Gasoline Range Research Articles

Modelling Laboratory Fischer-Tropsch Synthesis Using Cobalt Catalysts

AbstractThe main goal of this paper is to critically review current microkinetics available for Fischer-Tropsch synthesis (FTS) modelling, in order to propose the best way to follow this set of complex reactions; therefore a microkinetic model was developed for FTS, accomplishing surface chemistry, heterogeneous kinetics, and single-event previous development for Co-based catalysts. Model starts simulating CO activation on catalyst surface, and then formation of methane, ethane and subsequent chain growth. Reaction rates were derived following the formalism of Langmuir-Hinshelwood-Hougen-Watson (LHHW); surface steps were proposed in consequence of feasibility. Chain growth was modelled by single-event steps, taking into account geometrical conformation explicitly. Number of growth steps of 1-olefins was rectified as requiring one more active site than mechanisms proposed previously; it was found that formation of these olefins exhibits a fast drop in chain growth; this phenomenon is explained in terms of probable geometrical conformations that lead to the number of single events. Experimental results in literature about isothermal synthesis of hydrocarbons in the gasoline range were simulated in a fixed-bed laboratory reactor; thermodynamic consistency was derived from chemical equilibrium over all reactions occurring during FTS. Equilibrium constants were evaluated as function of Gibbs free energy, and partial pressures of reactants and products.

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.

An experimental and modeling study of vacuum residue upgrading in supercritical water

Arabian Heavy crude oil was fractionated into distillate and vacuum residue fractions. The vacuum residue fraction was treated with supercritical water (SCW) at 450°C in a batch reactor for 15–90 min. The main products were gas, coke, and upgraded vacuum residue; the upgraded residue consisted of gasoline, diesel, and vacuum gas oil range components. The molecular composition of gas and upgraded vacuum residue was analyzed using gas chromatography (GC, GC × GC). SCW treatment converted higher carbon number aliphatics (≥C21) and long‐chain (≥C5) alkyl aromatic compounds into C1C20 aliphatics, C1C10 alkylaromatics, and multiringed species. The concentrations of gasoline and diesel range compounds were greater in the upgraded product, compared to the feed. A first‐order, five lump reaction network was developed to fit the yields of gas, coke, diesel, and gasoline range components obtained from SCW upgrading of vacuum residue. Distillation of crude oil followed by SCW treatment of the heavy fraction approximately doubled the yield of chemicals, gasoline, and diesel, while forming significantly less coke than conventional upgrading methods. © 2018 American Institute of Chemical Engineers AIChE J, 64: 1732–1743, 2018

Use of light hydrocarbons for the oil-oil correlation in Pearl River Mouth Basin, South China Sea

The composition of 28 oil samples from Wenchang and Enping formations of Pearl River Mouth Basin (PRMB) was characterized and emphasis was placed on compositional variations in the gasoline range (i-C5H12-n-C8H18). The light hydrocarbons (LHs) were sensitively determined by gas purge microsyringe extraction (GP-MSE) coupled with gas chromatography-mass spectrometry (GC–MS) and GC-flame ionization detector (FID), respectively. According to the relative concentration of LHs, the Mango’s K1 parameter was calculated and a cross plot was obtained. Invariance in the K1 ratio was observed with a correlation coefficient approximately equal to 1 for all the studied crude oils, however, the absolute K1 values were different for each oil family, which indicates the distinct genetic features. Furthermore, several LH indicators were screened and a model was developed for correlating oils using LHs combined with multivariate statistical method. To validate the model, the correlation results based on routine biomarkers and LHs were compared by using normal oil samples, and consistent conclusions were achieved. As alternative to routine biomarkers, LHs show good potential in geochemical correlation of crude oils, especially when routine biomarkers are absent or at very low concentration in high maturated oil samples.

