Exhaust treatment technologies

Wash-coating techniques for metal foils exist in automotive exhaust treatment technology [646]. Adomaitis et al. has presented the Metreon process, which was developed for coating of unstructured Fecralloy metal foils [646]. The foils wrapped up as coils were processed through rolls, where they received a corrugated structure. 

Engine and vehicle technologies normally achieve their best emissions performance with high quality fuels. One property on which a great deal of attention has focussed is the sulphur content, partly because of the need to reduce PM and SO2 emissions and partly because fuel sulphur has an adverse effect on certain types of engine and exhaust after-treatment technology. In Europe the controls on fuel... 

This chapter is not intended as an exhaustive treatment of batteries as such. Rather, it seeks to bring to the fore the wide-ranging importance of one application of electron transfer batteries. Of no less importance in this connection is the enormous elfort of interdisciplinary research needed to develop batteries responsive to scientific advances and technological innovations—research that is strengthened under the pressure of market demand. 

Fig. 9.4 After-treatment technologies to meet exhaust emission standards...

The constant improvement of exhaustion and fastness properties of dyes is paralleled by a progressive improvement of wastewater treatment technologies which reduces the overall environmental impact both by primary and secondary measures. 

In contrast to ceramic and metallic monoHths developed for automotive exhaust treatment purposes, which nowadays carry chaimels on the microscale and are actually micro-reactors by definition, the micro-reactors discussed in this chapter rather cover plate heat-exchanger technology with chaimels on the microscale. An overview of the fundamentals, practical applications, and production issues of micro-reactors for fuel-processing purposes is provided. 

Catalytic Oxidization. A principal technology for control of exhaust gas pollutants is the catalyzed conversion of these substances into innocuous chemical species, such as water and carbon dioxide. This is typically a thermally activated process commonly called catalytic oxidation, and is a proven method for reducing VOC concentrations to the levels mandated by the CAAA (see Catalysis). Catalytic oxidation is also used for treatment of industrial exhausts containing halogenated compounds. 

The actual issues of EuroV standards aim at optimizing engine s design to decrease the engine-out N(), emissions in order to avoid the need for expensive after-treatments in the exhaust line. Only some heavily loaded applications would need such NOx after-treatment. Today, two major technological ways of NOx treatment are identified the NOxTrap and the selective catalytic reduction with ammonia (SCR-NH3). 

The SCR-NH3 is a continuous process for NO treatment and shows very efficient treatment efficiency. But this technology needs to put in the vehicle an additional tank for the urea storage. Moreover, this technology is constrained from an architectural point of view because two DOCs are necessary before and after the DeNO catalyst to hydrolyze urea and form ammonia and to prevent the NH3 release in the exhaust line. 

For this purpose, in addition to the continuous evolution of CR and exhaust gas recirculation (EGR), novel primary measures are under study, including the long route EGR to cool the recirculated exhaust gas, the use of premixed combustion [which implies, however, higher GO and unburned hydrocarbon (U HG) emissions], the reduction of the compression ratio, the shaping of the injection rate and so on. Still, the after-treatment catalytic technologies for O, removal and for CO/hydro-carbon (HG) and particulate matter (PM) reduction in passenger cars must be improved significantly. 

Ultrafiltration also has a fair to excellent track record of removing organic and inorganic constituents, although data about its performance are not as extensive. These and other related technologies are discussed in detail below, with specific reference to the treatment of wastewater to remove the nontraditional contaminants in the form of PPCPs. However, the accompanying text is not intended to be an exhaustive treatise on wastewater treatment, a subject for which interested parties are referred to more appropriate textbooks. 

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