High-octane Gasoline Research Articles

Research on Product Yield Prediction and Benefit of Tuning Diesel Hydrogenation Conversion Device Based on Data-Driven System

In the refining process, a large amount of data are generated in daily production, and how to make full use of these data to improve the accuracy of simulation is the key to improving the operation level of refineries. At the same time, with the increasing environmental regulations and the improvement of gasoline and diesel quality standards, the ratio of diesel to gasoline is also changing with people’s demand for fuel consumption. Catalytic cracking light cycle oil (LCO) hydrogenation conversion technology (react LCO into gasoline, RLG) can produce modified diesel with high-octane gasoline, a high cetane number, and a low sulfur content, which improves the added value of the product. In this article, based on the production and operation data of a 1 million tons/year RLG device, a device yield prediction model was established using a deep neural network (DNN) algorithm, and the model was further optimized using a genetic algorithm (GA) to maximize the economic benefits of the device. As a result, the gasoline production yield increased by more than 3%. The experimental results show that the established model has a good reference value for improving the economic benefits of the RLG device.

ANALYSIS OF THE EFFECTIVENESS OF USING SOLAR SYSTEMS BASED ON PHOTOVOLTAIC MODULES AND SOLAR COLLECTORS FOR ENERGY SUPPLY OF BUDGET FACILITIES

This article analyzes the operation of a solar energy system installed in a higher education institution, consisting of four photovoltaic stations connected to the electrical grid for self-consumption, and a solar hot water system with collectors and a storage tank. The operation of the system was modeled using the RETScreen, T*SOL, and PV*SOL software programs, based on averaged climate data obtained from the "Zhuliany" weather station. The solar system is installed on the south-facing roof of the building and consists of 262 monocrystalline silicon photovoltaic modules of Trina Solar TSM-DE08M (II) type with a power of 370 W, installed at an angle of 30° to the horizon, and 8 Veissmann Vitosol 300-T SP3 vacuum tube collectors with a power of 1.3 kW installed at an angle of 35°. The placement of the solar elements was determined through modeling, considering their dimensions, the features of the roof structure, the placement of ventilation systems, and the shading of the roof surfaces by other elements of the building in Kyiv. As a result of energy modeling, it was determined that the amount of thermal energy obtained is 6.823 MWh/year, and the amount of electrical energy is -109.16 MWh/year, with a total inverter capacity of 95 kW, a traditional fuel replacement coefficient of 50% for the photovoltaic system and 75% for the solar system with collectors, payback periods of 4.3 years for the photovoltaic system, and 13 years for the hot water system when replacing electric boilers and 16 years when obtaining hot water from a district heating network. The reduction in harmful emissions is 45 tons/year of CO2, which is equivalent to 104.3 barrels of crude oil or 19,279 liters of high-octane gasoline or 15.5 tons of recycled waste. Based on the analysis of the data, it is recommended to install such systems in higher education budget institutions to reduce electricity or natural gas consumption and reduce harmful emissions into the environment.

Direct conversion of methane to heavier gaseous alkanes using an electron beam

The circulation treatment of methane with 0.5 MeV electron beam in a cyclone-type reactor, which protects the synthesized products from back degradation, has been studied. As a result of the conversion, the content of methane in the circulating gas can be reduced to 30–43 wt%. The main products are C2C5 alkanes, and the ethane content in the mixture can reach almost 40 wt%. By-products are hydrogen and C6C13 high-octane gasoline alkanes. Electron beam treatment can also be used to concentrate helium in natural hydrocarbon mixtures. The key control factors for conversion are the composition of the feedstock, the rate of beam energy deposition in the gas, temperature, and the residence time of the gas components in the beam penetration area. The features of the use of powerful technological DC accelerators are noted.

