bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling and analysis of moving‐bed hot‐gas desulfurization processes
Authors: Ayala Raul E. , Kim Bang Mo 
Published: February 2007

AbstractRemoval of sulfur compounds from hot coal gas is a necessary step during power generation operations. Zinc ferrite has been identified as a promising absorbent material. A mathematical model describing the kinetics of zinc ferrite during absorption and regeneration as it applies to a steady‐state moving‐bed concept, where the solids are continuously transferred between absorber and regenerator vessels has been developed. Model predictions, based on experimental data, are presented for various flow configurations and operating conditions, including multistage operation of regeneration, where the effect of diffusion mechanisms, temperature, gas concentrations, and flow rates on conversion are presented.
Metal ion scavenging from water with fine mesh ion exchangers and microporous membranes
Authors: Grinstead Robert R. , Paalman H. Hunter 
Published: February 2007

AbstractThe productivity of ion exchange processes is usually limited by the diffusional process. The use of very fine mesh resins (down to 10–25 microns diameter) in very thin (ca 3–9 mm) beds supported on a microfiltration membrane of three micron pore diameter is described. These systems were used to process a simulated wastewater containing 4000 ppm of NaCl, plus some calcium and magnesium chlorides, as well as 0.2 ppm each of the metal ions Cu, Ni, Pb, Zn, and Cr (III). Regeneration with dilute HCl produced a concentrate of 1/1000 the volume of the feedwater treated.
Evaluation of alternative processes for final treatment of hazardous waste effluents
Authors: Meardon John A. , Lyandres Sol , Rees John T. , Shealy Stuart 
Published: February 2007

AbstractFive process unit operations were evaluated for effectiveness in treating aqueous effluent from a hazardous waste treatment facility. The aqueous effluent contained residual amounts of various organics and heavy metals. The objective of the pilot test program was to produce an aqueous product which could meet requirements for discharge to a POTW, or directly to the environment, and a solid product which could be disposed of in a Class I landfill. Processes evaluated included one primary, evaporative crystallization, two secondary, activated sludge bio‐treatment and reverse osmosis, and two tertiary, carbon adsorption and ultraviolet peroxidation. Test results from these process operations identified several processing configurations whereby the final treated product could meet discharge criteria. Performance results of each process unit operation are summarized and discussed.
Waste minimization opportunities at an electric arc furnace steel plant producing specialty steels
Authors: Drabkin Marvin , Rissmann Edwin 
Published: February 2007

AbstractWaste reduction assessments have been carried out in the Armco, Inc. Butler, Pennsylvania electric arc furnace (EAF) specialty steelmaking complex. These assessments were intended to develop waste reduction options for two hazardous waste streams at this facility: heavy metals waste and corrosive waste. Waste reduction options considered were in one of two categories: source reduction or recycling (in the same order of preference). Treatment was considered only if waste reduction options were unavailable.
Biodenitrification of uranium refinery wastewaters
Authors: Walker J. F. , Helfrich M. V. , Donaldson T. L. 
Published: February 2007

AbstractDesign verification studies and process development work were conducted at Oak Ridge National Laboratory in support of the new fluidized‐bed biodenitrification system under construction at the Feed Materials Production Center (FMPC) in Fernald, Ohio. Two bioreactors in series, each 6‐m tall, and one 12‐m‐tall bioreactor were operated for approximately 9 months using synthetic and actual wastewaters from the FMPC. The results indicate that satisfactory reaction rates can be achieved and maintained; however, some degree of water softening, pH adjustment within the bioreactors, and temperature control may be necessary.
Treatment of hazardous substances in wastewater treatment plants
Authors: Stenstrom Michael K. , Cardinal Lynne , Libra Judy 
Published: February 2007

AbstractFor many types of hazardous wastes, particularly those contained in high volume, low concentration wastewaters, biological treatment in existing facilities, perhaps in selected publicly owned treatment works (POTWs), may be a better alternative. The motivation for using existing biological facilities to treat hazardous wastes is very high since there is insufficient hazardous waste treatment capacity. This problem will become exacerbated in the future unless the current hazardous waste facility problems are resolved.
Biotreatment of dilute contaminated ground water using an immobilized microbe packed bed reactor
Authors: Portier Ralph J. , Nelson John A. , Christianson John C. , Wilkerson J. Mark , Bost Richard C. , Flynn Brian P. 
Published: February 2007

