Potential Greenhouse Gas Emission Reductions Research Articles

Computational Analysis of an Ammonia Combustion System for Future Two-Stroke Low-Speed Marine Engines

Ammonia, being 17.6% hydrogen by mass, is regarded as a hydrogen carrier and carbon-free fuel as long as its production methods rely on renewable energy sources. The production and combustion of green ammonia do not generate carbon dioxide, offering a promising avenue for substantial reductions in greenhouse gas (GHG) emissions from a well-to-wake perspective. This paper presents a comprehensive methodology for the development and validation of a thermodynamic model for a two-stroke low-speed marine engine incorporating a hybrid ammonia-diesel diffusion combustion system. The simulation tools are rigorously validated using experimental data obtained during diesel operation. Subsequently, the study explores various aspects of the novel ammonia-diesel combustion system, addressing combustion and emissions characteristics. The investigation incorporates diverse simulation scenarios involving direct fuel injection through dedicated valves into the cylinder head of a six-cylinder, turbocharged compression-ignition engine. The engine features two diesel injection valves, employed to initiate the combustion process, and two ammonia injection valves. Simulation scenarios include variations in the injection timing of the pilot diesel injector and the relative orientation of diesel and ammonia sprays. Case C emerges as the preferred configuration, demonstrating superior metrics in terms of combustion stability, air-fuel mixing, and emissions profile compared to other cases. The results indicate a reduction of CO2 emissions of approximately 95% in mass compared to the baseline diesel operation. Furthermore, notable reductions in NOx emissions are observed, preliminarily attributed to the lower flame temperature of ammonia. Despite the appearance of N2O emissions as a result of ammonia oxidation, the overall potential reduction in GHG emissions, in CO2-equivalent terms, exceeds 85% at selected operating points. This work contributes valuable insights into the optimization of cleaner propulsion systems for maritime applications, facilitating the industry’s transition toward more sustainable and environmentally friendly practices.

Analysis of Greenhouse Gas Emission Load and Emission Reduction from Switching to Electric Vehicles: A Case Study of Java Island

In order to mitigate the impact of climate change arising from Greenhouse Gas (GHG) emissions generated from the transportation sector, many countries including Indonesia, have initiated to develop policies to encourage environmentally friendly transportation technologies. Electric vehicles represent a highly sustainable alternative when compared to conventional vehicles. This study aims to assess the potential reduction of GHG emissions from the shifting to electric vehicle utilization on Java Island. The research method was conducted by modeling conventional vehicles until 2033 where there was a transition to electric vehicles throughout the model year and then calculating the GHG emission. This study employs three scenarios : Business As Usual (BAU), Electric Vehicle Plan (EVP) with existing scenario power plant and Electric Vehicle Plan (EVP) with National Energy Plan (NEP) scenario power plant. Model results revealed potential GHG emission reductions within 12.11% from the Existing EVP scenario and 12.54% from the NEP scenario against the BAU scenario due to the shifting usege of electric vehicles on Java island. Based on the model results, it is possible to determine that shifting from conventional vehicles to electric vehicles can reduce GHG emissions from conventional vehicle use.

Identifying the Nonlinear Impacts of Road Network Topology and Built Environment on the Potential Greenhouse Gas Emission Reduction of Dockless Bike-Sharing Trips: A Case Study of Shenzhen, China

Existing studies have limited evidence about the complex nonlinear impact mechanism of road network topology and built environment on bike-sharing systems’ greenhouse gas (GHG) emission reduction benefits. To fill this gap, we examine the nonlinear effects of road network topological attributes and built environment elements on the potential GHG emission reduction of dockless bike-sharing (DBS) trips in Shenzhen, China. Various methods are employed in the research framework of this study, including a GHG emission reduction estimation model, spatial design network analysis (sDNA), gradient boosting decision tree (GBDT), and partial dependence plots (PDPs). Results show that road network topological variables have the leading role in determining the potential GHG emission reduction of DBS trips, followed by land use variables and transit-related variables. Moreover, the nonlinear impacts of road network topological variables and built environment variables show certain threshold intervals for the potential GHG emission reduction of DBS trips. Furthermore, the impact of built environment on the potential GHG emission reduction of DBS trips is moderated by road network topological indicators (closeness and betweenness). Compared with betweenness, closeness has a greater moderating effect on built environment variables. These findings provide empirical evidence for guiding bike-sharing system planning, bike-sharing rebalancing strategy optimization, and low-carbon travel policy formulation.

