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Additives to a zeolite-containing cracking catalyst were synthesized and studied in order to enhance the resistance to the poisoning effect of nitrogen compounds (in particular indole) upon cracking of n-undecane as the model FCC hydrocarbon. The additives were represented by acid-activated clays and mixed oxides. The activation of clays in the catalyst by 5% sulfuric acid solutions was shown to enhance the resistance to nitrogen. The introduction of Mg, Al – mixed oxides in the catalytic system in the amount of 10 wt% increased its activity and resistance to indole. The highest resistance was observed for the systems containing magnesium‑aluminum oxides with a Me 2 + to Me 3 + molar ratio equal to 0.5: 1. Cobalt modification of these mixed oxides enhanced the activity and nitrogen resistance of the cracking catalysts. Use of such nitrogen-resistant catalysts will allow cracking of heavy raw materials. [ABSTRACT FROM AUTHOR]

Heat transfer and reaction behavior of aviation kerosene were investigated numerically and experimentally at a supercritical pressure. A global thermal cracking and catalytic reforming reaction model were modified and developed based on the experimental data. A set of surrogate components for aviation kerosene was built and its thermodynamic properties were predicted. Interactions among heat transfer, cracking and catalytic steam reforming reactions were simulated in a micro-channel reactor. Comparison between calculation and experiment showed that the numerical model can predict the wall and outlet fuel temperatures with an error not exceeding 5%. The conversion rate of kerosene and water were also in good agreement with experimental data. Heat transfer deterioration phenomenon can be observed when fuel contains water. Fuel with catalytic steam reforming reactions had the advantage of weakening the heat transfer deterioration and obvious promotion in heat sink. Heat transfer process can be divided into four sub-regions: entrance, gasification, transition and interactive reaction regions. The two kinds of reactions occurring in the reaction region significantly improve the heat sink of hydrocarbon fuel. Interactions between cracking and reforming reactions illustrated that the reaction region were considerably moved ahead due to the existing of steam reforming reactions, resulting in lower fuel temperature which led to a lower rate of thermal cracking and conversion. Thermal cracking reaction was inhibited by catalytic steam reforming reactions. [ABSTRACT FROM AUTHOR]

Refining of high acid crudes (HACs) is seriously limited by extensive corrosion of refinery equipment due to the presence of intrinsic naphthenic acids (NAs). Herein, in the absence of a catalyst or external hydrogen, effective removal of the NAs contained in HACs was achieved using methanol at moderate temperature and moderate pressure. Several process variables, including the temperature, crude concentration, and reaction time are explored to optimize the removal of NAs from HACs. At 250 °C, 6.4 MPa, and 33.3 wt% crude, a very low total acid number (TAN) of 0.08 mg-KOH/g-oil (96.9% reduction efficiency) with a high oil yield (95 wt%) is achieved. During the reduction of the TAN using methanol, some fraction of the resins and asphaltenes in the crude oil crack to form low-molecular-weight aromatic compounds. Compared to deacidification using methanol, pyrolysis (without methanol) results in a much lower TAN reduction efficiency (38.6%). The major deacidification mechanism using methanol is esterification, while that of pyrolysis (without methanol) is decarboxylation. [ABSTRACT FROM AUTHOR]

Jet fuel is used as a coolant before it is burned in the combustor of the aircraft. Insoluble particles and surface deposits can impair engine performance. Jet fuel thermal oxidation test (JFTOT) defines the standard test method for evaluation of the deposit formed through heating fuels in tubes caused by thermal oxidation (< 400 °C). At a higher temperature, fuel in the heating process decomposes leading to surface deposits by coking. In this work, we propose a method to evaluate the security of fuel flowing in the tube at high temperatures (> 500 °C). The heat transfer and cracking performances of two hydrocarbon fuels which are laboratory modified aviation kerosene (Fuel 1 ( ρ = 0.85 g/cm 3 ) and Fuel 2 ( ρ = 0.78 g/cm 3 )) have been investigated in a heat-exchanger under supercritical conditions ( T = 700–770 °C, p = 2.5–5.5 MPa, m = 0.4–1.0 g/s). The temperature and flow rate in this work are much higher than those in JFTOT. The safe run time (SRT) is used to evaluate the heat transfer security of each fuel. As the temperature increases or the flow rate decreases or the pressure increases, the SRTs of Fuel 1 and Fuel 2 decrease clearly. In general, the heat transfer security of Fuel 1 is better than that of Fuel 2. Moreover, the volumetric heat sink of Fuel 1 is larger than that of Fuel 2. So, the overall performance of Fuel 1 is more excellent when it is used as propellant and coolant for hypersonic aircraft. In consideration of the heat transfer security, heat sink and the required driving force for aircraft, the temperature of fuel at the exit of heat transfer passage should be set as 740 °C, the flow rate of fuel should be 0.6–1.0 g/s, the pressure of heat transfer passage should be 3.5 MPa. Based on these results, we find that the modification of a high density fuel is an effective way to prepare an advanced hydrocarbon fuel. [ABSTRACT FROM AUTHOR]

