Organic lignite coal

Lignite coal is able to adsorb 2,3-benzofuran from aqueous solution (Humenick et al. 1982), which indirectly confirms the expectation that the mobility of the chemical will be influenced by the distribution of organic carbon. 

Subbituminous coal A sedimentary rock composed of at least 50wt% and 70v% combustible organic materials that has less moisture than lignite coal, but more moisture than bituminous coal. 

It is interesting that a bituminous coal (Sample 4) gave organic acids qualitatively similar to those of lignite coal see Figure Id). Major identified compounds were p-hydroxybenzoic acid and two isomers of hydroxybenzenedicarboxylic acid, benzene di- and tricarboxylic acids. No ortho or meta isomer of hydroxybenzoic acid was detected. We have found that solvent-extractable hydrocarbons obtained from this raw coal consist mainly of n-alkanes (Cjj to 3 ). This is quite different from other results which showed that aromatic hydrocarbons were the major solvent-extractable material of several bituminous and anthracite coals (21). Indeed, petrographic analysis shows that this coal has a high content of sporinite (14.3 wt %) and a low content of vitrinite (30.2 wt %) (33). 

In a previous paper (21) we characterized aromatic acids trapped in lignite coal, and have found that these acids are quite similar qualitatively to those obtained from the present oxidation of the same pretreated coal. This indicated that the trapped acids were derived mainly from the hydrolytic degradation of lignin-like polymers. We also have observed that no trapped organic acid is isolated from the anthracite coal that no longer contains lignin-like polymers. 

Mercury concentrations were highest in lignite coal (0.12mg/kg DW), lowest in sub-bituminous coal (0.03 mg/kg DW) and intermediate (0.07 mg/kg DW) in bituminous coal samples measured. More recent information indicates that coal contains, on an average 0.2 mg Hg/kg and may contain as much as 1.0 mg/kg. Most of the mercury in coal is associated with arsenic-bearing pyrite other forms include organically bound mercurials, elemental mercury, and mercuric sulfides and selenides. In coal samples with low pyrite, mercury selenides may be the primary form. 

Usmani and Wahab ° determined the adsorption of lower aliphatic and some organic unsaturated fatty acids from their aqueous solutions on activated carbons prepared from wood, rice husk, and lignite coal. The adsorption depended on the porosity and the chemical stfucture of the carbon surface. It was also found that for a given acid the adsorption depended on the polarity of the carboxylic group, the length of the side chain, and the nature of the type of bonding. The adsorption followed both the Langmuir and the Freundlich adsorption equations. 

Carbonaceous and organic Peat, coals (e.g., lignites, anthracites), petroleum, bitumen, natural gas... 

Activated carbon is produced from nearly all carbon-containing organic materials, mainly wood, sawdust, nutshells, fruit stones, peat, lignite, coal, petroleum coke, etc. The use of a suitable precursor is mainly conditioned by its availability and cost, although it also depends on the main applications of the manufactured carbon and the type of installation available (Jankowska, 1991 Leon and Radovic, 1994 Rodrfguez-Reinoso, 2002). A general flow sheet for the manufacture of activated carbon is as Figure 9.1. 

Physical Properties. Physical properties of waste as fuels are defined in accordance with the specific materials under consideration. The greatest degree of definition exists for wood and related biofuels. The least degree of definition exists for MSW, related RDF products, and the broad array of ha2ardous wastes. Table 3 compares the physical property data of some representative combustible wastes with the traditional fossil fuel bituminous coal. The soHd organic wastes typically have specific gravities or bulk densities much lower than those associated with coal and lignite. 

Hydrocarbon resources can be classified as organic materials which are either mobile such as cmde oil or natural gas, or immobile materials including coal, lignite, oil shales, and tar sands. Most hydrocarbon resources occur as immobile organic materials which have a low hydrogen-to-carbon ratio. However, most hydrocarbon products in demand have a H C higher than 1.0. 

In carbon adsorption, contaminants are physically attracted or adsorbed on the surface of the carbon. Adsorption capacities are high for carbon because its porous nature provides a large surface area relative to its volume. Activated carbon is prepared from lignite, bituminous coal, coke, wood, or other organic materials such as coconut shells. 

Adsorption. Adsorption (qv) is an effective means of lowering the concentration of dissolved organics in effluent. Activated carbon is the most widely used and effective adsorbent for dyes (4) and, it has been extensively studied in the waste treatment of the different classes of dyes, ie, acid, direct, basic, reactive, disperse, etc (5—22). Commercial activated carbon can be prepared from lignite and bituminous coal, wood, pulp mill residue, coconut shell, and blood and have a surface area ranging from 500—1400 m /g (23). The feasibiUty of adsorption on carbon for the removal of dissolved organic pollutants has been demonstrated by adsorption isotherms (24) (see Carbon, activated carbon). Several pilot-plant and commercial-scale systems using activated carbon adsorption columns have been developed (25—27). 

FIGURE 15.7 Secondary changes in the total group composition of soluble organic matter as a result of simulated water washing extracts of the Miocene lignite and shale (both of the Bechatow open cast mine, Poland), the Upper Devonian shale (the Holy Cross Mountains, Poland), and the Upper Carboniferous bituminous coal (the Upper Silesia Coal Basin, Poland). 

Bitumen, asphalt, and other fossil organic materials such as coal, lignite and peat are found as natural deposits and have practically always been used in arts and handicrafts. Bitumen and asphalt were used in medicines and cosmetics, as pigments, as adhesives and in mummification balms in ancient Egypt [2,159,160]. 

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