EFFECT OF MTBE BLENDING ON THE PROPERTIES OF GASOLINE

The effect of blending MTBE in the gasoline was evaluated. MTBE effectively boost the octane numbers of gasoline without adversely effecting its other properties. However, MTBE is not as efficient as leadalkyl compounds as far as the specific octane number improvements are concerned. The addition of 5 to 30 volume percent MTBE increases 1.9 to 11.8 RON of a typical gasoline. MTBE addition also extends the volume of gasoline produces for a given crude by adding volume to the gasoline pool. MTBE provides much higher FEON to the gasoline in comparison with other gasoline components. A higher FEON increases the efficiency of the engine. MTBE is not affected by the lead level of the gasoline. For this reason, lost octane in future lead reductions of the gasoline in Saudi Arabia can be made up with MTBE. MTBE addition to the Saudi gasoline increases the RVP but within the specification of the gasoline. MTBE has favorable effect on the distillation characteristics of the gasoline. MTBE addition lowers the distillation temperature which improves driveability and cold engine operation. MTBEgasoline blends were found free of gums and peroxides after long term storage and pose no phase separation problems in the presence of water. MTBE is miscible in gasoline in all proportions and its solubility in water is low.     

THE EFFECT OF GASOLINE FUEL TYPE ON SI ENGINE NITROGEN-OXIDES AND CARBON MONOXIDE EMISSIONS UNDER PART-LOAD OPERATING CONDITIONS

ABSTRACT

Six different gasoline blends with different antiknock agents and aromatics content were investigated for its influence on SI engine nitrogen-oxides and carbon monoxide emissions at part- load operating conditions. The six fuel types used were leaded gasoline with 0·5 g Pb/1, commercial unleaded gasoline, unleaded synthetic gasoline and its blends with different proportions of methyl tertiary butyl ether MTBE l10, 15 and 20 vol%). A four- stroke, four- cylinder, spark- ignition Regata engine (type 138 B 3.000) was used for conducting this study. The exhaust gases were analyzed for nitrogen-oxides and carbon monoxide emitted at part-load operating conditions for the speed range of 1000 to 3000 rpm. The results of this investigation have shown that blending unleaded synthetic gasoline with ethers such as MTBE reduces the aromatic content of the fuel. The 20 vol% MTBE-fuel blend gave the lowest carbon monoxide emissions of all blends used at part load condition. On the other hand, the 10 vol% MTBE-fuel blend gave the lowest nitrogen-oxides emission of all blends at part-load condition. The carbon monoxide concentration in engine exhaust differs between increase and decrease at part-load condition when fuel aromatics content increases. It was also found that as the gasoline aromatics content increases in the blend, the nitrogen-oxides concentration in engine exhaust increases. So, substitution of MTBE for the higher aromatics gasoline blends may help improving state environment and air quality.     

EFFECT OF METHYL TERTIARY BUTYL ETHER (MTBE) AS A GASOLINE ADDITIVE ON ENGINE PERFORMANCE AND EXHAUST EMISSIONS

ABSTRACT

The effect of blending unleaded gasoline with different proportions of methyl-t-butyl ether MTBE (10, 15 and 20 vol % ) on engine performance was studied using a fixed compression ratio SI engine (Opel 4 -cylinder ). The exhaust gases were analyzed for carbon monoxide, carbon dioxide and the hydrocarbons emitted. The results have shown that MTBE blends gave slightly better engine performance than the unleaded gasoline as evidenced by the power output. Analysis of exhaust gases shows better carbon monoxide and hydrocarbon emissions for all MTBE blends tested than unleaded gasoline. A higher carbon dioxide exhaust emission of the blends than the unleaded gasoline also confirms their better combustion. The 20 vol % MTBE blend gave the lowest carbon monoxide and hydrocarbon emissions of all blends used. A comparison was also made between a     

THE EFFECT OF GASOLINE FUEL TYPE ON SI ENGINE NITROGEN-OXIDES AND CARBON MONOXIDE EMISSIONS UNDER PART-LOAD OPERATING CONDITIONS

