Biomass soot

But the most important challenge in NO and soot removal by plasma-assisted catalysis refers to the treatment of diesel exhaust [116]. The discovery of new combinations leading to both an advanced total oxidation of unburned organic fuels and fragments, and of soot is extremely important for the near-future. According to the new regulations concerning the use of biomass in the production of fuels, the achievements in the direction NO and soot removal by plasma-assisted catalysis should be extended to the removal of tars [117]. 

Klippel N, Nussbaumer T (2007) Health relevance of particles from wood combustion in comparison to Diesel soot. In 15th European biomass conference, Berlin 7-11 May 2007... 

The product of incomplete burning of various fuels (mainly fossil fuel and biomass burning) is called black carbon (BC), made up of soot and smoke aerosol that absorbs short-wave radiation. Estimates of direct RF due to BC and organic matter (OM) have led to values in the interval from +0.16 Wm-2 to +0.42 W m-2, and total absorbed radiation within 0.56 Wm 2-2 Wm-2 (the parameter BC + OM is the soot component that appears as a result of fossil fuel burning). About 10% (by mass) BC constitutes aerosol formed in biomass burning, for which RF values were obtained from 0.16Wm-2 to -0.74Wm-2, whereas the radiation absorbed by aerosol varies within 0.75 Wm-2 to 2Wm"2. 

Components of the products of biomass and fossil fuel burning responsible for radiation scattering (along with water-soluble organic and inorganic components emitted to the atmosphere as part of smoke and soot compounds) can also function as CCN. This means that emissions of BC and OM participate in the formation of indirect RF due to the impact of CCN on the formation of clouds and their properties. It follows from available estimates that such a contribution can exceed 80% with respect to total indirect RF. The BC impact can also manifest itself by local warming of the atmosphere and a decrease in cloud amount and their water content, which leads to an albedo decrease. 

The first case covers for example flue-gas treatment, which requires the filtration of fly-ash and the reduction of NOx, or gasification processes, where particulates and high-boiling tars have to be removed. An example of the second case is that of combustion processes, where incomplete combustion leads to the emission of carbonaceous particulates. The most relevant topic in this category is the reduction of diesel particulate emissions ( diesel soot ) by catalytic filtration. A more exotic example is the reaction cyclone for the thermal conversion of biomass, which also combines chemical reactions and separation in one apparatus, though its separation mechanism is not filtration. 

Partial oxidation of methane (or hydrocarbons) is another option to produce syngas [4], This process, which runs without a catalyst, needs high temperatures for high CH4 conversion and to suppress soot formation. The process can handle other feedstocks, such as heavy oil factions and biomass, and yields syngas with a H2/CO ratio of about 2. The process is eminently suitable for large-scale production of syngas (e.g. for gas-to-liquids [GTL] plants). 

Black carbon is a general denomination for materials such as soot, graphitic carbon and carbon black. The incomplete combustion of fossil fuels and biomass releases enormous quantities of these materials into the atmosphere, about 13Tgyear 1 on a global basis [55]. Both natural and anthropogenic processes contribute to this input. The chemical composition of the carbonaceous particles in the atmosphere is highly variable, as it depends on their formation process and ageing. 

The main contaminants in the product gases of biomass gasification are dust and soot particles, organic contaminants (often being referred to as tars [I]), alkali metals, acid... 

Within the Fischer-Tropsch research ECN Biomass concentrates on the definition of the gas cleaning with respect to the typical B R in urities, like NHj, HCl, HCN, H]S, COS, tars (heavy organic molecules), soot, and alkali metals, Traces (< ppm) of these compounds can already be a poison for the Fischer-Tropsch catalysts. For the implementation of B R and Fischer-Tropsch ECN its strategy is on the demonstration of integrated systems to reduce the time necessary to realise a first full-scale installation for conversion of biomass and residue, gas cleaning, and Fischer-Tropsch synthesis. To achieve this ECN focuses on two lines of development ... 

The supercritical water biomass conversion system used in this study was revised to be a batch-type reaction vessel from the semibatch-type employed in a previous work. This system can cover a range of up to 280MPa in pressure and up to SOOt in temperature. 

Aerosols (suspended particles) can be natural in origin or related to human activity such as combustion (of fossil fuels) or biomass burning. They can be, for example, sea salt, mineral dust, soot, dilute sulfuric acid droplets, and their existence will depend on the proximity of sources and suitable conditions (e.g., windspeed, humidity) for their formation and transport. Aerosols, which can both scatter and absorb, are most concentrated in the lower troposphere (planetary boundary layer) and decrease quickly with altitude. High altitude aerosols are usually insignificant in terms of UV transmission, except in unusual circumstances, such as immediately after a large volcanic eruption such as Mount Pinatubo in 1991. 

Visibility impairment in urban air is greatly affected by ambient particulate substances organics, soot (elemental carbon), soil dust, sulfates and nitrates. One of the primary particles, soot is emitted directly to urban air by diverse biomass burning, diesel engines and agricultural activities. All these process are greatly active in Asian cities. 

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