Organizational and Operational Techniques for Relieving Manpower Shortages in Air Pollution Control Agencies

Many governmental air pollution control agencies are confronted with a shortage of manpower, both in terms of numbers of people and qualifications of available staff members. This paper discusses a number of techniques which may be used to relieve this manpower shortage. The techniques are discussed in terms of collaboration between state and local agencies; organizational structures which make maximum use of scarce categories of people; program policies which conserve the time of agency staff; operating schemes which save travel time and minimize skills required; and working tools that can be used to get the greatest production with available personnel.     

Idle Emissions from Medium Heavy-Duty Diesel and Gasoline Trucks

Abstract

Idle emissions data from 19 medium heavy-duty diesel and gasoline trucks are presented in this paper. Emissions from these trucks were characterized using full-flow exhaust dilution as part of the Coordinating Research Council (CRC) Project E-55/59. Idle emissions data were not available from dedicated measurements, but were extracted from the continuous emissions data on the low-speed transient mode of the medium heavy-duty truck (MHDTLO) cycle. The four gasoline trucks produced very low oxides of nitrogen (NO_x) and negligible particulate matter (PM) during idle. However, carbon monoxide (CO) and hydrocarbons (HCs) from these four trucks were approximately 285 and 153 g/hr on average, respectively. The gasoline trucks consumed substantially more fuel at an hourly rate (0.84 gal/hr) than their diesel counterparts (0.44 gal/hr) during idling. The diesel trucks, on the other hand, emitted higher NO_x (79 g/hr) and comparatively higher PM (4.1 g/hr), on average, than the gasoline trucks (3.8 g/hr of NO_x and 0.9 g/hr of PM, on average). Idle NO_x emissions from diesel trucks were high for post-1992 model year engines, but no trends were observed for fuel consumption. Idle emissions and fuel consumption from the medium heavy-duty diesel trucks (MHDDTs) were marginally lower than those from the heavy heavy-duty diesel trucks (HHDDTs), previously reported in the literature.     

Review of Light-Duty Diesel and Heavy-Duty Diesel Gasoline Inspection Programs

Abstract

Emissions from diesel vehicles and gas-powered heavyduty vehicles are becoming a new focus of many inspection and maintenance (I/M) programs. Diesel particulate matter (PM) is increasingly becoming more recognized as an important health concern, while at the same time, the public awareness of diesel PM emissions because of their visibility have combined to increase the focus on diesel emissions in the United States. This has resulted in an increased interest by some states in including heavy-duty vehicle testing in their I/M program.

This paper provides an overview of existing I/M programs focused on testing light-duty diesel vehicles, heavyduty diesel vehicles, and heavy-duty gasoline vehicles (HDGVs). Information on 39 I/M programs in 27 different states in the United States plus 9 international inspection programs is included. Information on the status of diesel emissions technology and current test procedures is also presented. The goal is to provide useful information for air quality managers as they work to decide whether such I/M programs would be worth pursuing in their respective areas and in evaluating the emissions measurement technology to be used in the program. Testing of HDGVs is generally limited to idle testing, because dynamometer testing of these vehicles is not practical, and most were not certified on a chassis basis.

Testing of diesel vehicles has mostly been limited to SAE J1667 “snap-idle” opacity testing. Cost-effective technology for measuring diesel emissions currently does not exist, and, therefore, opacity-type measurements, although not effective at reducing the pollutants of most significant health concern, will continue to be used.     

加油站油气排放治理技术

分析了国内外加油站的油气排放治理现状,指出对我国加油站的油气排放进行全面治理已迫在眉睫。针对我国加油站油气排放的特点并在现有技术基础上,提出了“冷凝+吸附”油气处理集成技术,并借助Aspen模拟软件及实验对此技术进行了研究,结果认为该技术回收率高达99.2％,油气尾气浓度可控制在11.2 g/m³。该技术原理简单,成本低,可为提高加油站的本质安全、环境保护及节能降耗提供有力的技术支撑。     

Desulfurization of Caribbean Fuel

An American Petroleum Institute study of desulfurization of Caribbean fuel oil was completed in February 1967. The report is unique in that proprietary information was made available to the contractor, the Bechtel Corp., by task force members and licensors of desulfurization processes. Thus confidential information never before available to a single organization was used to develop feasibility and incremental costs of various processes for desulfurization. The report provides needed guideposts for decision-making by governmental units as well as by industry. Incremental costs are presented for intermediate levels of desulfurization from the normal level for Caribbean heavy fuel oil of 2.6% down to 0.5%, as well as the sensitivity of costs to sulfur credits and to rate of recovery of invested capital. Degree of justifiable confidence in the various data is discussed. Effects of desulfurization on other characterisics of the fuel oil are also discussed.     

