Gasoline Blends Research Articles

Combustion and emission of diesel/PODE/gasoline blended fuel in a diesel engine that meet the China VI emission standards

The present study examined the impact of blending polyoxymethylene dimethyl ethers (PODE) and gasoline with diesel on combustion and emission characteristics in an engine compliant with China VI emission standards. The effects on cylinder pressure, combustion duration, and emissions (CO, THC, PN, and NOx) by blending 20 % PODE into diesel and adjusting the gasoline content (0 %, 5 %, and 10 %) were analyzed. The results showed that the cylinder pressures and the combustion duration were reduced with the addition of PODE, compared to the cases of the pure diesel. Moreover, it was found that PODE contributed to reducing the emissions of CO, THC, and PN, and but increasing NOx emissions. Compared to the cases of PODE and diesel blended fuel, the effect of the addition of gasoline on the cylinder pressures and combustion duration presented a minor increasing tendency, and the lower proportion of gasoline blending was found to effectively curb NOx formation. Specifically, blending 5 % gasoline with a 20 % PODE and diesel mixtures resulted in a 4.01 % reduction in NOx emissions. Based on the results of the present study, it can be concluded that 5 % gasoline and 20 % PODE blend in diesel can enhance combustion efficiency and heat release rate and also can achieve a balanced reduction in NOx emissions. The present study provides valuable insights for the development of energy-saving and emission reduction technologies for diesel engines, highlighting the potential of optimized fuel blends to improve combustion and emissions control.

A Review on Investigation of Petrol and Ethanol Blend as fuel on Performance of Spark Ignition Engine

Abstract: Finding substitute fuels has been more popular in recent years as a response to escalating pollution levels and fuel shortages. The goal of this research is to find the ideal gasoline to ethanol ratio that will maximize engine performance and reduce emissions in spark ignition engines. In order to analyse the performance of different blending ratios, the research looks at metrics such carbon monoxide (CO) emissions, brake power (BP), brake specific fuel consumption (BSFC), and brake thermal efficiency (BTE). Blends of gasoline and ethanol with a 15% ethanol content greatly increase engine thermal efficiency at higher engine speeds. E12 mixes of gasoline and ethanol boost engine braking power while lowering CO emissions and breakspecific fuel usage. Blends of gasoline with ten to fifteen percent ethanol present a possible substitute.

Isomerization performance of n-hexane in hydrogen atmosphere over the multistage porous composite NixPy-MCM-41/MOR catalyst

With the increasingly strict environmental protection requirements and the continuous improvement for the performance of clean fuel, it is imperative to develop technology for producing high octane gasoline blending components. Alkane isomerization was one of the important ways due to it contain little olefin and aromatic components which are harmful to the environment. In this study, the multistage porous composite NixPy-MCM-41/MOR catalysts were synthesized in the hydrogen atmosphere, the conversion rate and selectivity of n-hexane hydrogen isomerization with different conditions was tested in a fixed bed reactor. The results shown that the loading volume of active components is 4.0 wt%, nickel-phosphorus ratio of 0.5, reaction temperature of 250 °C, reaction pressure 3.0 MPa and volume space velocity is 2.0 h−1 with the hydrogen condition showed good catalytic activity for the n-hexane isomerization. The conversion rate of n-hexane is 73.0 % and the selectivity of 84.0 %, respectively. The isomerization stability of the Ni2P-MCM-41/MOR catalyst was investigated. After the long period test, the catalytic activity of the catalyst could keep good. Based on the study of reaction effect with different test conditions in hydrogen atmosphere, the mechanism of alkane isomerization for Ni2P-MCM-41/MOR catalyst was proposed.

