Inserting renewable fuels and technologies for transport in Mexico City Metropolitan Area

This article describes three future scenarios for the potential reduction of CO₂ emissions and associated costs when biogenic ethanol blends and oxygenates are substituted for gasoline, and hybrid, flex fuel and fuel cell technologies are introduced in passenger automobiles (including pickups and sport-utility vehicles (SUVs)) in the densely populated Mexico City Metropolitan Area (MCMA), analyzed up to the year 2030. A reference (REF) scenario is constructed in which most automobiles are driven by internal combustion engines (ICE) fuelled by gasoline. In the first alternative scenario (ALT1), hybrid electric-ICE gasoline-fuelled cars are introduced in 2006. In the same year, ethyl tertiary butyl ether (ETBE) is introduced as a replacement for methyl tertiary butyl ether (MTBE) oxygenate for gasoline. In the second alternative scenario (ALT2), in addition to the changes introduced in ALT1, flex fuel ICE technology fuelled by E85 is introduced in 2008 and electric motor vehicles driven by direct ethanol fuel cells (DEFC) fuelled by E100 in 2013. A comparison between the reference and alternate scenarios shows that while the total number of vehicles is the same in each scenario, energy consumption decreases by 9% (ALT1) and 17% (ALT2), the total non-biogenic CO₂ emissions drop by 15% (ALT1) and 34% (ALT2), CO₂ mitigation cost is 140.14 $US1997/ton CO₂ (ALT2), and ALT1 has savings and is considered a “no regrets” scenario.     

Performance and exhaust emissions of a gasoline engine with ethanol blended gasoline fuels using artificial neural network

The purpose of this study is to experimentally analyse the performance and the pollutant emissions of a four-stroke SI engine operating on ethanol–gasoline blends of 0%, 5%, 10%, 15% and 20% with the aid of artificial neural network (ANN). The properties of bioethanol were measured based on American Society for Testing and Materials (ASTM) standards. The experimental results revealed that using ethanol–gasoline blended fuels increased the power and torque output of the engine marginally. For ethanol blends it was found that the brake specific fuel consumption (bsfc) was decreased while the brake thermal efficiency (η_b.th.) and the volumetric efficiency (η_v) were increased. The concentration of CO and HC emissions in the exhaust pipe were measured and found to be decreased when ethanol blends were introduced. This was due to the high oxygen percentage in the ethanol. In contrast, the concentration of CO₂ and NO_x was found to be increased when ethanol is introduced. An ANN model was developed to predict a correlation between brake power, torque, brake specific fuel consumption, brake thermal efficiency, volumetric efficiency and emission components using different gasoline–ethanol blends and speeds as inputs data. About 70% of the total experimental data were used for training purposes, while the 30% were used for testing. A standard Back-Propagation algorithm for the engine was used in this model. A multi layer perception network (MLP) was used for nonlinear mapping between the input and the output parameters. It was observed that the ANN model can predict engine performance and exhaust emissions with correlation coefficient (R) in the range of 0.97–1. Mean relative errors (MRE) values were in the range of 0.46–5.57%, while root mean square errors (RMSE) were found to be very low. This study demonstrates that ANN approach can be used to accurately predict the SI engine performance and emissions.     

The energy demand and the impact by fossil fuels use in the Mexico City Metropolitan Area, from 1988 to 2000

Temporary variation for the demand of refining products which are used in the Mexico City Metropolitan Area (MCMA) is presented. Its consequent energy contribution is evaluated from 1988 to 2000. The annual estimation was integrated from a detailed inventory of fuels volume, so as the calculus of its respective energy equivalence. The fuel quality specifications, which have been required by regional Air Quality authority for controlling emissions to the atmosphere, are also presented for the same period. The evolution demand of fuels, in term of volume, quality and its energy contribution for this area, is compared with the national demand. On this regard, fuel pool differs in each bound and the demand along the same period has been increasing on both regions but at different rates, with 21% at MCMA and 31% countrywide. In 2000, the MCMA demanded 14% of the internal refining products volume sales, which represented 17% of the energy contribution to the country for those fuels. Likewise, the energy use coefficient (GJ per capita) was applied to compare this region with country trends. During 1996 and up to 2000, the MCMA presented slightly minor energy use per capita, than the rest of the country, and this period was distinguished also for using cleaner fuels and for obtaining improvements in air quality. On the other hand, MCMA and country greenhouse gases emissions will increase because of their fossil fuel dependence, so several mitigation measures must be implemented in the next decades.     

