ISSN:0278-4491    

DOI:10.1002/ep.670050402

出版商:American Institute of Chemical Engineers    

年代:1986

数据来源: WILEY

ISSN:0278-4491    

DOI:10.1002/ep.670050403

出版商:American Institute of Chemical Engineers    

年代:1986

数据来源: WILEY

ISSN:0278-4491    

DOI:10.1002/ep.670050404

出版商:American Institute of Chemical Engineers    

年代:1986

数据来源: WILEY

摘要:

AbstractPrevious workers have shown that the recycle of product solids improves the utilization of slaked lime [Ca(OH)2] for SO2removal by spray dryers with bag filters. In laboratory‐scale experiments with a packed bed reactor, utilization was increased several‐fold when the Ca(OH)2was first slurried with one of several different fly ashes. The enhancement increased with the higher loading of fly ash [g fly ash/g Ca(OH)2]. Much higher Ca(OH)2utilization was achieved when silicic acid was used instead of fly ash. Scanning electron microscopy supports the explanation that Ca(OH)2and silica dissolve and reprecipitate as a more reactive calcium silicate. Other major constituents of fly ash have less or no effect at all on Ca(OH)2utilization. The amount of calcium in the fly ash did not affect the overall SO2removal after Ca(OH)2was added. Slurrying for longer than 2 hours at higher than 60°C can improve the utilization of Ca(OH)2slurried with fly

ISSN:0278-4491    

DOI:10.1002/ep.670050405

出版商:American Institute of Chemical Engineers    

年代:1986

数据来源: WILEY

摘要:

AbstractPilot plant tests have been conducted to evaluate sodium thiosulfate as an oxidation inhibition additive in five lime/limestone slurry flue gas desulfurization processes. It was found that the oxidation rate of absorbed sulfur dioxide (SO2) was reduced by more than 50 percent in the presence of 100 to 200 ppm of thiosulfate ion in the scrubbing slurry. Calcium sulfate dihydrate (gypsum) scaling was eliminated and the unsaturated (with respect to gypsum) operation mode was maintained by the addition of sodium thiosulfate. Other benefits of sodium thiosulfate addition observed at the pilot plant included improvement in solids dewatering properties for limestone processes and improvement in SO2removal efficiency for magnesium‐enhanced lime/limestone processe

ISSN:0278-4491    

DOI:10.1002/ep.670050406

出版商:American Institute of Chemical Engineers    

年代:1986

数据来源: WILEY

摘要:

AbstractSulfur dioxide (SO2) control processes which produce dry waste products have attracted increased interest in recent years based on economic and environmental considerations. This paper compares the chemical composition and physical properties of fly ash and dry waste products from existing SO2control processes with the properties of dry waste from emerging technologies such as furnace sorbent injection and fluidized bed combustion. Based on this information, design features are revieweded for material handling systems and for dry waste landfill sites. Environmental impacts from dry waste handling and disposal are discussed. The potential for commercial utilization of dry wastes from emerging SO2control technologies is also addressed.

ISSN:0278-4491    

DOI:10.1002/ep.670050407

出版商:American Institute of Chemical Engineers    

年代:1986

数据来源: WILEY

摘要:

AbstractDynamic dilution olfactometers provide a range of odor dilutions for presentation to panelists. Reliable odor thresholds of source emissions can be evaluated consistently only if the unknown odor thresholds fall in the middle of the dilution range of the olfactometer being used for a given test.This paper describes a fast and reliable procedure for ensuring that individual panelist thresholds will fall in the middle of the dilution range through selection of appropriate attenuators. The recommended approach makes use of the best capabilities of the ASTM and IITRI methods. It has been tested successfully with acetic acid vapors.

ISSN:0278-4491    

DOI:10.1002/ep.670050408

出版商:American Institute of Chemical Engineers    

年代:1986

数据来源: WILEY

摘要:

AbstractThe increase in atmospheric CO2, which results primarily from combustion of fossil fuels for energy, could cause dramatic global climatic and environmental changes—the so‐called “greenhouse effect.” This study explores the technical feasibilities and the cost of controlling CO2emissions from the stacks by removing, recovering, and disposing of CO2from fossil‐fuel power plants in the U.S. It is estimated that up to a 10% reduction in the annual incremental atmospheric CO2content would be achieved by the study control system. The total power required for such a control system ranges from 11 to 16% of the power‐generating capacity in various regions of the U.S. Overall, the study system could essentially increase the capital investment of a power plant by 70 to 150%, and increase production cost of electricity by 56 to 100%, depending on the location o

ISSN:0278-4491    

DOI:10.1002/ep.670050409

出版商:American Institute of Chemical Engineers    

年代:1986

数据来源: WILEY

摘要:

AbstractResults from a detailed analysis of sulfur dioxide (SO)2reductions achievable through “deep” physical coal cleaning (PCC) at 20 coal‐fired power plants in the Ohio‐Indiana‐Illinois region are presented here. These plants all have capacities larger than 500 MWe, are currently without any flue‐gas‐desulfurization (FGD) systems, and burn coal of greater than 1% sulfur content (in 1980). Their aggregate emissions of 2.4 million tons of SO2per year represent 55% of the SO2inventory for these states. The principal coal supplies for each power plant were identified and characterized as to coal seam and county of origin, so that published coal‐washability data could be matched to each supplier. The SO2reductions that would result from deep cleaning (Level 4) and moderate cleaning (Level 3) of each coal were calculated using a PCC computer model. For deep cleaning, percentage reductions in sulfur content ranged from zero to 52%, with a mean value of 29%, and costs ranged from a low of $364/ton SO2removed to over $2000/ton SO2removed. Because coal suppliers to these power plants employ some voluntary coal cleaning, the anticipated emissions reduction from current levels if deep cleaning were used should be near 20%. These emissions reductions were projected using conventional coal‐cleaning‐circuit designs. The basic elements of typical commercial PCC designs are briefly described, and current research and development activities in physical, chemical, and biological desulfurization of coal are reviewed. Possible governmental actions to either encourage or mandate coal cleaning are ident

ISSN:0278-4491    

DOI:10.1002/ep.670050410

出版商:American Institute of Chemical Engineers    

年代:1986

数据来源: WILEY

摘要:

AbstractFluidized bed reactor technology was investigated as a means of developing a new simple and low cost process for coal desulfurization. Preliminary experimental results obtained in a 2.54 cm batch fluidized bed reactor have shown that over 80% total sulfur reductions can be achieved by sequential chlorination and dechlorination/hydrodesulfurization of high sulfur pulverized coals. Proximate and ultimate analyses of desulfurized coals have revealed enhanced carbon and fixed carbon levels and substantially reduced volatile, oxygen and hydrogen contents. While there was a minor increase in the ash content and heating value, nitrogen and chlorine contents were essentially unchanged.Compared to an earlier slurry phase process, the fluidized bed reactors process has specific advantages such as shorter reaction times, fewer processing steps and reduced reactant requirements. A fluidized bed reactor process may thus have a potential of being developed into a simple and economic means of converting high sulfur coals to environmentally acceptable fuels.

ISSN:0278-4491    

DOI:10.1002/ep.670050411

出版商:American Institute of Chemical Engineers    

年代:1986

数据来源: WILEY