Dizel Motorlarda Benzin ve Atık Araç Lastiklerinden Elde Edilen Pirolitik Yağın Dizel Yakıt ile Karışımlarının Araştırılması

İçten yanmalı motorlarda alternatif yakıt arayışları uzun yıllardır araştırmaların yoğunlaştığı konulardan birisini oluşturmaktadır. Bu çalışma kapsamında, dizel bir motorda atık taşıt lastiklerinden (ATL) elde edilmiş pirolitik yağın (PY) yanma karakteristikleri ve egzoz emisyonlarına etkileri üzerine bir araştırma yürütülmüştür. ATL piroliz yöntemiyle üretilmiş ve hazır olarak temin edilmiştir. Bu amaçla, 4 zamanlı 4 silindirli 1.9 litre hacmine sahip, multijet bir dizel motor üzerinde deneysel bir araştırma gerçekleştirilmiştir. Çalışmada, dizel yakıtı ve %20 karışım oranlarında benzin B20(%80 dizel + %20 benzin) ve pirolitik yağ P20(%80 dizel + %20 pirolitik yağı) yakıt olarak kullanılmıştır. Bu çalışmada benzin ve pirolitik yağ kıyaslanarak dizel motorlarda uygulanan çift yakıt metodunda, benzine alternatif bir alternatif yakıt araştırması yürütülmüştür. Çalışmada, maksimum motor momentinin %25 kadar bir motor yükü sabit tutularak değişen motor devirlerinde araştırma yürütülmüştür. Elde edilen verilere göre kullanılan yakıtların motor yakıt sisteminde bir revizyon gerektirmeden kullanılabileceği gösterilirken, gelişmiş yanma stratejileri için bir bakış açısı ortaya konulmuştur. Özelikle P20 yakıtı kullanımında özgül yakıt tüketimi ve termal verimde iyileşme gözlenmiştir. Ayrıca B20 ve P20 kullanımları ile HC emisyonlarının kontrolüne dair umut verici sonuçlar elde edilmiştir. Sonuç olarak, mevcut çalışmada kullanılan ATL’den üretilmiş PY’nin dizel motorda alternatif yakıt olarak kullanılabileceği gözlemlenmiştir.

Experimental Investigation of Gaseous Emissions and Hydrocarbon Speciation for MF and MTHF Gasoline Blends in DISI Engine

Article Experimental Investigation of Gaseous Emissions and Hydrocarbon Speciation for MF and MTHF Gasoline Blends in DISI Engine Rafiu K. Olalere 1,2, Gengxin Zhang 1, and Hongming Xu 1,3, * 1 Department of Mechanical Engineering, School of Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK 2 Department Mechanical Engineering, Lagos State University of Science and Technology, Ikorodu 02341, Nigeria 3 State Key Laboratory of Automotive Safety and Energy, Tsinghua University, Beijing 100084, China * Correspondence: h.m.xu@bham.ac.uk Received: 8 November 2023 Accepted: 25 March 2024 Published: 28 March 2024 Abstract: With the increasing shortage of fossil energy, the development of engines urgently requires alternative fuels. Gaseous emissions of a gasoline direct injection spark ignition engine fueled with blends of 2-methylfuran (MF 20% vol. and gasoline 80% vol.) and 2-methyltetrahydrofuran (MTHF 20% vol. and gasoline 80% vol.) were experimentally investigated using Gasmeth FTIR. Experiments were conducted at air-fuel ratio (λ = 1) and at engine speed of 1500 rpm using the fuels optimised spark timing. Effects of fuel injection sweeps (180–280 °CA BTDC) on the emission characteristics of blends were investigated at the intermediate load of 5.5 bar IMEP. Hydrocarbon emission (HC) for gasoline is about 41% and 16% higher compared to MF20 and MTHF20 respectively. Carbon monoxide emission for the fuels increases as the injection timing is retarded but the Nitrogen oxide (NOx) emissions was observed to reduce with the retarded injection timing. Both MF20 and MTHF20 recorded high NOx emissions compared to gasoline. The results indicated ethylene (25–26%) as the major component of the HC speciation in the fuels investigated. The unburnt furan samples for blend fuels were determined to be less than 3% of HC emissions, which could be considered a safe level for exposure.