The effects of ethanol–unleaded gasoline blends on engine performance and exhaust emissions in a spark-ignition engine

Alcohols have been used as a fuel for engines since 19th century. Among the various alcohols, ethanol is known as the most suited renewable, bio-based and ecofriendly fuel for spark-ignition (SI) engines. The most attractive properties of ethanol as an SI engine fuel are that it can be produced from renewable energy sources such as sugar, cane, cassava, many types of waste biomass materials, corn and barley. In addition, ethanol has higher evaporation heat, octane number and flammability temperature therefore it has positive influence on engine performance and reduces exhaust emissions. In this study, the effects of unleaded gasoline (E0) and unleaded gasoline–ethanol blends (E50 and E85) on engine performance and pollutant emissions were investigated experimentally in a single cylinder four-stroke spark-ignition engine at two compression ratios (10:1 and 11:1). The engine speed was changed from 1500 to 5000 rpm at wide open throttle (WOT). The results of the engine test showed that ethanol addition to unleaded gasoline increase the engine torque, power and fuel consumption and reduce carbon monoxide (CO), nitrogen oxides (NO_x) and hydrocarbon (HC) emissions. It was also found that ethanol–gasoline blends allow increasing compression ratio (CR) without knock occurrence.     

Life-cycle greenhouse gas emissions and energy balances of sugarcane ethanol production in Mexico

The purpose of this work was to estimate GHG emissions and energy balances for the future expansion of sugarcane ethanol fuel production in Mexico with one current and four possible future modalities. We used the life cycle methodology that is recommended by the European Renewable Energy Directive (RED), which distinguished the following five system phases: direct Land Use Change (LUC); crop production; biomass transport to industry; industrial processing; and ethanol transport to admixture plants. Key variables affecting total GHG emissions and fossil energy used in ethanol production were LUC emissions, crop fertilization rates, the proportion of sugarcane areas that are burned to facilitate harvest, fossil fuels used in the industrial phase, and the method for allocation of emissions to co-products. The lower emissions and higher energy ratios that were observed in the present Brazilian case were mainly due to the lesser amount of fertilizers applied, also were due to the shorter distance of sugarcane transport, and to the smaller proportion of sugarcane areas that were burned to facilitate manual harvest. The resulting modality with the lowest emissions of equivalent carbon dioxide (CO_2e) was ethanol produced from direct juice and generating surplus electricity with 36.8 kgCO_2e/GJ_ethanol. This was achieved using bagasse as the only fuel source to satisfy industrial phase needs for electricity and steam. Mexican emissions were higher than those calculated for Brazil (27.5 kgCO_2e/GJ_ethanol) among all modalities. The Mexican modality with the highest ratio of renewable/fossil energy was also ethanol from sugarcane juice generating surplus electricity with 4.8 GJ_ethanol/GJ_fossil.     

Properties of a new gasoline oxygenate blend component: 3-Hydroxybutyrate methyl ester produced from bacterial poly-3-hydroxybutyrate

3-Hydroxybutyrate methyl ester (HBME) was prepared from hydrolysis of bacterial poly-3-hydroxybutyrate (PHB) using methanol as an esterification agent in the presence of sulfuric acid. Physicochemical and fuel related properties of HBME were studied for the possibility of using HBME as a gasoline additive. When HBME was blended with 97# gasoline in volume ratios of 5%, 8.5%, 10%, 15% and 20%, respectively, it was found that HBME had similar or better properties as a fuel additive compared with ethanol in terms of oxygen content, dynamic viscosity, flash point and boiling point. The blending of HBME and gasoline showed only little difference compared with the 97# gasoline in terms of octane number (RON) and distillation ranges, especially for the HBME 8.5% and 10% blends, which demonstrated an over 93% combustion heat of gasoline with less than 5% reduction in RON.     

Fossil energy savings and GHG mitigation potentials of ethanol as a gasoline substitute in Thailand

One of the Thai government's measures to promote ethanol use is excise tax exemption, making gasohol cheaper than gasoline. The policy in favour of biofuels is being supported by their contribution to fossil energy savings and greenhouse gas (GHG) mitigation. An analysis of energy balance (EnB), GHG balance and GHG abatement cost has been done to evaluate molasses-based ethanol (MoE) in Thailand. A positive EnB of 19.2 MJ/L implies that MoE is a good substitute for gasoline, effective in fossil energy savings. GHG balance assessment based on the baseline scenario shows that emissions are most likely to increase with the substitution. Scenarios using biogas captured from spent wash treatment and rice husk to substitute coal used in ethanol conversion give encouraging results in improving the GHG balance. However, the higher price of MoE over gasoline currently has resulted in high GHG abatement costs, even under the best-case scenario. Compared to the many other climate strategies relevant to Thailand, MoE is much less cost effective. Governed by the rule of supply and demand, a strong fluctuation in molasses price is considered the main cause of volatile MoE price. Once supplies are stable, the trend of price drops would make MoE a reasonable option for national climate policy.     