Pore structure modification of ZIF-8 by ligand exchange for separation mono- and di-branched isomers of hexane via thermodynamic and kinetic mechanism

Isomeric C6 alkanes are high-quality raw materials for producing high octane gasoline. Among them, the octane number of di-branched C6 alkanes is significantly higher than that of mono-branched C6 alkanes. Therefore, efficient and economical separation of mono- and di-branched C6 alkanes has received widespread attention. Herein, ZIF-8 with mixed ligands (named as ZIF-8-IM) was successfully synthesized by exchanging some 2-methylimidazole (MIM) ligands in the framework of ZIF-8 with imidazole (IM), and the microstructure of ZIF-8-IM were analyzed from N2 adsorption. Adsorption thermodynamic and kinetic properties of n-hexane (nHEX), 3-methylpentane (3MP) and 2,3-dimethylbutane (23DMB) on ZIF-8-IM were determined by IGA-100 intelligent weight analyzer. Column breakthrough experiments were carried out to confirm the separation performance of of 3MP/23DMB binary mixture and nHEX/3MP/23DMB ternary mixture on ZIF-8-IM and ZIF-8. Results show that the microporous structure of ZIF-8 is changed by ligand exchange, which means the most probable pore diameters at 1.08 nm and 1.34 nm of ZIF-8 are converted to 1.06 nm and 1.19 nm of ZIF-8-IM. The adsorption equilibrium and kinetic characteristics of mono-branched 3MP are significantly enhanced due to the microstructural changes in ZIF-8-IM. The equilibrium adsorption capacity of 3MP on ZIF-8-IM is 1.6 times that of 23DMB, and the diffusional time constant is 4–13 times that of 23DMB. By relying on the synergistic effect of thermodynamic and kinetic characteristics, efficient adsorption and separation of 3MP/23DMB mixtures can be achieved with a separation factor of 2.24 on ZIF-8-IM. In addition, ZIF-8-IM can also achieve clear separation of nHEX/3MP/23DMB ternary mixtures, obtaining individual nHEX, 3MP, and 23DMB products. The results of this study show excellent application prospects in the production of the raw materials for high octane gasoline and molecular oil refining processes.

Experimental investigation of waste polyolefin composition on thermal conversion into petroleum-derived products

Thermal pyrolysis of polyolefins has been proposed as one of the possible ways to obtain petroleum-derived products (fuels and chemicals) from waste plastics however, there is a lack of deep understanding of the correlation between the structure and composition of polyolefin feedstock with pyrolysis oil. Pyrolysis oil has been obtained from polyethylene (PE) and polypropylene (PP) in a tubular reactor at 500 °C. TGA-DTG, 13C CP-MAS NMR, FTIR, and XRD were used to analyze the polyolefin (PE and PP) feedstock, while pyrolysis oil was characterized by GC–MS, FTIR, and 1H NMR techniques. The pyrolysis oil from virgin and waste PP yielded branched alphaolefins and cycloparaffins, while virgin and waste PE produce linear alpha olefins and linear paraffins. Mixed waste plastic (MWP) produces major amount of linear paraffins and linear alpha olefins, indicating the overall trend of branching in polyolefins (PE and PP) from feedstock to product oil is retained after pyrolysis. The alpha olefins can be used as chemical intermediates, while 2,4 dimethyl 1-heptene from PP can be used as a fine chemical precursor better feedstock for gasoline. Segregation of waste plastics is challenging task in real life but source segregation and selective collection of waste plastics from various sources can produce useful products like high octane gasoline range hydrocarbons and high-value chemicals.

INFLUENCE OF THE PREPARATION METHOD OF BISMUTH-CONTAINING ZEOLITE CATALYSTS ON THEIR ACTIVITY IN STRAIGHT-RUN GASOLINE PROCESSING