Impacts of ethanol blended fuels and cold temperature on VOC emissions from gasoline vehicles in China

The Chinese central government has initiated pilot projects to promote the adoption of gasoline containing 10%v ethanol (E10). Vehicle emissions using ethanol blended fuels require investigation to estimate the environmental impacts of the initiative. Five fuel formulations were created using two blending methods (splash blending and match blending) to evaluate the impacts of formulations on speciated volatile organic compounds (VOCs) from exhaust emissions. Seven in-use vehicles covering China 4 to China 6 emission standards were recruited. Vehicle tests were conducted using the Worldwide Harmonized Test Cycle (WLTC) in a temperature-controlled chamber at 23 °C and −7 °C. Splash blended E10 fuels led to significant reductions in VOC emissions by 12%–75%. E10 fuels had a better performance of reducing VOC emissions in older model vehicles than in newer model vehicles. These results suggested that E10 fuel could be an option to mitigate the VOC emissions. Although replacing methyl tert-butyl ether (MTBE) with ethanol in regular gasoline had no significant effects on VOC emissions, the replacement led to lower aromatic emissions by 40%–60%. Alkanes and aromatics dominated approximately 90% of VOC emissions for all vehicle-fuel combinations. Cold temperature increased VOC emissions significantly, by 3–26 folds for all vehicle/fuel combinations at −7 °C. Aromatic emissions were increased by cold temperature, from 2 to 26 mg/km at 23 °C to 33–238 mg/km at −7 °C. OVOC emissions were not significantly affected by E10 fuel or cold temperature. The ozone formation potential (OFP) and secondary organic aerosol formation potential (SOAFP) of splash blended E10 fuels decreased by up to 76% and 81%, respectively, compared with those of E0 fuels. The results are useful to update VOC emission profiles of Chinese vehicles using ethanol blended gasoline and under low-temperature conditions.

A Comprehensive Analysis of Hydrogen–Gasoline Blends in SI Engine Performance and Emissions

This study investigates the influence of adding hydrogen as an additive to gasoline in a four-stroke engine, utilizing comprehensive thermodynamic comparative analysis conducted with self-developed engine model. This research aims to assess the performance, emissions, and efficiency of the engine when using gasoline–hydrogen blends, and to provide insights into the potential benefits of this approach. First, the engine performance and emissions under different hydrogen blending levels were examined. A range of different air/fuel ratios (rich to lean) and varying percentages of hydrogen were considered. This systematic variation allowed for a detailed evaluation of the influence of hydrogen content on combustion efficiency, power output, and emissions characteristics. The analysis results included key parameters such as indicated specific fuel consumption and mean effective pressure. Additionally, the study focused on the range prediction of nitrogen oxide (NOx) emissions, which are a critical environmental concern associated with internal combustion engines. The analysis of pressure and temperature profiles throughout the engine cycle shed light on the combustion characteristics and efficiency improvements associated with hydrogen addition. In terms of emissions, the study projected that all emissions were reduced except NOx, which is highly dependent on hydrogen percentage, and might be reduced in some cases, but with the higher temperatures and pressures associated with hydrogen addition, in most cases, there is actually a NOx increase, especially at higher engine loads.

Unsupervised Clustering-Assisted Method for Consensual Quantitative Analysis of Methanol-Gasoline Blends by Raman Spectroscopy.

Methanol-gasoline blends have emerged as a promising and environmentally friendly bio-fuel option, garnering widespread attention and promotion globally. The methanol content within these blends significantly influences their quality and combustion performance. This study explores the qualitative and qualitative analysis of methanol-gasoline blends using Raman spectroscopy coupled with machine learning methods. Experimentally, methanol-gasoline blends with varying methanol concentrations were artificially configured, commencing with initial market samples. For qualitative analysis, the partial least squares discriminant analysis (PLS-DA) model was employed to classify the categories of blends, demonstrating high prediction performance with an accuracy of nearly 100% classification. For the quantitative analysis, a consensus model was proposed to accurately predict the methanol content. It integrates member models developed on clustered variables, using the unsupervised clustering method of the self-organizing mapping neural network (SOM) to accomplish the regression prediction. The performance of this consensus model was systemically compared to that of the PLS model and uninformative variable elimination (UVE)-PLS model. Results revealed that the unsupervised consensus model outperformed other models in predicting the methanol content across various types of methanol gasoline blends. The correlation coefficients for prediction sets consistently exceeded 0.98. Consequently, Raman spectroscopy emerges as a suitable choice for both qualitative and quantitative analysis of methanol-gasoline blend quality. This study anticipates an increasing role for Raman spectroscopy in analysis of fuel composition.