Performance and emissions of gasoline blended with fusel oil that a potential using as an octane enhancer

Fusel oil produced in small quantities as a by-product obtained through the fermentation of some agricultural products. Thereby the possibility of using fusel oil to replace gasoline or blending at high percentage unavailing. The fusel oil has both high research and motor octane rating RON and MON (106 and 103). This paper examines the impact of using fusel oil as an octane enhancer for gasoline fuel on the performance, combustion and emissions of 4-cylinder spark ignition engine. The test was achieved at two ratios of fusel oil -gasoline blends and pure gasoline at different speeds and loads. The fusel oil is showed to be a novel and useful octane enhancer for gasoline blendstocks in a spark ignition engine. Furthermore, fusel oil is a suitable candidate fusel for octane enhancer on-demand applications and further experimentation in spark ignition engine warranted. The high octane number and oxygen content of fusel oil lead to improving the engine performance under high engine speed and rich mixture (? < 1) due to the complete combustion. The brake power and BTE enhanced with fusel oil compared to gasoline while BSFC increased. The NO_x emission decreased as the fusel oil used While the HC and CO₂ emissions increased.     

Marginal reductions in vehicle emissions under a dual-blend ethanol mandate: Evidence from a natural experiment

Among the many reasons policy makers across the world have sought to supplement fuel supplies with ethanol-blended fuels are the cited environmental benefits that come with replacing a fossil-fuel with a cleaner burning alternative. Dual-blend ethanol mandates, in which multiple ethanol blends are simultaneously available, are one way policy markers can move forward with more aggressive mandates more quickly. The recent ethanol mandate in the state of New South Wales, Australia offers a unique natural experiment to quantify the potential environmental benefits and costs of a dual blend ethanol policy. This paper estimates the impact on carbon dioxide (CO₂) emissions from road-activity that are attributable to the implementation of the New South Wales ethanol requirements. We find that there was a decrease in emissions due to the policy, but that the decrease is relatively minor given the size of the market and that it comes at a high cost. The cost was over $1200 per ton of carbon to reduce gasoline emissions by just 1.2%.     

Water use impact of ethanol at a gasoline substitution ratio of 5% from cassava in Nigeria

The process of fuel ethanol production from cassava root is connected to a chain of impacts on the water resource of the country where the cassava plant is grown and the root processed into fuel ethanol. The paper assesses the impact of the domestic production of 5 per cent ethanol (E5) needed under the Nigerian biofuel programme from cassava root on the water resource of Nigeria. Using the 2007 Premium Motor Spirit (PMS) consumption as the baseline, Nigeria will require about 0.49 hm³ of ethanol to blend 9.32 hm³ of PMS to arrive at the 2007 consumption estimates. The impact of the domestic production of this ethanol requirement translates to about 6.0 km³ of water; out of which about 48 per cent is green and about 52 per cent is blue. Addressing future impact typical of a developing economy like Nigeria, a three-scenario analysis was adopted to examine the impact of future growth in cassava-fuel ethanol requirement on the water resource of Nigeria, and also, the impact of improved water use on the future water footprint of E5. The projected water impact of cassava-ethanol production into the future ranges from 6.02 to 7.28 km³, while improved water use could lower these values by about 0.04–2.35 km³ for the same period, 2010 to 2020, under the projection assumptions made.     

The empirical effects of a gasoline tax on CO2 emissions reductions from transportation sector in Korea

The introduction of carbon tax is expected to mitigate GHG emissions cost-effectively. With this expectation identifying the impacts of carbon tax on energy demand and GHG emission reductions is an interesting issue. One of the basic methods of estimating these impacts is using the price elasticity.     

