scholarly journals Comparison of energy and greenhouse gas balances of biogas with other transport biofuel options based on domestic agricultural biomass in Finland

2008 ◽  
Vol 17 (3) ◽  
pp. 240 ◽  
Author(s):  
H. L. TUOMISTO ◽  
J. HELENIUS
Keyword(s):  
Greenhouse Gas ◽  
Energy Input ◽  
Ghg Emissions ◽  
Raw Material ◽  
Energy Output ◽  
Published Data ◽  
N2o Emissions ◽  
Organic Farm ◽  
Unit Energy ◽  
Life Cycle Perspective

Biofuels have been promoted as a way to reduce greenhouse gas (GHG) emissions, but it is questionable whether they indeed do so. The study compared energy and GHG balances of transport biofuels produced in Finnish conditions. Energy and GHG balances were calculated from a life cycle perspective for biogas when timothy-clover and reed canary grass silages and green manure of an organic farm were used as a raw material. The results were compared with published data on barley-based ethanol, rape methyl ester (biodiesel) and biowaste-based biogas. The energy input for biogas was 22–37% of the output depending on the raw material. The GHG emissions from field-based biogas were 21–36% of emissions from fossil-based fuels. The largest energy input was used in the processing of the biofuels while most of the greenhouse gases were emitted during farming. The GHG emissions of the field-based biogas were emitted mainly from fuels of farming machinery, nitrous oxide (N2O) emissions of the soil and the production of ensiling additives. The energy efficiency was most sensitive to the methane yield, and GHG emissions to the N2O emissions. Biogas had clearly lower energy input and GHG emissions per unit energy output than domestic barley-based ethanol and biodiesel.;

scholarly journals Quantifying the Effects of Biochar Application on Greenhouse Gas Emissions from Agricultural Soils: A Global Meta-Analysis

2020 ◽  
Vol 12 (8) ◽  
pp. 3436 ◽  
Author(s):  
Qi Zhang ◽  
Jing Xiao ◽  
Jianhui Xue ◽  
Lang Zhang
Keyword(s):  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Crop Yield ◽  
Radiative Forcing ◽  
Specific Activity ◽  
C:N Ratio ◽  
Ghg Emissions ◽  
N2o Emissions ◽  
Response Ratio ◽  
Gas Emissions

Agricultural disturbance has significantly boosted soil greenhouse gas (GHG) emissions such as methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O). Biochar application is a potential option for regulating soil GHG emissions. However, the effects of biochar application on soil GHG emissions are variable among different environmental conditions. In this study, a dataset based on 129 published papers was used to quantify the effect sizes of biochar application on soil GHG emissions. Overall, biochar application significantly increased soil CH4 and CO2 emissions by an average of 15% and 16% but decreased soil N2O emissions by an average of 38%. The response ratio of biochar applications on soil GHG emissions was significantly different under various management strategies, biochar characteristics, and soil properties. The relative influence of biochar characteristics differed among soil GHG emissions, with the overall contribution of biochar characteristics to soil GHG emissions ranging from 29% (N2O) to 71% (CO2). Soil pH, the biochar C:N ratio, and the biochar application rate were the most influential variables on soil CH4, CO2, and N2O emissions, respectively. With biochar application, global warming potential (impact of the emission of different greenhouse gases on their radiative forcing by agricultural practices) and the intensity of greenhouse gas emissions (emission rate of a given pollutant relative to the intensity of a specific activity) significantly decreased, and crop yield greatly increased, with an average response ratio of 23%, 41%, and 21%, respectively. Our findings provide a scientific basis for reducing soil GHG emissions and increasing crop yield through biochar application.

scholarly journals Smallholder African farms in western Kenya have limited greenhouse gas fluxes

2015 ◽  
Vol 12 (18) ◽  
pp. 15301-15336 ◽  
Author(s):  
D. E. Pelster ◽  
M. C. Rufino ◽  
T. Rosenstock ◽  
J. Mango ◽  
G. Saiz ◽  
...  
Keyword(s):  
Greenhouse Gas ◽  
Crop Production ◽  
Crop Yields ◽  
N Uptake ◽  
Ghg Emissions ◽  
Sub Saharan Africa ◽  
N2o Emissions ◽  
Vegetation Types ◽  
Western Kenya ◽  
The Impact

