Achieving acceptable air quality: some reflections on controlling vehicle emissions

Motor vehicle emissions have been and are being controlled in an effort to abate urban air pollution. This article addresses the question: Will the vehicle exhaust emission control and fuel requirements in the 1990 Clean Air Act Amendments and the California Air Resources Board regulations on vehicles and fuels have a significant impact? The effective control of in-use vehicle emissions is the key to a solution to the motor vehicle part of the urban air pollution problem for the next decade or so. It is not necessary, except perhaps in Southern California, to implement extremely low new car emission standards before the end of the 20th century. Some of the proposed gasoline volatility and composition changes in reformulated gasoline will produce significant reductions in vehicle emissions (for example, reduced vapor pressure, sulfur, and light olefin and improved high end volatility), whereas others (such as substantial oxygenate addition and aromatics reduction) will not.     

Methanol: A Versatile Fuel for Immediate Use: Methanol can be made from gas, coal, or wood. It is stored and used in existing equipment

We believe that methanol is the most versatile synthetic fuel available and its use could stretch or eventually substitute for, the disappearing reserves of low-cost petroleum resources. Methanol could be used now as a means for marketing economically the natural gas that is otherwise going to waste in remote locations. If methanol were used as an additive to gasoline at a rate of 5 to 15 percent, for use in internal combustion engines, there would be an immediate reduction in atmospheric pollution, there would be less need for lead in fuel, and automobile performance would be improved. With increasing production of fuel-grade methanol from coal and other sources, we foresee the increasing use of methanol for electrical power plants, for heating, and for other fuel applications. We hope that a practical methanol fuel cell will be commercially available by the time that methanol becomes plentiful for fuel purposes. Methanol offers a particularly attractive form of solar-energy conservation, since agricultural and forest waste products can be used as the starting material. Indeed, at 1 percent conversion efficiency the forest lands could supply the entire present energy requirements of the United States.     

Ozone control and methanol fuel use

Methanol fuel use in motor vehicles and stationary combustion has the potential to improve air quality. A modeling study of methanol fuel use in Los Angeles, California, shows that the low chemical reactivity of methanol vapor slows ozone formation and would lead to lower ozone concentrations. Predicted peak ozone levels decreased up to 16 percent, and exposure to levels above the federal standard dropped by up to 22 percent, when pure (M100) methanol fuel use was simulated for the year 2000. Similar results were obtained for 2010. Use of a gasoline-methanol blend (M85) resulted in smaller reductions. Predicted formaldehyde levels and exposure were not increased severely, and in some cases declined, in the simulations of methanol use.     

汽油机不稳定燃烧边缘的稳定控制

介绍了供给汽油机稀混合气的方法和系统,分析了混合气逐步变稀时对汽油机性能的影响;提出了不稳定燃烧边缘的稳定控制理论,并为台架实验所证实。     

Liquid hydrogen as a fuel for the future

The use of liquid hydrogen as a long-term replacement for hydrocarbon fuel for land and air transportation seems technically feasible. It is an ideal fuel from the standpoint of a completely cyclic system, serving as a "working substance" in a closed chemical and thermodynamic cycle. The energy-per-unit-weight advantage (a factor of 3) over gasoline or any other hydrocarbon fuel makes liquid hydrogen particularly advantageous for air craft and long-range land transport. As a pollution-free fuel, it must be seriously considered as the logical replacement for hydrocarbons in the 21st century.     

