Waste-gas emission

TREATMENT OF WASTE GAS EMISSIONS FROM PULP AND PAPER INDUSTRIES... 

A modern enameling plant permits economical wire production and at the same time low solvent emissions by utilizing the heat of combustion of the solvents contained in the enamel. The solvents are usually burned catalytically using noble metal catalysts that have a permanent degree of efficiency of >95% at working temperatures of around 600 °C. The waste gas emission levels produced are below the limits currently specified by the laws. 

For this purpose, waste gases from the various process stages are assembled in two separate systems waste-gas system 1 ( rich gas ) is used for the collection of combustible but not explosive gases (waste-gas concentration >explosive range), and waste-gas system 2 ( lean gas ) is used for the collection of waste gases of low concentration (waste-gas concentration < explosive range). Extensive changes to the viscose staple fiber plant were necessary to minimize waste-gas emission ... 

Waste gas emission limits as set out by national regulations (see e.g. the German air regulations TA-Luft ) are easier to maintain if waste gas is continuously emitted. Cryogenic solvent recovery plants become more cost-effective if larger amounts of nitrogen can be used as an inert gas for other operations. The CRYOCON process from Linde (see Fig. 2.31) is a typical example of such an installation. 

Many of the plasma catalysis schemes described in this chapter are not optimised in a way that is suitable for processing large volumes of waste gas in an efficient manner on a larger scale. Plasma reactors are generally limited to rather low gas flows compared to normal waste gas emissions and are presently best suited to niche applications of small flows with low concentrations of pollutants. A more energy-efficient configuration can be constructed where the pollutant is initially adsorbed... 

Anaerobic. Moisture is added to the waste mass in the form of recirculated leachate and from other sources to obtain optimal moisture levels. Biodegradation occurs in the absence of oxygen (anaerobically) and produces landfill gas. Landfill gas, primarily methane, can be captured to minimize greenhouse gas emissions and for energy projects. 

Another critical part of the incinerator design is the pollution control system.11 Pollution control systems directly influence the levels and kinds of pollutants that are released and that can potentially reach the public. Most modern hazardous waste incinerators are designed with extensive air pollution removal systems. For example, a common pollution control system might include a system that cools or quenches gases produced by burning waste, followed by a system that reduces acid gas emissions, and ultimately followed by a particulate removal system such as fabric filters (bag-houses), electrostatic precipitators, venturi scrubbers, and others.10... 

In more recent applications, several types of ET cover designs also have incorporated synthetic materials, such as geomembranes, which are used to enhance the function of minimizing water into the waste. For example, the Operating Industries Inc. Landfill in California has incorporated a soil layer with a geosynthetic clay liner in the design. The cover system for this site will reduce surface gas emissions, prevent oxygen intrusion and percolation, and provide for erosion control.68... 

The major emissions from the combustion of fuel are C02, SO, NO and particulates14. The products of combustion are best minimized by making the process efficient in its use of energy through efficient heat recovery and avoiding unnecessary thermal oxidation of waste through minimization of process waste. Flue gas emissions can be minimized at source by ... 

Sulfate, halide, and carbonate minerals form in mine waste as a result of chemical weathering reactions and as a by-product of mineral processing. The formation of carbonate minerals is of particular interest for its potential in offsetting greenhouse gas emissions associated with mining. We have documented secondary carbonate mineral precipitation at the Mount Keith Nickel Mine (Western Australia) and the... 

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