Waste to Biomass Resource

Refuse-Derived Fuel. Many processing faciUties divert a portion of the material that is not recovered for recycling to waste-to-energy plants, also referred to as resource recovery faciUties, where the material is employed as fuel. The processes involved in the production of refuse-derived fuel (RDF) are outlined in Figure 4 (23). Nine different RDFs have been defined, as Hsted in Table 3 (24). There are several ways to prepare RDF-3, which is perhaps the most popular form and is the feed used in the preparation of densified refuse-derived fuel (d-RDF). AH forms of RDF are part of the broader set of waste-derived fuels (WDF), which includes various waste biomass, eg, from silvaculture or agriculture (see Fuels frombiomass Fuels fromwaste). 

The physical, chemical, and thermodynamic characteristics of biomass resources vary widely. This variation can occur among different samples of what would nominally seem to be the same resource. Also, variations could occur from one region to another, especially for waste products. This wide variation sometimes makes it difficult to identify a typical value to use when designing a gasification plant. 

These systems offer the opportunity to produce hydrogen from renewable resources in the mid-term (five to ten years). Using agricultural residues and wastes, or biomass specifically grown for energy uses, hydrogen can be produced using a variety of processes. 

In addition to the variations in the LHC composition that occur from species to species, each species has its extractives, which include resins and waxes. These constituents are capable of interfering with cellulose hydrolysis because of their hydrophobic nature. Tannins and other highly reactive materials are constituents of some woody species. When LHC is obtained from nonwoody (herbaceous) species, the range of interfering constituents increases greatly. Sugars, starches, dextran, carotenoids, and many isoprenoids are to be found. Operators of a cellulose hydrolysis process that uses municipal solid waste as its biomass resource may experience seasonal variations in composition and chance inclusion of crankcase oil and other products that inhibit enzymes or kill yeast. 

AND IN THE ECONOMY ENERGY RESOURCES AND RESERVES Renewable Energy from Biomass Waste-to-Energy Systems... 

Wood is one of our most important renewable biomass resources. Unlike most biomass sources, wood is available year roimd and is more stable on storage than other agricultural residues. In the United States, wood residues from industrial by-products totaled 60.8 x 10 metric tons in 1993 (73). Increasingly, residues are incorporated into manufactured wood products and are used as a fuel, replacing petroleum, especially at wood-industry plants (73) some is converted to charcoal but most is used in the pulp and paper industry. Residues are also available for manufacturing chemicals, generally at a cost equivalent to their fuel value (see Fuels FROM BIOMASS Fuels from waste). 

Biomass resources will become more important in the future as alternatives to fossil resources, which will be exhausted sooner or later. The features of biomass arc renewable, carbon-neutral, and abundant. However, these resources have not been utilized efficiently and their unused portions are wasted in the world, Human beings are, thus, urged to develop efficient utilization technology of biomass, especially cellulosic biomass resources. 

Naftali Muriithi (Kenyatta University, Kenya) has recognised the potential value in municipal waste as a resource. With increasing population, waste is also increasing rapidly. However this waste is difficult to recycle because it tends to be very heterogeneous in nature. It may be a mix of domestic and industrial materials and can also contain medical waste. A specific opportunity is to make use of nutrients present in biomass ash from domestic waste. Key factors to make this work will include more proactive government policy and constructing the right infinstructure. 

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