Abstract. Few field studies examine greenhouse gas (GHG) emissions from African agricultural systems resulting in high uncertainty for national inventories. We provide here the most comprehensive study in Africa to date, examining annual CO2, CH4 and N2O emissions from 59 plots, across different vegetation types, field types and land classes in western Kenya. The study area consists of a lowland area (approximately 1200 m a.s.l.) rising approximately 600 m to a highland plateau. Cumulative annual fluxes ranged from 2.8 to 15.0 Mg CO2-C ha−1, −6.0 to 2.4 kg CH4-C ha−1 and −0.1 to 1.8 kg N2O-N ha−1. Management intensity of the plots did not result in differences in annual fluxes for the GHGs measured (P = 0.46, 0.67 and 0.14 for CO2, N2O and CH4 respectively). The similar emissions were likely related to low fertilizer input rates (≤ 20 kg ha−1). Grazing plots had the highest CO2 fluxes (P = 0.005); treed plots were a larger CH4 sink than grazing plots (P = 0.05); while N2O emissions were similar across vegetation types (P = 0.59). This case study is likely representative for low fertilizer input, smallholder systems across sub-Saharan Africa, providing critical data for estimating regional or continental GHG inventories. Low crop yields, likely due to low inputs, resulted in high (up to 67 g N2O-N kg−1 aboveground N uptake) yield-scaled emissions. Improving crop production through intensification of agricultural production (i.e. water and nutrient management) may be an important tool to mitigate the impact of African agriculture on climate change.

Towards a benchmarking tool for minimizing wastewater utility greenhouse gas footprints

2012 ◽  
Vol 66 (11) ◽  
pp. 2483-2495 ◽  
Author(s):  
L. Guo ◽  
J. Porro ◽  
K. R. Sharma ◽  
Y. Amerlinck ◽  
L. Benedetti ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Greenhouse Gas ◽  
Ghg Emissions ◽  
Treatment Plant ◽  
N2o Emission ◽  
Mitigation Strategies ◽  
N2o Emissions ◽  
N2o Production ◽  
Average Value ◽  
And Control

A benchmark simulation model, which includes a wastewater treatment plant (WWTP)-wide model and a rising main sewer model, is proposed for testing mitigation strategies to reduce the system's greenhouse gas (GHG) emissions. The sewer model was run to predict methane emissions, and its output was used as the WWTP model input. An activated sludge model for GHG (ASMG) was used to describe nitrous oxide (N2O) generation and release in activated sludge process. N2O production through both heterotrophic and autotrophic pathways was included. Other GHG emissions were estimated using empirical relationships. Different scenarios were evaluated comparing GHG emissions, effluent quality and energy consumption. Aeration control played a clear role in N2O emissions, through concentrations and distributions of dissolved oxygen (DO) along the length of the bioreactor. The average value of N2O emission under dynamic influent cannot be simulated by a steady-state model subjected to a similar influent quality, stressing the importance of dynamic simulation and control. As the GHG models have yet to be validated, these results carry a degree of uncertainty; however, they fulfilled the objective of this study, i.e. to demonstrate the potential of a dynamic system-wide modelling and benchmarking approach for balancing water quality, operational costs and GHG emissions.

Greenhouse gas emissions of Canadian beef production in 1981 as compared with 2011

2016 ◽  
Vol 56 (3) ◽  
pp. 153 ◽  
Author(s):  
G. Legesse ◽  
K. A. Beauchemin ◽  
K. H. Ominski ◽  
E. J. McGeough ◽  
R. Kroebel ◽  
...  
Keyword(s):  
Greenhouse Gas ◽  
Crop Yields ◽  
Average Daily Gain ◽  
Ghg Emissions ◽  
N2o Emissions ◽  
Beef Production ◽  
Slaughter Weight ◽  
Ch4 Production ◽  
Breeding Herd ◽  
The Impact

The present study compared the greenhouse gas (GHG) emissions, and breeding herd and land requirements of Canadian beef production in 1981 and 2011. In the analysis, temporal and regional differences in feed types, feeding systems, cattle categories, average daily gains and carcass weights were considered. Emissions were estimated using life-cycle assessment (cradle to farm gate), based primarily on Holos, a Canadian whole-farm emissions model. In 2011, beef production in Canada required only 71% of the breeding herd (i.e. cows, bulls, calves and replacement heifers) and 76% of the land needed to produce the same amount of liveweight for slaughter as in 1981. Compared with 1981, in 2011 the same amount of slaughter weight was produced, with a 14% decline in CH4 emissions, 15% decline in N2O emissions and a 12% decline in CO2 emissions from fossil fuel use. Enteric CH4 production accounted for 73% of total GHG emissions in both years. The estimated intensity of GHG emissions per kilogram of liveweight that left the farm was 14.0 kg CO2 equivalents for 1981 and 12.0 kg CO2 equivalents for 2011, a decline of 14%. A significant reduction in GHG intensity over the past three decades occurred as a result of increased average daily gain and slaughter weight, improved reproductive efficiency, reduced time to slaughter, increased crop yields and a shift towards high-grain diets that enabled cattle to be marketed at an earlier age. Future studies are necessary to examine the impact of beef production on other sustainability metrics, including water use, air quality, biodiversity and provision of ecosystems services.