Assessing the Environmental and Downstream Human Health Impacts of Decentralizing Cancer Care

Greenhouse gas (GHG) emissions from health care are substantial and disproportionately harm persons with cancer. Emissions from a central component of oncology care, outpatient clinician visits, are not well described, nor are the reductions in emissions and human harms that could be obtained through decentralizing this aspect of cancer care (ie, telemedicine and local clinician care when possible). To assess potential reductions in GHG emissions and downstream health harms associated with telemedicine and fully decentralized cancer care. This population-based cohort study and counterfactual analyses using life cycle assessment methods analyzed persons receiving cancer care at Dana-Farber Cancer Institute between May 2015 and December 2020 as well as persons diagnosed with cancer over the same period from the Cancer in North America (CiNA) public dataset. Data were analyzed from October 2023 to April 2024. The adjusted per-visit day difference in GHG emissions in kilograms of carbon dioxide (CO2) equivalents between 2 periods: an in-person care model period (May 2015 to February 2020; preperiod) and a telemedicine period (March to December 2020; postperiod), and the annual decrease in disability-adjusted life-years in a counterfactual model where care during the preperiod was maximally decentralized nationwide. Of 123 890 included patients, 73 988 (59.7%) were female, and the median (IQR) age at first diagnosis was 59 (48-68) years. Patients were seen over 1.6 million visit days. In mixed-effects log-linear regression, the mean absolute reduction in per-visit day CO2 equivalent emissions between the preperiod and postperiod was 36.4 kg (95% CI, 36.2-36.6), a reduction of 81.3% (95% CI, 80.8-81.7) compared with the baseline model. In a counterfactual decentralized care model of the preperiod, there was a relative emissions reduction of 33.1% (95% CI, 32.9-33.3). When demographically matched to 10.3 million persons in the CiNA dataset, decentralized care would have reduced national emissions by 75.3 million kg of CO2 equivalents annually; this corresponded to an estimated annual reduction of 15.0 to 47.7 disability-adjusted life-years. This cohort study found that using decentralization through telemedicine and local care may substantially reduce cancer care's GHG emissions; this corresponds to small reductions in human mortality.

Comparison of Greenhouse Gas Emission Assessments of Solar and Energy Efficiency Improvements at Small Water Resource Recovery Facilities

Small water resource recovery facilities (WRRFs) account for the majority of centralized systems in the world and have higher energy intensities than large facilities. This study compares potential greenhouse gas emission reductions based on on-site solar energy and energy efficiency (E2) improvements made at small WRRFs. Case study data from 31 existing small WRRFs in Nebraska were collected and included 35 site-specific energy efficiency (E2) recommendations and on-site solar renewable energy systems integrated at three facilities, and the data were used to compare the benefits of on-site solar energy and E2 improvements made at small WRRFs. Improvements in E2 (e.g., improved aeration control) presented the largest reduction in emissions per dollar invested. They often exhibited shorter paybacks, with operational changes in aeration strategies showing the highest impact (up to 0.2 kg CO2eq/m3 treated water). On-site solar systems showed the largest net potential for reducing environmental footprint (0.35 kg CO2eq/m3) but often showed the smallest emissions reduction per cost. While the use of both E2 improvements and the integration of on-site solar renewable energy can significantly improve the sustainability of small WRRFs, on-site solar has advantages for small facilities in that it often requires less operational involvement, allows for greater facility resiliency, and presents less uncertainty in terms of environmental benefit.

