Biodiesel greenhouse gas emissions full#

Others are less apparent, including those that result from activities along the biofuel supply chain (for example, nitrate leaching into surface waters as a result of nitrogen fertilizer application on corn fields) and those that could occur beyond the supply chain via market-mediated effects (for example, loss of biodiversity upon land-use change induced by higher corn prices). Some effects are easily noticed (for example, odors emanating from an ethanol plant). LIFE-CYCLE APPROACH FOR ASSESSING ENVIRONMENTAL EFECTS: AN OVERVIEWД«iofuels affect the environment at all stages of their production and use. It discusses opportunities to minimize negative environmental effects at the end of the chapter.ДЄlthough the committee stresses the importance of comparing environmental effects of biofuels to petroleum-based fuels, environmental effects of petroleum-based fuels have been covered in other publications (NRC, 2003, 2010a) and are beyond the scope of this study.It uses regional environmental assessments of biofuel production as an illustration because the effects of biofuel production are location-specific, and conclusions drawn from regional environmental assessments could differ from an assessment of cumulative effects across the nation.Gaps in data availability and deficiencies in existing modeling platforms, each of whichД¬ontributes to uncertainty in assessing environmental effects, are also pointed out in the following areas: Methods for assessing effects and the anticipated results or observed effects reported in the published literature are presented. Each environmental effect is discussed, when applicable, in the context of feedstock production, conversion to fuels, and combustion and over the life cycle of biofuel production and use. It examines the current state of knowledge about key environmental effects.It provides an overview of the life-cycle assessment methodology typically used to assess environmental effects of biofuel production and use.This chapter covers the following topics on the potential environmental effects of increasing biofuel production: Furthermore, certain stages in the life cycle of biofuels have greater environmental effects than others, and thus deserve particular attention in targeting strategies for optimizing environmental outcomes.

Biodiesel greenhouse gas emissions full#

There is neither a simple nor single means of comparing biofuels and petroleum-derived fuels over their full life cycles and over their entire suites of environmental effects, yet decades of research on this topic have revealed that some ways of producing biofuels from certain feedstocks offer distinct advantages over others and thus have greater potential for providing environmental benefits over petroleum-derived fuels. Hence, the environmental benefits and negative effects over the life cycle of petroleum-based fuels and biofuels would have to be compared against each other so that policymakers can decide which tradeoffs are acceptable. Each stage in a biofuelвЂ™s life cycle uses nonrenewable resources and generates emissions that affect land, air, and water. Biofuels, too, have their environmental costs (NRC, 2003, 2010a), but displacing petroleum-based fuels with biofuels can reduce the nationвЂ™s dependence on imported oil and potentially reduce overall environmental harm (Robertson et al., 2008). Petroleum extraction, transport, refining, and combustion have many known negative environmental effects, including disruption of sensitive ecological habitats and high greenhouse-gas (GHG) emissions. Ecosystem carbon payback times range from 11 to 42 years.Environmental Effects and Tradeoffs of Biofuels The largest greenhouse gas emissions result from land use change effects, followed by the transesterification, fertilizer production, agricultural production processes, milling and transportation. The output to input ratios are positive in all cases. The findings demonstrate that there are considerable differences between the farming systems and the locations in net energy yields (43.6 to 49.2 GJ t-1 biodiesel yr-1) as well as greenhouse gas emissions (1969.6 to 5626.4 kg CO2eq t-1 biodiesel yr-1). Results show that the accompanied implications of palm oil biodiesel produced in Kalimantan and Sumatra are different: energy input in Sumatra is higher than in Kalimantan, except for transport processes the input/output ratios are positive in both regions and all production systems. The objectives of this study are to identify the energy balance of Indonesian palm oil biodiesel production, including the stages of land use change, transport and milling and biodiesel processing, and to estimate the amount of greenhouse gas emissions from different production systems, including large and small holder plantations either dependent or independent, located in Kalimantan and in Sumatra.