摘要:

AbstractVolatile organic compound (VOC) emissions from gasoline storage and distribution facilities are coming under increased scrutiny in both the United States and Europe. The recently passed European Community stage 1 directive for gasoline emissions has established an emissions limit of 35 grams total organic compounds (TOC) per cubic meter gasoline loaded (35 g TOC/m3). Similarly, the United States Environmental Protection Agency Standard 40 CFR Part 63 has established an emission limit of 10 mg TOC per liter of gasoline loaded (10 g TOC/m3). The German TA‐Luft standard, the most stringent known gasoline emission regulation, has set an emissions limit of 150 mg TOC (excluding methane) per cubic meter of loaded product (0.15 g TOC/m3).The Dow Chemical Company has successfully applied the SORBATHENERegistered Trademark of Radian International LLC.Solvent Vapor Recovery Unit technology, a pressure swing adsorption process, to meet these increasingly stringent gasoline and light hydrocarbon vapor emission standards. Working through technology licensees (Radian International LLC, Austin, Texas and McTay Engineering, Bromborough, United Kingdom), a field trial demonstrating 99+% recovery efficiencies has been conducted at a major U.S. gasoline, storage and distribution terminal, and the first commercial SORBATHENE gasoline vapor recovery unit has been installed at a major storage and distribution terminal in Leeds, United Kingdo

ISSN:0278-4491    

DOI:10.1002/ep.3300160115

出版商:American Institute of Chemical Engineers    

年代:1997

数据来源: WILEY

摘要:

AbstractMore than 45 experimental tests have been conducted on a 10,000 Nm3/h spray‐drying desulfurization pilot plant. The effects of SO2and fly ash concentration, Ca/S ratio, approach to saturation temperature, unit load changes, and the utilization of seawater as make‐up water on both spray dryer behavior and treated flue gas properties were analyzed. This experimental study allows us to reach some conclusions about how to achieve optimum operating conditions and to assess the impact of spray drying on a downstream

ISSN:0278-4491    

DOI:10.1002/ep.3300160116

出版商:American Institute of Chemical Engineers    

年代:1997

数据来源: WILEY

摘要:

AbstractThis paper summarizes a case study involving a site with inorganic arsenic‐contaminated soils. Detailed soil characterization studies involving sequential extraction testing indicated that the arsenic was primarily associated with the organic fraction and the iron oxide/manganese oxide fraction of the soil. A preliminary treatability study demonstrated that adequate leaching of arsenic was possible. Alkaline leaching was specific for arsenic. Future plans include a program of bench‐scale treatability and field pilot studies focusing on soil washing technology applicat

ISSN:0278-4491    

DOI:10.1002/ep.3300160117

出版商:American Institute of Chemical Engineers    

年代:1997

数据来源: WILEY

摘要:

AbstractThe U.S. Environmental Protection Agency (U.S. EPA) and the U.S. Coast Guard (USCG) conducted a joint demonstration of in situ remediation of a JP‐4 jet fuel spill at the USCG Support Center in Elizabeth City, North Carolina. The jet fuel was trapped beneath a clay layer that extended from the surface to a depth of 1.5 m. The water table was 2.0 m below land surface, and jet fuel extended from a depth of 1.0 to 3.5 m. Air was injected under pressure to depress the water table and bring the entire spill into the unsaturated zone, where hydrocarbons could be removed by volatilization and biodegradation. The injected air was recovered through soil vacuum extraction (SVE) at the treatment area. To document actual removal of hydrocarbons, core samples were acquired in August 1992 before air injection, and September 1994 at the end of the demonstration. The spill originally contained 3600 kg of JP‐4. Between the core sampling events, only 55% of the total petroleum hydrocarbons were removed, but more than 98% of benzene was removed. The initial goal was to reduce the concentration of total petroleum hydrocarbons (TPH) to concentrations less than 100 mg/kg soil. This was not accomplished within 18 months of operation. During the period of operation, ground water was monitored for the concentration of benzene, toluene, ethylbenzene, and the xylene isomers (BTEX), and methyl tertiary butyl ether (MTBE). The concentration of BTEX and MTBE in the subsurface was reduced to a very low level, but concentrations of benzene and MTBE in ground water did not meet the EPA drinking water standards in the most heavily impacted wells. The effluent gas from SVE was monitored for the concentration of total hydrocarbon vapors. Based on analysis of soil cores, 2000 kg of TPH was removed during the demonstration. About 1700 kg of hydrocarbon was collected through the SVE system, accounting for most of the actual removal. The rate of biodegradation was estimated from the rate of oxygen consumption in the unsaturated zone when the air injection pumps were turned off. Within the area containing nonaqueous phase liquid (NAPL), the biodegradation rate based on oxygen consumption ranged from 0.72 to 13 mg hydrocarbon/kg soil/day, with an average of 3 mg hydrocarbon/kg soil/day. The mass balance revealed that the contribution of biodegradation was apparently overestimated from oxygen consumption in the soil

ISSN:0278-4491    

DOI:10.1002/ep.3300160118

出版商:American Institute of Chemical Engineers    

年代:1997

数据来源: WILEY

摘要:

AbstractRocketdyne's Santa Susana Field Laboratory has been treating groundwater to remove chlorinated solvents since 1987. Six air stripping treatment installations, using vapor‐phase carbon to control air emissions, have consistently met effluent quality standards over nine years of operation. In 1995, Rocketdyne embarked on an inspection and maintenance program to thoroughly check tower equipment and packing condition and to improve treatment efficiency using new packing technology now available.Baseline removal efficiency measurements were made on one large‐capacity air stripper, which was then shut down for inspection. The original random packing was found to be fouled, and had settled too far below the level of the spray nozzle. The packing was removed, and replaced with a newer, high‐efficiency packing. As a result, single‐stage removal efficiency for trichloroethylene increased from 98.5% to>99.6%.Aside from demonstrating the improvement attainable by upgrading the packing media, Rocketdyne's maintenance program also highlighted the critical importance of proper liquid distribution. At one point, the refurbished air stripper was overpacked, resulting in concentration of the water spray near the center of the packed section. The liquid distribution was found to remain grossly nonuniform even after the water had trickled down over 8.2 meters of packing in a 91‐cm diamet