Effect of alternative dosing strategies on sustainable healthcare: A carbon footprint analysis of nivolumab and pembrolizumab treatment in the Netherlands.

e13564 Background: Hospitals contribute significantly to greenhouse gas (GHG) emissions and face a moral obligation to prioritize reduction of GHG emissions. Drugs constitute an important component of the GHG emissions of hospitals. Alternative dosing strategies (ADS) have been implemented to improve the cost-effectiveness of pembrolizumab and nivolumab (Table). However, the impact of these ADS on GHG emissions remains unknown. Therefore, this study aimed to analyse the effect of ADS implementation on the carbon footprint of treatment with pembrolizumab and nivolumab. Methods: Life Cycle Assessment (LCA) methodology was used to quantify the environmental impact. The impact category climate change was used to quantify the carbon emissions (CO2e). The GHG Protocol was used to categorize the emissions into scopes 1, 2 and 3. Life Cycle Inventory and Impact data from an academic hospital in Rotterdam were used in the LCA to calculate the CO2e for pembrolizumab and nivolumab, their different dosing intervals, and the impact of ADS. Results: In 2022, the carbon emissions related to nivolumab and pembrolizumab treatment were 445 tons CO2e, with an average of 94 kg CO2e per dosage. Pharmaceutical production was the main driver of treatment-related GHG emissions (93% of total emissions on average). Applying ADS, resulted in carbon emission reductions of 21.4-26.2% and 9.3-11.2% for pembrolizumab and nivolumab respectively (table 1). Conclusions: This study shows the substantial environmental impact of cancer treatments with pembrolizumab and nivolumab and calls for further implementation of ADS for pembrolizumab and nivolumab and other anti-PD-(L)1 monoclonal antibodies and more sustainable pharmaceutical production processes. These findings help to create environmental awareness and contribute to the promotion and understanding of sustainable low-carbon healthcare practices. Overview of registered doses of pembrolizumab and nivolumab, alternative dosing strategies and potential reductions in GHG emissions, based on real world data in The Erasmus University Medical Center in Rotterdam, the Netherlands. [Table: see text]

Urban Mobility Mode Shift to Active Transport: Sociodemographic Dependency and Potential Greenhouse Gas Emission Reduction

The aim of this study was to explore the association between travel mode choice and individual sociodemographic characteristics among urban city dwellers, as the selection of daily travel modes is influenced by several factors. The study collected 1,290 short daily trips data from 415 respondents living in Klang Valley using a random sampling technique. Logit regression models were utilized to identify the impact of sociodemographic traits on travel mode choices. Men, low education levels, students, and households without children and do not own private vehicles are more likely to choose active transportation. Besides, the study examines the potential for greenhouse gas (GHG) emission reduction. Based on Life Cycle Assessment (LCA), 142 kgCO2e or 108 kgCO2e/km of GHG were released by automobiles from the collected travel trip data. The result shows that active transport could potentially achieve 14.52% GHG emission reduction by stated preference and nearly 17% GHG emission reduction by criteria fulfillment. These findings could provide valuable information for developing practical planning policies aimed at reducing GHG emissions from the road transport sector.

Reduction of Greenhouse Gas Emissions through Community-Scale Pyrolysis Technology in Bogor City and its Financial Feasibility

Population growth affects the generation of plastic waste and could potentially increase greenhouse gas (GHG) emissions through the burning process. This has become a severe problem as it contributes to global warming. Therefore, plastic waste management is required, for instance, by using pyrolysis technology on a community scale. Such a project will reduce plastic waste and GHG emissions by processing plastic into valuable products. This study aims (1) to estimate potential GHG emissions before the project implementation, (2) to estimate potential GHG emissions reduction after the project implementation, and (3) to assess both potential revenue and profit of pyrolysis products. This study employs SNI 19-3694-1994 method to estimate household waste generated, the clean development mechanism (CDM) method to estimate GHGs emissions reduction, and the profit comparison method (PCM) to asses both revenue and profit of pyrolysis products. The results show that GHG emissions before the project will be 3.69 t CO2e in 2021 and could increase to 4.61 t CO2e in 2030. Potential GHG emissions reduction depends on the fuel types to heat the reactor. Only electric pyrolysis will reduce GHG emissions by up to 0.46 t CO2e (13%) annually. This project is not financially feasible because operational costs (15,772,779 IDR) exceed the annual revenue (1,014,000 IDR).

Mitigating greenhouse gas emissions on Dutch dairy farms. An efficiency analysis incorporating the circularity principle.