基于CFD的客车空气动力学分析

为了解决客车在高速行驶时,气动阻力急剧增加,耗油量增加的问题,针对某国产大型客车的简化模型及改进模型,应用计算流体力学原理和方法对模型的外流场进行了数值模拟,得到了两种客车模型的表面压力分布、速度矢量分布以及气动阻力系数等气动特性．对比分析表明：增大前围与顶部的圆角可以降低客车气动阻力,但是对后部流场影响很小．     

Volatile metal complexes

Fundamental investigations of the chemical and physical properties of metal beta-diketonate complexes have revealed unusual volatility, as well as solvolytic and thermal stability and solubility in organic solvents. Certain general rules describing the volatility of metal beta-diketonates on the basis of ligand shell character and metal ion size have arisen from extensive gas chromatographic and vapor pressure studies. Several practical applications of volatile beta-diketonates teke advantage of their special properties. In ultratrace metal analysis by gas chromatography, use of these chelates has allowed the detection of smaller amounts of certain metals than can be detected by any other analytic method. Certain rare earth beta-diketonates have been found useful as antiknock additives in gasoline and as catalysts for the removal of carbonaceous deposits from the combustion chambers of internal combustion engines.     

用排气管温度加热气化醇类燃料在柴油机上的试验研究

 针对高原地区空气含氧量低,发动机功率不足,以及有限的石油和空气污染严重等问题。结合柴油机的结构特点、醇类燃料的特性,在不改变原机结构的前提下,增设一套醇类燃料（甲醇或乙醇）供给装置,醇类燃料供给装置供给的醇类靠排气温度加热气化并同进气流一同流入气缸。醇类燃料供给装置与原供油装置相互配合,实现辅助燃料（轻柴油）引燃,主要燃料为甲醇或乙醇,从而在达到不降低发动机功率的状况下,醇类燃料替代柴油,并且有效降低排放的目的。试验表明：此方法简单可行,除在单缸柴油机上采用外,可向多缸机推广应用,这对解决能源紧缺,降低排放,实现可持续发展,有较强的现实意义。同时对改善高原地区发动机动力性,有着其特殊的作用。     

Activation of Motor Fuel and Reduction in Its Consumption in Automotive Internal Combustion Engines

Large-scale developments, bench motor, chromatography, tribochemical, environmental, and operational tests of devices certified under Russian Federation patent no. 2411074 have been organized to determine the stability, efficiency, and irreversibility of activating diesel fuel, gasoline, aircraft fuel, and rubsen oil. That said, the fractional composition of fuel is lightened, the modification continues even after the fuel leaves the agitator, and a portion of activated fuel added to inactivated fuel increases the share of activated fuel in inactivated fuel, similarly to the activation of water. The activation reduces the fuel consumption by 20–27% without cutting down the ICE power, reduces the smokiness of diesel engines and toxicity of gasoline engines, and lowers the freezing point of diesel fuel and purifies it from resins and sulfur compounds. The tests have served to propose broad-scale tests of the agitator on automotive ICEs, its official tests and certification.     

Visibility and soiling: a comparison of the effects of leaded and unleaded gasolines

The emissions from a fleet of late-model cars fueled with commercial, high-aromatic, unleaded gasoline caused nearly twice as much atmospheric light extinction as those from a matched fleet fueled with commercial, low-aromatic, leaded gasoline, when both were driven according to a consumer operating cycle in an idle traffic tunnel. The increased extinction and greater soiling potential result mainly from greater light absorption by the air-suspended particles from the unleaded fleet.     

汽油机燃用C5代用燃料研究初探

以Ｃ５（碳－５）为代用燃料，与７０号汽油制成混合燃料，在汽油发电机组上进行了试用。试验结果表明：代用混合燃料能够代替汽油机中燃烧。在标定工况下，燃用Ｃ５占混合燃料质量配比为３２．４％与１００％的混合燃料，比燃用７０号汽油耗油率分别下降８．６％和９．６％。     