Divided Combustion Chamber Gasoline Engines A Review for Emissions and Efficiency

To facilitate the distinction among different engine types, this paper indicates first a general classification of gasoline engines. This classification contains the group of stratified charge engines, and shows that, within this group, the divided combustion chamber engine type constitutes a major subdivision. Three characteristic designs of this type of engine are described in some detail, and fuel economy and emission results are presented. Data obtained with one of these engines indicate excellent fuel consumptions, showing at light loads values close to those achieved by Diesel engines. Data also show that automobiles equipped with another of the engines described in the paper have passed, with ample margin, the 1975 Federal Emission Standards, without added devices for exhaust gas treatment, while maintaining satisfactory fuel economy. Some aims that should be pursued in order to achieve, simultaneously, both the optimal fuel economy and emission reduction potential of the stratified engine are outlined. It is concluded that substantial improvements should yet be expected if the proven advantages of the divided combustion chamber engine are recognized and sufficient efforts are applied for further development.     

Using the Gasoline Additive MTBE in Forensic Environmental Investigations

A variety of additives are used in gasoline, and they can sometimes be used to help identify the source, timing, or number of gasoline spills at a site. The physicochemical characteristics of the additive MTBE, and its historical use pattern in the United States since 1979, make it a key compound to study when conducting forensic investigations of gasoline spills. MTBE's low octanol : water distribution coefficient and high solubility cause it to dissolve into groundwater more readily than other gasoline components. Thus, the initial appearance of MTBE in the groundwater is often a good indicator of a recent gasoline spill. MTBE's very low retardation and minimal biodegradation in groundwater can be used with transport rate calculations to establish relatively accurate estimates of spill timing. Because MTBE moves faster in groundwater than BTEX compounds, if a gasoline spill site has a BTEX plume that is longer than the MTBE plume, it is certain that at least two distinctly different gasoline releases have occurred. This allows for the identification of new gasoline spills, even when substantial subsurface petroleum contamination already exists. An example application is reviewed to demonstrate the use of MTBE data in forensic investigations.     

The Influence of Gasoline Formulation on Specific Pollutant Emissions

ABSTRACT

Many recent works have dealt with the influence of fuel composition on regulated and specific pollutant emissions from spark ignition engines. While many qualitative correlations have been already proposed, only a few quantitative ones are known (benzene remains an exception).

This paper describes qualitative and quantitative correlations between fuel composition and specific pollutant emissions (individual hydrocarbons, aldehydes, ketones, alcohols, and organic acids) of a spark ignition engine. The aim of this work was to find the precursors of the main specific pollutants. Then, for each of them, a multilinear equation has been calculated, illustrating the correlation between its concentration in exhaust gases and its content in the fuel. The results of these calculations point out which initial compound favors the formation of a determined pollutant. As lean conditions are probably going to be used in future commercial engines, the fuel effect has been studied for a broad range of equivalence ratios (from 0.8 to 1.2).     

Fingerprinting of Gasoline and Coal Tar NAPL Volatile Hydrocarbons Dissolved in Groundwater

Accidental spills and chronic leaks of fuel oil or other hydrocarbon material (e.g., coal tar) often result in subsurface accumulation of nonaqueous phase liquid (NAPL), which can be a subsequent source of contamination in groundwater. Linking hydrocarbons in groundwater to a source NAPL has been difficult when using standard target analytes (e.g., BTEX) because of differences in partitioning properties of the analytes between the source NAPL and groundwater. Because aqueous solubility is predicted to be the controlling influence in the partitioning of hydrocarbons from NAPL to groundwater, a solubility-based approach to matching dissolved hydrocarbons in groundwater to their source NAPL has been developed and validated for two sites with commonly encountered types of NAPL contamination. Specifically, a gasoline LNAPL and a coal tar DNAPL from two separate sites (West Virginia and California) and groundwater interfaced with these NAPLs were analyzed for approximately 50 gasoline-range hydrocarbons consisting of paraffin, isoparaffin, (mono-) aromatic, naphthene, and olefin compounds (PIANO). Solubility characteristics of selected alkyl aromatic hydrocarbons from the PIANO analysis were used to identify a set of diagnostic hydrocarbons, expressed as hydrocarbon ratios, which were found to be useful in distinguishing the source(s) of hydrocarbons in groundwater. At the West Virginia site, the diagnostic ratios in a downgradient groundwater sample were similar to those of a gasoline NAPL at that site, indicating the source of hydrocarbons to the groundwater was the upgradient gasoline NAPL. The diagnostic ratios of the groundwater in contact with the gasoline NAPL and the remote groundwater were also similar, providing evidence that the diagnostic ratios were retained during transport in the aquifer. At the California site, diagnostic ratios in a cross-gradient groundwater sample differed from those of the coal tar NAPL at that site, indicating that the remote groundwater hydrocarbons did not originate from the coal tar contamination. Environmental factors such as selective degradation of specific isomers and various geological conditions (e.g., soil mineralogy, and organic content) may confound the application of this solubility-based fingerprinting approach. Thus, it is recommended that multiple diagnostic pairs be simultaneously evaluated when considering this fingerprinting approach for specific sites and product types.     