Optoacoustic interferometric characterization system (OPTICS) for the evaluation of fuel quality through speed of sound measurements

Ultrasonic techniques have been applied to assess crucial physical parameters in various types of fuels including the speed of sound (SoS), the bulk modulus and the acoustic attenuation coefficient. Such investigations may have important practical significance as the knowledge of fuel properties is directly related to the analysis of combustion characteristics, engine’s overall performance and exhaust emission in the environment. Nevertheless, typical pulse-echo acoustic methods, require the exact determination of both acoustic source – reflector distance and the time of flight of a finite temporal width ultrasonic pulse, setting thus an upper limit as regards the accuracy of the measurements. To encounter these challenges, we present a novel technology implemented through a low-cost and potentially portable optoacoustic interferometric characterization system (OPTICS) for the investigation of SoS variations in common fuels including automotive diesel, hydrous ethanol and gasoline. At 25 °C, diesel/kerosene blends demonstrated a SoS variation ranging from 1322.91 m/s (0.6 diesel volume fraction) to 1349.79 m/s (diesel fuel only), whereas hydrous ethanol samples varied between 1199.92 m/s (0.95 ethanol volume fraction) to 1149.39 m/s (pure ethanol only). Finally, assessments for 95 and 100 research octane number (RON) gasoline blends showed a SoS range from 1134.42 m/s (RON 95) to 1159.86 m/s (RON 100). The high precision and repeatability (relative uncertainty: ∼10-4) of the performed SoS measurements in controlled samples, has demonstrated the promising potential of OPTICS for the evaluation of fuel physical properties as well as the potential detection of contamination with adulterants.

On the influence of different alcohol-type biofuels on performance and engine emissions of an SI engine

Greenhouse gas emissions (G.H.G.) from vehicles are the main source of pollution. In this transition period from fossil fuels to the use of synthetic fuels, the diversification of alternative fuels used to fuel internal combustion engines is seen as one of the best alternatives for reducing G.H.G. In Europe, conforming to the stringent emission reduction targets for 2030, as well as trying to fulfil the regulations of the new Euro VII standard will force engine manufacturers to adopt alternative fuel solutions with a low environmental impact. However, fossil fuels will continue to be used but alternative fuels will substantially decrease our dependence on petroleum-derived fuels. Modern simulation software tools make it easy to produce a fairly accurate analysis of how an internal combustion engine works without the need for prototyping. Packages such as Ricardo WAVE or AVL Boost, are relatively cheap and represent accessible tools for developing, designing, and testing modern internal combustion engines. AVL Boost is a widely used engine simulation tool a 1D (one-dimensional) simulation software that allows engineers and researchers to model, simulate, and optimize various internal combustion engines, including spark ignition (SI) engines, diesel engines, and hybrid powertrains. The software also offers a high degree of flexibility in terms of alternative fuel blends. This paper evaluates the influences of using alcohol-based biofuels on performance metrics and pollutant emissions, such as brake power, brake thermal efficiency, and emissions, such as CO, CO2, and NOx in a spark ignition engine. The effects of varying alcohol fractions in the gasoline-alcohol blends on engine performance and emissions are analysed and explained. In this study, several types of ethanol in gasoline blends were simulated (E25, E50, E85). The one-dimensional model of the tested engine was developed based on the design dimensions of the 1.2L TCe H5FT engine produced by Renault. In the context of maintaining constant engine power output, the findings from the simulation results indicate that the utilization of alcohol-based blends with a high volumetric percentage of alcohol (ranging from 70-90%) can result in a substantial increase in fuel consumption, particularly in the case of methanol blends. Consequently, this phenomenon is associated with an elevated emission of carbon dioxide (CO2). However, it should be noted that despite this drawback, there is evidence of an inclination towards reduced emissions of other pollutants due to the enhanced combustion processes facilitated by the higher ratio of oxygenated compounds and a lower peak temperature. Methanol, one of the two alcohols investigated in this study, is not recommended for usage in fuel blends for several reasons. Firstly, the consumption rate of methanol is higher compared to ethanol, which can result in increased fuel usage. Secondly, methanol poses health risks due to its toxicity at certain levels, posing potential hazards in handling and utilization. Moreover, high concentrations of methanol are not easily miscible with gasoline without the addition of co-solvents, further limiting its feasibility as a viable fuel component.