New methods of zeolite HZSM-5 modification with bismuth compounds are proposed. The choice of bismuth as a modifying agent is due to the systematisation and generalisation of the available literature data and experimental results of studying the chemistry and synthesis of bismuth compounds of various compositions. Phases in the resulting bismuth-containing zeolite systems were identified by X-ray phase analysis, and the state of bismuth in chemical compounds was determined. The number and strength of acid sites in the original and modified samples were determined by the method of temperature-programmed desorption of ammonia. The catalytic activity of zeolites was studied in the process of hydrogen-free processing of the straight-run gasoline fraction of oil into high-octane gasolines. The effect of modification methods and process temperature on the structural-group hydrocarbon composition, the yield of gaseous and liquid reaction products was studied, and the octane numbers of the resulting gasolines were determined. It is shown that over the bismuth-containing zeolite catalysts, in comparison with unmodified zeolite, the yield of the target product, high-octane gasoline containing a smaller amount of aromatic hydrocarbons, increases, which makes it more environmentally friendly. It has been established that the production of high-octane gasolines that meet modern requirements for motor fuels is possible over modified zeolites within a wider process temperature range. Based on the studies performed, methods for modifying the HZSM-5 zeolite with bismuth are proposed on the basis of the studies performed. The proposed methods make it possible to improve the efficiency of the catalyst in the process of upgrading the straight-run gasoline fraction of oil.

Production of High-Octane Number Gasoline from Basra Low Octane-Number Gas Condensate and Ethanol over Modified Zn/ZSM5 Zeolite Catalyst

Catalytic transformation of a low-octane number stable gas condensate to high-octane number gasoline (RON: research octane number) is an economically and strategically vital process. In this research, modifying ZSM5 zeolite (80 Si/Al ratio) by impregnation with 2% Zn (Zn/ZSM5) was carried out to increase the selectivity for isomerization and aromatization thereby enhance the octane number. The process was conducted by using stable gas condensate 85 vol% with 15 vol% ethanol in a fixed bed reactor. Zn/ZSM5 and ZSM5 were examined in a pilot scale under different conditions temperature 360-420 °C LHSV1.2-2 h−1, pressure 5 bar. Catalysts were characterized before and after Zn loading using Fourier Transform Infra Red (FT-IR), Brunauer-Emmett-Teller (BET), X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Field Emission Scanning Electron Microscope (FESEM), Transmission Electron Microscope (TEM), and N2-adsorption. The SEM, FESEM, and TEM have shown that no change in morphology and metal distribution. The XRD and FTIR characterizations revealed the modified catalysts retained their crystallinity after metal impregnation while N2-adsorption isotherm demonstrates no significant change in porosity. The results of Zn/ZSM5 display an optimum result at 420 °C, 1.2 h−1, 5 bar with enhancement of RON from 60.5 to 89 whereas ZSM5 shows RON enhancement from 60.5 to 82. Post Zn loading, PONA test has shown an increase for iso-paraffin from 45.4 to 47.4%, and aromatics from 10.8 to 14. The findings translate the effectiveness of using Zn on ZSM5 for gas condensate – gasoline transformation. Copyright © 2023 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Effect of Aniline Derivatives on Auto Ignition of Hydrocarbon Fuels: Mechanistic Insight of Antiknock Activity

In view of rising concerns over global warming it is very important to reduce greenhouse gas emissions and accelerate decarbonization. Worldwide transportation sector has a massive contribution in producing greenhouse gases over periods. So, depletion of GHG emission is of utmost importance. Petroleum refining industries continuously made efforts to control CHG emissions by formulating high octane gasoline fuels which increase vehicle efficiency and enhance fuel economy for spark ignition internal combustion engines. High Octane gasoline fuels helps in reducing knocking of the SI Engine cars and eventually intensify vehicle efficiency and fuel economy. Over the period of time several potential chemical octane boosters were developed to improve the octane number of the standard gasoline fuel. Aromatic Amine derivatives are well known octane boosters. This present review work summaries the available data regarding the mechanistic interpretation of antiknock action of aromatic amines by controlling the auto ignition process of hydrocarbon fuels. Key Words: Fuel Economy, Engine Efficiency, Octane Booster, Resonance, Autoignition, Research Octane Number