AbstractCircular agriculture is vital to achieve a substantial reduction of greenhouse gas (GHG) emissions. Optimizing resources and land use are an essential circularity principle. The objective of this article is to assess the extent to which land optimization can simultaneously reduce GHG emissions and increase production on dairy farms. In addition, we explore the potential reduction of GHG emissions under four different pathways. The empirical application combines the network Data Envelopment Analysis (DEA) with the by‐production approach. This study focuses on a representative sample of Dutch dairy farms over the period of 2010–2019. Our results suggest that farms can simultaneously increase production and reduce GHG emissions by both 5.1%. However, only 0.6% can be attributed to land optimization. The land optimization results show that on average 25.3% of total farm size should be allocated to cropland, which is 6.7% more than the actual land allocation. GHG emissions could be reduced by 11.79% without changing the level of inputs and outputs. This can be achieved by catching up with the mitigation practices of the best performing peers.

Evaluation of greenhouse gas emission reduction potential of a demand–response solution: a carbon handprint case study of a virtual power plant

Abstract The transition towards zero-carbon energy production is necessary to limit global warming. Smart energy systems have facilitated the control of demand-side resources to maintain the stability of the power grid and to provide balancing power for increasing renewable energy production. Virtual power plants are examples of demand–response solutions, which may also enable greenhouse gas (GHG) emission reductions due to the lower need for fossil-based balancing energy in the grid and the increased share of renewables. The aim of this study is to show how potential GHG emission reductions can be assessed through the carbon handprint approach for a virtual power plant (VPP) in a grid balancing market in Finland. According to our results, VPP can reduce the hourly based GHG emissions in the studied Finnish grid systems compared with the balancing power without the VPP. Typical energy sources used for the balance power are hydropower and fossil fuels. The reduction potential of GHG emissions varies from 68% to 98% depending on the share of the used energy source for the power balancing, thus VPPs have the potential to significantly reduce GHG emissions of electricity production and hence help mitigate climate change.

Contribution of Obi Island Reducing the Carbon Footprint in the Transport Sector

Transportation is one of the main sectors contributing to greenhouse gas (GHG) emissions that cause global climate change. One of the decarbonization strategies from the transportation sector that can be implemented is by switching to a sustainable mode of transportation, especially battery electric vehicles (BEV). Since mid-2021, Obi Island has been producing Mixed Hydroxide Precipitate (MHP). It is an intermediate product of limonite nickel ore processed using hydrometallurgical processing techniques through the first refining plant in Indonesia using High Pressure Acid Leaching (HPAL) technology. The MHP will be processed into Nickel Sulfate (NiSO4.6H2O) and Cobalt Sulfate (CoSO4.7H2O), the primary precursor materials for electric vehicles. The potential GHG emissions reduction in the transportation sector from the processing of limonite nickel ore in Obi Island is 2.04 MtCO2 in 2022 to 21.02 MtCO2 in 2040 with a total accumulation until 2040 of 344.56 MtCO2.

Techno-Economic Assessment and Potential Greenhouse Gas Emission Reduction of Standalone Solar PV and Hybrid Solar PV-Diesel Generator Systems in Fiji Islands

The high cost of extending national grid to the highly dispersed Fiji Islands has made many locations to be without electricity. Therefore, techno-economic assessment of standalones (solar PV, diesel generator) and hybrid solar PV-diesel generator systems in four different regions of Fiji Islands have been carried out. The potential reduction in greenhouse emission of standalone diesel generator has been estimated and compared with that of the hybrid system. Solar radiation data for the four selected locations (Ba, Suva, Labasa and Rakiraki) have been fed into the Homer software for analysis. This study is a comparative study of the four selected locations. Only the current price of diesel of $0.8 and the mean radiation of 5.64, 5.13, 4.79 and 5.22 kWh/m2-day for the four selected locations, respectively, have been used thus there has been no variation in the value of these factors. It has been shown that Ba is the best location with the least levelized cost of energy of $0.4976/kW, while the highest levelized cost of energy of $0.5734/kW has been obtained for Rakiraki for standalone PV solar energy system. The obtained findings can be a useful guide to stakeholders in Fiji and the world at large for effective energy planning.

