Composition, biomass characteristics

Ash Characteristics. The elemental ash composition of biomass waste and municipal soHd waste differs dramatically from that of coal (qv). ... 

Municipal solid waste (MSW), 25 864 as biomass, 3 684 cadmium in, 4 489-490 characteristics of leachates in, 25 867t characterizing, 25 866-869 collection of, 25 869-870 composition analysis for, 27 365t ferrous scrap in, 27 411 incineration of, 25 872-873 mixed, 27 367-369 preparation of, 27 367-369 processing, 27 364-371 quantity and composition of, 27 362-364 recovery rates for, 27 364, 366-367t recycled, 27 360, 362-371 toxic chemicals in, 25 875-876 Municipal waste sludge, as biomass, 3 684 Municipal water, for aquaculture, 3 198 Municipal water softening methods,... 

Pyrolysis and liquefaction processes take an intermediate position in the sense that they maintain some larger molecular characteristics. Pyrolysis is a process in which the biomass material is quickly heated. The thermal cracking process, de-polymerizes waste or dry biomass and produces a liquid of complex composition (Fig. 1.17). 

Of the many factors which influence product yields in a fluid catalytic cracker, the feed stock quality and the catalyst composition are of particular interest as they can be controlled only to a limited extent by the refiner. In the past decade there has been a trend towards using heavier feedstocks in the FCC-unit. This trend is expected to continue in the foreseeable future. It is therefore important to study how molecular types, characteristic not only of heavy petroleum oil but also of e.g. coal liquid, shale oil and biomass oil, respond to cracking over catalysts of different compositions. 

Fabrication. Processes for fabricating solid fuel pellets from a variety of feedstocks, particulady RDF, wood, and wood and agricultural residues, have been developed. The pellets are manufactured by extrusion and other techniques and, in some cases, a binding agent such as a thermoplastic resin is incorporated during fabrication. The fabricated products are reported to be more uniform in combustion characteristics than the raw biomass. Depending on the composition of the additives in the pelletized fuel, the heat of combustion can be higher or lower than that of the unpelletized material. 

Approximately 89 million metric t of organic chemicals and lubricants, the majority of which are fossil based, are produced annually in the United States. The development of new industrial bioproducts, for production in standalone facilities or biorefineries, has the potential to reduce our dependence on imported oil and improve energy security. Advances in biotechnology are enabling the optimization of feedstock composition and agronomic characteristics and the development of new and improved fermentation organisms for conversion of biomass to new end products or intermediates. This article reviews recent biotechnology efforts to develop new industrial bioproducts and improve renewable feedstocks and key market opportunities. 

Stauffer, M.D., Chubey, B.B., and Dorrell, D.G., Growth, yield and compositional characteristics of Jerusalem artichoke as they relate to biomass production, in Fuels from Biomass and Wastes, Klass, D.L. and Emert, G.H., Eds., Ann Arbor Science, Ann Arbor, MI, 1981, pp. 79-97. 

An alternative, at least semi-quantitative method to follow changes in biomass composition is infrared (IR) spectroscopy [22]. From dried samples of microbial cells, IR spectra can be obtained which contain information on all major cell components. The spectra are analysed as a multi-component mixture Characteristic bands in the spectra are identified, the extinction coefficients for each component (protein, carbohydrate, lipid, and nucleic acids) at each band are determined, and the concentrations are calculated by a system of linear equations. The method gives results on all major cell components simultaneously, and is relatively quick and easy to perform, compared to the chemical analysis methods. For details see Sect. 8.4 below. 

Most important are likely environmental factors associated with cultivation, crop management, and postharvest processes that can be controlled to some extent and on the other hand also have a large impact on the chemical composition, cell-wall architecture, or conversion processing behavior of plant biomass. These factors could form the basis of a testable strategy to decrease the variance associated with these characteristics. 

Bio-oil from rapid pyrolysis is usually a dark brown, free-flowing liquid having a distinctive smoky odor. It has significantly different physical and chemical properties compared to the liquid from slow pyrolysis processes, which is more like a tar. Bio-oils are multicomponent mixtures comprised of different size molecules derived primarily from depolymerization and fragmentation reactions of the three key biomass building blocks cellulose, hemicellulose, and lignin. Therefore, the elemental composition of biooil resembles that of biomass rather than that of petroleum oils. Basic properties of biooils are shown in Table 33.7. More detail on fuel-related characteristics is provided in the literature.571... 

Due to the very different nature of biomass feedstocks, with a wide variety of composition and chemical species, it is expected that each kind of biomass will be the source of particular experimental problems, with its own unique characteristics. Hence, it is likely that the composition of the fuel gas and the formation of gaseous pollutants will be highly dependent on the feedstock. Therefore, the sampling system should be in some sense tailor-made and periodic checks of the reliability and accuracy of the sampling system will be made in order to enhance it. 

ABSTRACT The radiative pyrolysis of wood (thick cylinders and chip beds) has been investigated experimentally for external radiative heat fluxes in the range 28-80kW/m, resulting in maximum sample temperatures of 600-950K. Radial temperature profiles, product yields and composition, and devolatilization rates have been measured. The influences of wood variety (hardwoods and softwoods) on the pyrolysis characteristics are discussed and comparisons are made with biomass (agricultural residues). 

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