Catalyst deactivation and the effect of catalyst makeup on the FCC unit

One of the significant processes of the crude oil refining process is the fluid catalytic cracking (FCC) unit. This unit produces olefins and other feedstock for the petrochemical industry as well as high octane gasoline, naphtha, light cycle oil, and heavy cycle oil. Attrition is one of the forms of catalyst deactivation on FCC catalyst which affects its operation, thereby giving rise to a high amount of catalyst makeup to compensate for the losses in this unit. This study investigated the effect of catalyst attrition on a commercial FCC unit through an analysis of its technical data from 4-run operations. The catalyst loss profile was evaluated while the scanning electron microscopy (SEM) showed abrasion as the dominant attrition type in the unit, hence resulting in many catalyst particles being lost as micro fines through elutriation. A simulation study was carried out using ASPEN HYSYS version 8.8 to assess the effects of reduction and increment of fresh catalyst makeup on the product yield while a cost analysis was done to evaluate the economic implication. The results showed that a 2% reduction of the current daily catalyst makeup gave the same yield as that of the reference value. The products also had similar qualities showing that $117,000.00/annum could be saved by a 2% reduction of the current catalyst makeup.

Low carbon energy technologies envisaged in the context of sustainable energy for producing high-octane gasoline fuel

With increasing issues, concerning the depletion of petroleum fossil fuels and the environment, various researchers have examined an innovative and appropriate surrogated fuel. Various advanced countries maximize alternative fuel to fight against atmospheric alteration. In this perspective, the current research aims to introduce low-carbon energy technologies envisaged in the context of sustainable energy for generating high-octane gasoline fuel. Four gasoline feedstocks were selected for investigation in the present research as materials. Particularly, these components are gasoline additives, such as bioethanol (E), di-isobutylene (DIB), and dimate (D) with baseline motor gasoline stream, like hydrocracked gasoline (HG). To execute the present work, several gasoline fuels and experimental facilities that correspond to European standard regulations were employed. Additionally, the composition of the optimum sample was 50 % of hydrocracked gasoline, 35 % of bioethanol, 10 % of di-isobutylene, as well as 5 % of dimate. Therefore, the optimal gasoline blend provided high-octane gasoline RON 98 with great ecological characteristics. Besides, the experimental results displayed that the antidetonation performance can be varied consecutively as bioethanol > di-isobutylen > dimate > hydrocracked gasoline by octane number. What’s more, the simultaneous incorporation of bioethanol, di-isobutylene, and dimate changed antiknock characteristics, in terms of vapor pressure, the distillation curve, as well as the density in a route that could impact engine operation. Conclusively, the acquired results stated that it might be merits to utilize bioethanol to provide the added value of hydrocracked gasoline, di-isobutylene, and dimate to establish an innovative high gasoline product in RON of 98 considered the restrictions for high olefins content.

Study on efficient utilization of light cycle oil with combined process

ABSTRACT A combined process of hydrotreating, fractionating, solvent extraction, and fluid catalytic cracking (FCC) was proposed to improve the added value of light cycle oil (LCO). In the process, hydrotreating LCO (HLCO) was divided into light and heavy fractions by fractionating. The bicyclic and tricyclic aromatics in the heavy fraction of HLCO were extracted to produce chemical products by solvent extraction. The raffinate oil and the light fraction of HLCO, rich in saturated hydrocarbons and monocyclic aromatic hydrocarbons, were processed to produce high-octane gasoline by FCC. According to the results, the combined process solved the problem of polycyclic aromatic hydrocarbons of HLCO being challenging to be cracked in FCC reaction, reduced the yield of dry gas and coke by 43.01 wt%, reduced the yield of diesel with low added value by 32.33 wt%, and optimized the product structure. In other words, the process makes efficient use of the aromatic and nonaromatic components in LCO.

Temperature-swing molecular exclusion separation of hexane isomers in robust MOFs with double-accessible open metal sites

The separation of hexane isomer mixtures into their individual components is one of the most important while challenging industrial process to produce high-octane gasoline. Herein robust M(pz)[Ni(CN)4], termed MpzNi (M = Co, Ni, pz = pyrazine) that can realize efficient separation of ternary mixtures into the pure, individual components. As optimal pore channels with double-accessible open metal sites providing the adsorbate-dependent affinity differences for molecular exclusion behavior via temperature programming, CopzNi reached optimum performance with not only exceptional selectivity of linear/monobranched alkanes and monobranched/dibranched alkanes, but also notably higher adsorption capacity than those of the previously reported adsorbents. Breakthrough experiments with equimolar ternary C6 alkane isomers and binary branched mixtures confirmed CopzNi can highly capture n-hexane and 2-methylpentane from their mixtures. The excellent separation efficiency, lower-energy regeneration, scalability, recyclability as well as high stability render the CopzNi a benchmark candidate for implementation in the current separation processes.

