• Energy Research

Abstract The use of agricultural residues to produce biomass briquette fuel (BBF) can reduce waste of resources and consumption of fossil fuels. We report the first detailed environmental impact assessment of cornstalk-based BBF in China using a cradle-to-grave life cycle assessment (LCA). The LCA study was conducted based on a typical large-scale cornstalk BBF demonstration project in China with an integrated and automated production system. The key life cycle stages such as cornstalk growth, cornstalk transportation, BBF production, transportation and utilisation were investigated. Our results suggest that cornstalk BBF in China is much more environmentally friendly than coal and is favourable when compared with other types of solid fuels produced from different biomass feedstock. For example, the climate change and fossil depletion impacts of cornstalk BBF in China (11 g CO2 eq./MJ and 2 g oil eq./MJ, respectively) are an order of magnitude lower than those of coal (146 g CO2 eq./MJ and 26 g oil eq./MJ, respectively). The results of this study can assist policy makers in evaluating the potential benefits of the large scale use of BBF made from agricultural residues.

Abstract The use of agricultural residues to produce biomass briquette fuel (BBF) can reduce waste of resources and consumption of fossil fuels. We report the first detailed environmental impact assessment of cornstalk-based BBF in China using a cradle-to-grave life cycle assessment (LCA). The LCA study was conducted based on a typical large-scale cornstalk BBF demonstration project in China with an integrated and automated production system. The key life cycle stages such as cornstalk growth, cornstalk transportation, BBF production, transportation and utilisation were investigated. Our results suggest that cornstalk BBF in China is much more environmentally friendly than coal and is favourable when compared with other types of solid fuels produced from different biomass feedstock. For example, the climate change and fossil depletion impacts of cornstalk BBF in China (11 g CO2 eq./MJ and 2 g oil eq./MJ, respectively) are an order of magnitude lower than those of coal (146 g CO2 eq./MJ and 26 g oil eq./MJ, respectively). The results of this study can assist policy makers in evaluating the potential benefits of the large scale use of BBF made from agricultural residues.

Algae and jatropha, two types of promising and unconventional biomass, are investigated in this study for large-scale production of biodiesel. The aim is to evaluate the potential advantages and the magnitude of closeness of life cycle balances between these two biodiesel pathways compared to fossil diesel, by taking into account possible uncertainties. The geographical location of this study is India with a prospect of utilizing available wastelands in southern regions. The results indicate that the environmental performance of algal biodiesel is comparable to that of jatropha biodiesel. Both show significant GHG emission and fossil energy depletion reductions which are in the range of 36-40 and 10-25% respectively compared to fossil diesel in the studied geographic context.

Algae and jatropha, two types of promising and unconventional biomass, are investigated in this study for large-scale production of biodiesel. The aim is to evaluate the potential advantages and the magnitude of closeness of life cycle balances between these two biodiesel pathways compared to fossil diesel, by taking into account possible uncertainties. The geographical location of this study is India with a prospect of utilizing available wastelands in southern regions. The results indicate that the environmental performance of algal biodiesel is comparable to that of jatropha biodiesel. Both show significant GHG emission and fossil energy depletion reductions which are in the range of 36-40 and 10-25% respectively compared to fossil diesel in the studied geographic context.

Abstract This study analysed the sustainability of fuel-ethyl levulinate (EL) production along with furfural, as a by-product, from cornstalk in China. A life cycle assessment (LCA) was conducted using the SimaPro software to evaluate the energy consumption (EC), greenhouse gas (GHG) and criteria emissions, from cornstalk growth to EL utilisation. The total life cycle EC was found to be 4.54 MJ/MJ EL, of which 94.7% was biomass energy. EC in the EL production stage was the highest, accounting for 96.8% of total EC. Fossil EC in this stage was estimated to be 0.095 MJ/MJ, which also represents the highest fossil EC throughout the life cycle (39.5% of the total). The ratio of biomass to fossil EC over the life cycle was 17.9, indicating good utilisation of renewable energy in cornstalk-based EL production. The net life cycle GHG emissions were 96.6 g CO 2 -eq/MJ. The EL production stage demonstrated the highest GHG emissions, representing 53.4% of the total positive amount. Criteria emissions of carbon monoxide (CO) and particulates ⩽10 μm (PM10) showed negative values, of −3.15 and −0.72 g/MJ, respectively. Nitrogen oxides (NO x ) and sulphur dioxide (SO 2 ) emissions showed positive values of 0.33 and 0.28 g/MJ, respectively, mainly arising from the EL production stage. According to the sensitivity analysis, increasing or removing the cornstalk revenue in the LCA leads to an increase or decrease in the EC and environmental emissions while burning cornstalk directly in the field results in large increases in emissions of NMVOC, CO, NO x and PM10 but decreases in fossil EC, and SO 2 and GHG emissions.

Abstract This study analysed the sustainability of fuel-ethyl levulinate (EL) production along with furfural, as a by-product, from cornstalk in China. A life cycle assessment (LCA) was conducted using the SimaPro software to evaluate the energy consumption (EC), greenhouse gas (GHG) and criteria emissions, from cornstalk growth to EL utilisation. The total life cycle EC was found to be 4.54 MJ/MJ EL, of which 94.7% was biomass energy. EC in the EL production stage was the highest, accounting for 96.8% of total EC. Fossil EC in this stage was estimated to be 0.095 MJ/MJ, which also represents the highest fossil EC throughout the life cycle (39.5% of the total). The ratio of biomass to fossil EC over the life cycle was 17.9, indicating good utilisation of renewable energy in cornstalk-based EL production. The net life cycle GHG emissions were 96.6 g CO 2 -eq/MJ. The EL production stage demonstrated the highest GHG emissions, representing 53.4% of the total positive amount. Criteria emissions of carbon monoxide (CO) and particulates ⩽10 μm (PM10) showed negative values, of −3.15 and −0.72 g/MJ, respectively. Nitrogen oxides (NO x ) and sulphur dioxide (SO 2 ) emissions showed positive values of 0.33 and 0.28 g/MJ, respectively, mainly arising from the EL production stage. According to the sensitivity analysis, increasing or removing the cornstalk revenue in the LCA leads to an increase or decrease in the EC and environmental emissions while burning cornstalk directly in the field results in large increases in emissions of NMVOC, CO, NO x and PM10 but decreases in fossil EC, and SO 2 and GHG emissions.