Sources of Biomass

Car mileage Otto, 7.4 1/100 km diesel, 6.1 1/100 km. Biogas production from crop remaining. 

The data presented in Table 2.1.1 clearly illustrate the advantage of transformation technologies utilizing the whole plant material and not only the oil or sugar and starch fraction. 

An alternative to the utilization of food crops in biofuel production is lignocellu-lose, which can for instance be utilized in biomass-to-liquid (BTL) processes. That way, a direct competition between food and fuel production can be avoided. This feedstock is much more abundant than vegetable oils or sugar and starch crops. 

Moreover, lignocellulose is not edible and could theoretically be utilized without any impact on food production. The cellulose and hemicellulose fraction of lignocellulose may serve for the production of cellulosic ethanol, which could be produced via acid or enzymatic catalyzed hydrolysis of cellulose, followed by further fermentation to yield ethanol. Alternatively, the whole plant can be gasified to yield syngas, followed by methanol or dimethyl ether synthesis or Fischer-Tropsch technology that produces hydrocarbon fuels. Furthermore, controlled (bio-)chemical transformations to novel fuel compounds based on cellulose, hemicellulose, or lignin are possible, and numerous recent publications emphasize intense research in this direction. 

---

Recently, however, we have embarked on a programme aimed at developing biodegradable and renewable support materials based on the very abundant sources of biomass such as starch, chitosan and cellulose, in addition to the inorganic materials mentioned above. 

In the production of antibiotics, sufficient growth of fungi in submerged cultures has created potential sources of biomass as SCP and as flavour additives to replace mushrooms the biomass contains 50-65% protein.1,5 Production of mushroom from lignocellulosic waste seems to be a suitable and economical process since the raw material is inexpensive and available in most countries. 

Chemical engineering in general and chemical reaction engineering in particular are in key position to carry out this transformation. One of the most important sources of biomass is forests, not only the rain forests and eucalyptus trees growing in the tropical areas of the earth but also the forests in the Northern hemisphere, for instance in Canada, USA, Russia, and in the Fenno-Scandic region. The big... 

There is no doubt that plants represent one of the most productive and yet inexpensive sources of biomass. The absence of contaminating animal pathogens, the eukaryotic translational machinery and the ease of plant virus manipulation make plants... 

Both in the USA and the EU, the introduction of renewable fuels standards is likely to increase considerably the consumption of bioethanol. Lignocelluloses from agricultural and forest industry residues and/or the carbohydrate fraction of municipal solid waste (MSW) will be the future source of biomass, but starch-rich sources such as corn grain (the major raw material for ethanol in USA) and sugar cane (in Brazil) are currently used. Although land devoted to fuel could reduce land available for food production, this is at present not a serious problem, but could become progressively more important with increasing use of bioethanol. For this reason, it is important to utilize other crops that could be cultivated in unused land (an important social factor to preserve rural populations) and, especially, start to use cellulose-based feedstocks and waste materials as raw material. 

Lignocellulosic agroindustrial byproducts are renewable, widespread, and generally an inexpensive source of biomass. Brewery s spent grain (BSG) is a disposal residue generated throughout the year in large amounts, for... 

Pulp and paper refers to the processes employed to convert wood fiber into paper and allied products used in such applications as communications, packaging, and construction. Pulp and paper technologies or processes capitalize upon the anatomical, physical, and chemical properties of wood and, to a much lesser extent, other sources of biomass. The application of those technologies or processes has led to the development of a highly capital intensive industry with worldwide sales on the order of 100 billion per year. 

Although Jerusalem artichoke tops need extensive drying, they can be a useful source of biomass for direct combustion. Trials in Lithuania have confirmed Jerusalem artichoke s suitability as an energy crop. The bulk density of tops harvested in autumn was 78 kgm3, compared to 65 kgm3 in the spring, while the average net calorific value of dry biomass harvested in autumn was 18.0... 

Many of the processes new to this edition reflect recent trends in the global chemical industry. There is now much less emphasis on new processes for making basic chemicals and more emphasis on pollution prevention and waste disposal. Petrochemical processes, based on petroleum and natural gas, are giving way to biochemical processes, using a variety of sources of biomass. 

The 50-MW plant in Burlington, Vermont, was limited in capacity by the wood fuel available witbin the area circumscribed by a radius of 80 km (50 mi.) from the plant. This is considered by most energy specialists to be the maximum distance that wood fuel can be obtained and economically transported to the plant by truck or rail. For captive sources of biomass fuels, the capacity can be larger. One example is the 60-MW, wood waste-fueled power plant located in Williams Lake, British Columbia (Baker, 1995). This plant is located in the center of a major lumber industry region that has five large sawmills located within 5 km of each other. The mills produce more than 540,000 green tonnes of bark, sawdust, and other wood waste products per year. 

Howlett, K., and Gamache, A. (1977). Forest and Mill Residues as Potential Sources of Biomass, Vol, VI, Final Report, MTR 7347. The MITRE Corporation, McLean, VA. 

Various pulping technologies for wood and other biomass have been used for centuries to produce fiber, primarily for paper production. These processes effecbvely separate and clean the cellulose for use as fiber. However, the hemicellulose and lignin byproducts are not typically used for chemical products. The depolymerized hemicellulose in pulping liquor is a large source of biomass carbohydrate that could potentially be used for chemical producbon. 

The principal sources of biomass used for energy purposes are wood, gathered from forests, orchards and farms, agricultural crop residues and animal wastes. Human wastes can also be potentially... 

---