This paper deals with the theoretical modeling of a high temperature reactor devoted to the thermal cracking of tars contained in a gas coming from a biomass gasifier. The aim of this paper is to give an insight into the chemical reactions that take part in this conversion but also into the reactions that may occur in such environment. The investigation is carried on using the simplest continuous reactor configuration that exists (completely stirred tank reactor), which allows to address the effects of chemical reactions without taking into account the mixing. This paper presents the complete set of reactions taken into account. It can also be noticed that this model also describes possible gasification of char particles entering the reactor. An in-depth analysis of the weight of the involved reactions is proposed for the nominal conditions of the reactor operation. The results of the model are also compared to the results of a previous one, highlighting the benefits of the actual model. These results are also compared to values obtained during operation of a pilot plant. Finally, the influence of five of the operating parameters of the reactor is theoretically investigated. It shows that these parameters can have an important impact on reactor operation, but also that conditions can be found that always lead to a conversion of at least 95% of the incoming tars. [ABSTRACT FROM AUTHOR]

Naphtha is an important feedstock for the petrochemical industry and accurate measurement of its detailed composition is essential for the optimization of pyrolysis processes. In the present work, the suitability of using near infrared (NIR) for the determination of 38 parameters used to characterize naphtha was evaluated: pooled composition (PIONA); specific composition groups (C3 paraffins; C4–C12 n-paraffins; C4–C12 iso-paraffins; C5–C7 + naphthenics; C8–C10 aromatics; C4–C6 olefins) and individual components (toluene, benzene, iso-pentane, cyclopentane, methyl cyclopentane; cyclohexane, xylenes, 1,3 butadiene and isoprene). Besides the usual comparison against reference methods, NIR predictions were also evaluated for their ultimate use in determining the coil outlet temperature (COT) for process control. 28 models for the naphtha parameters presented root mean square error (RMSEP) values lower or close to the reproducibility of the reference method and exhibited satisfactory correlation values ( r 2 ) when compared with r 2 max . Among the ten remaining parameters, two (1,3 butadiene and isoprene) presented very low concentrations and it was not possible to obtain a suitable model. Eight parameters had RMSEP values higher than the intralaboratory reproducibility and/or r 2 values lower than expected. Despite this, the complete naphtha composition obtained from NIR prediction was demonstrated to be quite suitable for COT simulation, providing accurate COT values compared to the values estimated from the reference method. [ABSTRACT FROM AUTHOR]

Pine bark biochar generated by slow pyrolysis (950°C) was used as a low cost catalyst to decompose toluene (model tar compound) over a temperature range of 600–900°C. Relative to thermal cracking, fractional toluene conversion increased from 13 to 94% when increasing temperatures from 600 to 900°C (2500ppmv, SV=0.76s−1, 3.8g catalyst) and Arrhenius analysis indicated an activation energy of 91kJ/mol, comparable to that of synthetic catalysts (e.g., 80.24kJ/mol for Ni/Mayenite and 196kJ/mol for olivine) and lower than that of thermal cracking (356kJ/mol). The reaction rate for toluene decomposition increased linearly from 550 to 700°C with a concentration range of 1000–4600ppmv indicating a first order rate law with respect to toluene. Benzene was detected as a potential intermediate in the decomposition of toluene with selectivity ranging from 0 to 28% at temperatures from 600 to 900°C respectively, and its formation increased with increasing toluene conversion. Toluene conversion ranged between 40 and 95% with benzene selectivity from 0 to 20% at 800°C during catalyst longevity studies of 6days. These results indicate that biochar generated from slow pyrolysis of pine bark at high temperature can be used as a low cost catalyst for tar removal from syngas. However, the tar removal rates using the biochar catalyst were lower than that of olivine and nickel based catalysts indicating the need to increase catalytic activity. [ABSTRACT FROM AUTHOR]

