Carbon materials nitrogen content

In the present context, heavy oils and residua can also be assessed in terms of sulfur content, carbon residue, nitrogen content, and metals content. Properties such as the API gravity and viscosity also help the refinery operator to gain an understanding of the nature of the material that is to be processed. The products from high-sulfur feedstocks often require extensive treatment to remove (or change) the corrosive sulfur compounds. Nitrogen compounds and the various metals that occur in crude oils will cause serious loss of catalyst life. The carbon residue presents an indication of the amount of thermal coke that may be formed to the detriment of the liquid products. 

The first significant alloy developed commercially to meet these requirements contained 26% chromium and 1% molybdenum. To obtain the desired corrosion resistance and acceptable fabrication characteristics, the material had to have very low interstitial element contents. To achieve these levels, the material was electron-beam rerefined imder a vacuum. It was known as E-Brite alloy. Carbon plus nitrogen contents were maintained at levels below 0.02%. 

Although these studies utilizing Incorporated debris are valuable because they show the potential for allelochemlcals to be released from plant litter, they suffer from a disadvantage. The amount of debris added and Its carbon to nitrogen ratio might lead to alterations In nutrient contents In the soil as the result of proliferation or shifts In populations of micro-organisms. Thus, a control In which a material of similar C/N ratio but lacking allelochemlcals needs to be Included for such studies to be conclusive. The above studies did not Include such controls and thus are not definitive. 

Several researchers emphasized that compost is also an excellent material to use to prevent the acidification and the deterioration of soil productivity [8, 51-54]. Several factors including moisture content, temperature, aeration rate, and carbon to nitrogen ratio have direct influence on composting process, which has been reviewed in detail in the past. 

The parent siliceous materials of the SBA-15 and MLV types were synthesised after typical procedures [2], The carbon replicas were prepared via polymerisation, catalysed by ferric chloride, of pyrrole introduced into the mesopores of matrices [3]. The products were characterised by the nitrogen adsorption, TEM, and thermal analysis (DTG, DTA). The nitrogen content in carbons was determined using elemental analysis, XPS, and EDX, while the Si and Fe contents, with XPS. The replicas of SBA-15 and MLV-0.75 are denoted as CMK-3Nx and OCM-.Nx, respectively, were x refers to the number of g of FeCl3 per 1 g of silica used for preparations. 

Classical characterization methods (gas sorption, TEM, SEM, FTIR, XPS and elemental analysis) were used to describe the resulting porous carbon structures. Temperature-dependent experiments have shown that all the various materials kept the nitrogen content almost unchanged up to 950 °C, while the thermal and oxidation stability was found to be significantly increased with N-doping as compared to all pure carbons. Last but not least, it should be emphasized that the whole material synthesis occurs in a remarkably energy and atom-efficient fashion from cheap and sustainable resources. 

Violence of the reaction, sometimes explosive, with e.g., acetic acid, benzene, ether, is associated with both their carbon and hydrogen contents. If nitrogen is also present, explosive fluoroamino compounds may be involved. Fibrous materials —cotton, paper, wood — invariably ignite. 

The high-boiling distillates, such as the atmospheric and vacuum gas oils, are not usually produced as a refinery product but merely serve as feedstocks to other processes for conversion to lower-boiling materials. For example, gas oils can be desulfurized to remove more than 80% of the sulfur originally in the gas oil with some conversion of the gas oil to lower-boiling materials (Table 6-11). The treated gas oil (which has a reduced carbon residue as well as lower sulfur and nitrogen contents relative to the untreated material) can then be converted to lower-boiling products in, say, a catalytic cracker where an improved catalyst life and volumetric yield may be noted. 

Harradine, F., and Jenny, H. (1958). Influence of parent material and climate on texture and nitrogen and carbon contents of virgin California soils I. Texture and nitrogen contents of soils. Soil Sci. 85(5), 235-243. 

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