Food-related energy requirements

I have used data from input-output studies to determine the quantities of primary and electric energy consumed in the agricultural, processing, transportation, wholesale and retail trade, and household sectors for personal consumption of food. Before one draws conclusions from these results, it is important to note the assumptions and approximations used in this analysis. First, the economic input-output data published by the Department of Commerce are subject to a number of inaccuracies, including lack of complete coverage for an industry, restriction of data for proprietary reasons, and use of different time periods for different data. Second, aggregation can combine within the same sector industries whose energy intensities differ widely. For example, eating and drinking establishments probably consume more energy per dollar of sales (because of refrigerators, stoves, and freezers) than do department stores. However, both types of establishment are included in retail trade. Thus energy use for food-related retail trade may be underestimated because of aggregation. Third, the energy coefficients are subject to error. In particular, the coefficients for the agricultural and trade sectors are vulnerable because energy use within these sectors is not well documented. Finally, the scaling factor used to estimate food-related energy use for the 1960's is approximate, in that it neglects the possibility that these energy coefficients changed differently with time. Because of these limitations, which are described more fully by Herendeen (6), a number of important issues were not addressed here. such as relative energy requirements for fresh, frozen, and canned vegetables; and for soybeans as compared to beef. This analysis shows that the U.S. food cycle consumes a considerable amount of energy, about 12 percent of the total national energy budget. The residential sector, which accounts for 30 percent of the total, is the most energy-intensive sector in terms of energy consumed per dollar of food-related expenditure. This is because food-related expenditures in homes are primarily for fuel to operate kitchen appliances and automobiles. The electricity consumed in these activities constitutes 22 percent of the total amount used in the United States. More than half of the electricity is used in homes, and more than two-thirds in the trade and household sectors. Thus agriculture and processing consume little electricity relative to the total amount used. From past trends, it appears that the amount of energy used in food-related activities will continue to increase at a rate faster than the population, principally because of growing affluence, that is, the use of processed foods, purchase of meals away from home, and the use of kitchen appliances equipped with energy-intensive devices, such as refrigerators with automatic icemakers. However, fuel shortages, rapidly increasing fuel prices, the growing need to import oil, and a host of other problems related to our use of energy suggest that these past trends will not continue. Fortunately, there are many ways to reduce the amounts of energy used for food-related activities. In the home, for example, smaller refrigerators with thicker insulation would use less electricity than do present units. If closer attention were given to the use of ranges and ovens (for example, if oven doors were not opened so often) energy would be saved. Changes in eating habits could also result in energy savings. Greater reliance on vegetable and grain products, rather than meats, for protein would reduce fuel use. Similarly, a reduction in the amounts of heavily processcd foods consumed-TV dinners and frozen desserts-would save energy. Retailers could save energy by using closed freezers to store food and by reducing the amount of lighting they use. Processors could use heat recovery methods, more efficient processes, and less packaging. Shipping more food by train rather than by truck would also cut energy use. Farmers could reduce their fuel use by combining operations (for example, by harrowing, planting, and fertilizing in the same operation), by reducing tillage practices, by increasing thc use of diesel rather than gasoline engines, and by increasing labor inputs. A partial return to organic farming (that is, greater use of animal manure and crop rotation) would save energy because chemical fertilizers require large energy inputs for their production.     

Ethanol for a sustainable energy future

Renewable energy is one of the most efficient ways to achieve sustainable development. Increasing its share in the world matrix will help prolong the existence of fossil fuel reserves, address the threats posed by climate change, and enable better security of the energy supply on a global scale. Most of the "new renewable energy sources" are still undergoing large-scale commercial development, but some technologies are already well established. These include Brazilian sugarcane ethanol, which, after 30 years of production, is a global energy commodity that is fully competitive with motor gasoline and appropriate for replication in many countries.     

Gasohol: Does It or Doesn't It Produce Positive Net Energy?

A detailed analysis of energy inputs and outputs is performed on grain-based gasohol (10 percent grain-based ethanol, 90 percent gasoline). Existing differences of opinion on the energy balance derive mainly from variations in interpretation which are several examples of inherent methodological problems in energy analysis. The result is strongly dependent on assumptions about use of crop residues for fuel and the miles-per-gallon rating of gasohol. In terms of total nonrenewable energy, gasohol is close to the energy break-even point. On the other hand, in terms of petroleum or petroleum-substitutable energy, gasohol is an unambiguous energy producer, since most energy inputs to the process can be supplied by nonpetroleum sources such as coal.     