Abstract: ZSM-5 catalysts (C(X)-ZSM-5) with micropores and mesopores were prepared by a carbon templating method with a variation of carbon template content (X=0, 10, 20, 30, 40, and 50wt.%), and they were applied to the production of light olefins (ethylene and propylene) through catalytic cracking of C5 raffinate. The effect of carbon template content on the physicochemical properties and catalytic activity of C(X)-ZSM-5 catalysts was investigated. It was revealed that physicochemical properties of C(X)-ZSM-5 catalysts were strongly influenced by carbon template content. Adsorption ability for n-pentane and mesopore volume of C(X)-ZSM-5 catalysts increased with increasing carbon template content. It was also found that catalytic performance of C(X)-ZSM-5 catalysts was closely related to the mesoporosity of the catalyst. Conversion of C5 raffinate and yield for light olefins increased with increasing mesopore/micropore volume ratio of the catalyst, while selectivity for ethylene and propylene showed constant values. Thus, carbon template content in the C(X)-ZSM-5 catalysts strongly affected the mesoporosity of the catalyst, and in turn, mesoporosity played an important role in determining the catalytic performance in the production of light olefins through catalytic cracking of C5 raffinate. [Copyright &y& Elsevier]

Abstract: A novel fixed-bed biomass gasification process (Fraunhofer ISE gasification process) for the production of tar-free synthesis gas was developed and demonstrated in a small-scale 50kW LHV (biomass) pilot plant. The process consists of four zones. Separated by moving grates to control the residence time in every zone. Thermal cracking of all higher hydrocarbons and tars occurs due to temperatures in the cracking zone of up to 1000°C, ensured via partial combustion of the raw gas. In addition, coke in the cracking zones acts catalytically. In order to increase the heating value of the product gas all remaining carbon is partially oxidized and the produced CO/CO2 is blended with the product gas. To demonstrate feasibility of the process, a pilot plant was designed, commissioned and tested. The gasifier produced a combustible gas with a lower heating value of 5.8MJ/Nm3 and CO, H2 and CH4 concentrations of 24, 14 and 2vol.%, respectively. Tar contents below 50mg/Nm3 were achieved in continuous operation. The results suggested a considerable effect of the temperature and the bed height in the tar cracking zone on the reduction of the tar content in the produced gas. [Copyright &y& Elsevier]

Abstract: Attempts have been made to understand the non-isothermal kinetics of cracking of Jatropha oil (JO), vacuum residue (VR) and high density polyethylene (HDPE) and their combined co-cracking using different heating rates of 5Kmin−1, 10Kmin−1, 15Kmin−1 and 20Kmin−1 under the nitrogen (N2) atmosphere. The Flynn–Wall–Ozawa and Kissinger–Akahira–Sunose (KAS) models were employed to study the kinetic analysis of the samples. To evaluate the exponential factor the model fitting of Coats –Redfern approach was used. The distribution of the activation energy for these entire combined reaction scheme has been discussed. Authors have reported that the non-isothermal kinetic studies of the co-cracking of JO+VR and VR+HDPE show the existence of synergism in their co-cracking reactions, however JO+HDPE co-cracking shows interaction among the reactive cracked intermediates of JO and HDPE. [Copyright &y& Elsevier]

Abstract: Thermal pyrolysis of plastic wastes in tubular reactor has been studied with Direct Computer Mapping based simulation methodology, combined with genetic algorithm. Degradation process was carried out in laboratory and pilot scale tubular reactor. The investigated pyrolysis temperature range was 465–545°C, and raw material feeding rate was between 6 and 20g/min. A dynamic simulation model has been developed based on a four-step degradation scheme, considering four cracking product fractions (gas, naphtha, middle distillate and heavy oil) and their hydrocarbon composition (paraffin, olefin and aromatic). A collaborating genetic algorithm was used for the identification of kinetic and stoichiometric model parameters. Having analyzed the identification results we concluded that some of the stoichiometric parameters, moreover all of the kinetic parameters and vapour/liquid phase ratios were independent from the reaction parameters, however they depend on the quality of raw material. The temperature and feeding rate dependency of the model were considered by two calculated parameters (pLiq, pAro). According to the investigations, the rate determining factor of the degradation process is the effectively utilized enthalpy resulting from the heat transfer through the wall of the equipment. The simplified dynamic simulation model can support the scale-up procedure of the pyrolysis technology. [Copyright &y& Elsevier]