Assessing pre-pandemic carbon footprint of diet transitions in UK nations and regions

Food supply chains hold significant embodied carbon emissions that need to be mitigated and neutralized. This study aimed to explore the historical Greenhouse Gas (GHG) emissions associated with household food consumption at a local scale i.e. across the eight English regions and the four nations that comprise the United Kingdom (UK). UK EatWell guidelines were used to explore the potential change in emissions and food costs in a scenario of transitions to healthier diets across the study areas. These emissions were calculated based on food consumption data before the advent of the Covid-pandemic i.e. between the years 2001 and 2018. Spatial data analysis was used to explore if the study areas had any significant correlations with respect to the emissions during the study period. The results displayed a potential reduction in GHG emissions for all study areas in the explored scenario. Further impacts include a reduction in household food costs across a majority of the areas during the study period. However, a consistent trend of significant correlations among the study areas was absent. This study concludes that local or regional policymaking should take precedence over national regulations to achieve healthier diets that are both carbon-neutral and affordable for the households.

Potential global GHG emissions reduction from increased adoption of metals recycling

Materials production is a significant contributor to greenhouse gas (GHG) emissions, and as consumption of commodities and resources continues to increase, so does the environmental footprint of extraction per unit of material. Primary production of metals has been progressing with steadily declining ore grades, resulting in higher energy requirements for extraction and processing of larger ore volumes bearing lower metal concentrations. Secondary production from recycled material stocks requires less energy than primary production and thereby has a lower GHG footprint. An LCA-based assessment of potential future adoption scenarios (Plausible, Ambitious, Maximum) of secondary production in the total global market for major commodity metals was conducted to identify the GHG emissions reductions possible from increased metal recycling and secondary production. The Plausible and Ambitious future scenarios result in 4.5 to 12 Gt of GHG emissions reduction globally from 2014 to 2050, and a Maximum future scenario results in over 42 Gt of GHG emissions reductions for the same period. The results of the analyses of the Plausible and Ambitious scenarios, though not close to maximizing use of total scrap available, clearly indicate that even small increments of improved metal recovery for secondary production have significant potential for GHG emission reductions. Analysis of material feedstock costs was also performed to assess the cost to producers of switching from virgin feedstocks to recycled materials.

Estimating & comparing greenhouse gas emissions for existing intramuscular COVID-19 vaccines and a novel thermostable oral vaccine.

BackgroundClimate impacts are rarely considered in health impact and economic assessments of public health programs. This study estimates the greenhouse gas (GHG) emissions averted by a novel oral SARS-CoV-2 (COVID-19) vaccine compared with four existing intramuscular vaccines: AstraZeneca's COVISHIELD®, Pfizer/BioNTech's COMIRNATY®, Moderna's mRNA-1273, and Johnson & Johnson's Ad26.COV2.S COVID-19 vaccine.MethodsWe estimated GHG emissions averted for five vaccine modalities across nine countries. GHG emissions averted were derived from differences in cold chain logistics, production of vaccine supplies, and medical waste disposal. Countryspecific data including population coverage and electricity production mix were included in GHG emissions calculations. Results are presented in averted GHG per vaccine course and country level based on modeled vaccination demand.FindingsPer course, an oral vaccine is estimated to avert between 0.007 and 0.024 kgCO2e compared with Johnson & Johnson, 0.013 to 0.048 kgCO2e compared with AstraZeneca, 0.23 to 0.108 kgCO2e compared with Moderna, and 0.134 to 0.466 kgCO2e compared with Pfizer/BioNTech. The total GHG averted varied across countries based upon predicted demand, mix of electrical production, and vaccination strategy with the largest emissions reductions projected for India and the United States.InterpretationOur results demonstrate large potential GHG emissions reductions from the use of oral vs. intramuscular vaccines for mass COVID-19 vaccination programs. Up to 82.25 million kgCO2e could be averted from utilization of an oral vaccine in the United States alone, which is equivalent to eliminating 17,700 automobiles from the road for one year.FundingFunding was provided by Vaxart, Inc. Vaxart, Inc. is currently developing an oral COVID-19 vaccine, the characteristics of which were utilized to define the thermostable oral vaccine discussed in this study. Apart from providing data on the characteristics of the oral vaccine under development, the funders had no influence over the study design, methods, statistical analyses, results, framing of results, decision to submit the manuscript for publication, or choice of journal.