Transformation of Jatropha oil to biofuel using transition metal salts as heterogeneous catalysts

In this study, Jatropha oil was catalytically cracked using Co(NO3)2 and Mn(NO3)2 as heterogeneous catalysts at different ratios of 0.5%–3% to obtain different grades of biofuel. The physical and fuel properties of the obtained biofuels were characterized by measuring the following properties: density, viscosity, specific gravity, pour point, flash and fire points, cetane number, carbon and ash residues and sulfur content. The determined properties were located within the limits of the specific standards of ASTM specifications. The type of transition metal and the ratio of the used catalysts were greatly affect the physical and fuel properties of the obtained biofuels. Comparing the reactivity of (Co(NO3)2 and Mn(NO3)2) as catalytic cracking catalysts revealed that Co(NO3)2 is more reactive than Mn(NO3)2. Using of low catalysts ratio produced biofuel comparable to biodiesel according to ASTM specifications; while higher catalyst ratio produced biofuel comparable to bio-gasoline. Lighter fractions of the biofuel in the range of gasoline were produced at higher catalysts ratios and the optimum concentration was 3%. The reactivity of the two salts was discussed based on their electronic configurations.

Molecular Representation of the Petroleum Gasoline Fraction

The computer-aided reconstruction of gasoline composition is an active area of petroleum and petrochemical research as a result of the demand for molecular-level management of the petroleum feed streams. To that end, in this work, a molecular compositional model based on a predefined representative molecular set was built that allows for the conversion of conventional bulk property data to an approximate molecular composition. The selection of representative molecules was based on their presence in gasoline molecular compositional measurement and their potential contribution to the key physical properties. Around 170 hydrocarbons and heteroatom species were chosen as predefined identities of molecules that can exist in a gasoline sample. The physical property data of all of the representative molecules were collected, and suitable mixing rules for the gasoline range stream were applied for the accurate prediction of bulk properties. The approximate concentration of representative molecules was obtained th...

Infrared spectroscopy and multivariate methods as a tool for identification and quantification of fuels and lubricant oils in soil.

Environmental contamination caused by leakage of fuels and lubricant oils at gas stations is of great concern due to the presence of carcinogenic compounds in the composition of gasoline, diesel, and mineral lubricant oils. Chromatographic methods or non-selective infrared methods are usually used to assess soil contamination, which makes environmental monitoring costly or not appropriate. In this perspective, the present work proposes a methodology to identify the type of contaminant (gasoline, diesel, or lubricant oil) and, subsequently, to quantify the contaminant concentration using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy and multivariate methods. Firstly, gasoline, diesel, and lubricating oil samples were acquired from gas stations and analyzed by gas chromatography to determine the total petroleum hydrocarbon (TPH) fractions (gasoline range organics, diesel range organics, and oil range organics). Then, solutions of these contaminants in hexane were prepared in the concentration range of about 5-10,000mgkg-1. The infrared spectra of the solutions were obtained and used for the development of the pattern recognition model and the calibration models. The partial least square discriminant analysis (PLS-DA) model could correctly classify 100% of the samples of each type of contaminant and presented selectivity equal to 1.00, which provides a suitable method for the identification of the source of contamination. The PLS regression models were developed using multivariate filters, such as orthogonal signal correction (OSC) and general least square weighting (GLSW), and selection variable by genetic algorithm (GA). The validation of the models resulted in correlation coefficients above 0.96 and root-mean-square error of prediction values below the maximum permissible contamination limit (1000mgkg-1). The methodology was validated through the addition of fuels and lubricating oil in soil samples and quantification of the TPH fractions through the developed models after the extraction of the analytes by the EPA 3550 method adapted by the authors. The recovery percentage of the analytes was within the acceptance limits of ASTM D7678 (70-130%), except for one sample (69% of recovery). Therefore, the methodology proposed here provides faster and less costly analyses than the chromatographic methods and it is adequate for the environmental monitoring of soil contamination by gas stations.

Feasibility analysis of high–low temperature Fischer–Tropsch synthesis integration in olefin production

A novel system combining high- (HTFT) and low-temperature Fischer–Tropsch synthesis (LTFT) in olefin production is proposed. Utilizing syngas from coal gasification as the feed gas, the combined system integrates the advantages of HTFT and LTFT and results in an increased range of products, namely α-olefins (mainly C4, C6, and C8), synthetic lubricant, gasoline, diesel, and naphth. The system avoids the risk of product market fluctuation and especially realizes the objective of diversifying production and maximizing economic benefit. Innovative ethylene oligomerization process is suggested to increase the α-olefins production. Different schemes of Fischer–Tropsch synthesis process are simulated by the aid of Aspen Plus software and a feasibility analysis on each of them is also done. In an economic perspective, the optimal ratio of HTFT to LTFT for the HTFT–LTFT combined plant with ethylene oligomerization scheme is 3:2. The project presents a low fresh water consumption of 0.138kWh/USD, electricity consumption of 3.78×10−3kWh/USD and CO2 emission of 2.52kWh/USD, and is expected to have a net present value of 8.66 billion USD and an annual average of return on investment of 42.03% under the current crude oil price 0.25–0.31USD/L (2015–2017). These data demonstrate that the combined system has excellent economic profits and a remarkable ability to resist market risks compared to traditional single HTFT or LTFT process under a low crude oil price (below 0.5USD/L).