Abstract: Evaluation of opportunity to raise Euro V diesel production by increasing fluid catalytic cracking (FCC) light cycle oil (LCO) production was carried at the Lukoil Neftochim Bourgas, Bulgaria (LNB) refinery. The FCC LCO (IBP-360°C) production was investigated in the FCC conversion range between 69 and 83wt.% and LCO initial boiling point (IBP) between 177 and 210°C. It was found that the LCO yield increased from 16.0 up to 20.7wt.% by decreasing conversion from 83 to 69wt.%. At constant conversion in the FCC unit of 79.7wt.% the LCO yield increased from 17.8 to 24.8wt.% by decreasing the IBP from 210 to 177°C. A further 3.5wt.% LCO yield increase and meeting the diesel flash point specification of 55°C can be achieved by lowering the LCO IBP down to 163°C. It was found that during hydrotreatment of a blend of the LNB middle distillates and LCO in a high pressure (70bars) hydrotreater employing Co-Mo catalyst the maximum LCO (IBP=210; FBP=300°C) content that allows meeting the EN specifications is 10wt.%. If the LCO IBP is reduced to 177°C then the maximum LCO content in the feed can reach 20wt.%. The limitation of density not higher than 0.845g/cm3 in the hydrotreated product at 15°C is the restriction for further increase of LCO content in hydrotreater feed. Replacing the Co-Mo catalyst by Ni-Mo and noble metal catalysts in the high pressure hydrotreater can allow more than double increase of LCO content in hydrotreater feed. Hydrogen chemical consumption in that case, however is also more than twofold. [Copyright &y& Elsevier]

Abstract: Several models have been reported in the literature for thermal cracking of petroleum residues. Most of these models are either highly empirical or first principles based models requiring detailed analysis of the feedstock. The present paper is an attempt to put forward a critical appraisal of various published models. The authors have also generated the experimental data on a batch reactor for different feedstocks, and multi-lump parameter models (reported elsewhere) have been developed with the generated data. Three different models for prediction of experimental yields in terms of gas and distillate fractions (i.e. kerosene, LGO and VGO) have been critically evaluated in the light of experimental data. [Copyright &y& Elsevier]

Abstract: This paper investigates the effect of fluid catalytic cracking (FCC) feed hydrotreatment and its severity increase on product yields and quality obtained in a commercial and a laboratory MAT FCC units. The hydrotreatment of Ural heavy vacuum gas oil reduces not only sulfur, nitrogen, Conradson carbon and metals content in the FCC feed but also increases the mononuclear aromatic hydrocarbons content by 8% absolute at almost no change in the total aromatics content. Regardless of this 8% increase of the mononuclear aromatics in the hydrotreated FCC feed the conversion increase in both commercial and laboratory MAT units was only 2%. The severity increase in the FCC feed hydrotreater leads to a higher conversion in the FCC, higher hydrogen transfer rate that results in higher isobutane/butylenes ratio, lower gasoline olefins content, and higher gasoline motor octane number. The hydrotreatment of the Ural heavy vacuum gas oil exhibited the same changes in FCC catalyst selectivities: lower coke and LCO selectivities and higher gasoline selectivity in both commercial riser FCC unit that has between 2 and 3s time on stream, and the fixed bed reactor MAT unit, that has 30s time on stream. [Copyright &y& Elsevier]

Abstract: In this paper the influence of admixtures of rapeseed, soybean and palm oil into VGO on FCC performance has been studied. The oils were mixed in steps of 20wt.% and tested in a fully continuous operated FCC pilot plant. The experiments show that the product distribution changes slightly. Higher ratios of vegetable oils hardly affect the gasoline yields but cause a decrease in cracking gas. Oxygen contained in the vegetable oils is converted predominantly to water. It has been demonstrated that the obtained gasoline is oxygen free and shows improved properties for RON and MON. The cracking gas contains high amounts of propene and ethene, which can be used as base materials for the production of synthetic materials from renewable sources. [Copyright &y& Elsevier]

