Chemical emission control

Transport fuels Bulk chemicals Fine chemicals Emissions control... 

Emission Standards. In order to have a nationwide basis for air pollution emission controls and to set a minimum emission limit, the EPA developed New Source Performance Standards (NSPS). The NSPS set specific poUutant emission limits or describe the best available control technology (BACT) that should be appUed at that source. The EPA has issued NSPS, which apply to new constmction as weU as to large modifications, for many different sources. Sources in the chemical industry include the foUowing. 

The chemical industry was the first to utilize catalytic oxidation extensively for emission control, building units capable of treating up to 50 m /s (100,000 scfm) of exhaust gas containing VOCs. Catalytic systems accounted for roughly one-fourth of the 200 million market for VOC control systems in 1992, and over one thousand catalytic oxidization devices were in place by the end of that year (5). 

Process vents and drains, including emission control devices, are often overlooked but are important elements in the safety of batch systems. Inadequate attention to these items can result in incompatible chemical mixtures within the... 

It was not nndl the 1950s that detonation flame arresters made of crimped metal ribbon elements were developed and began to be used more freqnendy (Binks 1999). The major impetus for die use of crimped metal ribbon detonation flame arresters in the US was the enactment of clean air legislation (Clean Air Act of 1990) which inadvertently created a safety problem by requiring reductions in volatile organic compound (VOC) emissions. To do this, manifolded vent systems (vapor collection systems) were increasingly installed in many chemical process industry plants which captured VOC vapors and transported them to suitable recovery, recycle, or destruction systems. This emission control requirement has led to the introdnction of ignition risks, for example, from a flare or via spontaneous combustion of an activated carbon adsorber bed. Multiple... 

Ozog, H., and Erny, W. J. 1999. Safety Hazards Associated with Air-Emission Controls. Paper 5d. Proe. 33rd Annual AIChE Loss Prevention Symposium, March 14-17, 1999, Houston, TX. American Institute of Chemical Engineers, New York, NY. 

A catalytic oxidation system may cost 150 per car, but the catalyst cost is estimated to be 30, less than 1% of the cost of an automobile (2). In a few years, the gross sale of automotive catalysts in dollars may exceed the combined sale of catalysts to the chemical and petroleum industries (3). On the other hand, if the emission laws are relaxed or if the automotive engineers succeed in developing a more economical and reliable non-catalytic solution to emission control, automotive catalysis may turn out to be a short boom. Automotive catalysis is still in its infancy, with tremendous potential for improvement. The innovations of catalytic scientists and engineers in the future will determine whether catalysis is the long term solution to automotive emissions. 

Emission control from heavy duty diesel engines in vehicles and stationary sources involves the use of ammonium to selectively reduce N O, from the exhaust gas. This NO removal system is called selective catalytic reduction by ammonium (NH3-SGR) and it is additionally used for the catalytic oxidation of GO and HGs.The ammonia primarily reacts in the SGR catalytic converter with NO2 to form nitrogen and water. Excess ammonia is converted to nitrogen and water on reaction with residual oxygen. As ammonia is a toxic substance, the actual reducing agent used in motor vehicle applications is urea. Urea is manufactured commercially and is both ground water compatible and chemically stable under ambient conditions [46]. 

Hocking, M. B., Modem Chemical Technology and Emission Control, Springer-Verlag, Berlin, 1984, 141. 

Automotive emission control, 10 30-67 for alternative fuels, 10 59-60 alternative systems, 10 58-59 catalytic converter chemical reactions and surface chemistry, 10 46—50 catalytic converter design, 10 39—46 diesel engine, 10 60-62 emission control system, 10 38-39 emission regulation and testing, 10 31-35... 

Transition metal oxides (in absence of water) are therefore essential catalysts for many chemical processes such as oxidation (e.g., oxidation of CO in emission control), dehydrogenation (e.g., production of aldehydes from alcohol), and selective reduction (e.g., reduction of NO). Usually, activation of an oxide by heating is a pre-... 

Besides fuel and power production, there is the opportunity of recovering chemicals from pyrolysis liquids (Fig. 7.5). Even if there is a wide range of specialties that can be extracted or derived, including food flavorings, resins, agrochemicals, fertilizers and emissions control agents, this application is likely to lie in niche markets. 

Are there controlled chemical emissions from the manufacturing plant ... 

A realistic and detailed chemical model has great value. The stepwise addition of various primary pollutants can be made to evaluate the importance of each, llie effects of various emission control strategies on the chemistry of oxidant formation can be studied easily and quickly. It is possible to calculate the importance and concentration of various reactive intermediates. One can estimate the concentrations of various compounds that have not yet been observed in smog. And it is possible to pinpoint some of the important gaps, in order to stimulate future experimental studies. 

Methods for the direct and continual measurement of chemicals in the particles of the atmospheric haze that are known to be formed during photochemical-pollution episodes and are already suspect as respiratory irritants . By implementing such measurements, it will be possible to find out to what extent the occurrence of such substances can be reduced by various emission controls. To assess actual population expo-... 

Since the beginning of the environmental movement in the 1960s many people have asked repeatedly if we better off environmentally today and, if so, can we do even more than we have done In some respects we see a bad side. The chemical industry still has a large amount of toxic chemical emissions. Pollution control is getting more expensive. On the brighter side. 

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