Greenhouse gas mitigation potential of replacing diesel fuel with wood-based bioenergy in an arctic Indigenous community: A pilot study in Fort McPherson, Canada

Remote and northern communities surrounded by forested areas are well positioned to use wood-based bioenergy to meet their energy needs and thereby reduce their greenhouse gas (GHG) emissions. However major gaps remain regarding the GHG mitigation potential considering the challenges along the biomass supply chain. Using Fort McPherson, an Indigenous community located in the Northwest Territories (NWT), Canada, we developed a life cycle assessment based model to estimate the potential GHG emission reductions and timing. We also built two main bioenergy scenarios testing 1) wood chips made from locally harvested willow or 2) imported pellets made from sawmill residues including key parameters like transport distances, boiler efficiency, and emission factors. We found that replacing diesel fuel with bioenergy resulted in GHG savings as high as 32,166 t of CO2 eq over 100 years. GHG benefits can be achieved within 0–20 years for local wood chips or 2–37 years for imported sawmill residue pellets. Increases in transport distance and decreases in biomass boiler efficiency resulted in delays in GHG emissions benefits for both local chips and imported pellets. This study shows that the use of local or imported forest biomass to replace diesel in remote northern communities’ energy systems can generate GHG savings within a time-frame that is relevant to current climate change concerns. In addition to GHG mitigation potential, we discuss the socio-economic and environmental factors to take into consideration at the community level when deciding between local or imported biomass supply chains.

Non-technological and behavioral options for decarbonizing buildings – A review of global topics, trends, gaps, and potentials

Worldwide, energy use in buildings with the same function differed by a factor of 3–10, owing to behavioral issues. Future lifestyle changes in developed countries are expected to result in significant energy use reductions of up to 50% by 2050, with a correspondingly large impact on greenhouse gas (GHG) emissions. However, neither clear categorizations of behavioral or nontechnological (NT) climate mitigation solutions (CMS), nor corresponding estimates of global potentials for energy savings and GHG mitigation are available. Using a systematic map methodology, review of frameworks, and topic modeling, we propose a taxonomy that conceptually covers various demands (maintained/reduced), perspectives (individual/collective), and direct energy use (yes/no), resulting in five types of NT solutions: active and passive management and operation (MO), demand flexibility, sufficient comfort levels, circular and sharing economy, and organizational and social innovations. A knowledge glut for active and passive MO has been identified, with clusters in Europe and North America. Furthermore, evidence gaps were discovered in terms of geographical scope (with very little literature available about Africa and the Middle East, Latin America and the Caribbean, and Eastern Europe and West-Central Asia), stakeholder perspectives, and some measures (circular and sharing economy, flexibility of demand over time, social and organizational innovations). There was insufficient evidence on current NT CMS adoption and implementation costs. Quantified potentials were mostly found for developed countries and residential buildings, with more energy savings than GHG mitigation studies. Whereas these potentials are substantial, they vary largely among regions and solutions. The potential energy-saving ranges between 5% and 40% for most regions and CMS. The greatest potential GHG emissions reductions are seen in the circular and sharing category (25% to 70%). For other actions, most potentials range from 5% to 30%. More research is needed to provide evidence on rebound effects that can offset the climate benefits of NT solutions, business models that demonstrate their financial viability, and policy actions that trigger the already identified climate mitigation potentials of NT solutions.

Potential biomethane production from crop residues in China: Contributions to carbon neutrality

