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     

燃用乙醇汽油对发动机润滑油性能的影响

选用12辆试验样车(一种化油器型发动机和两种电喷型发动机)用含乙醇体积分数分别为7.7％、10％、15％的乙醇汽油和93号标准汽油进行了低、中、高速和山区道路的共8×10~4km对比行车试验。经试验前后对样车发动机进行拆检和发动机润滑油分析结果表明,燃用乙醇汽油样车的发动机润滑油氧化性能、表面沉积物形成、试验样车发动机主要零部件的磨损与燃用93号标准汽油样车的相当。     

汽油烃组成对汽车排放的影响

使用不同烃组成的6种汽油分别在满足国III、国IV排放标准的车型上进行了I型、IV型和VI型排放试验,研究了汽油烯烃、芳烃含量对常温冷启动后、低温冷启动后尾气排放和蒸发排放的影响。结果表明,汽油组成对排放的影响与汽车技术密切相关,满足国IV排放标准的车型上,当芳烃体积分数为35%、油品烯烃体积分数控制在25%时,HC,CO,NOx三种排放物较低;芳烃含量对排放的影响与发动机技术相关,但基本上呈现出芳烃含量较低时排放也较低的趋势;总蒸发排放物随油品烯烃含量增加而增加;油品的非烷烃类烃含量（即烯烃含量与芳烃含量之和）越高,车辆低温冷起动后HC、CO排放越高。     

燃油组分对车用汽油机排放特性的影响分析

综述了燃油中烷烃、烯烃、芳烃等组分对于车用汽油机排放特性的影响。未燃烷烃是烷烃燃料HC排放的主要成分,烯烃燃料的HC排放主要包括丙烯、异丁烯、戊烯等,1,3-丁二烯的排放随燃油烯烃含量的增加而增加;苯、甲苯、乙苯等的排放随芳烃含量的增加而增加;发动机燃烧工况如空燃比、点火角度等对各种HC排放的具体组成有显著影响。因此,不仅需要加强降低燃油烯烃、芳烃含量的研究,也应该借助发动机燃烧过程的优化来降低因烯烃、芳烃含量高对排放造成的不利影响。     

燃油烃类组分对车用汽油机排放特性的影响

综述了燃油中烷烃、烯烃、芳烃等组分对车用汽油机排放特性的影响。未燃烷烃是烷烃燃料HC排放的主要成分,烯烃燃料的HC排放主要包括丙烯、异丁烯、戊烯等,1,3-丁二烯的排放随燃油烯烃含量的增加而增加;苯、甲苯、乙苯等的排放随芳烃含量的增加而增加;发动机燃烧工况如空燃比、点火角发等对各种HC排放的具体组成有显著影响。因此,不仅需要加强降低燃油烯烃、芳烃含量的研究．也应该借助发动机燃烧过程的优化来降低因烯烃、芳烃含量高对排放造成的不利影响。     

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.     

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.     

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.     

EFFECT OF MTBE BLENDING ON THE PROPERTIES OF GASOLINE

ABSTRACT

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.     

含锰车甩汽油见光后诱导期及辛烷值的变化

对加有甲基环戊二烯三羰基锰抗爆剂的车用汽油见光后诱导期、辛烷值的变化进行了试验考察。试验结果表明:含锰车用汽油见光后锰抗爆剂抗爆作用丧失、诱导期急剧下降,汽油变浑浊并有沉淀生成;避光保存时,其性质在半年内不会有大的变化。对金属锰基有机化合物的抗爆作用机理及见光失效原因进行了初步分析,提出了含锰车用汽油在取样、储存及检验过程中应避光操作。对于汽油见光所引起的质量变化,应当引起有关生产、销售、监督及检验等部门的高度重视,并应加强对含锰汽油在储存、使用中发生的变化进行考察和研究。     

生物基汽油添加剂组分对汽油机油耗的影响

通过汽油机台架试验,对一种加入汽油中的改性生物基添加剂组成及其添加比例对发动机燃油经济性的作用及效果进行了研究。结果表明,尽管增溶剂能提高添加剂原液与汽油在低温下的互溶性,但是仅加入增溶剂对发动机的燃油经济性几乎没有任何改善;添加剂原液对发动机燃油经济性的改善幅度最大,最高可达8％左右,而且存在一个最佳添加比例,以使发动机获得最好的综合性能。     

含锰车用汽油见光后诱导期及辛烷值的变化

对加有甲基环戊二烯三羰基锰抗爆剂的车用汽油见光后诱导期、辛烷值的变化进行了试验考察。试验结果表明：含锰车用汽油见光后锰抗爆剂抗爆作用丧失、诱导期急剧下降，汽油变浑浊并有沉淀生成；避光保存时，其性质在半年内不会有大的变化。对金属锰基有机化合物的抗爆作用机理及见光失效原因进行了初步分析，提出了含锰车用汽油在取样、储存及检验过程中应避光操作。对于汽油见光所引起的质量变化，应当引起有关生产、销售、监督及检验等部门的高度重视，并应加强对含锰汽油在储存、使用中发生的变化进行考察和研究。     