Six different gasoline blends with different antiknock agents and aromatics content were investigated for its influence on SI engine nitrogen-oxides and carbon monoxide emissions at part- load operating conditions. The six fuel types used were leaded gasoline with 0·5 g Pb/1, commercial unleaded gasoline, unleaded synthetic gasoline and its blends with different proportions of methyl tertiary butyl ether MTBE l10, 15 and 20 vol%). A four- stroke, four- cylinder, spark- ignition Regata engine (type 138 B 3.000) was used for conducting this study. The exhaust gases were analyzed for nitrogen-oxides and carbon monoxide emitted at part-load operating conditions for the speed range of 1000 to 3000 rpm. The results of this investigation have shown that blending unleaded synthetic gasoline with ethers such as MTBE reduces the aromatic content of the fuel. The 20 vol% MTBE-fuel blend gave the lowest carbon monoxide emissions of all blends used at part load condition. On the other hand, the 10 vol% MTBE-fuel blend gave the lowest nitrogen-oxides emission of all blends at part-load condition. The carbon monoxide concentration in engine exhaust differs between increase and decrease at part-load condition when fuel aromatics content increases. It was also found that as the gasoline aromatics content increases in the blend, the nitrogen-oxides concentration in engine exhaust increases. So, substitution of MTBE for the higher aromatics gasoline blends may help improving state environment and air quality.     

Octane Rating of Gasoline and Octane Booster Additives

Gasoline is a petroleum-derived liquid that is used primarily as a fuel in internal combustion engines (ICE), particularly spark ignition Otto Engine. Gasoline is a blend of hydrocarbons with some contaminants, including sulfur, nitrogen, oxygen, and certain metals. The four major constituent groups of gasoline are olefins, aromatics, paraffins, and napthenes. Octane number (ON) is measure of the ignition quality or flammability of gasoline. The ONs are Research Octane Number (RON) and Motor Octane Number (MON). RON is measured relative to a mixture of isooctane and n-heptane. Antiknock Index (AKI) is a measure of a fuel's ability to resist engine knock or octane quality. The AKI is an arithmetic average of RON and MON. The ON decreases with an increase chain length in the hydrocarbon molecule. The ONs increase with carbon chain branching. Another way of increasing the ON is used gasoline octane boosters as additives, such as tetraethyl lead (TEL), methyl tertiary-butyl ether (MTBE), and ferrocene. Aromatic alcohols, ethanol, and methanol also increase the ON of gasoline. The advantage to adding oxygenates, such as MTBE, methanol, and ethanol, to gasoline is that they cause very little pollution when they burn and are cleaner fuels.     

EFFECT OF METHYL TERTIARY BUTYL ETHER (MTBE) AS A GASOLINE ADDITIVE ON ENGINE PERFORMANCE AND EXHAUST EMISSIONS

The effect of blending unleaded gasoline with different proportions of methyl-t-butyl ether MTBE (10, 15 and 20 vol % ) on engine performance was studied using a fixed compression ratio SI engine (Opel 4 -cylinder ). The exhaust gases were analyzed for carbon monoxide, carbon dioxide and the hydrocarbons emitted. The results have shown that MTBE blends gave slightly better engine performance than the unleaded gasoline as evidenced by the power output. Analysis of exhaust gases shows better carbon monoxide and hydrocarbon emissions for all MTBE blends tested than unleaded gasoline. A higher carbon dioxide exhaust emission of the blends than the unleaded gasoline also confirms their better combustion. The 20 vol % MTBE blend gave the lowest carbon monoxide and hydrocarbon emissions of all blends used. A comparison was also made between a     

汽油辛烷值促进剂异庚酯在汽油调合中的应用

介绍了汽油辛烷值促进剂异庚酯的主要成分和性能指标、主要特点以及在汽油调合中的应用情况。结果表明:异庚酯对汽油感受性良好,使汽油的辛烷值提升幅度大,高于MMT和MTBE,且能够同时实现汽油清净化。     

提高汽油辛烷值的新途径

介绍了目前正在应用或开发的一些提高汽油辛烷值的新工艺,包括改变汽油基础组分提高汽油的辛烷值和添加非铅汽油添加剂。     

汽油的烯烃对发动机排放的影响

讨论了汽油中的烯烃与发动机排放之间的关系。研究表明,当烯烃含量增加时,发动机排放的ＮＯｘ和１,３－丁二烯增加,ＨＣ、挥发性有机化合物和甲醛减少,乙醛和苯的排放量不变;虽然烯烃含量增加,使发动机尾气臭氧形成的比活性提高,但对臭氧形成的能力影响不大。烯烃是一种辛烷值资源,应该加以利用,并且烯烃对发动机沉积物的负面影响可以通过加入汽油清净剂等方法加以控制。因此,应该允许汽油中含有一定量的烯烃。     