scholarly journals How Can Existing Buildings with Historic Values Contribute to Achieving Emission Reduction Ambitions?

2021 ◽  
Vol 11 (13) ◽  
pp. 5978
Author(s):  
Selamawit Mamo Fufa ◽  
Cecilie Flyen ◽  
Anne-Cathrine Flyen
Keyword(s):  
Cultural Values ◽  
Adaptive Reuse ◽  
Ghg Emissions ◽  
Raw Material ◽  
Existing Buildings ◽  
Case Study Analysis ◽  
Methodological Choices ◽  
Intervention Measures ◽  
Life Cycle Perspective ◽  
Environmental Goals

In line with the Paris Agreement, Norway aims for an up to 55% reduction in greenhouse gas (GHG) emissions by 2030 compared to 1990 levels and to be a low-emission society by 2050. Given that 85–90% of today’s buildings are expected to still be in use in 2050, refurbishment and adaptive reuse of existing buildings can help in achieving the environmental goals. The aim of this work is to provide a holistic picture of refurbishment and adaptive reuse of existing buildings, including buildings with heritage values, seen from a life cycle perspective. The methods applied are a literature review of LCA studies and experiences from quantitative case study analysis of selected Norwegian case studies. The findings show that extending the service life of existing buildings by refurbishment and adaptive reuse has significant possibilities in reducing GHG emissions, keeping cultural heritage values, and saving scarce raw material resources. The findings show limited LCA studies, uncertainties in existing LCA studies due to variations in case-specific refurbishment or intervention measures, and a lack of transparent and harmonized background data and methodological choices. In conclusion, performing a holistic study covering the whole LCA and including socio-cultural values and economic aspects will enable supporting an argument to assert the sustainability of existing buildings.

scholarly journals Greenhouse Gas Impact of Algal Bio-Crude Production for a Range of CO2 Supply Scenarios

2021 ◽  
Vol 11 (24) ◽  
pp. 11931
Author(s):  
Pratham Arora ◽  
Ronald R. Chance ◽  
Howard Hendrix ◽  
Matthew J. Realff ◽  
Valerie M. Thomas ◽  
...  
Keyword(s):  
Life Cycle ◽  
Natural Gas ◽  
Greenhouse Gas ◽  
Power Plants ◽  
Ghg Emissions ◽  
Growth Cycle ◽  
Hydrothermal Liquefaction ◽  
Raw Material ◽  
Carbon Utilization ◽  
Ghg Reduction

Refined bio-crude production from hydrothermal liquefaction of algae holds the potential to replace fossil-based conventional liquid fuels. The microalgae act as natural carbon sequestrators by consuming CO2. However, this absorbed CO2 is released to the atmosphere during the combustion of the bio-crude. Thus, the life-cycle greenhouse gas (GHG) emissions of refined bio-crude are linked to the production and supply of the materials involved and the process energy demands. One prominent raw material is CO2, which is the main source of carbon for algae and the subsequent products. The emissions associated with the supply of CO2 can have a considerable impact on the sustainability of the algae-based refined bio-crude production process. Furthermore, the diurnal algae growth cycle complicates the CO2 supply scenarios. Traditionally, studies have relied on CO2 supplied from existing power plants. However, there is potential for building natural gas or biomass-based power plants with the primary aim of supplying CO2 to the biorefinery. Alternately, a direct air capture (DAC) process can extract CO2 directly from the air. The life-cycle GHG emissions associated with the production of refined bio-crude through hydrothermal liquefaction of algae are presented in this study. Different CO2 supply scenarios, including existing fossil fuel power plants and purpose-built CO2 sources, are compared. The integration of the CO2 sources with the algal biorefinery is also presented. The CO2 supply from biomass-based power plants has the highest potential for GHG reduction, with a GHG footprint of −57 g CO2 eq./MJ refined bio-crude. The CO2 supply from the DAC process has a GHG footprint of 49 CO2 eq./MJ refined bio-crude, which is very similar to the scenario that considers the supply of CO2 from an existing conventional natural gas-based plant and takes credit for the carbon utilization.