Two-stage catalytic fast hydropyrolysis of biomass for the production of drop-in biofuel

The major obstacles for the production of drop-in fuel from traditional fast pyrolysis are low bio-oil yield, poor fuel heating value and high solid yield. To overcome these obstacles, we studied the introduction of high pressure hydrogen into the pyrolysis reactor, in a process known as catalytic fast hydropyrolysis (CFHP). CFHP of anisole, a bio-oil model compound, was performed at different temperatures and pressures, to determine the effects of those variables on the CFHP reaction network. Alkanes were observed at low temperature and high pressure, whereas aromatics were dominant at low pressure and high temperature. Aspen modelling and calculation of reaction equilibrium constants showed that there is a thermodynamic barrier for simultaneous pyrolysis and hydrogenation at 600 °C. Reduced heating rates and CFHP followed by second-stage hydroprocessing (SH) were proposed as a means to control reaction temperature and efficiently deoxygenate CFHP vapors. The two-stage CFHP followed by hydroprocessing produced nearly 18 mol% carbon yield to alkanes, and a total bio-oil carbon yield of 25 mol%. The approximate bio-oil higher heating value (HHV) and aromaticity were 43.4 MJ/kg and 28 wt%, respectively, both within the range of gasoline.

One-Pot Conversion of Methane to Light Olefins or Higher Hydrocarbons through H-SAPO-34-Catalyzed in Situ Halogenation.

Methane was converted to light olefins (ethene and propene) or higher hydrocarbons in a continuous flow reactor below 375 °C over H-SAPO-34 catalyst via an in situ halogenation (chlorination/bromination) protocol. The reaction conditions can be efficiently tuned toward selective monohalogenation of methane to methyl halides or their in situ oligomerization to higher hydrocarbons. The presence of C5+ hydrocarbons in the reaction products clearly indicates that by using a properly engineered catalyst under optimized reaction conditions, hydrocarbons in the gasoline range can be produced. This approach has significant potential for feasible application in natural gas refining to gasoline and materials under moderate operational conditions.

Catalytic Performance for Hydrocarbon Production from Syngas on the Promoted Co-Based Hybrid Catalysts; Influence of Pt Contents

Fischer-Tropsch synthesis (FTS) reaction from syngas was investigated on the Pt-promoted cobalt-based hybrid catalysts prepared by co-precipitation method in a slurry of ZSM-5 (Si/Al=25). The hybrid catalysts were compared with each other for the different content of Pt as a promoter and are characterized using BET, XRD, H2-TPR and NH3-TPD. Their physicochemical properties were correlated with the activity and selectivity of the catalysts. As results, all hybrid catalysts show the C5-C9 yield (%) higher than that of Co-Al2O3/ZSM-5 catalyst. The Pt-promoted hybrid catalysts were found to be more promising towards production of the hydrocarbons of gasoline range and over C10.

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.

Transportation fuel from plastic: Two cases of study

Synthesis of liquid fuels from waste is a promising pathway for reducing the carbon footprint of transportation industry and optimizing waste management towards zero landfilling.The study of commercial plants that conduct pyrolysis of plastics from post-consumer recycled materials and directly mine from old landfills without any pre-treatment has revealed two cases that show the feasibility of manufacturing transportation fuels via these methods.Pyrolysis oil, consisting of almost 26% hydrocarbons within the gasoline range and almost 70% within the diesel range, is upgraded to transportation fuel in the existing refinery. A batch operating plant is able to deliver relatively good quality pyrolysis oil from post-consumer plastic waste, owing to the catalyst employed. Simple distillation was also evaluated as an alternative and cheaper upgrading process into transportation fuels, meeting EN590 diesel and ISO8217 marine fuel standards.Even though the two installations are outside the European Union, they represent good examples of the “circular economy” concept envisaged by the European Union via its ambitious “Circular Economy Package [1]”, providing real world data for comparison with other experimental and lab results.1In a circular economy waste and resource use are minimized, and when a product reaches the end of its life, it is used again to create further value.