Effect of different types of fuels tested in a gasoline engine on engine performance and emissions

In this study, three different fuels named G100 (pure gasoline), E20 (volume 20% ethanol and 80% gasoline blend) and ES20 (20% sodium borohydride added ethanol solution and 80% gasoline) were used to test in a gasoline engine. First of all, G100 fuel, E20 and ES20 blended fuels, respectively, were tested in a gasoline engine and the effects of fuels on engine performance and exhaust emissions were investigated experimentally. Experiments were carried out at full load and at five different engine speeds ranging from 1400 to 3000 rpm, and engine performance and exhaust emission values were determined for each test fuel. When the test results of the engine operated with E20 and ES20 blended fuels are compared with the test results of the engine operated with gasoline; engine torque of E20 blended fuel increased by 1.87% compared to pure gasoline, while engine torque of ES20 blended fuel decreased by 1.64%. However, the engine power of E20 and ES20 blended fuels decreased by 2.02% and 5.10%, respectively, compared to the power of pure gasoline engine, while their specific fuel consumption increased by 5.02% and 6.57%, respectively, compared to pure gasoline fueled engine. On the other hand, CO and HC emissions of the engine operated with E20 and ES20 blended fuels decreased compared to the pure gasoline engine, while CO₂ and NO_x emissions increased.     

Utilization of biomass in the U.S. for the production of ethanol fuel as a gasoline replacement—I terrestrial resource potential

With relatively minor adjustments in the agricultural sector, large additional amounts of starch derived from feed corn, surplus and distressed grain, and set-aside land could presently be used for ethanol production. The quantity of ethanol that could be produced would be sufficient to replace anywhere from 5 to 27 per cent (5.5–30 billion gallons) of present gasoline requirements. Thus, the ethanol requirement for total gasohol use (10 per cent) in the U.S. could be met in the short period of time required for facility construction with no evident impact on food production. Increased supplies of ethanol will make feasible the introduction of ethanol fueled engines. High-yield sugar crops planted on new acreage could provide an additional 10 billion gal. of ethanol by the year 2000; conversion of the waste biomass from this crop to ethanol could also add substantially to this amount. Utilization of novel cellulose conversion technology can provide fermentable sugars from municipal wastes, agricultural and forest wastes, and ultimately, highly productive silvicultural operations. The wastes alone could yield over 36 billion gal. of 192° PR ethanol-fuel by the year 2000. Fast-growing woody species from silviculture are expected to yield a conservative average of 10 over-dry tons per acre per yr, convertible to 710 gal. of ethanol in a process that has 37 per cent yield. Advantages over sugar/starch crops include year-round harvesting, and use of marginal acreage. Commercial forest land presently suitable for silviculture is about 100 million acres in large tracts plus 200 million acres in small private tracts. The potential additional yield of ethanol from lignocellulosic biomass appears to be well in excess of liquid fuel requirements of an enhanced efficiency transport sector in the U.S. at present mileage demands. No conflict with food production would be necessary.     

Price ceilings as focal points to reach price uniformity: Evidence from a Chinese gasoline market

This paper studies the price uniformity in the Chinese gasoline market, using station-level data of Hohhot city, Inner Mongolia. We first document that the mode prices of the gasoline stations are consistent with the price ceilings set by the government, implying that the price ceiling regulation in the Chinese gasoline market may serve as a focal point for the gasoline stations to reach price uniformity. We corroborate the focal point hypothesis by providing evidence showing that some stations would “jump” to the ceilings as their prices approach the ceilings. Also, we find that local market structure, distance between stations, station capacity, market characteristics, and past pricing behavior could affect the probability of gas stations to price at the ceilings. Moreover, a higher price ceiling would reduce the probability that stations reach price uniformity. Our results provide another piece of evidence to the literature regarding the unintended effect of price ceiling regulation.     

Effect of ethanol blending with biodiesel on engine performance and exhaust emissions in a CI engine

The use of biodiesel as an alternative diesel engine fuel is increasing rapidly. However, due to technical deficiencies, they are rarely used purely or with high percentages in unmodified diesel engines. Therefore, in this study, we used ethanol as an additive to research the possible use of higher percentages of biodiesel in an unmodified diesel engine. Commercial diesel fuel, 20% biodiesel and 80% diesel fuel, called here as B20, and 80% biodiesel and 20% ethanol, called here as BE20, were used in a single cylinder, four strokes direct injection diesel engine. The effect of test fuels on engine torque, power, brake specific fuel consumption, brake thermal efficiency, exhaust gas temperature, and CO, CO₂, NO_x and SO₂ emissions was investigated. The experimental results showed that the performance of CI engine was improved with the use of the BE20 especially in comparison to B20. Besides, the exhaust emissions for BE20 were fairly reduced.     

A novel approach to utilize esterified rice bran oil as an additive with gasoline and ethanol blends in MPFI SI engine.