Using the Gasoline Additive MTBE in Forensic Environmental Investigations

A variety of additives are used in gasoline, and they can sometimes be used to help identify the source, timing, or number of gasoline spills at a site. The physicochemical characteristics of the additive MTBE, and its historical use pattern in the United States since 1979, make it a key compound to study when conducting forensic investigations of gasoline spills. MTBE's low octanol: water distribution coefficient and high solubility cause it to dissolve into groundwater more readily than other gasoline components. Thus, the initial appearance of MTBE in the groundwater is often a good indicator of a recent gasoline spill. MTBE's very low retardation and minimal biodegradation in groundwater can be used with transport rate calculations to establish relatively accurate estimates of spill timing. Because MTBE moves faster in groundwater than BTEX compounds, if a gasoline spill site has a BTEX plume that is longer than the MTBE plume, it is certain that at least two distinctly different gasoline releases have occurred. This allows for the identification of new gasoline spills, even when substantial subsurface petroleum contamination already exists. An example application is reviewed to demonstrate the use of MTBE data in forensic investigations.     

Agriculture as Provider of Both Food and Fuel

A database of global agricultural primary production has been constructed and used to estimate its energy content. The portion of crops available for food and biofuel after postharvest losses was evaluated. The basic conditions for agriculture and plant growth were studied, to ensure sustainable scenarios regarding use of residues. The available energy contents for the world and EU27 was found to be 7,200–9,300 and 430 TWh, respectively, to be compared with food requirements of 7,100 and 530 TWh. Clearly, very little, or nothing, remains for biofuel from agricultural primary crops. However, by using residues and bioorganic waste, it was found that biofuel production could theoretically replace one-fourth of the global consumption of fossil fuels for transport. The expansion potential for global agriculture is limited by availability of land, water, and energy. A future decrease in supply of fossil energy and ongoing land degradation will thus cause difficulties for increased biofuel production from agriculture.     

Auto Emissions,Engine Size,and Fuel Economy

EPA Reference Method 25 for measurement of total gaseous nonmethane organics as carbon in source emissions was evaluated in the laboratory and through field testing. Laboratory evaluation included development and testing of a nonmethane organic analyzer. In addition, a series of tests was performed on the condensate trap recovery system. The tests involved evaluation of two different condensate trap recovery system designs. The first design was very similar to the Federal Register design and the second design was a modified system for minimizing interference from trapped carbon dioxide. Field testing of the method was performed at two different printing plants. Both plants used carbon bed adsorption for solvent recovery and control of VOC emissions. Samples were collected from the inlet and outlet streams of adsorption units at both plants. In addition to Method 25 samples, Method 18 samples were collected for analysis by gas chromatography with flame ionization detection. The results of all the laboratory and field test samples are described.     

Particle Mass Emission Rates from Current-Technology,Light-Duty Gasoline Vehicles

ABSTRACT

Now that the U.S. Environmental Protection Agency has promulgated new National Ambient Air Quality Standards for PM_2.5, work will begin on generating the data required to determine the sources of ambient PM_2.5 and the magnitude of their contributions to air pollution. This paper summarizes the results of an Environmental Research Consortium program, carried out under the auspices of the U.S. Council for Automotive Research. The program focused on particulate matter (PM) emissions from representative, current-technology, light-duty gasoline vehicles produced by DaimlerChrysler Corp., Ford Motor Co., and General Motors Corp. The vehicles, for the most part taken from the manufacturer's certification and durability fleets, were dynamometer-tested using the three-phase Federal Test Procedure in the companies' laboratories. The test fleet was made up of a mixture of both low-mileage (2K-35K miles) and high-mileage (60K-150K miles) cars, vans, sport utility vehicles, and light trucks. For each vehicle tested, PM emissions were accumulated over 4 cold-start tests, which were run on successive days. PM emission rates from the entire fleet (22 vehicles total) averaged less than 2 mg/mile. All 18 vehicles tested using California Phase 2 reformulated gasoline had PM emission rates less than 2 mg/ mile at both low and high mileages.     

Emissions from Carbureted and Timed Port Fuel Injected Engines

A comparison was made between the exhaust emission characteristics of a popular make car when equipped with the stock carburetor and when equipped with a timed-port fuel injection system. A brief optimization study was made to adjust the spark timing and fuel flow characteristics to minimize emissions. Performance and economy were compared between the fuel injected and carbureted versions. Emission measurements of CO, CO₂, and hydrocarbon were made in road tests by proportional sampling and through the California Cycle by continuous nondispersive infra red instrumentation.