Abstract: An assessment of the process conditions for the isomerization–cracking of long-chain n-paraffins over commercial Pt/SO4 2––ZrO2 catalysts was made. Pretreatment and reaction conditions were optimized with a focus on the maximization of the yield of short, high octane branched paraffins for the gasoline pool. While selectivity was an important issue attention was also paid to the reduction of the yield to gases (C1–C4). Therefore cracking had to be modulated to produce the correct molecular size adjustment without scission to too much smaller fragments. Skeletal isomerization was to be maximized. The activity in both acid-catalyzed reactions had to be tuned while keeping a stable activity level. The only pretreatment condition assessed was the calcination temperature (screened in the 600–800°C range). Calcination at 600°C produced the highest activity level while 700°C was convenient from the point of view of selectivity. The optimum temperature coincided with the production of the highest concentration of Brönsted acid sites. Regarding the reaction conditions, increasing temperature values augmented the conversion but also increased the cracking. Therefore optimum values were found at a moderate temperature, 225°C, given the high reactivity of the feed. Space velocity values were analyzed with attention to the liquid C5+ yield, the selectivity to branched isomers and the stability of the catalysts. Best yields to branched naphtha products were obtained at WHSV=18h–1. The H2/hydrocarbon molar ratio was a function of the catalyst coking rate. A value of 10 was enough to attain a stable conversion value. The values of liquid yield as a function of pressure displayed a volcano pattern that was rationalized in terms of a non-classical bifunctional mechanism of reaction. High pressure values increased the concentration of Brönsted acid sites and hence the activity while high pressures enhanced hydrocracking and decreased the liquid yield. The optimal pressure value was 20atm. [Copyright &y& Elsevier]

Abstract: The article is devoted to the study of rapeseed oil cracking in the presence of zeolite catalysts in order to prepare the liquid fraction with the properties close to fossil diesel.To evaluate the cracking products, the chromatographic methods GL and GC/MS were used, together with the determination of viscosities, acid values and densities. The cracking of rapeseed oil in the presence of zeolite-type catalysts in batch arrangement at temperatures between 350 and 440°C gave a yield of liquid condensate 85 to 90wt.%. After removal of volatile components 3 to 9wt.% by distillation at the temperatures up to 190°C, the GL chromatogram of treated condensate was similar to that of fossil diesel fuel. The paper deals with the influence of the kind and amount of catalyst on composition and properties of treated products with the use of GL and GC/MS chromatography and with the tests of blends of fossil diesel fuel with cracking products at contents up to 7vol.%. The blended fuels meet all parameters specified by standard EN 590 for diesel fuel. [Copyright &y& Elsevier]

Abstract: In this work the utility of new possible petrochemical feedstocks obtained by plastic waste cracking has been studied. The cracking process of polyethylene (PE), polyethylene–polypropylene (PEPP) and polyethylene-polystyrene (PEPS) has been carried out in a pilot scale tubular reactor. In this process mild reaction parameters has been applied, with the temperature of 530°C and the residence time of 15min. The produced hydrocarbon fractions as light- and middle distillates were tested by using a laboratory steam cracking unit. It was concluded that the products of the mild cracking of plastic wastes could be applied as petrochemical feedstocks. Based on the analytical data it was determined that these liquid products contained in significant concentration (25–50wt.%) of olefin hydrocarbons. Moreover the cracking of polystyrene containing raw material resulted in liquid products with significant amounts of aromatic hydrocarbons too. The steam cracking experiments proved that the products obtained by PE and PEPP cracking resulted in similar or better ethylene and propylene yields than the reference samples, however the aromatic content of PEPS products reduced the ethylene and propylene yields. [Copyright &y& Elsevier]

Abstract: Triacyl glycerides (TGs) are naturally occurring oils produced by a significant variety of crops, microorganisms (bacteria and algae), and animals (certain fats). The diversity and prevalence of the sources of these compounds suggest that they may serve as an attractive alternative to crude oil as the feedstock for the production of transportation fuels and certain industrial chemicals — organic compounds with carbon chain lengths in the range of C7 to C15. In the present study a series of batch thermal cracking reactions was performed using soybean oil and canola oil under reaction conditions leading towards attractive yields of potentially valuable (as fuels and/or chemicals) shorter chain products. An attractive yield of alkanes and fatty acids (from oil cracking) or esters (from biodiesel) was obtained. From a parametric study reaction temperature, followed by residence time, was found to have the most significant effect. Significantly, cracking under increased pressures in a hydrogen atmosphere did not improve the yields of desirable species. [Copyright &y& Elsevier]

