摘要:

AbstractThermal separation is an emerging technology for the treatment of contaminated soils and solids. The process removes organic contaminants by indirectly heating the soils and olids to temeratures sufficient to vaporize the harazdous components. The organic vapors in the desorber off‐gas are treated either by oxidation in a RCRA‐standard secondary combustion chamber or by condensation and conventional treatment of the small amount of the resultant condensate.This process had its first successful pilot demonstrations in treating Herbicide Orange contaminated soils at the Naval Construction Battalion Center and at Johnston Island, where dioxin contamination was reduced to less than 1 ppb.This paper summarizes the results of a series of pilot tests, conducted under a TSCA R&D permit, on 3 soils contaminated with PCBs at concentrations ranging from 250 ppm to 4%. To demonstrate the process on an engineering scale, IT made 13 runs in the pilot thermal separator at rates ranging from 18 to 32 kg/hr. Reported are results on the effect of temperature and residence time on the quality of treated soil. The report also summarizes pilot results on a mixed waste soil and soils contaminated with P

ISSN:0278-4491    

DOI:10.1002/ep.670100114

出版商:American Institute of Chemical Engineers    

年代:1991

数据来源: WILEY

摘要:

AbstractAn anomalous phenomenon known as the “thermal siphon” effect has been observed in four operational incinerators with vertical secondary combustion chambers (SCCs). The kiln and air pollution control (APC) system pressures in all four cases have, under certain conditons, been observed to be negative while the pressure at the top of the SCC is positive. This paper will focus on an explanation of this unusual fluid flow phenome

ISSN:0278-4491    

DOI:10.1002/ep.670100115

出版商:American Institute of Chemical Engineers    

年代:1991

数据来源: WILEY

摘要:

AbstractSelective Catalytic Reduction (SCR) has been applied as a NOx abatement technique for stationary sources of nitrogen oxides (NOx) in Japan since the early 1970s. To date, there are over 100 SCR installations operating in Japan.During the 1980s, a number of SCR systems have been installed in the United States, primarily in California. Among these applications are fired heater, boiler, and gas turbine/heat recovery steam generator (HRSG) installation. These installations provide a basis to assess the state‐of‐the‐art for applying SCR to comply with refinery NOx emission limita

ISSN:0278-4491    

DOI:10.1002/ep.670100116

出版商:American Institute of Chemical Engineers    

年代:1991

数据来源: WILEY

摘要:

AbstractA study was conducted on treating a simulated leachate that contained high concentrations of ammonia‐nitrogen ranging between 20 and 1000 mg/L. A pilot sized rotating biological contractor (RBC) was used to treat a surrogate leachate composed of primary effluent that was adjusted with glucose and ammonium chloride to achieve various concentrations of dissolved organic carbon (DOC) and ammonia‐nitrogen. Experiments were conducted to determine:The rate of ammonia conversionThe drop in pH at high ammonia concentrationsThe effect of low pH on ammonia conversionThe effect of high ammonia levels (1000 mg/L) on ammonia conversionThe effect of temperature on the reaction rate constant The results from these experiments and the applicability of a RBC to treat leachates containing high concentrations of ammonia‐nitrogen are rep

ISSN:0278-4491    

DOI:10.1002/ep.670100117

出版商:American Institute of Chemical Engineers    

年代:1991

数据来源: WILEY

摘要:

AbstractThe capture and disposal of carbon dioxide from the flue gas of fossil‐fueled power plants is technically feasible, albeit it requires a significant fraction of the energy content of the fossil fuel and additional equipment with large capital expenditures. The five processes investigated for capturing CO2from the flue gas of coal‐fired power plants are (a) combustion of coal in an atmosphere of oxygen and recycled flue gas; (b) scrubbing the flue gas with a recyclable solvent (monoethanolamine); (c) cryogenic CO2fractionation of the flue gas; (d) separation of CO2by selective membrane diffusion; and (e) scrubbing of the flue gas with seawater. The captured CO2is envisioned to be liquefied at 150 atm, piped to the deep ocean, and released through a diffuser. Model calculations show that with appropriate release conditions the formed CO2drops can be completely dissolved in seawater. The process that requires least incremental energy is air separation/flue gas recycling. In this process about 30% of the total energy content of the coal is consumed, and the thermal efficiency of a power plant is reduced from 35% to about 25%. Excluding pipeline and deep water disposal costs, we estimate that electricity production costs will increase by about

ISSN:0278-4491    

DOI:10.1002/ep.670100118

出版商:American Institute of Chemical Engineers    

年代:1991

数据来源: WILEY

摘要:

AbstractA 0.28‐2.8 m3/min (10‐100 cfm) moving bed carbon adsorption pilot plant has been developed for testing of low (10–200 ppm) concentration VOC emissions. The pilot plant uses a cross‐flow arrangement with the air flowing horizontally through the adsorption bed while the carbon adsorbent particles flow vertically downward. At the bottom of the system, the “used” activated carbon is regenerated using a direct contact heat exchanger. The regenerated carbon is then transported to the top of the moving bed via a screw feeder and pneumatic transport tube. A small gas flow containing the VOCs removed from the used adsorbent is emitted continuously from the adsorbent regenerator. When a carbon flow rate of 2.3 kg/hr (5 lbs/hr), a face velocity of 0.32 m/sec (63 ft/ min), and an emissions stream containing 30 ppm ethanol were used, the observed collection efficiency was approximately 90%. The ability to regenerate the carbon was tested by first operating the system in a static mode, that is air being drawn into the system while the adsorption bed was not moving. This was continued until approximately 70% of the inlet gas VOCs passed through the system without being adsorbed. The carbon flow was then started and the VOC concentration in the off gases of the absorbent regenerator was measured as the partially saturated carbon passed through the system. The VOC concentration in the gases emitted from the adsorbent regenerator was about a factor of ten higher than the VOC concentration in the air entering the ads

ISSN:0278-4491    

DOI:10.1002/ep.670100119

出版商:American Institute of Chemical Engineers    

年代:1991

数据来源: WILEY

ISSN:0278-4491    

DOI:10.1002/ep.670100101

出版商:American Institute of Chemical Engineers    

年代:1991

数据来源: WILEY