AbstractA biological treatment process employing immobilized microbial populations was field tested on contaminated ground water having dilute concentrations of volatile organics and organic pesticides. The process, consisting of two packed bed reactors in series containing specific adapted microbial strains immobilized on a porous diatomaceous earth support, was operated in a plug flow configuration over a 90‐day period at a flow rate of 80 gallons per day (gpd). Process viability of this multiple microbe/multiple toxicant treatment approach was determined based upon comparisons to carbon adsorption technology.
Chemical demilitarization: Disposing of the most hazardous wastes
Authors: Rife R. , Thomas T. W. , Norberg D. W. , Fournier R. L. , Rinker F. G. , Bonomo M. S. 
Published: February 2007

AbstractThis country's aging stockpile of chemical warfare munitions require safe and economical disposal. These munitions present a unique challenge for demilitarization, since handling of both explosives and toxic material is required. The first full‐scale munitions disposal facility is presently undergoing testing and systemization on Johnston Island. The technology developed for incorporation into the Johnston Atoll Chemical Agent Disposal System maximizes the use of automated equipment, provides the containment necessary to protect the worker and environment, and thermally destroys both the toxic fill and explosives from the munitions.
Evaluation of membrane processes for the reduction of trace organic contaminants
Authors: Lyandres Sol , Meardon John , Rees John 
Published: February 2007

AbstractReverse osmosis (RO) was experimentally tested on liquid condensates produced from a pilot evaporative crystallizer. The condensates contained residual light organic compounds. The original sources of the condensate feeds were two solar evaporation ponds that received treated liquid effluents from a hazardous waste treatment and disposal facility. The objective of the tests was to reduce total organics concentrations (TOC) to levels acceptable for discharge into the local POTW or surface waters.
Myers dump case history: Innovative utilization of air stripper‐activated carbon technologies
Authors: Binkley Jeffrey S. , Matz Sally , Myers Kenneth L. , Theisen Kenneth 
Published: February 2007

AbstractThe treatment of residential well water contaminated with volatile organic compounds (VOCs) has typically included the use of granulated activated carbon (GAC) filters. The significant carbon replacement costs associated with filtration has prompted research into more cost effective alternatives. Another alternative for treatment of ground water contaminated with VOCs is air stripping. This process does not require extensive maintenance costs but it generally cannot achieve the required removal levels for small scale applications. The combination of these two technologies can result in achieving optimum removal levels while reducing carbon replacement costs. The case history described in this paper outlines the removal effectiveness monitoring program of a remediation technology utilizing air strippers in conjunction with GAC filters. Specific topics discussed in this paper include: site background, health effects, system design and installation, removal effectiveness monitoring, quality assurance program, and effectiveness and efficiency of the technology.
Reduction of sulfur dioxide by syngas to elemental sulfur over iron‐based mixed oxide supported catalyst
Authors: Jin Yun , Yu Qiquan , Chang Shih‐Ger 
Published: February 2007

AbstractAn iron‐based supported catalyst has been developed for the reduction of SO2 by synthesis gas to obtain more than 97% yield of elemental sulfur with a single stage reactor for 340–480°C (30–40 mesh particles), 440–580°C (d · 3 mm × h · 5 mm granules). Parametric studies on the performance of the catalyst have been conducted. The parameters studied include temperature, space velocity, molar ratio of H2 to CO, molar ratio of syngas to SO2 in the feed, and particle size of the catalyst. A lifetime test has been successfully performed. The mass balance of sulfur and carbon has been demonstrated.
Performance update: Low pressure wet air oxidation unit at grangemouth, Scotland
Authors: Matthews Roger 
Published: February 2007

AbstractIn response to a requirement to provide a low‐capital, low operating cost solution for the treatment of steam cracker spent caustic, BP Chemicals Ltd. (BPCL) and Stone and Webster Engineering Ltd. (SWEL) have jointly developed a Low Pressure Wet Air Oxidation Process.The first of these units has been in operation at the BPCL Grangemouth, Scotland facility for the last three years. In that time, it has demonstrated totally effective sulfide removal, surpassing design targets, and producing a neutralized effluent well within the allowable discharge consents for the site.The Grangemouth unit is designed to treat the spent caustic effluent from two crackers with a combined capacity of 600 KTA (currently being expanded to 700 KTA) from both liquid and gas feedstocks. A significant feature of the installation has been the extremely high level of reliability and availability, ensuring trouble‐free operation and full compliance with effluent consent levels mandated by the regulatory authorities. At the same time, the unit has demonstrated very low operating and maintenance costs.The design basis and initial commercial experience was presented at the AIChE Spring National Meeting in April 1994 [1]. This paper concentrates on the operational history of the Grangemouth unit, highlighting the process developments and improvements that have been made in the last three years.
Why valves leak: A search for the cause of fugitive emissions
Authors: Bello C. E. , Siegell J. H. 
Published: February 2007