Characterization of Flex-Fuel Prechamber Enabled Mixing-Controlled Combustion With Gasoline/Ethanol Blends at High Load

Abstract This numerical study focuses on the characterization of prechamber-enabled mixing-controlled combustion (PC-MCC) at ∼18 bar brake mean effective pressure (BMEP) and 2200 rpm with 10% by volume ethanol-gasoline blend (E10) and pure ethanol (E100). Computational fluid dynamic (CFD) simulations of a stock and prechamber retrofitted single-cylinder Caterpillar C9.3B are carried out using CONVERGE. Prechamber equivalence ratio at spark timing, prechamber spark timing advance, and main chamber injection strategy are assessed with respect to their impact on ignition assistance performance and emissions characteristics relative to a diesel baseline at the same boundary conditions. Simulation results indicate that PC-MCC is flex-fuel capable and operates well for both E10 and E100 at the operating conditions considered. The results demonstrate that the use of a pilot-main injection strategy enables spark timing in the prechamber to be advanced and thus reduces spark plug firing pressure while maintaining robust ignition assistance. Results also indicate that the rich prechamber operation is favored for improved ignition assistance capabilities. The findings of this work suggest that a heavy-duty vehicle using a PC-MCC engine can utilize any blend of gasoline and ethanol, up to including pure ethanol, with no major sacrifices in performance relative to the diesel engine.

Experimental Study of Isopropyl Acetate and Acetone Additive Gasoline on a Spark-Ignition Engine and its Impact on Green Environment

Background & Aim: Gasoline engines using alcohol fuels are being researched in the present trend since they are seen to be viable as diesel engines. The effect of isopropyl acetate and acetone additive blends on gasoline is explored in this study using a single-cylinder four-stroke gasoline engine operating at a constant speed of 2500 rpm under all loading conditions. Methods: Two gasoline blends are prepared by adding 5 % and 10 % by volume of isopropyl acetate and acetone separately. Properties are investigated and tested for its engine performance and emission. objective: There are not much research about the effect of Isopropyl acetate as a fuel additive in gasoline engine. Hence the main objective lies on extract information on using this additive in SI engine Results: The trial results demonstrated that the A5 (5% Acetone + 95% Gasoline) brake thermal efficiency improved when compared to pure gasoline. At maximum engine load, all additive blends have lower brake specific fuel consumption than pure gasoline. However, under full load, the emissions of various additive blends are lower than those of pure gasoline. Conclusión: Results revealed that IA5 (5 % Isopropyl acetate + 95 % Gasoline), IA10 (10 % Isopropyl acetate + 90 % Gasoline), and A10 (10 % Acetone + 90 % Gasoline) are considered good for decreasing HC, NOx, and CO emissions respectively. The findings of this study can be considered as a patent to lay the information on these types of alcohols in gasoline engines.