Abstract: The hydrocracking behavior the product of a Fischer–Tropsch synthesis consisting of a C4–C30 mixture of paraffins and olefins on a platinum/amorphous silica–alumina catalyst has been analyzed and optimized. The influence of temperature on the selectiveness of the hydrocracking has been investigated. Time and temperature optimization was performed in order to obtain the best operating conditions for the enhancement of gasoline and diesel cuts. This work presents a mathematical model of the tubular reactor used in hydrocracking the heavy hydrocarbon fraction produced by the Fischer–Tropsch synthesis. The system was studied to optimize the operating conditions as to produce the highest amounts of diesel and/or gasoline. The hydrocarbon product distribution changes during hydrocracking were modeled considering a commercial bifunctional catalyst. The model was validated with data reported in the literature and has presented a satisfactory fitting to the experimental data with a confidence level of 95%. The production of specific cuts such as diesel and gasoline was optimized after the model has been validated. The results showed that lower temperatures (550 K) favor the cracking of heavy hydrocarbons chains into diesel and higher temperatures (650 K) favor a more effective cracking generating higher amounts of gasoline. [Copyright &y& Elsevier]

Abstract: The laboratory findings were presented for a single-stage hydrocracking process of vacuum residue (VR) of Ural crude. The Ni–Mo/Al2O3 catalyst in suspension was used in tests. The amounts and quality of the obtained products were related to process parameters. Hydrocracking of VR was carried out in a continuous flow reactor, at the temperature of 410–450 °C and pressure of 12–20 MPa, at the liquid space velocity (LHSV) of 0.25–0.75 h−1, and at the gas space velocity of 2500 h−1. The studied catalyst Ni–Mo/Al2O3 was found moderately active in the VR cracking process, while it turned out an efficient catalyst for the hydrofining processes. The catalyst concentration and hydrogen pressure had no effect on hydrocracking of VR, and hydrofining of cracking products was affected slightly only over the studied scope of parameters. The reaction temperature and LHSV exerted dramatic effects on hydrocracking of VR and on the asphaltenes and CCR contents, while their effect on hydrofining of cracking products was much lower. The temperature of 430 °C resulted in VR conversion to distillates (b.p.<538 °C) of 61.6–88.7 wt.% and in sulphur conversion of 70–85 wt.%. [Copyright &y& Elsevier]

The application of dielectric heat transfer in the catalytic cracking and hydrocracking of gas oils has been investigated. A three-phase spouted-bed catalytic reactor has been designed and operated using dielectric radio frequency (RF) heating. The electromagnetic power was transferred to the reactor by a 27.12 MHz RF generator acting through two capacitor plates. In this technique, heat is generated to the catalyst held in the electromagnetic field and thermal energy dissipated to the surroundings of the catalyst volume preventing carbon formation by eliminating secondary reactions. Energy transfer from the RF filed to the reaction was solely dependent on the dielectric properties of solids in the reactor, effectively the catalyst or transient carbon. Three zeolitic catalysts have been tested. These catalysts were 13X, 5A and Ammonium Y Zeolite. Two different gas oils have been used as feedstocks for the experiments. Saudi Light Vacuum Gas Oil (SALVGO) supplied by Saudi Aramco Oil and North Sea Light Gas Oil (BPLGO) supplied by BP Oil. A comparative study of the two gas oils cracked over 13X zeolitic catalyst has been presented. The analysis of the feedstocks have shown that SALVGO contains hydrocarbons in the range C11–C30 with average molecular weight of 294, while BPLGO contains hydrocarbons in the range C11–C25 with average molecular weight of 243. The analysis of cracked products have shown a production of lower olefins such as propene and butene with hydrogen sulphide from SALVGO at a conversion of 87% and aromatics such as benzene and toluene from BPLGO at a conversion of 72%. The successful use of zeolitic catalyst in producing lower olefins and aromatics with an RF dielectric reactor suggests exploring this type of reactor for objectives such as the production of reformulated gasoline, in which butene is used as feedstock for production of high-octane gasoline components such as MTBE and alkylate. [Copyright &y& Elsevier]