scholarly journals Effect of Manure from Cattle Fed 3-Nitrooxypropanol on Anthropogenic Greenhouse Gas Emissions Depends on Soil Type

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 371
Author(s):  
Tien L. Weber ◽  
Xiying Hao ◽  
Cole D. Gross ◽  
Karen A. Beauchemin ◽  
Scott X. Chang
Keyword(s):  
Life Cycle ◽  
Greenhouse Gas ◽  
Best Management Practices ◽  
Soil Type ◽  
Ghg Emissions ◽  
Soil Types ◽  
N2o Emissions ◽  
Enteric Fermentation ◽  
Ch4 Emissions ◽  
Gray Luvisol

Cattle production is a large source of greenhouse gas (GHG) emissions from the Canadian livestock sector. Efforts to reduce CH4 emissions from enteric fermentation have led to modifications of diet composition for livestock, resulting in a corresponding change in manure properties. We studied the effect of applying manure from cattle fed a barley-based diet with and without the methane inhibitor supplement, 3-nitrooxypropanol (3-NOP), on soil GHG emissions. Three soils common to Alberta, Canada, were used: a Black Chernozem, a Dark Brown Chernozem, and a Gray Luvisol. We compared the supplemented (3-NOPM) and non-supplemented manure (BM) amendments to a composted 3-NOPM (3-NOPC) amendment and a control with no manure amendment (CK). In an 84-day laboratory incubation experiment, 3-NOPM had significantly lower cumulative CO2 emissions compared to BM in both the Black Chernozem and Gray Luvisol. The cumulative N2O emissions were lowest for 3-NOPC and CK and highest for 3-NOPM across all soil types. Cumulative CH4 emissions were only affected by soil type, with a net positive flux from the fine-textured Gray Luvisol and Dark Brown Chernozem and a net negative flux from the coarse-textured Black Chernozem. Cumulative anthropogenic GHG emissions (CO2-equivalent) from soil amended with 3-NOPM were significantly higher than those for both BM and CK amendments in the Black Chernozem, while the cumulative anthropogenic GHG emissions from the 3-NOPC treatment were similar to or significantly lower than those for the BM and CK treatments across all soil types. We conclude that soil GHG emissions resulting from the 3-NOPM amendment are dependent on soil type and 3-NOPM could potentially increase soil GHG emissions compared to BM or CK. Although we show that the composting of 3-NOPM prior to soil application can reduce soil GHG emissions, the composting process also releases GHGs, which should also be considered in assessing the life-cycle of manure application. Our results provide a first look at the potential effect of the next stage in the life cycle of 3-NOP on GHG emissions. Further research related to the effect of soil properties, particularly in field studies, is needed to assess the best management practices related to the use of manure from cattle-fed diets supplemented with 3-NOP as a soil amendment.

scholarly journals Modeling impacts of farming management practices on greenhouse gas emissions in the oasis region of China

2011 ◽  
Vol 8 (8) ◽  
pp. 2377-2390 ◽  
Author(s):  
Y. Wang ◽  
G. J. Sun ◽  
F. Zhang ◽  
J. Qi ◽  
C. Y. Zhao
Keyword(s):  
Greenhouse Gas ◽  
Ghg Emissions ◽  
Fertilizer Application ◽  
Application Rate ◽  
Return Rate ◽  
N2o Emissions ◽  
Co2 Fluxes ◽  
Dndc Model ◽  
Agricultural Ecosystems ◽  
Fertilizer Application Rate

Abstract. Agricultural ecosystems are major sources of greenhouse gas (GHG) emissions, specifically nitrous oxide (N2O) and carbon dioxide (CO2). An important method of investigating GHG emissions in agricultural ecosystems is model simulation. Field measurements quantifying N2O and CO2 fluxes were taken in a summer maize ecosystem in Zhangye City, Gansu Province, in northwestern China in 2010. Observed N2O and CO2 fluxes were used for validating flux predictions by a DeNitrification-DeComposition (DNDC) model. Then sensitivity tests on the validated DNDC model were carried out on three variables: climatic factors, soil properties and agricultural management. Results indicated that: (1) the factors that N2O emissions were sensitive to included nitrogen fertilizer application rate, manure amendment and residue return rate; (2) CO2 emission increased with increasing manure amendment, residue return rate and initial soil organic carbon (SOC); and (3) net global warming potential (GWP) increased with increasing N fertilizer application rate and decreased with manure amendment, residue return rate and precipitation increase. Simulation of the long-term impact on SOC, N2O and net GWP emissions over 100 yr of management led to the conclusion that increasing residue return rate is a more efficient method of mitigating GHG emission than increasing fertilizer N application rate in the study area.