Effects of intake manifold geometry in H2 & CNG fueled engine combustion

This study attempted to identify the effect of optimized intake manifold geometry on the behaviors and emission level of hydrogen compressed natural gas (H2CNG) fueled engine. For this purpose, a commercial Hyundai Sonata spark ignition engine (SIE) is modified to operate with CNG and hydrogen blend. The optimal intake pipe length was predicted using an analytical acoustic method. A new intake manifold is designed and implemented utilizing natural supercharging managed by over-pressure waves acoustic propagation. Several tests are conducted on the engine using the new manifold with a speed range from 1000 to 5000 rpm. Based on various engine speeds, the variation of brake torque (BT), in-cylinder pressure, NOx and CO emissions investigated by using gasoline, CNG and hydrogen CNG blend (HCNG) fueled engines via external mixtures. The first finding of the study is that the novel geometry improves the in-cylinder pressure by 10% at 3500 rpm. However, high engine speeds show a reduction of 14% in NOx and 40% in HC while speeds below 2000 rpm reduce CO by 40%. The second finding is that the new optimized geometry serves to get rid of both the auto-igni-tion and the backfire for high ratio of hydrogen in the blend.

The Effect of using an Ethanol blended fuel on Emissions in an SI Engine

The economic impact of limited fossil fuel resources plus the mandatory limit for carbon dioxide (CO2) emissions become important factors to developing alternative fuels for internal combustion engines. Ethanol (CH3CH2OH) blends are considered as alternative fuels due to their ability to reduce the greenhouse exhaust emissions. This study highlights the effects of unleaded gasoline (E0) and ethanol- unleaded gasoline blend E30 (with 30% volume of ethanol) on engine performance and exhaust emissions experimentally using a 1.4 litre four cylinder four stroke SI engine with a compression ratio of 9:1, for a variety of load and engine speed conditions.. The results indicate that the blend E30 slightly increases the engine’s torque and power after mid-engine speeds together with fuel consumption. However, exhaust emissions at 25% open throttle sees a reduction of carbon monoxide (CO), carbon dioxide (CO2) and hydrocarbons (HC) whilst nitrogen oxide (NOX) emissions increase at the lower speeds. At full throttle, E30 reduces the CO considerably whilst CO2 and NOX increase. Similar quantities of HC are produced.

Improving Physical Properties of Polythene Pyrolytic Oil Through Gasoline Blending

Improving Physical Properties of Polythene Pyrolytic Oil Through Gasoline Blending

Effects of pilot injection on ignition performance for F-24/Gasoline fuel blends

This study experimentally investigates the effects of pilot injection on first stage and overall ignition behavior for different fuel blends. A conventional petroleum-derived fuel (F-24) with a Derived Cetane Number (DCN) of 48.5 and gasoline (GAS), which has a low DCN of 21.4 but high volatility, were blended at different volumetric ratios. These blends were injected into a high temperature, pressure vessel using either a single or pilot-main injection strategy. Four optical diagnostics (formaldehyde PLIF, OH* chemiluminescence, schlieren, and Mie scattering) were employed to visualize the ignition process and to evaluate liquid length, penetration distance, heat release rate, the first stage, and overall ignition delays. It is shown that the higher GAS blend ratios result in longer ignition delay and less overall heat release attributed to the poor reactivity of GAS. In such cases, the contributions of the extended first stage ignition delay to the extended overall ignition delay decrease with GAS blend ratio. Furthermore, some of the high GAS blend fuels exhibit no overall ignition at all due to the excessive fuel-air mixing. The study then shows that this decrease in ignition performance with GAS can be mitigated by introducing pilot injection, which shortens the ignition delays and provides more overall heat release. Specifically, at low GAS blend ratios, the ignition exhibits mixing controlled combustion where the ignition of pilot fuel-air mixture induces the main fuel ignition. For pilot-main injections, the decrease in first stage ignition delay accounts for the average of 87 % of the reduced overall ignition delay, suggesting that the reduced ignition delay with pilot injection is primarily due to the reduced time for fuel atomization, vaporization, and decomposition of the main fuel. These results will contribute to the development of ignition models capable of capturing the impact of fuel composition and pilot injection on ignition performance.