Synthesis of modified catalyst and stabilization of CuO/NH4‐ZSM‐5 for conversion of methanol to gasoline

AbstractIn this article, the catalytic conversion of methanol to gasoline range hydrocarbons has been studied over CuO/ NH4‐ZSM‐5(3,5,7,9%) catalysts prepared via sono‐chemistry methods. In order to improve, copper oxide can be used as a booster on NH4‐ZSM‐5 this catalyst property. Accordingly, the conversion process of Methanol to Gasoline (MTG) was conducted under a pressure of 1 atm and temperature of 400°C by a fixed‐bed reactor on copper oxide catalysts which were prepared based on synthetic NH4‐ZSM‐5. The synthetic catalyst was investigated by such analyses as BET, XRD, FT‐IR, and SEM. Formation of copper oxide phase and proper distribution of copper oxide were proven on the basic level of using XRD analysis. BET analysis showed the reduction in catalyst level and SEM images depicted the proper distribution of particles. The present investigation is to study the effect of CuO loading on NH4‐ZSM‐5 support for conversion of methanol to gasoline range hydrocarbons. A series of CuO/ NH4‐ZSM‐5 catalysts were prepared, characterized, and experimented for their performance on methanol conversion and hydrocarbon yield.

Glycerol conversion over palladium- and alumina-impregnated KIT-6 for the production of gasoline range hydrocarbons

The use of large pore size catalyst with high surface area is explored in this work by using KIT-6 silica-based mesoporous material for the conversion of glycerol to higher hydrocarbons. Palladium and alumina were incorporated into the KIT-6 for providing Lewis acid sites and removal of oxygen. A decrease in surface area and pore diameter was observed with the incorporation of alumina and palladium on KIT-6. Ethanol was used as diluent as glycerol is viscous in nature and has issues related to flow in the preheater. An increase in the conversion was observed from 78 to 93.7% with the increase in temperature from 400 to 700 °C; however, the liquid yield was observed to decrease above 600 °C. GC (FID) analysis showed that the maximum values (38.9%) for gasoline range hydrocarbons fraction were obtained at 550 °C. No significant effect was observed on the liquid-phase yield with the addition of palladium; however, it was observed that the liquid product obtained in the presence of palladium has higher H/C ratio, indicating the formation of paraffinic compounds and removal of oxygen. GC/MS analysis showed the presence of mostly oxygenated long-chain hydrocarbons.

Sodium‐Containing Spinel Zinc Ferrite as a Catalyst Precursor for the Selective Synthesis of Liquid Hydrocarbon Fuels

A microwave-assisted hydrothermal synthesis produces ZnFe2 O4 containing Na residue as a precursor to a CO2 hydrogenation catalyst that displays high CO2 conversion and high selectivity to liquid hydrocarbon products in the gasoline and diesel range with high olefin-to-paraffin ratios. Compared to reference catalysts derived from Fe2 O3 and a ZnO-Fe2 O3 physical mixture, the ZnFe2 O4 -derived catalyst contains well-dispersed iron particles with Zn serving as a structural promoter. A profound effect of the residual Na as an electronic promoter is also observed, which improves the selectivity for C5+ hydrocarbons and olefins. The ZnFe2 O4 -derived catalyst exhibits excellent performance in the CO2 Fischer-Tropsch reaction as it forms the active Hägg iron carbide (χ-Fe5 C2 ) phase readily through the in situ carburization of iron.