ISSN:0278-4491    

DOI:10.1002/ep.3300160119

出版商:American Institute of Chemical Engineers    

年代:1997

数据来源: WILEY

摘要:

AbstractControl of mercury (Hg) emissions from municipal waste combustors (MWCs) and coal‐fired utilities has attracted attention due to current and potential regulations. Among several techniques evaluated for Hg control, dry sorbent injection (primarily injection of activated carbon) has shown promise for consistently removing high levels of Hg from MWC or coal flue gas. However, the performance in terms of amount of Hg removed per amount of sorbent varies widely between the MWC and coal‐fired applications and from unit to unit.In this study, we have conducted bench‐scale experiments under conditions simulating MWCs and coal‐fired units to study Hg capture by dry sorbents. The effect of reaction temperature on the capture of different Hg species [Hg0and Hg(II)] by various types of dry sorbents was the focus of bench‐scale tests. An attempt has also been made in this study to compare the bench‐scale results with results obtained from pilot studies and to explain disparities in fuel‐ and unit‐specific performance. Our investigations showed that the reaction temperature and Hg species strongly affect Hg control. The results obtained in this suggested the two following mechanisms for Hg capture:iCapture of Hg0by activated carbons is limited by sorption kinetics, andiiCapture of mercuric chloride (HgCl2) by activated carbons is limited by collision with c

ISSN:0278-4491    

DOI:10.1002/ep.3300160120

出版商:American Institute of Chemical Engineers    

年代:1997

数据来源: WILEY

摘要:

AbstractIT Corporation (IT) has prepared a conceptual design of a red water incinerator pilot plant. This system consisted of a circulating bed combustion (CBC) system with a capacity of 5.4 liters per minute (L/M) (1.5 gallons per minute [gpm]) of red water followed by a hot cyclone, partial quench, baghouse, induced draft fan, and a stack.Red water, a waste stream from the manufacture of trinitrotoluene (TNT), contains between 15 and 30 percent solids, of which approximately 45 percent are sodium salts and 55 percent are sulfonated derivatives of TNT isomers. It was anticipated that treatment of red water in a circulating or fluid‐bed combustor would result in the buildup of molten sodium and its salts on the bed material. The molten sodium and its salt may cause bed particles to agglomerate and decrease fluidization, ultimately resulting in failure of the system.During the course of the design, several process challenges developed primarily due to the composition of the red water and its impact on the system components and optimization of process parameters. Of all the process concerns encountered during the process design of the CBC pilot plant, the challenges that most concerned the author are the role of sodium salts in agglomeration and defluidization at operating temperatures and high levels of nitrogen oxides/sulfur oxides (NOx/SOx) emissions associated with circulating or fluid‐bed incinerator of red water.An initial treatability study utilizing a bench‐scale, 10‐centimeter (4‐inch) diameter fluid‐bed system that approximately simulates a CBC was conducted at Hazen Research in Golden, Colorado. Due to the nonavailability of the actual red water, a surrogate red water solution containing 15 percent dissolved solids was used during the 2‐day testing. The study focused on the role of the salts in agglomeration and defluidization associated with fluid‐bed incineration of red water.This paper discusses the process challenges faced during the conceptual design of the pilot‐scale system and the results of the bench‐scale testing. Also presented are potential solutions and recommended tests and analyses for the pilot plant tests based on experience during the design of pilot‐scale system and the lessons learned fro

ISSN:0278-4491    

DOI:10.1002/ep.3300160121

出版商:American Institute of Chemical Engineers    

年代:1997

数据来源: WILEY

摘要:

AbstractAfter recycle of spent materials has been optimized, a proportion of waste must be dealt with in the most environmentally friendly manner available. For materials such as municipal waste, clinical waste, toxic waste and special wastes such as low radioactive wastes, incineration is often the most appropriate technology. The study of incineration must take a process system approach covering the following aspects:•Collection and blending of waste•The two stage combustion process•Quenching, scrubbing and polishing of the flue gases•Dispersion of the flue gases and disposal of any solid or liquid effluentThe design of furnaces for burning a bed of material is being hampered by lack of an accurate mathematical model of the process, and some semi‐empirical correlations have to be used at present. The prediction of the incinerator gas phase flow is in a more advanced stage of development using computational fluid dynamics (CFD) analysis, although further validation data is still required. Unfortunately, it is not possible to scale down many aspects of waste incineration, and tests on full scale incinerators are essential. Thanks to a close relationship between SUWIC and Sheffield Heat&Power Ltd., an extended research program has been carried out at the Bernard Road Incinerator plant in Sheffield. This plant consists of two Municipal (35 MW) and two Clinical (5 MW) Waste Incinerators which provide district heating for a large part of city. The heat is distributed as hot water to commercial, domestic (>5000 dwellings) and industrial buildings through 30 km of 14′ pipes plus a smaller pipe distribution system. To improve the economics, a 6 MW generator is now being added to the system.During the last decade, many investigations have been carried out [1–6] and a SUWIC laboratory is located

ISSN:0278-4491    

DOI:10.1002/ep.3300160122

出版商:American Institute of Chemical Engineers    

年代:1997

数据来源: WILEY

ISSN:0278-4491    

DOI:10.1002/ep.3300160101

出版商:American Institute of Chemical Engineers    

年代:1997

数据来源: WILEY