Fisher–Tropsch Synthesis for Conversion of Methane into Liquid Hydrocarbons through Gas-to-Liquids (GTL) Process: A Review

The interest in Gas-to-Liquid technology (GTL) is growing worldwide because it involves a two-step indirect conversion of natural gas to higher hydrocarbons ranging from Liquefied Petroleum Gas (LPG) to paraffin wax. GTL makes it possible to obtain clean diesel, naphtha, lubes, olefins, and other industrially important organics from natural gas. This article is a brief review discussing the state-of-the-art of GTL, including the basics of syngas manufacturing as a source for Fischer-Tropsch synthesis (FTS), hydrocarbons synthesis (Fischer-Tropsch process), and product upgrading. Each one is analyzed, and the main characteristics of traditional and catalysts technologies are presented. For syngas generation, steam methane reforming, partial oxidation, two-step reforming, and autothermal reforming of methane are discussed. For Fischer–Tropsch, we highlight the role of catalysis and selectivity to high molecular weight hydrocarbons. Also, new reactors technologies, such as microreactors, are presented. The GTL technology still faces several challenges; the biggest is obtaining the right H2:CO ratio when using a low steam-to-carbon ratio. Despite the great understanding of the carbon formation mechanism, little has been made in developing newer catalysts. Since 60–70% of a GTL plant cost is for syngas production, it needs more attention, particularly for developing the catalytic partial oxidation process (CPO), given that modern CPO processes using a ceramic membrane reactor reduce the plant’s capital cost. Improving the membrane’s mechanical, thermal, and chemical stability can commercialize the process. Catalytic challenges accompanying the FTS need attention to enhance the selectivity to produce high-octane gasoline, lower the production cost, develop new reactor systems, and enhance the selectivity to produce high molecular weight hydrocarbons. Catalytically, more attention should be given to the generation of a convenient catalyst layer and the coating process for a given configuration.

Unraveling the Superior Role of Characterizing Methyl Ester of Isohexene as an Innovative High-Octane Gasoline Mixing Component

High concentrations of isoolefinic hydrocarbons can adversely affect the physical, chemical, mechanical, and ecological characteristics of gasoline fuels. One of the solutions to reduce olefin contents is the utilization of the methoxylation process. The current paper declares a perspective toward a gasoline-component-first technique, revealing an innovative high-octane additive on the basis of isoolefinic components, like isohexene. The olefin content of isohexene was 94% volumetrically. This affected the chemical oxidation under atmospheric conditions. Several gasoline fuels and experimental facilities that match European and Russian requirements were used to execute the recent work. The objective of the methoxylation process is to enhance the chemical oxidation fuels to raise the portion of aliphatic hydrocarbon isomers, to decrease unwanted olefin content, as well as to generate high-octane motor ethers as gasoline octane boosters. The product can be defined as methyl ester of isohexene (MEIH). Various MEIH blends have been measured with other gasoline octane boosters and refinery products. The results proved that antidetonation properties of MEIH were higher than those of base gasolines, tertiary amyl methyl ether (TAME), and isohexene and approximately equal to that of methyl tertiary butyl ether (MTBE). Additionally, the results of the calculated MEIH mixing octane rating were from 104.3 to 131.5 for the research method and from 87.5 to 120.0 for the motor method. Likewise, the olefin content of MEIH was 74.2% when the methoxylation process was applied for isohexene. The oxygen content of MEIH was 3.3 wt %, with no oxygen content in the sample of isohexene. Those have been done thanks to the utilization of the methoxylation process of isohexene. Finally, MEIH provided an individual perspective as a liquid transportation fuel with merits over isohexene, in terms of antidetonation properties, olefin contents, as well as a distillation characteristic range.