Preference Prediction-based Evolutionary Multi-objective Optimization for Gasoline Blending Scheduling

Preference Prediction-based Evolutionary Multi-objective Optimization for Gasoline Blending Scheduling

Bambusa tulda: A potential feedstock for bioethanol and its blending effects on the performance of spark ignition engine

Alternatives to conventional fuel sources must be investigated due to strict regulatory requirements and the depletion of fossil fuel supplies. As a result, of better transportation and population growth, the requirement for energy is increasing daily. Bioethanol may be used successfully to replace both gasoline and spark ignition engine diesel. Most nations blend 10% bioethanol with gasoline in automobiles. Several nations, notably India, have announced that they will soon begin blending 20% bioethanol with gasoline. Bambusa Tulda is used as a raw material for the extraction of bioethanol, which is a type of Indian bamboo. This study covers both the ethanol extraction from bamboo and the effects of various mixtures on spark-ignited engine performance. Four separate blends were developed on a volumetric basis at varying engine speeds, and the wide-open throttle was utilized to evaluate the performance and emissions of each mix with a constant compression ratio of 10:1. When bioethanol was enhanced, combustion efficiency, indicated power, engine power, mechanical efficiency, and volumetric efficiency all increased. Hydrocarbon, carbon monoxide, and carbon dioxide emissions decreased, while nitrogen oxide emissions increased. The engine performance of BE 15 was found to be the greatest among all the gasoline blends tested. According to this study, when nitrogen oxide emission control methods are applied, bamboo may be used as a feedstock for the manufacture of second-generation bioethanol. This invention offers a bioethanol production process that is good for environmental sustainability.

Alternative Options for Ebullated Bed Vacuum Residue Hydrocracker Naphtha Utilization

The vacuum residue hydrocracker naphtha (VRHN) is a chemically unstable product that during storage changes its colour and forms sediments after two weeks. It cannot be directly exported from the refinery without improving its chemical stability. In this research, the hydrotreatment of H-Oil naphtha with straight run naphtha in a commercial hydrotreater, its co-processing with fluid catalytic cracking (FCC) gasoline in a commercial Prime-G+ post-treater, and its co-processing with vacuum gas oil (VGO) in a commercial FCC unit were discussed. The hydrotreatment improves the chemical stability of H-Oil naphtha and reduces its sulphur content to 3 ppm. The Prime-G+ co-hydrotreating increases the H-Oil naphtha blending research octane number (RON) by 6 points and motor octane number (MON) by 9 points. The FCC co-cracking with VGO enhances the blending RON by 11.5 points and blending MON by 17.6 points. H-Oil naphtha conversion to gaseous products (C1–C4 hydrocarbons) in the commercial FCC unit was found to be 50%. The use of ZSM 5 containing catalyst additive during processing H-Oil naphtha showed to lead to FCC gasoline blending octane enhancement by 2 points. This enabled an increment of low octane number naphtha in the commodity premium near zero sulphur automotive gasoline by 2.4 vol.% and substantial improvement of refinery margin. The processing of H-Oil naphtha in the FCC unit leads also to energy saving as a result of an equivalent lift steam substitution in the FCC riser.

Optimum Design of Naphtha Recycle Isomerization Unit with Modification by Adding De-Isopentanizer

Environmental standards have recently imposed very rigorous limitations on the amounts of benzene, aromatics, and olefins, which can be found in finished gasoline. Reduction of these components could negatively affect the octane number of gasoline, so the isomerization process is gaining importance in the present refining context as an excellent safe alternative to increase the octane number of gasoline. The main aim of the naphtha isomerization unit is to modify the molecular structure of light naphtha to transform it into a more valuable gasoline blend stock, and simultaneously the benzene content is reduced by saturation of the benzene fraction. In this work, Aspen HYSYS version 12.1 is used to simulate the hydrogen once-through isomerization unit of an Egyptian refinery plant, located in Alexandria, in order to determine the properties, composition, and octane number of the isomerate product. Many potential changes are investigated in order to find the best design that efficiently raises octane number with the least amount of expense. Firstly, the plant is modified by adding one fractionator either before or after the reactor, then by adding two fractionators before and after the reactor; then the configuration which gives the highest product octane number with the highest Return on Investment (ROI) is chosen as the recommended optimum configuration. The results show that using two fractionators before and after the reactor is the best configuration. Optimization of this best configuration resulted in an increase in octane number by 7% and a decrease in the total cost by 13%.