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1.
Environ Sci Technol ; 44(1): 538-44, 2010 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-19961171

RESUMO

The use of coal is responsible for (1)/(5) of global greenhouse gas (GHG) emissions. Substitution of coal with biomass fuels is one of a limited set of near-term options to significantly reduce these emissions. We investigate, on a life cycle basis, 100% wood pellet firing and cofiring with coal in two coal generating stations (GS) in Ontario, Canada. GHG and criteria air pollutant emissions are compared with current coal and hypothetical natural gas combined cycle (NGCC) facilities. 100% pellet utilization provides the greatest GHG benefit on a kilowatt-hour basis, reducing emissions by 91% and 78% relative to coal and NGCC systems, respectively. Compared to coal, using 100% pellets reduces NO(x) emissions by 40-47% and SO(x) emissions by 76-81%. At $160/metric ton of pellets and $7/GJ natural gas, either cofiring or NGCC provides the most cost-effective GHG mitigation ($70 and $47/metric ton of CO2 equivalent, respectively). The differences in coal price, electricity generation cost, and emissions at the two GS are responsible for the different options being preferred. A sensitivity analysis on fuel costs reveals considerable overlap in results for all options. A lower pellet price ($100/metric ton) results in a mitigation cost of $34/metric ton of CO2 equivalent for 10% cofiring at one of the GS. The study results suggest that biomass utilization in coal GS should be considered for its potential to cost-effectively mitigate GHGs from coal-based electricity in the near term.


Assuntos
Carvão Mineral , Eletricidade , Combustíveis Fósseis , Madeira , Ontário
2.
Bioresour Technol ; 101(6): 1570-80, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19963372

RESUMO

The recently identified limitations of 1st-generation biofuels produced from food crops (with perhaps the exception of sugarcane ethanol) have caused greater emphasis to be placed on 2nd-generation biofuels produced from ligno-cellulosic feedstocks. Although significant progress continues to be made to overcome the technical and economic challenges, 2nd-generation biofuels production will continue to face major constraints to full commercial deployment. The logistics of providing a competitive, all-year-round, supply of biomass feedstock to a commercial-scale plant is challenging, as is improving the performance of the conversion process to reduce costs. The biochemical route, being less mature, probably has a greater cost reduction potential than the thermo-chemical route, but here a wider range of synthetic fuels can be produced to better suit heavy truck, aviation and marine applications. Continued investment in research and demonstration by both public and private sectors, coupled with appropriate policy support mechanisms, are essential if full commercialisation is to be achieved within the next decade. After that, the biofuel industry will grow only at a steady rate and encompass both 1st- and 2nd-generation technologies that meet agreed environmental, sustainability and economic policy goals.


Assuntos
Biocombustíveis , Biotecnologia/métodos , Monitoramento Ambiental/métodos , Lignina/química , Agricultura/métodos , Ração Animal , Biomassa , Biotecnologia/economia , Custos e Análise de Custo , Fontes Geradoras de Energia , Meio Ambiente , Poluentes Ambientais , Gases , Efeito Estufa , Hidrólise
3.
Appl Biochem Biotechnol ; 129-132: 22-40, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16915629

RESUMO

A lignocellulosic-based biorefining strategy may be supported by biomass reserves, created initially with residues from wood product processing or agriculture. Biomass reserves might be expanded using innovative management techniques that reduce vulnerability of feedstock in the forest products or agricultural supply chain. Forest-harvest residue removal, disturbance isolation, and precommercial thinnings might produce 20-33 x 10(6) mt/yr of feedstock for Canadian biorefineries. Energy plantations on marginal Canadian farmland might produce another 9-20 mt. Biomass reserves should be used to support first-generation biorefining installations for bioethanol production, development of which will lead to the creation of future high-value coproducts. Suggestions for Canadian policy reform to support biomass reserves are provided.