The separation performance of two-dimensional ZnPP-grid molecular sieve for C6 alkane molecules:A first-principles calculation

Membrane separation technology plays a vital role in producing high-octane gasoline field. Based on the first-principles calculation, ZnPP-Grid molecular sieve with uniform intrinsic pore is used to systematically evaluate the separation performance of hexane isomers and cyclohexane. The difference of energy barriers indicates that ZnPP-Grid membrane allows linear hexane molecule to pass through the pore, but block di-branched 2,2-dimethylbutane molecule. The analysis of geometric and energy variation reveals that during penetration processes, the effect of molecular changes on the penetration barrier is greater than the effect of ZnPP-Grid membrane deformation on barrier, which is related to the size and structural flexibility of molecules and ZnPP-Grid molecular pore. Especially, when cyclic cyclohexane molecule travels to the pore area, the maximum geometric distortion of pore-rimmed atoms have not caused higher energy barrier than mono-branched 3-methylpentane, which also proves the flexibility of ZnPP-Grid membrane. The molecular sieve exhibits superior hexane/cyclohexane, hexane/branched isomers separation performance with high selectivity of 108–1080 within 150 K–400 K. More importantly, the hexane isomers mono-branched 3-methylpentane/di-branched 2,2-dimethylbutane can be discriminated with high selectivity ∼1029 at 300 K, which helps to obtain high-octane gasoline. The results demonstrate that the ZnPP-Grid molecular sieve is probably an excellent molecular sieve in petrochemical industry.

Pervaporation separation of C6 alkane isomers by Al-bttotb membrane

The metal-organic framework (MOF) membrane has been widely studied in gas separation applications. However, less attention was paid to organic liquids separation, particularly for the separation of straight and branched alkane isomers which is critical to producing high-octane gasoline. Our work is the first example of a dense and defect-free Al-bttotb membrane synthesized on α-Al2O3 support surface through solvothermal in-situ synthesis. The microstructure of the membrane surface was adjusted by controlling the growth rate of the crystal facet through the addition of formic acid during synthesis. The resultant membrane showed great thermal stability, long-term stability, and chemical stability due to the bonding reaction between the ligands and the support surface. The pervaporation test showed that Al-bttotb membrane preferentially permeated straight and mono-branched alkane. The mass fraction of n-hexane (nHEX, straight) and 3-methylpentane (3MP, mono-branched) was accumulated from 66.66% on the feed side to 88.53% on the permeate side after 20 h of the test, while a mass fraction of 2,2-dimethylbutane (22DMB) decreased from 33.33% to 11.47%. This work sheds new light on the separation of organic liquids through MOF polycrystalline membrane.

Process design and mechanism analysis of reactive distillation coupled with extractive distillation to produce an environmentally friendly gasoline additive

Ethyl tert-butyl ether is a high-octane gasoline blending component with excellent performance and has important industrial application value. When ethanol and isobutylene react to form ethyl tertiary butyl ether, there is an azeotrope system of ethyl tertiary butyl ether and ethanol. The efficient production of ethyl tert-butyl ether and the precise separation of the ethyl tert-butyl ether/ethanol azeotrope are the keys to the entire process. In this work, reactive extractive distillation process and reactive extractive dividing-wall process were designed to achieve high-quality production and separation of ethyl tert-butyl ether. By analyzing the relative volatility of the solvents and combining molecular dynamics simulation and quantum chemical calculations, ethylene glycol was selected as the extractant for the separation of ethyl tert-butyl ether/ethanol. Based on the total annual cost as the objective function, three different ethyl tert-butyl ether production and separation processes were optimized and obtained the best process parameters. Finally, the whole process was analyzed from the aspects of economy, environment and exergy loss efficiency. Compared with common process, the total annual cost of reactive extractive dividing-wall process was reduced by 14.56%. The global warming potential, acidification potential and abiotic depletion potential of the reactive extractive dividing-wall process were 28.38%, 29.03%, and 28.36% lower than those of common process respectively. The exergy loss efficiency of reactive extractive dividing-wall process was reduced by 10.9%. The results showed that reactive extractive dividing-wall process has obvious economic advantages and environmental benefits and the actual production of ethyl tert-butyl ether and the separation of ethyl tert-butyl ether/ethanol azeotrope system have certain guiding significance.