scholarly journals The Effects of System Changes in Grazed Dairy Farmlet Trials on Greenhouse Gas Emissions

Animals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 234 ◽  
Author(s):  
Tony van der Weerden ◽  
Pierre Beukes ◽  
Cecile de Klein ◽  
Kathryn Hutchinson ◽  
Lydia Farrell ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
New Zealand ◽  
Greenhouse Gas ◽  
Production Systems ◽  
Current System ◽  
Ghg Emissions ◽  
N Leaching ◽  
N2o Emissions ◽  
System Changes ◽  
Emissions Intensity

An important challenge facing the New Zealand (NZ) dairy industry is development of production systems that can maintain or increase production and profitability, while reducing impacts on receiving environments including water and air. Using research ‘farmlets’ in Waikato, Canterbury, and Otago (32–200 animals per herd), we assessed if system changes aimed at reducing nitrate leaching can also reduce total greenhouse gas (GHG) emissions (methane and nitrous oxide) and emissions intensity (kg GHG per unit of product) by comparing current and potential ‘improved’ dairy systems. Annual average GHG emissions for each system were estimated for three or four years using calculations based on the New Zealand Agricultural Inventory Methodology, but included key farmlet-specific emission factors determined from regional experiments. Total annual GHG footprints ranged between 10,800 kg and 20,600 kg CO2e/ha, with emissions strongly related to the amount of feed eaten. Methane (CH4) represented 75% to 84% of the total GHG footprint across all modelled systems, with enteric CH4 from lactating cows grazing pasture being the major source. Excreta deposition onto paddocks was the largest source of nitrous oxide (N2O) emissions, representing 7–12% of the total GHG footprint for all systems. When total emissions were represented on an intensity basis, ‘improved’ systems are predicted to generally result in lower emissions intensity. The ‘improved’ systems had lower GHG footprints than the ‘current’ system, except for one of the ‘improved’ systems in Canterbury, which had a higher stocking rate. The lower feed supplies and associated lower stocking rates of the ‘improved’ systems were the key drivers of lower total GHG emissions in all three regions. ‘Improved’ systems designed to reduced N leaching generally also reduced GHG emissions.

scholarly journals Characterizing Greenhouse Gas Emissions and Global Warming Potential of Wheat-Maize Cropping Systems in Response to Organic Amendments in Eutric Regosols, China

Atmosphere ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 614
Author(s):  
Hamidou Bah ◽  
Xiao Ren ◽  
Yanqiang Wang ◽  
Jialiang Tang ◽  
Bo Zhu
Keyword(s):  
Global Warming ◽  
Greenhouse Gas ◽  
Global Warming Potential ◽  
Cropping Systems ◽  
Inorganic Nitrogen ◽  
Ghg Emissions ◽  
Organic Amendments ◽  
Mineral Fertilizers ◽  
N2o Emissions ◽  
Pig Slurry

Characterizing greenhouse gas (GHG) emissions and global warming potential (GWP) has become a key step in the estimation of atmospheric GHG concentrations and their potential mitigation by cropland management. However, the impacts of organic amendments on GHG, GWP, and yield-scaled GWP on cropland have not been well documented. Here, we investigate four amendment treatments (no amendment, mineral fertilizers, and pig slurry or crop residue combined with mineral fertilizers) during a two-year field experiment in rain-fed wheat-maize cropping systems. The results show that the average annual cumulative methane (CH4) flux ranged from −2.60 to −2.97 kg·C·ha−1 while nitrous oxide (N2O) flux ranged from 0.44 to 4.58 kg·N·ha−1 across all four treatments. N2O emissions were significantly correlated with soil inorganic nitrogen (i.e., NH4+-N and NO3−-N), and soil dissolved organic carbon (DOC) during both the winter wheat and summer maize seasons. On average, organic amendments combined with mineral fertilizers increased the annual GWP by 26–74% and yield-scaled GWP by 19–71% compared to those under only mineral fertilizers application. This study indicates that the fertilization strategy for Eutric Regosols can shift from only mineral fertilizers to organic amendments combined with mineral fertilizers, which can help mitigate GHG emissions and GWP while maintaining crop yields.

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