ABSTRACT

In this work, we have attempted to add biodiesel as an additive with gasoline and ethanol blend to analyze the effect on performance and emission characteristics. The esterified rice bran oil is chosen as an additive. This focus of this work is to study the behavior of an SI engine for various blend proportions and to identify the optimum blend proportion that yields better results. MPFI engine was used to conduct the load test with gasoline as the base reference fuel. Blends of gasoline-ethanol and rice bran oil were prepared, and the tests were done for all the blends. The observed results were presented and discussed. Adding ethanol to the gasoline results in improved combustion that causes an increase in brake thermal efficiency and brake power. With esterified rice bran oil as an additive gives a reduction in specific fuel consumption, hydrocarbon emission, and carbon monoxide emissions. The optimum blends that have excellent benefits are identified.     

Hydrogen-rich gas production from gasoline in a short contact time catalytic reactor

Presented is a study of hydrogen-rich gas generation by selective catalytic oxidation of gasoline in a nearly adiabatic monolith reactor. Experiments were conducted using a gasoline mixture containing 191 hydrocarbon species, while corresponding thermodynamic models employed a surrogate mixture of 29 organics with well-defined properties. Based on the data obtained, it was demonstrated that a nearly equilibrium synthesis gas could be produced using catalytic monoliths. Also discussed are problems encountered with a short contact time reactor operating at a pilot-scale, issues that are largely independent of the catalysts employed. It was found that this particular reactor design is prone to pre-reformation of the fuel prior to catalytic reaction. In addition, the breakthrough of the feed mixture was found to arise near the reactor wall under certain circumstances. Feed composition, superficial velocity, and various reactor design factors were all found to affect these phenomena.     

昆明市能源消费碳排放变化的因素分解及对策研究

随着昆明市社会经济的快速发展,能源消耗及环境问题日益严重,减少二氧化碳排放、建设低碳城市已成为昆明市可持续发展的关键.基于扩展的Kaya恒等式建立了因素分解模型,并应用对数平均Divisia指数方法(LMDI)对昆明市2005—2010年能源消费碳排放变化情况进行了分解分析.研究表明:现阶段昆明市能源消费碳排放最大的影响因素是经济产出规模,其贡献率达到155.76%;而能源效率仅次于经济产出呈现负效应,其贡献率为-87.68%;其它表现为正效应的影响因素分别为产业结构、人口规模、产业能源消费碳排放,其贡献率分别为14.36%、13.42%、4.13%.“十二五”及未来一段时期,调整产业结构、优化能源结构、提高能源效率及发展碳汇项目是昆明市二氧化碳减排的重点任务,为昆明市低碳城市建设提供保障.     

Biodiesel production from acid oils and ethanol using a solid basic resin as catalyst

In the search of an alternative fuel to substitute diesel fuel, biodiesel appears as one of the most promising sources of energy for diesel engines because of its environmental advantages and also due to the evolution of the petroleum market.Refined oil is the conventional raw material for the production of this biofuel; however, its major disadvantage is the high cost of its production. Therefore, frying oils, waste oils, crude oils and/or acid oils are being tested as alternative raw materials; nevertheless, there will be some problems if a homogeneous basic catalyst (NaOH) is employed due to the high amount of free fatty acid present in the raw oil.In this work, the transesterification reaction of acid oil using solid resin, Dowex monosphere 550 A, was studied as an alternative process. Ethanol was employed to have a natural and sustainable final product. The reaction temperature's effects, the initial amount of free fatty acid, the molar ratio of alcohol/oil and the type of catalyst (homogeneous or heterogeneous) over the main reaction are analyzed and their effects compared.The results obtained show that the solid resin is an alternative catalyst to be used to produce fatty acid ethyl esters (FAEEs) by a transesterification reaction with a final conversion over 90%. On the other hand, the time required to achieve this conversion is bigger than the one required using conventional technology which employs a homogeneous basic catalyst. This reaction time needs to be optimized.     

A preliminary economic analysis of buffalo gourd as a diesel fuel and ethanol feedstock in the high plains of New Mexico,Texas and Oklahoma

Buffalo gourd is native to the semi-arid south-western United States, requires substantially less water than conventional crops, and yields a seed oil that is intermediate in properties between soy and sunflower oils, as well as large starchy roots suitable for fermentation to ethanol. Based on conservative yield data for buffalo gourd products of 85 and 267 gal/acre of oil and ethanol, respectively, net annual revenues for buffalo gourd cultivation and processing in New Mexico are estimated to be $137/acre and $70/acre for dryland and irrigated production, respectively. The field cost to produce a gallon of liquid fuels in New Mexico is estimated to be $ 1.26 for irrigated corn, $1.24 for dryland grain sorghum, $1.63 for dryland wheat, and $0.34 for buffalo gourd.