Benchmarking Cu/BEA and HBEA catalysts for high-octane gasoline synthesis

We distinguish rates at which carbon deposition occurs during initiation, rates at which catalytic centers are lost during deactivation, and paraffin-to-olefin ratio during propagation as benchmarks that distinguish 5 wt% Cu/H-BEA and H-BEA (Si/Al = 13.5) catalysts during dimethyl ether (DME) homologation in the presence of hydrogen. Studies that systematically vary initial DME contact time (210, 94, and 45 molH+, initial s (mol C)−1), DME pressure (4 and 22 kPa), and H2 pressure (1, 24, and 48 kPa) reveal that Cu enables lower carbon deposition rates (on a per proton basis) in the induction period, increases the effluent paraffin-to-olefin ratio during propagation, and decreases instantaneous site-loss yields during termination by 1.5–2× (moles of active sites lost per mole of DME) thus augmenting the degree of product saturation and catalyst stability during DME homologation. These results provide mechanistic insights revealing the critical role of Cu in facilitating DME homologation to high value, high-octane gasoline-range hydrocarbons with higher cumulative turnovers than proton form H-BEA.

Direct Conversion of Renewable CO2-Rich Syngas to High-Octane Hydrocarbons in a Single Reactor

The synthesis of branched hydrocarbons for high-octane gasoline and sustainable aviation fuel directly from CO2-rich syngas in a single reactor holds potential to decrease capital and operating costs and increase overall energy and carbon efficiencies in a biorefinery. Here, we report the cascade chemistry of syngas to hydrocarbons under mild reaction conditions in a single reactor with C4+ single-pass yields of 13.7–44.9%, depending on the relative catalyst composition employing our dimethyl ether homologation catalyst, Cu/BEA zeolite. With co-fed CO2 at a concentration representative of biomass-derived syngas, 2.5:1:0.9 for H2:CO:CO2, a hydrocarbon yield of 12.2% was observed with similar selectivity to C4+ products compared to the CO2-free feed. Definitive evidence of CO2 incorporation into the hydrocarbon products was demonstrated with isotopically labeled 13CO2 co-feed experiments, where mass spectrometry confirmed the propagation of 13C into the C4+ hydrocarbons, highlighting the feasibility to co-convert CO and CO2 in this single reactor approach.

MECHANISM OF CATALYTIC ISOMERIZATION–DISPROPORTIONATION PROCESSING OF STRAIGHT-RUN GASOLINE

The isomerization-disproportionation conversion of straight-run gasoline over the Co/HZSM/SO42--ZrO2 (SZ) composite catalytic system at atmospheric hydrogen pressure has been studied. Optimal process conditions (1800С; Н2/СН=3; WHSV = 2.5 h-1) was established, under which the conversion of С8+ hydrocarbons is 77.3%, and the sum of high-octane gasoline components С5–С6 alkanes increases from 11% to 61%. Тhe effect of C4-, C5–C6 products and H2O on this isomerization-disproportionation process have been studied. It is shown that, unlike the main C5–C6 products, side C4-products affect the stability of the process, and the catalyst is deactivated under the water's influence. Comparative studies of the conversion of a mixture of straight-run gasoline and C2H5OH showed that H2O vapor formed sites deactivate the centers located on the SZ. It has been established that the mechanism of isomerization-disproportionation conversion of straight-run gasoline with the participation of a composite catalytic system is realized through the conjugated interaction of red-ox centers contained on SZ with acid-base centers of Co/HZSM-5, responsible, respectively, for the formation of intermediate compounds [С4+C7] and their and their further hydro cleavage