Woody Biomass (woody + biomass)

Distribution by Scientific Domains


Selected Abstracts


From renewable energy to fire risk reduction: a synthesis of biomass harvesting and utilization case studies in US forests

GCB BIOENERGY, Issue 3 2009
A. M. EVANS
Abstract The volatile costs of fossil fuels, concerns about the associated greenhouse gas emissions from these fuels, and the threat of catastrophic wildfires in western North America have resulted in increased interest and activity in the removal and use of woody biomass from forests. However, significant economic and logistical challenges lie between the forests and the consumers of woody biomass. In this study, we provide a current snapshot of how biomass is being removed from forests and used across the United States to demonstrate the wide variety of successful strategies, funding sources, harvesting operations, utilization outlets, and silvicultural prescriptions. Through an analysis of 45 case studies, we identified three themes that consistently frame each biomass removal and utilization operation: management objectives, ecology, and economics. The variety and combination of project objectives exemplified by the case studies means biomass removals are complex and difficult to categorize for analysis. However, the combination of objectives allows projects to take advantage of unique opportunities such as multiple funding sources and multiparty collaboration. The case studies also provide insight into the importance of ecological considerations in biomass removal both because of the opportunity for forest restoration and the risk of site degradation. The national view of the economic aspects of biomass removal provided by this wide variety of case studies includes price and cost ranges. This study is an important first step that helps define woody biomass removals which are becoming an essential part of forestry in the 21st century. [source]


A large carbon pool and small sink in boreal Holocene lake sediments

GLOBAL CHANGE BIOLOGY, Issue 10 2004
Pirkko Kortelainen
Abstract Model-based estimates suggest that lake sediments may be a significant, long-term sink for organic carbon (C) at regional to global scales. These models have used various approaches to predict sediment storage at broad scales from very limited data sets. Here, we report a large-scale direct assessment of the standing stock and sedimentation rate of C for a representative set of lakes in Finland. The 122 lakes were selected from the statistically selected Nordic Lake Survey database, they cover the entire country and the water quality represents the average lake water quality in Finland. Unlike all prior estimates, these data use sediment cores that comprise the entire sediment record. The data show that within Finland, aquatic ecosystems contain the second largest areal C stocks (19 kg C m,2) after peatlands (72 kg C m,2), and exceed by significant amounts stocks in the forest soil (uppermost 75cm; 7.2 kg C m,2) and woody biomass (3.4 kg C m,2). Kauppi et al. (1997). The Finnish estimate extrapolated over the boreal region gives a total C pool in lakes 19,27 Pg C, significantly lower than the previous model-based estimates. [source]


Production of bio-crude from forestry waste by hydro-liquefaction in sub-/super-critical methanol

AICHE JOURNAL, Issue 3 2009
Yun Yang
Abstract Hydro-liquefaction of a woody biomass (birch powder) in sub-/super-critical methanol without and with catalysts was investigated with an autoclave reactor at temperatures of 473,673 K and an initial pressure of hydrogen varying from 2.0 to 10.0 MPa. The liquid products were separated into water soluble oil and heavy oil (as bio-crude) by extraction with water and acetone. Without catalyst, the yields of heavy oil and water soluble oil were in the ranges of 2.4,25.5 wt % and 1.2,17.0 wt %, respectively, depending strongly on reaction temperature, reaction time, and initial pressure of hydrogen. The optimum temperature for the production of heavy oil and water soluble oil was found to be at around 623 K, whereas a longer residence time and a lower initial H2 pressure were found to be favorite conditions for the oil production. Addition of a basic catalyst, such as NaOH, K2CO3, and Rb2CO3, could significantly promote biomass conversion and increase yields of oily products in the treatments at temperatures less than 573 K. The yield of heavy oil attained about 30 wt % for the liquefaction operation in the presence of 5 wt % Rb2CO3 at 573 K and 2 MPa of H2 for 60 min. The obtained heavy oil products consisted of a high concentration of phenol derivatives, esters, and benzene derivatives, and they also contained a higher concentration of carbon, a much lower concentration of oxygen, and a significantly increased heating value (>30 MJ/kg) when compared with the raw woody biomass. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source]


Elucidation of the interaction among cellulose, xylan, and lignin in steam gasification of woody biomass

AICHE JOURNAL, Issue 2 2009
Chihiro Fushimi
Abstract The reaction mechanism for gas and tar evolution in the steam gasification of cellulose, lignin, xylan, and real biomass (pulverized eucalyptus) was investigated with a continuous cross-flow moving bed type differential reactor, in which tar and gases can be fractionated according to reaction time. In the steam gasification of real biomass, the evolution rates of water-soluble tar (derived from cellulose and hemicelluloses) and water-insoluble tar (derived from lignin) decrease with increasing reaction time. It was found that the evolution of water-soluble tar occurs earlier than in the gasification of pure cellulose, indicating an interaction of the three components. The predicted yield of water-insoluble tar is substantially less than that of real biomass. This implies that the evolution of tar from the lignin component of biomass is enhanced, compared with pure lignin gasification, by other components. The gas evolution rate from real biomass is similar to that predicted by the superposition of cellulose, lignin, and xylan. © 2008 American Institute of Chemical Engineers AIChE J, 2009 [source]


Drying technology for woody biomass for fine grinding by vibration mills

ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 2 2007
J. Kobayashi
Abstract An effective fine grinding technology for woody biomass using a new vibration mill is proposed and evaluated in this study. Grinding properties of woody biomass depend largely on its moisture content. In this study, the drying behavior of woody biomass and the effect of moisture content on fine grinding with a vibration mill are discussed. Simultaneous drying and pulverization of woody biomass using a continuous vibration mill was carried out and the drying characteristics were investigated. Copyright © 2007 Curtin University of Technology and John Wiley & Sons, Ltd. [source]