中国燃料乙醇发展现状及未来发展方向

阐述了燃料乙醇的目前形式以及发展现状,提出了发展燃料乙醇意义,如可以解决“三农”问题、可以替代部分普通汽油、符合国家安全战略的需要等,还对我国燃料乙醇产业面临的问题以及未来的发展燃料乙醇的方向等问题进行了分析.     

Energy, manpower, and the highway trust fund

If energy conservation were a goal of a federal budget policy maker, such conservation could be achieved by reinvesting the highway trust fund in any of several other alternative federal programs (except criminal justice), especially in railroad and mass transit construction and national health insurance (see Table 1). Total employment would increase in each alternative program examined. For example, if construction monies were shifted from highways to railroads, the energy required for construction would be reduced by about 62 percent and employment would increase by 3.2 percent. By comparing the dollar, energy, and employment requirements of a highway transportation system with such requirements for a railroad transportation system, we obtained detailed information from which we concluded the following: 1) Passenger transport by railroad was much less dollar and energy demanding and required more labor than car transport in 1963. If the dollar savings had been respent in an average way by consumers, the net impact would have been to reduce the energy savings and further increase employment. A similar conclusion was reached in a study of bus substitution for automobiles in urban areas (20). If the marginal substitution effects would have held over the whole range of change, and the dollar savings had been spent on the construction of railways, then about 3.0 billion gallons of gasoline could have been saved annually and 1.2 million new jobs created. 2) Freight transport by railroad was less expensive, in terms of dollar, energy, and labor requirements, than was truck transportation in 1963. If, under a national shift to rail freight, the dollar savings had been absorbed as personal consumption expenditures, a net increase of labor and energy would have ensued. If the dollar savings had been absorbed as a tax and respent on railroad and mass transit construction, about 0.3 billion more gallons of gasoline (energy equivalent) would have been consumed annually and 1.2 million jobs created, under a complete shift to rail. Had there been a full shift from intercity car and truck transportation to transportation by railroad with dollar savings spent on railway construction, 2.7 billion gallons of gasoline (energy equivalent) could have been saved and 2.4 million new jobs could have been created in 1963.     

Ethanol can contribute to energy and environmental goals

To study the potential effects of increased biofuel use, we evaluated six representative analyses of fuel ethanol. Studies that reported negative net energy incorrectly ignored coproducts and used some obsolete data. All studies indicated that current corn ethanol technologies are much less petroleum-intensive than gasoline but have greenhouse gas emissions similar to those of gasoline. However, many important environmental effects of biofuel production are poorly understood. New metrics that measure specific resource inputs are developed, but further research into environmental metrics is needed. Nonetheless, it is already clear that large-scale use of ethanol for fuel will almost certainly require cellulosic technology.     

Catalytic production of high-grade fuel (gasoline) from biomass compounds by shape-selective catalysis

Shape-selective hydrocarbon catalysis, such as the conversion capability of zealite catalysts of the ZSM-5 type to produce high-grade gasoline from methanol, can be extended to produce a similar gasoline or aromatics from plant extracts. Examples are rubber latex, corn oil, and peanut oil. Novel mechanisms for shape-selective reaction sequences are demonstrated.     

城市发展的三维趋势探讨——浅析“JD模式”

城市规划由平面的布置转向三维的规划,历史源远。本文仅以JD模式探讨城市规划发展的趋势,一种由平面扩张转到内涵挖潜、立体的发展。JD模式主要是采取人车分离的立体开发方式,利用架空平台组织人流,把地面层用于汽车交通和停车,优化组合空间资源。     

原木纵向输送机布满系数的研究

在林区贮木场利用纵向输送机进行选材作业时，由于原木在输送途中的多点卸载，用充满系数描述输送机上的实际负荷已不符合实际。本文提出了布满系数这个新概念，用以描述输送机上的实际载荷，并定量分析了二者之间的关系。根据统计资料计算，在整条输送机上，布满足系数仅为充满系数的一半。因而，在计算输送机的牵引力时，应以布满系数为根据。