Chemical Pulp Paper Production

More than 48% of the raw material fiber used for paper production (chemical pulp or mechanical pulp) in the United States in 2002 was recovered or reclaimed, with recovered paper contributing 37.7% and wood residues 10.6%. The total has been more or less constant, with the percentage of recovered paper increasing and that of wood residues declining recently due to their increased use in oriented strand board and composite panels. Primary fibers are a renewable, domestic resource, much of which is currently supplied by tree plantations. Short-rotation forestry can be used to further increase the productivity of these plantations. (more…)

Biomass Storage and Pretreatment of Biomass Feedstock

Biomass Storage

Biomass storage is required to ensure the continuous operation of the facility. To limit the space required for storage at the plant site, biomass must be stored in relatively high piles. Two main problems associated with fuel storage are decomposition and selfheating. Self-heating increases the rate of decomposition and fire risk, and it encourages the growth of thermophilic fungi whose spores can cause a respiratory condition in humans similar to farmers lung. Some small virgin biomass losses may occur at the storage stage, but they are likely to be negligible. For intermediary storage of the fuel between the pretreatment (e.g., drying and sizing) and gasification stage, storage silos may be used. (more…)

Drying Biomass Feedstock During Gasification Process

The moisture content of the feedstock affects the gas composition and the energy balance of the process since gasification is an endothermic process. Water vapor, however, is an essential component of gasification reactions. Therefore, there is a trade-off between the extent of fuel drying and the quality of product gas. Drying of the feedstock to a moisture content of approximately 15% is commonly adopted. Fuel drying is likely to be the most energy intensive activity in the biomass gasification process. Important contributions can be made to the energy balance by using flue gases or steam to dry the biomass. The heat used for drying does not have to be high temperature, and a low temperature level is actually desired because it will prevent the evaporation of undesirable organic components. (more…)

Bioenergy from Dependent Resources (Forestry, Vegetable Oils, Waste)

Agricultural and forestry residues provide the largest proportion of biomass used for the production of biomas bioenergy. Some estimates suggest that globally available biomass role in the form of recoverable residues represents about 40 Ejyr -1, enough to meet 10% of the total present energy use of 406 Ejyr -1 . However, realizing this potential is limited by factors such as ease and cost of recovery and environmental concerns relating to sustainable land use practices. (more…)

Biodegradable Materials Definition and Example

Biodegradable materials are considered those materials that can be destroyed by microorganisms. To prevent the accumulation of non-biodegradable compounds in nature, there are two solutions that are currently under investigation: use roots or microbial strains that can attack thought products were not degradable, biodegradable materials or develop common strains. (more…)