介孔H-ZSM-5分子筛的制备及以其为载体的催化剂的催化裂化汽油加氢性能

以廉价的橡胶乳液-3为介孔模板剂,通过优化晶化温度、晶化时间和凝胶中橡胶乳液-3干基与硅元素的质量比（R）,以及采用蒸汽/柠檬酸组合处理,获得孔结构和酸性适宜的介孔H-ZSM-5分子筛,并对以此分子筛为载体制备的辛烷值恢复催化剂进行催化裂化汽油（催化汽油）加氢性能评价。表征结果表明：R、晶化温度和晶化时间的最佳值依次为0.26,190 ℃,48 h;蒸汽/柠檬酸组合处理在显著提高介孔H-ZSM-5分子筛介孔比例的同时可在较大范围内调控其酸性。以硫质量分数为113 μg/g、烯烃体积分数为40.9%的催化汽油为原料的加氢性能评价结果表明：与上一代工业化辛烷值恢复催化剂相比,新制备的辛烷值恢复催化剂作用下的加氢产品的烯烃体积分数降低2.2百分点,异构烷烃体积分数增加1.1百分点,芳烃体积分数增加1.1百分点,脱硫率增加11.5百分点,研究法辛烷值（RON）损失减小0.5个单位,液体收率相当。介孔H-ZSM-5分子筛具有较大平均孔径、较高强L酸酸量与B酸酸量的比值、较多弱酸量,有利于提高其对催化汽油降烯烃、保持高RON和高液体收率的能力;其较大平均孔径有利于活性金属在介孔分子筛中的分散,从而使其对催化汽油表现出较高的脱硫性能。     

调合汽油研究法辛烷值模型的建立

建立了适用于MTBE-重整汽油-烷基化油-直馏汽油-催化裂化汽油调合汽油的研究法辛烷值模型。实算表明，模型与有关的实测辛烷值符合较好。所有的模型参数只需要从二元调合组分的数据得到，并能较准确地预测多元调合汽油的辛烷值。将模型用于汽油调合过程价格优化获得了满意的结果。     

丁醇作为汽油调合组分的可行性研究

研究了丁醇与常规汽油组分以不同比例调合后油品的辛烷值、馏程、蒸气压调合特性,通过金属试片和橡胶试片在不同丁醇含量汽油中的浸泡试验,对丁醇汽油的金属腐蚀性和材料相容性进行了评价。结果表明：丁醇在调合特性方面与汽油组分的匹配性良好;丁醇汽油对除铸铁外的金属件腐蚀性很小,可用于不含铸铁的燃油进气系统中;氟橡胶、氯丁胶、丁腈胶等橡胶试件性能受丁醇汽油的影响较小,更适宜作为燃用丁醇汽油的发动机橡胶零部件或丁醇汽油储运、加油设施中的橡胶件;丁醇作为车用汽油调合组分具有可行性,调合丁醇的质量分数在10%~16%较为合理。     

间接烷基化工艺及其技术经济评估

近20年来MTBE一直作为汽油高辛烷值添加剂，但随着MTBE在美国消费量减少或禁用，全球MTBE的消费量相对减少。采用丁烯二聚、加氢制异辛烷的间接烷基化工艺改建现有MTBE装置已成为解决MTBE装置和异丁烯原料出路的一条重要途径。本文介绍了InAlk,SP-Isoether,Seletopol,NExOclane 4种间接烷基化工艺，并对其技术经济进行了评估。由于这些工艺可提供一种高质量汽油，因而MTBE装置的改造将很具吸引力。     

