure (12 bar), without compromising CO conversion, which remained as high as 79%.

Co-based MOR/ZSM-5 composite zeolites over a solvent-free synthesis strategy for improving gasoline selectivity

Composite zeolites containing ZSM-5 are known to be very active for catalytic conversion of syngas into gasoline range hydrocarbons under Fischer-Tropsch synthesis. In this work, a novel MOR/ZSM-5 composite zeolite with immersed Co particles was successfully fabricated under a facile solvent-free synthesis method. The final catalysts were characterised by XRD, SEM and TEM procedures to evaluate the structural properties and morphologies of Co@MOR/ZSM-5. Variation in the crystallization time played a vital role during zeolite synthesis. Perfect crystal structure for solvent-free Co@MOR/ZSM-5 was found at 72 h of crystallization time and proved to exhibit the greatest gasoline selectivity of 72.3%. This composite zeolite synthesized by solvent-free method with outstanding performance, has all potential to act as highly effective heterogeneous catalyst in the near future.

Complete encapsulation of zeolite supported Co based core with silicalite-1 shell to achieve high gasoline selectivity in Fischer-Tropsch synthesis

Zeolite-based capsule catalysts have exhibited significant results in terms of catalytic activity and product selectivity in Fisher-Tropsch synthesis. Herein, we synthesized a ZSM-5 supported Co based microcapsule catalyst encapsulated by microporous silicalite-1 shell via hydrothermal synthesis process. Synthesized microcapsule catalyst has a uniform microporous structure with an additional stay zone for both reactants as well as product inside its channels and showed significantly high CO conversion rate (68.9%) and gasoline range hydrocarbon selectivity (74.7%) with a low CO2 and CH4 selectivity (2.8% and 8.7%, respectively). This microcapsule catalyst may consider to be used on commercial scale because of its facile preparation method and promising performance.

Comparison of methanol to gasoline conversion in one-step, two-step, and cascade mode in the presence of H-ZSM-5 zeolite

ABSTRACTIn this report, three technological modes for methanol-to-gasoline reaction in the presence of H-ZSM-5 catalyst are compared: (i) direct methanol transformation to hydrocarbons; (ii) two-step (methanol-dimethyl ether-hydrocarbons); and (iii) cascade pathway. Light hydrocarbon gases (methane, ethylene, propylene, and isobutene) and liquid aromatic hydrocarbons (benzene, toluene, xylene, cresol, durol, naphthalene, methylnaphthalene, ethyl naphthalene, isopropyl naphthalene, methyl isopropyl naphthalene, etc.) were found to be the main reaction products. The experimental results showed that the classical two-step methanol to gasoline (MTG) process nowadays remains the most effective for gasoline-range hydrocarbons production, while one-step and cascade schemes require further investigation and the development of reactor systems as well as the operating conditions. The product distribution of MTG synthesis after 120 h on stream in the case of two-step mode was found to be the following: liquid C6–C8 hydrocarbons – 23%; C1–C5 gaseous products – 65%; heavy C9–C12 hydrocarbons – 10%.