Development of sustainable coal to liquid processes: Minimising process CO2 emissions

Traditional coal-to-liquid (CTL) plants are synonymous with the production of carbon dioxide. Coal may be gasified in the presence of steam and oxygen to produce gas comprising carbon dioxide (CO2), carbon monoxide (CO), methane (CH4), hydrogen (H2) and steam (H2O). The gases can be reacted to a myriad of chemicals and fuels via the Fischer-Tropsch (FT) reaction. However, excess carbon dioxide is generated via the Water-Gas-Shift reaction during preparation of CO:H2 ratios for FT. Here, a process development is represented on a CHO phase diagram, where unique regions are identified for autothermal operations for coal conversion. Considerations are given to develop idealised processes for the production of liquid chemicals from coal which emit minimal process CO2, require minimal energy input and do not require steam. This is achieved by co-feeding coal with methane and identifying endothermic-exothermic process pairs for methane-coal dry reforming. Furthermore, it is shown that a preferred method to produce liquid fuels from coal is by first creating dimethyl ether (DME) as an intermediate, followed by the dehydration of DME to liquid fuels (gasoline range). For this route, via DME, the CO2 emission was found to be four times less than idealised CTL processes.

Catalytic distillation of an atmospheric petroleum resid using HZSM-5 and HY zeolites

ABSTRACTThis work presents a study of the reactive distillation of atmospheric petroleum residue (ATR) containing 10% in mass of HY or HZSM-5 zeolites. The process aims the upgrade of ATR in order to obtain valuable products. The fundamental characteristic of the process is the immediate separation under thermal conditions and subsequent reaction of the products generated by the zeolite catalysts, favoring the displacement of the equilibrium towards the desired reactions. Such reactions occurred in the heterogeneous form, adding the HY or HZSM-5 zeolites to the ATR charge, and heating the mixtures at temperatures in the range of 50 to 500°C. The heating promotes intense heat exchange, solid-liquid reactions, obtaining the desired products. In the reactive distillation process, in presence of the acid sites of the zeolites, the short contact time of the hydrocarbons thermally cracked at low pressures favored secondary cracking reactions, increasing the selectivity to lower weigh molecular hydrocarbons, in the range of liquid gases, naphta, gasoline, jet fuel, diesel and lubricants. The obtained results proved that catalytic or reactive distillation is a promising technology for waste recovery that is surplus to the atmospheric and vacuum distillation processes for the refineries.

Assessment of the Fuel Composition Impact on Black Carbon Mass, Particle Number Size Distributions, Solid Particle Number, Organic Materials, and Regulated Gaseous Emissions from a Light-Duty Gasoline Direct Injection Truck and Passenger Car

The influence of the aromatic hydrocarbons in gasoline on the fuel distillation parameter, as well as the particle number (PN), black carbon (BC), and other regulated gaseous emissions from a passenger car (PC) and light-duty truck (LDT), was assessed by operating two vehicles fueled with U.S. Environmental Protection Agency Tier 3 certification gasoline and two gasoline test fuels over two standard drive cycles. The two gasoline test fuels represent a range of commercial motor gasoline, with one containing less naphthalenes and lower heavy fraction volatility (T80, T90, and final boiling point) than the other. Observations showed that various gasolines have minor impact on both vehicles on regulated gaseous emissions and fuel consumption. Particulate emissions from both vehicles showed similar trends with fuel type, with lower naphthalene containing gasoline produced lower PN and BC emissions. In addition, the effect of fuel on particle emissions varied with vehicle type, drive cycle, and power to weight...

Heterogeneous catalysts for gas-phase conversion of ethylene to higher olefins

Abstract The reduced availability of propylene and C4 products from steam crackers continues to provoke on-purpose technologies for light olefins such that almost 30% of propylene in 2025 is predicted to be supplied from unconventional sources. Furthermore, the recent discoveries of natural gas reservoirs have urged interest in the conversion of surplus alkanes and alkenes, especially ethane and ethylene. The direct conversion of ethylene to propylene or a combination of value-added chemicals, including butylenes and oligomers in the range of gasoline and diesel fuel, provides the capability of responding to the fluctuations in the balance between supply and demand of the main petrochemicals. A comprehensive review of heterogeneous catalysts for the gas-phase conversion pathways is presented here in terms of catalytic performances (ethylene conversion and product selectivities), productivities, lifetimes, active sites, physicochemical properties, mechanisms, influence of operating conditions, deactivation and some unresolved/less-advanced aspects of the field. The addressed catalysts cover both zeolitic materials and transition metals, such as tungsten, molybdenum, rhenium and nickel. Efforts in both experimental and theoretical studies are taken into account. Aside from the potential fields of progress, the review reveals very promising performances for the emerging technologies to produce propylene, a mixture of propylene and butenes, or a liquid fuel from ethylene.