The Chinese government has set an ambitious goal of achieving carbon neutrality by 2060. Realizing negative greenhouse gas (GHG) emissions will require technologies like anaerobic digestion to recover biomethane from organic biomass. As the world's main grain-producing country, China has abundant crop residues, >85% of which were utilized as fertilizer, fodder, industrial material, biofuel, and base material in 2019. However, the potential contribution of crop residues to energy and reduced GHG emissions following anaerobic digestion have been scarcely evaluated. Based on crop yield and the field residue index, the annual quantity of crop residues in China from 2000 to 2019 was estimated. The annual crop residue yield increased between 2003 and 2014, and then remained constant at ~970 × 10 6 t/a, with an estimated 495 × 10 6 t/a being available for biomethane production. This corresponded to a potential biomethane yield of 82.25 × 10 9 m 3 /a, which could have met 29.2% of the annual natural gas consumption and 2.25% of the annual energy consumption in China in 2018 and 2019, respectively. Furthermore, the estimated potential GHG emission reduction was 197 × 10 6 t/a (CO 2 equivalent), representing ~2% of China's GHG emissions in 2019. Nevertheless, to reach the expected goal, some crucial technical and equipment-oriented research and development should be promoted to adapt to the characteristics of China's crop residues and regional environment. Moreover, governmental support policies on subsidies would be required for the development of the biomethane industry, which should prioritize northern regions with relatively high quantities of crop residues. • Energy and GHG emission reduction potential of straw biogas in China was assessed. • Biomethane yield of 82.25 × 10 9 m 3 /a could be produced from available residues. • GHG emission reduction potential from residues could be 197 × 10 6 t CO 2 eq/a. • The utilization mode of straw may need to be restructured for carbon neutrality. • Recommendations were proposed to help overcome barriers in straw biogas industry.

Potential changes in GHG emissions arising from the introduction of biorefineries combining biofuel and electrofuel production within the European Union – A location specific assessment

In the upcoming decade, biofuels made from agricultural residues, wastes and by-products will most likely present an integral part of biofuel provision to achieve greenhouse gas (GHG) reduction targets. This study provides an evaluation of potential changes in GHG emissions arising from the introduction of alternative fuels. To this end, potential changes in GHG emissions arising from the introduction of 36 biorefinery configurations in 26 EU member states providing a broad spectrum of products (e.g. biofuels, chemicals, feed and food additives) are assessed. Additional electrofuel production using biogenic CO2 is evaluated. The assessment considers country specific energy supply, market conditions and soil characteristics. The potential changes in GHG emissions arising from the introduction of these facilities range from −206 to 135 and from −221 to −17 g CO2 per MJ of bioethanol provided from wheat grains and wheat straw, respectively. The analysis reveals a high variability in GHG intensities related to marginal feedstock and energy supply as well as potentially occurring displacement effects depending on location. A Monte Carlo simulation confirms potential reductions in GHG emissions. Furthermore, the analysis shows that the methodology used within the EU to evaluate GHG emissions provided by the Renewable Energy Directive (II) denies market access to certain types of biorefineries and production modalities that bear the potential to reduce GHG emissions. It is concluded that EU biofuel policy strategies targeting (advanced) biofuels should consider local conditions and markets and should especially pay attention to potential changes in other markets.

The climate change mitigation potential of sugarcane based technologies for automobiles; CO2 negative emissions in sight

Abstract Continuous effort to mitigate climate change relies on new technologies able to satisfy human demand for energy services with high energy efficiency and reasonable costs. We show that blending a well-known technology with recently introduced and proven technical advances can mitigate climate change in the road transport sector. Furthermore, the achievement of a reasonable cost target is proved to be true when internal combustion engines (ICE) light duty vehicles (LDVs), powered by gasoline fuel, are replaced by plug-in hybrid LDVs (PHEV), powered by ethanol and electricity produced from sugarcane, using well established technology. The only improvements in such ethanol producing technology are the addition of woody biomass to extend the operation of sugar mills and the capture of carbon dioxide (CO2) generated during sugar fermentation into ethanol. Both actions are already adopted and well developed. The study quantifies greenhouse gas (GHG) emissions, expressed as carbon dioxide equivalent (CO2e) emissions and the present value cost for operation of a global fleet of 1 billion LDV over a 60-year period. The PHEV powered by sugar cane products reduces GHGs emissions partly through negative emissions, at a lower cost than gasoline fueled ICE vehicles or electric vehicles. Total potential GHG emission reduction is significant but lower than what is required for the transport sector to fulfill international commitments. Nevertheless, if 1 billion sugarcane-based PHEV hit the streets by the year 2060, 6.18 Gt CO2e/year can be avoided while the necessity of land for biomass plantation is kept at a reasonable value (86 Mha).