复合剂与抗氧剂对煤基汽油机油氧化安定性的影响

以煤基费-托合成油为API III+润滑油基础油,利用高压差式扫描量热仪（PDSC）和热氧化模拟试验（TEOST MHT-4）测定配制煤基汽油机油样品的起始氧化温度和高温沉积物生成量,考察了复合剂和抗氧剂对煤基润滑油基础油起始氧化温度和高温沉积物的影响。结果表明：复合剂与抗氧剂的加入量不会持续增强油品的氧化安定性,过量的抗氧剂反而会因其自身氧化而增加高温沉积物生成量;全配方煤基5W-30汽油机油样品PDSC测试起始氧化温度为259.94 ℃,TEOST MHT-4试验高温沉积物为18 mg;与某品牌石油基5W-30汽油机油相比,煤基汽油机油具有更好的氧化安定性和更少的高温沉积物生成量。     

车用汽油/喷气燃料混合油作为汽油机燃料的研究

综合利用实验室理化性能分析、发动机台架试验和实际行车试验等方式对车用汽油/喷气燃料混合油用作汽油应急替代燃料的可行性进行研究。结果表明,汽油中掺入喷气燃料后,挥发性下降,抗爆性变差。随着汽油中掺入喷气燃料比例的增加,发动机功率逐渐下降、油耗率逐渐上升,当喷气燃料体积分数为40%时,发动机功率下降5.3%～11.7%,油耗率平均增加3.8%,而且发动机油稀释加重,排放变差。因此,对于汽油机来说,混合油会对发动机产生一定的损害,只能作为应急替代燃料使用,而且喷气燃料的体积分数应低于40%。     

汽油芳烃对发动机沉积物的影响

采用实验室模拟手段以及Ford2-3 L标准发动机台架试验研究了汽油芳烃对发动机进气阀以及燃烧室沉积物的影响。结果表明,随着芳烃含量的增加,进气阀和燃烧室沉积物质量增大,并且不同结构的二甲苯对沉积物的影响不同,其中对二甲苯形成沉积物的趋势最大;相对于烯烃,芳烃含量对进气阀以及燃烧室的沉积物形成影响较大。     

含磷硼酸酯润滑油添加剂的合成与性能测试

用硼酸与月桂醇和五氧化二磷反应合成了含磷硼酸酯润滑油添加剂。合成的最佳工艺条件为月桂醇与硼酸和五氧化二磷摩尔比为 8∶ 1∶ 1 ,脱水反应 6h。用四球机测试了含该添加剂 0 .5 %～ 5 %的基础油的抗磨性能。四球机试验结果表明含磷硼酸酯添加到基础油中能显著提高其抗磨性能 ,且添加量存在一个最佳值。     

叔丁醇与甲醇合成甲基叔丁基醚的研究

介绍以叔丁醇和甲醇为原料,采用国产催化剂A催化醚化反应制MTBE,并用Aspen Plus软件模拟后续精馏分离装置的技术和工艺。采用小试装置考察了工艺条件对反应的影响。结果表明:在空速1.0 h~(-1)、压力2.3 MPa、温度140℃、甲醇与叔丁醇摩尔比3∶1条件下,叔丁醇转化率可达79%以上,MTBE选择性可达73%以上。Aspen Plus软件模拟结果表明,采用醇类化合物替代水作为萃取剂,能够解决叔丁醇、水的共沸问题,并将系统中的水基本脱除,能够促使主反应向右进行,有效提高叔丁醇的转化率。     

节能型汽油机油及有机钼减摩剂减摩性能评价

不断提高节能技术是推动汽车工业发展的三大动力之一。而提高内燃机燃油经济性的途径主要是通过适当降低内燃机油粘度和减少机件之间的摩擦损耗来实现。文章借助从德国OPTIMOL公司引进的SRV@4型摩擦磨损试验机,采用满足ASTMD6425方法的球-盘摩擦副,利用SRV@4型摩擦磨损试验机试验参数可实现动态控制的优势,选择合适的模拟试验条件,模拟内燃机“边界-混合”润滑状态,测定确定条件下油品的摩擦系数,该方法对程序ⅥB台架试验的通过油和失败油有较好的区分,且对油溶性有机钼减摩剂减摩效果的评价具有良好的区分性。     

月桂酰基丙氨酸作为润滑油添加剂的性能研究

利用月桂酰氯和丙氨酸在碱性溶液中反应制备出了N—月桂酰基丙氨酸。用红外光谱对其主要官能团进行了表征；考察了该物质作为润滑油添加剂对HVI350矿物基础油的生物降解性能的影响，并用四球摩擦磨损试验机考察了N—月桂酰基丙氨酸在HVI350矿物基础油中的摩擦磨损性能。结果表明：N—月桂酰基丙氨酸作为矿物油添加剂表现出极好的提高矿物油生物降解性的作用，良好的抗磨减摩性能，并且具有优良的抗腐蚀性和防锈性，是一种环境友好型的多功能润滑添加剂。     

水溶性杂环三嗪衍生物润滑添加剂的合成及摩擦学性能研究

对摩擦性能优良的三嗪杂环进行水溶性改良，合成了一种无灰无磷水基润滑添加剂2 ,4 ,6-三(N，N-二羟乙基氨基亚甲基硫代)-均三嗪(SNOT)，并用红外光谱仪(IR)对其结构进行了分析。以自来水为基础液，采用四球摩擦磨损试验机考察了其在基础液中的摩擦学性能。结果表明：添加剂能够较大程度地提高基础液的极压值，并显著提高其抗磨减摩性能。通过磨斑表面的金相照片和X光能量色散谱(EDS)分析可知，在摩擦过程中, 该添加剂与摩擦副表面发生了复杂的摩擦化学反应, 在其表面生成硫、氮等的复合边界润滑膜，从而起到了极压抗磨减摩作用。