AbstractTo better focus fugitive emission control efforts, a number, of valves that were removed from service due to poor emissions control performance were inspected for signs of damage to the stem sealing system. Corrosion and pitting of the stem were found to be the highest identifiable causes of high valve fugitive emissions. Most valves, however, had no identifiable damage and poor emissions control performance in these cases is believed to be due to poor packing materials or poor packing installation procedures.
Mercury control in municipal waste combustors and coal‐fired utilities
Authors: Krishnan S. V. , Gullett Brian K. , Jozewicz Wojciech 
Published: February 2007

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 [Hg0 and 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:

Capture of Hg0 by activated carbons is limited by sorption kinetics, and
Capture of mercuric chloride (HgCl2) by activated carbons is limited by collision with carbon particles.
Process challenges and evaluation of bed agglomeration in a circulating bed combustion system incinerating red water
Authors: Acharya Prakash 
Published: February 2007

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 from bench‐scale testing.
The haztimator knowledge‐based (expert) system: Providing Design and Time/Cost Estimates for Hazardous Waste Remediation
Authors: Staudinger Jeff , Oralkan Gaye A. , Levitt Raymond E. , Roberts Paul V. 
Published: February 2007

AbstractDevelopment, implementation and tentative validation of a prototype of the Haztimator system, a knowledgebased (expert) system (KBS) intended to provide design and time/cost estimates for hazardous waste remediation projects, is presented. The prototype evaluates one potential remedial alternative, soil vapor extraction followed by vapor‐phase granular activated carbon for air emissions control. Haztimator represents the first known expert system in the environmental field with a primary knowledge domain of system design. As shown by this work, the environmental field is a prime example of a problem domain where KBS development can be used as a tool for obtaining and exploiting “compiled” knowledge—knowledge which can be used to explain heuristics in terms of first principles.
Hindcasting volatile chemical emissions to air from ponded recycle oil
Authors: Thibodeaux Louis J. , Carver James C. 
Published: February 2007

AbstractBecause of weathering, while abandoned for over a decade, the floating oil at the site of a former oil recycling operation became depleted of numerous volatile and semi‐volatile constituents. The chemical record preserved in the bottom sediment provided the key information from which operating conditions over the period 1973–1982 could be reconstructed. Chemical concentrations in the oil could be determined and coupled with an environmental chemodynamic model to quantifying chemical release rates to air. The oil contained elevated levels of naphthalene. The oil, BTX fraction, several chlorinated solvents, and two PCB Aroclors were modeled. Annual average emission rates were 4000 kg for naphthalene, 840 for TCE, 300 for benzene and 14 for A‐1248. Fundamental results obtained are: a) the criteria required for using historic, bed‐sediment data to reconstruct key chemical processing information at a former plant site and b) field data on volatile and semi‐volatile chemical emission kinetics from deep, floating oil pools.
Industrial boiler retrofit for NOX control: Combined selective noncatalytic reduction and selective catalytic reduction
Authors: Groff Paul W. , Gullett Brian K. 
Published: February 2007

AbstractA 590 kW (2 MMBtu/hr), oil‐fired, three‐pass, fire‐tube package boiler was retrofit with a combined selective noncatalytic reduction (SNCR) and selective catalytic reduction (SCR) system and demonstrated 85% nitrogen oxide (NOx) reduction with less than 6 ppm ammonia slip. A urea‐based SNCR solution was injected in the first pass, reducing NOx and providing ammonia reagent for the SCR. A catalyst housing was designed to fit between the second and third passes, where the access doors of the boiler normally attach. The SCR catalyst volume of 0.04 m3 (1.5 ft3) provided a space velocity of 10,000 hr−1 at a pressure drop of less than 1.5 cm (0.5 in) of water. Numerous runs demonstrated system repeatability and ease of operation. Continued tests using an on‐line ammonia monitor, an on‐line reagent flow meter, and a different fuel were conducted to show sustained performance and applicability.
Chemical evolution of liquid redox processes
Authors: Deberry David 
Published: February 2007

