Reduction of emissions

The 1990 Clean Air Act Amendments Hst 189 hazardous air pollutants (HAPs) that the EPA must regulate to enforce maximum achievable control technology (MACT) to standards which are to be set by the year 2000. The 33/50 project calls for reduction of emissions of 17 specified solvents to predetermined levels by 1995. The SARA statute provides a mechanism by which the community can be informed of the existence, quantities, and releases of toxic chemicals, and requires that anyone releasing specific toxic chemicals above a threshold level to annually submit a toxic chemical release form to the EPA. The status of various ketones under these regulations is shown in Table 4. 

G. P. Blair and co-workers, "The Reduction of Emissions and Euel Consumption by Direct Air-Assisted Euel Injection iato a Two-Stroke Engine," The 4th Gracy Two-Wheeler Symposium, Technical University, Gra2, Austria, 1991. 

Control and reduction of emissions of acidifying pollutants have been legislated in United States, Canada and in some European nations. When these reductions are affected, a reduction of about 60,000 in the number of acidified lakes is expected to be achieved in Canada. However, many highly sensitive lakes will be expected to remain acidified. 

Persistent organic pollutants (POP) and heavy metals were in the focus of interest until the begiiming of the 1990s and intensive monitoring programs and ecotoxico-logical studies had been conducted. As a result, due to adoption of appropriate measures and elimination of the dominant pollution sources a drastic reduction of emission of these nonpolar hazardous compounds have been achieved and today these compounds are less relevant for the industrialized countries. 

Fig. 2 Increase in fluorescence of the genuine fluorescence (A) by treatment with Benedict s reagent (B) and immersion in a paraffin solution (C) and reduction of emission intensities with time for the two cumarins umbelliferone and scopoletin (curves).

It is evident therefore that the reduction of emissions by action at source can have a significant impact on the size and hence the cost of an end-of-pipe treatment system. On this basis, it should be established practice in industry that no capital expenditure for end-of-pipe treatment should be made until all waste reduction opportunities have been exhausted. This has not often been the case, and many treatment plants have been built that are both larger and more complicated than is necessary. 

In addition to dissipation of the substance from the model system through degradation, other dissipative mechanisms can be considered. Neely and Mackay(26) and Mackay(3) have also introduced advection (loss of the chemical from the troposphere via diffusion) and sedimentation (loss of the chemical from dynamic regions of the system by movement deep into sedimentation layers). Both of these mechanisms are then assumed to act in the unit world. This approach makes it possible to investigate the behavior of atmosphere emissions where advection can be a significant process. Therefore, from a regulatory standpoint if the emission rate exceeds the advection rate and degradation processes in a system, accumulation of material could be expected. Based on such an analysis reduction of emissions would be called for. 

Europe s carbon market is growing quickly after the introduction of tradable annual allowances for greenhouse gas emissions under the Kyoto treaty that went into effect in 2005. In this new market-based emissiontrading system, light polluters can sell some of their surplus allowances to heavier polluters. This can result in a reduction of emissions at a lower cost than if each installation had been obliged to meet an individual target but the allowances to produce one kilowatt-hour of coal-fired power can cost more than the coal itself. 

Finally, it is worthy note that regulatory disincentives to voluntary reductions of emissions from petrolenm refineries also exist. Many environmental statutes define a baseline period and measnre progress in pollution reductions from that baseline. Any reduction in emissions before it is required could lower a facility s baseline emissions. Conseqnently, fnture regulations requiring a specified reduction from the baseline conld be more difficult (and consequently, more costly) to achieve because the most easily applied and hence the most cost-effective reductions would already have been made. With no credit given for voluntary reductions, those facilities that do the minimum may be in fact be rewarded when emissions reductions are reqnired. 

A critical question concerning atmospheric concentrations of ozone and other photochemical oxidants is What fraction of the observed values in each locale can be controlled by reduction of emissions Some contend that natural background concentrations exceed the federal ambient air quality standard (0.08 ppm). Another point of view is that background ozone concentrations rarely exceed about 0.05-0.06 ppm at the surface and that higher concentrations are caused by man-made sources. 

For heavy-duty trucks, since 2000, particulate emissions have been reduced by 80%, NOx will be reduced by 60% in 2008 with EU V. A further reduction of emission limits with EU VI is being considered for 2013 (Schulte-Braucks, 2006). 

Gasoline and diesel fuels are used worldwide in enormous amounts and are produced by the petroleum industry by oil refining (see Chapter 2). Liquid transportation fuels are conveniently transported, distributed, and dispensed directly into our vehicles and aircraft. Increased environmental concerns did much to begin to assure cleaner burning of our fuels. In the United States, law requires significant reduction of emissions and resulted in lead-free and more recently reformulated gasoline... 

Figure 1. Chrysophyte- and diatom-inferred pH reconstruction for Baby Lake, Sudbury, Ontario, Canada. Recent lake-water pH measurements are shown on the graph as open squares. The figure shows the decrease of lake pH attributed to the emission of sulfates from smelters in the Sudbury area, and the recovery after 1970 following major reductions of emissions. (Reproduced with permission from reference 8. Copyright 1992 Kluwer Academic...

A large national contribution as indicated by a relatively large change in regional PMjo levels due to a national reduction of emissions can be identified for Milan, Paris, Lisbon and Stuttgart, whereas large transboundary contributions have been calculated for Kosice.11... 

Other POPs, such as y-HCH, showed very significant reductions in the ambient air concentrations, which was in agreement with the reductions of emissions from agriculture. The concentrations of these compounds in northern Europe are at present between 1 and 4 pg/m3 and around 20 pg/m3 in central Europe. On the other hand, HCB did not show any decrease in atmospheric levels and remained around 50 pg/m3 on the European continent and at 5 pg/m3 in Iceland. 

It is especially rewarding that the solutions of practical engineering problems, such as the reduction of emissions of nitrogen and sulfur oxides and polycyclic aromatic compounds from boilers, furnaces, and combustors, are amenable to the application of chemical engineering fundamentals. Guidance for preferred temperature-concentration history of the fuel may be given by reaction pathways and chemical kinetics, and elements of combustion physics, i.e., mixing and heat transfer may be used as tools to achieve the preferred temperature-concentration history in practical combustion systems. 

Lastly, the results of Responsible Care commitments have been discussed with many national governments (and NGOs) in the context of reduction of emissions (air, water, waste, greenhouse gases, etc.). 

The Stockholm Convention (UNEP 2009a) entered into force in 2004, restricting 12 persistent and bio-accumulating toxic chemicals. An additional 9 substances were included in 2009. In coming decades, the major issue under the convention will be the reduction of emissions of dioxins and furans from combustion. 

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