催化汽油加氢装置GARDES技术的工业应用

中国石油四川石化有限责任公司1.1 Mt/a催化裂化汽油加氢装置采用中国石油石油化工研究院与中国石油大学（北京）合作研发的GARDES汽油加氢技术,以催化裂化汽油为原料,生产硫含量满足GB 17930-2016的车用汽油（V）（简称国V汽油）调合组分。标定结果表明,以硫质量分数69.6 μg/g,烯烃体积分数30.3%,芳烃体积分数18.4%的催化裂化汽油为原料,经GARDES技术处理后,混合汽油产品的硫质量分数为7.1 μg/g,辛烷值（RON）为91.7,比全馏分汽油原料的辛烷值（RON）损失0.5个单位,混合汽油收率99.41 %,优于控制指标,装置综合能耗略高于控制指标。     

MTBE碱洗-萃取蒸馏脱硫实验研究

根据硫醇具有弱酸性的特点,采用碱洗-萃取蒸馏法对MTBE进行了脱硫实验研究。研究结果表明：在NaOH质量分数28%、m(NaOH):m(MTBE)=0.015、碱洗温度35 ℃、碱洗时间6 s、相分离温度35 ℃、相分离时间5 min的条件下,MTBE硫质量分数可从132.5 μg/g降至76.2 μg/g;采用DMF为萃取剂,将碱洗后的MTBE在蒸馏温度80℃、蒸馏时间25 min、剂油质量比1.5的条件下进行3级萃取蒸馏,MTBE硫质量分数可降至8.7μg/g,质量收率为99.64%;将萃取溶剂在空速60 h-1、温度100 ℃的实验条件下用N2汽提再生,经6次再生后回用, MTBE的硫质量分数均能降到10 μg/g以下,再生效果较好。     

我国汽油添加剂的现状与发展趋势

综述了我国汽油高辛烷值添加剂醚类的生产技术的发展,介绍了我国醇类添加剂的发展情况和国内新开发的几种汽油添加剂。     

发展FCC轻汽油醚化工艺

我国FCC汽油作为车用汽油的主要调合组分，其比例已占70％以上，是车用汽油质量不能进一步提高的瓶颈所在．FCC轻汽油醚化工艺将其中的叔碳烯烃转化为醚，在一定程度上弥补了MTBE产量的不足，除提高辛烷值和增加含氧量外，还可降低汽油的烯烃含量和蒸气压，一举多得，值得开发、推广。     

Role of Gasoline Specifications in the Control of Environmental Pollution

Abstract

Gasoline is a mixture of about 100 hydrocarbon compounds. Molecular carbon numbers range from C6–C12 and evaporating between ambient temperatures to about 220°C. Gasoline is used in spark ignition engines (cars and motorcycles). The grades and types of gasoline are usually defined in terms of octane numbers. The specifications of gasoline is based mainly on physical properties, which can be related to performance such as volatility and octane number. Chemical components such as oxygen, sulfur, lead, and benzene are also significant. The present trend is to incorporate generic fractions such as aromatics and olefinics in the specifications. How these parameters (specifications) relate to the various fuel requirements and subsequently affect the environment is described in this article.     

INDIAN GASOLINE QUALITY AND REQUIREMENT OF DEPOSIT CONTROL ADDITIVES FOR ENGINE INTAKE SYSTEM CLEANLINESS

ABSTRACT

To meet the growing demand of gasoline, heavier ends of crude are being converted into distillate products through secondary refining processes such as fluid catalytic cracking (FCC), thermal cracking, etc. Present day gasoline in India consists of a mixture of unstable streams such as coker, FCC and visbreaker naphtha besides straight run (SR) naphtha and reformate, affecting the overall quality and stability of the fuel. Out of thirteen refineries in India, nine are equipped with FCC units. In these refineries, gasoline is composed of 50 to 90% of FCC stock. This paper presents data on Indian gasoline quality. Effectiveness of a number of commercially available multifunctional additives on carburettor and intake valve cleanliness was studied on gasolines from different refineries. In addition, the effect of these additives on engine performance and emissions is reported.     

MTBE作为清洁汽油组分的前景

MTBE作为优良的汽油调合组分 ,迄今已使用 2 0余年。近几年因在美国某些地下水中检测到MTBE ,由此引起人们对饮用水安全的担心。目前世界某些国家和地区已制定了相应的对策。本文分析了MTBE用于汽油的利弊 ,探讨了MTBE作为汽油调合组分的前景 ,并介绍了MTBE可能的替代方案