AbstractA multitude of processes have been proposed for removal of hydrogen sulfide from gaseous streams. Removal of H2S from sour natural gas streams is particularly difficult since low outlet concentrations must be reached before the gas is put into a pipeline. Liquid redox sulfur recovery (LRSR) processes use a solution containing an oxidizing agent that absorbs H2S from the gas stream and oxidizes it to sulfur. The chemistry of these processes has undergone considerable evolution in the last 30 years.A number of tradeoffs must be considered in designing LRSR processes. For example, the rate of reaction of the oxidized agent with H2S often determines the scrubbing efficiency, but excessive rates of sulfur formation in the scrubber can lead to plugging. Systems based on vanadium and/or anthraquinone disulfonates (ADA) as the redox catalyst had several drawbacks, most of which can be traced to sluggish redox agent kinetics. Current LRSR processes use chelated iron as the catalyst for sulfur recovery. This gives faster scrubbing and re‐oxidation kinetics, but chemical degradation of the chelating agent can affect the economics of the process. Plugging of sorption vessels continues to be a problem in some applications. New nonaqueous solvent‐based or biological processes may overcome these problems.
Estimating physical properties for control equipment design
Authors: Logan Douglas A. 
Published: February 2007

AbstractThere is a great deal of information about physical properties available to engineers. The trick is in knowing where to find what is needed when it is needed. Many of the widely available sources lack information that is needed for process design. Material Safety Data Sheets (MSDSs) include relatively little physical properties data and no transport properties. Standard references like Perry's Chemical Engineer's Handbook, the CRC Handbook of Chemistry and Physics, and Lange's Handbook of Chemistry may not have data for a particular property or compound.The handbooks have information about hydrocarbons, and some of the common industrial alcohols, ketones, and esters. Data on some common industrial solvents, such as the glycol ethers and their acetates, is rather sketchy in the classic manuals. What can an engineer do if there is a need for data not available in the common references?For example, USEPA published several guidance manuals that present cost estimating techniques for air pollution control equipment. Engineers working in industry and for regulatory agencies apply the guidance in these manuals in trying to determine whether any of several control options represent the Best Available Control Technology (BACT) for an emissions source. BACT is the maximum level of control, considering economic factors as well as pollutant removal.Even the simplified design procedures in USEPA's Control Technology for Hazardous Air Pollutants require information that is just not found on an MSDS. Incinerator operating cost estimates depend on the heat available from the pollutants, the heat of combustion. The sizing and cost estimating procedure for refrigerated condensers calls for vapor pressure data, the heat of vaporization, and the heat capacity (specific heat). A cost estimate for an absorption system to scrub air pollutants demands vapor‐liquid equilibrium information, diffusivities, and the pollutant molar volume.Instead of starting a game of phone tag with the vendor's customer service department or spending several hundred dollars for a reference book you may not need again for five years, why not try estimating techniques for physical properties? These techniques have been around for a long time and offer reasonable accuracy within their limits. Estimated values are certainly accurate enough for budgetary‐quote‐level design procedures.More accurate estimating techniques are available [3]. The drawback to more sophisticated methods is increased complexity. Often, the more precise estimate calls for a multi‐step calculation, with several adjustable parameters. The methods described here are fairly simple, either empirical formulas or group contribution schemes.
Modeling and optimization of a municipal treatment plant using enviropro designer
Authors: Santamarina Victor E. 
Published: February 2007

AbstractThe increasingly stringent environmental regulations on discharge standards have rendered the optimal design and operation of industrial and municipal treatment plants a challenging task. The new regulations require tracking and control of VOCs and heavy metals if such chemicals are present in the influent stream. Further, they require more effective removal of nutrients (organic nitrogen, and phosphorus). To address the above issues at our facility, EnviroPro Designer, a comprehensive environmental simulator from Intelligen, Inc., was used to model and analyze our wastewater treatment plant. The work was performed in two phases. In phase one, we developed and validated a model of the existing facility. In phase two, we carried out sensitivity analysis and evaluated a number of process modification scenarios. This paper will describe the findings of our modeling work and our experience from using EnviroPro Designer.