Assuntos
Produtos Agrícolas/economia , Produtos Agrícolas/provisão & distribuição , Fontes Geradoras de Energia/economia , Fontes Geradoras de Energia/estatística & dados numéricos , Resíduos Industriais/economia , Resíduos Industriais/estatística & dados numéricos , Modelos Econômicos , Biomassa , Canadá , Conservação dos Recursos Naturais/economia , Conservação dos Recursos Naturais/estatística & dados numéricos , Análise Custo-Benefício/métodos
4.
Appl Biochem Biotechnol ; 129-132: 55-70, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16915631

RESUMO

Softwoods are generally considered to be one of the most difficult lignocellulosic feedstocks to hydrolyze to sugars for fermentation, primarily owing to the nature and amount of lignin. If the inhibitory effect of lignin can be significantly reduced, softwoods may become a more useful feedstock for the bioconversion processes. Moreover, strategies developed to reduce problems with softwood lignin may also provide a means to enhance the processing of other lignocellulosic substrates. The Forest Products Biotechnology Group at the University of British Columbia has been developing softwood-to-ethanol processes with SO2-catalyzed steam explosion and ethanol organosolv pretreatments. Lignin from the steam explosion process has relatively low reactivity and, consequently, low product value, compared with the high-value coproduct that can be obtained through organosolv. The technical and economic challenges of both processes are presented, together with suggestions for future process development.


Assuntos
Fontes Geradoras de Energia/economia , Fontes Geradoras de Energia/estatística & dados numéricos , Etanol/metabolismo , Resíduos Industriais/economia , Resíduos Industriais/estatística & dados numéricos , Árvores/microbiologia , Madeira , Biomassa , Canadá , Conservação dos Recursos Naturais/economia , Conservação dos Recursos Naturais/estatística & dados numéricos , Análise Custo-Benefício/métodos , Modelos Econômicos
5.
J Environ Manage ; 78(2): 114-27, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16095806

RESUMO

The modern environmental management literature stresses the need for community involvement to identify indicators to monitor progress towards sustainable development and environmental management goals. The purpose of this paper is to assess the impact of participatory processes on sustainability indicator identification and environmental management in three disparate case studies. The first is a process of developing partnerships between First Nations communities, environmental groups, and forestry companies to resolve conflicts over forest management in Western Canada. The second describes a situation in Botswana where local pastoral communities worked with development researchers to reduce desertification. The third case study details an on-going government led process of developing sustainability indicators in Guernsey, UK, that was designed to monitor the environmental, social, and economic impacts of changes in the economy. The comparative assessment between case studies allows us to draw three primary conclusions. (1) The identification and collection of sustainability indicators not only provide valuable databases for making management decisions, but the process of engaging people to select indicators also provides an opportunity for community empowerment that conventional development approaches have failed to provide. (2) Multi-stakeholder processes must formally feed into decision-making forums or they risk being viewed as irrelevant by policy-makers and stakeholders. (3) Since ecological boundaries rarely meet up with political jurisdictions, it is necessary to be flexible when choosing the scale at which monitoring and decision-making occurs. This requires an awareness of major environmental pathways that run through landscapes to understand how seemingly remote areas may be connected in ways that are not immediately apparent.


Assuntos
Participação da Comunidade , Conservação dos Recursos Naturais , Botsuana , Colúmbia Britânica , Guernsey
6.
Appl Biochem Biotechnol ; 121-124: 765-78, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15930556

RESUMO

The biorefinery is a key concept used in the strategies and visions of many industrial countries. The potential for Canadian biorefineries based on lignocellulosic forest and agricultural residues is examined. The sector is described in terms of research interests, emerging companies, and established corporate interests. It is found that the Canadian biorefining sector currently has an emphasis on specific bioproduct generation, and the process elements required for a true sugar-based process are in the research phase. A Canadian national strategy should focus on increasing forest industry participation, and increasing collaboration with the provinces, particularly in western Canada.


Assuntos
Agricultura/economia , Reatores Biológicos/economia , Biotecnologia/economia , Biotecnologia/métodos , Indústria Química/economia , Política Pública , Avaliação da Tecnologia Biomédica , Agricultura/métodos , Agricultura/tendências , Biotecnologia/tendências , Canadá , Indústria Química/métodos , Indústria Química/tendências , Conservação dos Recursos Naturais/economia , Conservação dos Recursos Naturais/tendências
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