Indirect Greenhouse Gas Emissions Research Articles

Enabling Full Supply Chain Corporate Responsibility: Scope 3 Emissions Targets for Ambitious Climate Change Mitigation

There is building consensus that nonstate actors have the potential to drive more ambitious action toward climate targets than governments, thus driving the necessary transition to ensure that humanity remains within a safe operating space. These bottom-up mitigation activities, however, require individual targets on both direct and indirect (upstream) greenhouse gas (GHG) emissions in order to reconcile trade-offs between global and local sustainability goals. Here we use a scenario-driven approach based on a global multiregional input-output (GMRIO) model to develop scope 3 emission reduction targets for individual economic sectors, comparable across countries and geographies. Under an ambitious carbon mitigation scenario for 2035 (that follows a trajectory of 1.75 °C total warming by 2100), global upstream scope 3 emission intensities need to be reduced by an additional 54% compared to a baseline scenario with reference technology. On a sectoral basis, this is equivalent to a 58-67% reduction in energy, transport, and materials, a 50-52% reduction in manufacturing, services, and buildings, and a 39% reduction in agriculture, forestry, and other land use. By aligning indirect supply chain targets with ambitious carbon mitigation scenarios, our approach can be used by nonstate actors to set actionable scope 3 targets and to build climate-compatible business models.

Towards the circular nitrogen economy – A global meta-analysis of composting technologies reveals much potential for mitigating nitrogen losses

Composting is an important technology to treat biowastes and recycle nutrients, but incurs nitrogen (N) losses that lower the value of the final products and cause pollution. Technologies aimed at reducing N losses during composting have inconsistent outcomes. To deepen insight into mitigation options, we conducted a global meta-analysis based on 932 observations from 121 peer-reviewed published studies. Overall, N losses averaged 31.4% total N (TN), 17.2% NH3-N, and 1.4% N2O-N, with NH3-N accounting for 55% of TN losses. The primary drivers affecting N losses were composting method, type of biowaste, and duration of composting. N losses were significantly impacted by the carbon-to-nitrogen (C/N) ratio of the input materials (feedstock of nutrient dense biowastes and C-rich bulking agents), moisture content and pH. Our analysis revealed N-conserving optima with C/N ratios of 25–30, 60–65% moisture content and pH 6.5–7.0. In situ mitigation technologies that control feedstock and processing conditions reduced average N losses by 31.4% (TN), 35.4% (NH3-N) and 35.8% (N2O-N). Biochar and magnesium-phosphate salts emerged as the most effective N-conserving strategies, curbing losses of TN by 30.2 and 60.6%, NH3 by 52.6 and 69.4%, and N2O by 66.2 and 35.4% respectively. We conclude that existing technologies could preserve ~0.6 Tg of biowaste-N globally, which equates to 16% of the chemical N-fertilizer used in African croplands, or 39% of the annual global increases of 1.58 Tg fertilizer-N. However, the adoption of N-conserving technologies is constrained by a lack of knowledge of best practice, suitable infrastructure, policies and receptive markets. To realize an N-conserving composting industry that supports sustainable practices and the circular nitrogen economy, stakeholders have to act collectively. Benefits will include lowering direct and indirect greenhouse gas emissions associated with agriculture, and facilitating the recarbonization of soils.

Investigation on energy performance of existing commercial buildings with heritage values by incorporating retrofit options

The buildings sector accounts for 24% of Australia’s indirect Greenhouse Gas (GHG) emissions. Due to the life expectancy of existing building stock the greatest reduction in emissions before 2030 could be achieved through retrofits. Research in the past has shown that energy consumption in commercial buildings is complex and diverse due to the wide range of building fabrics and mechanical systems employed. Typically, the most effective energy saving strategies in commercial buildings have been in improving the heating, ventilation and air-conditioning (HVAC) design and efficiency, including improving the efficiency of chillers and heat pumps, and design strategies such as efficient mechanical ventilation systems, night purges, thermal mass and daylighting. This paper investigates and evaluates the energy performance of four commercial case study buildings with heritage values with various retrofit options in different climatic conditions in Australia. The paper explored the use of thermal and airflow modeling in assisting to understand the impacts of various retrofit options unto the energy efficiency of the case study buildings. The findings suggest different retrofit options that should be considered for achieving optimum energy efficiency impacts for existing buildings in Australia.

Sustainable supply chain management and partner engagement to manage climate change information

AbstractClimate change poses significant new risks and challenges for businesses and their supply chains. Additionally, in many sectors, Scope 3 indirect greenhouse gas emissions resulting from the sourcing and distribution of goods and services are larger than firms' own carbon footprints. Here we study how firms engage their key stakeholders in their supply chains in obtaining, processing, and transferring relevant climate change‐related information designed to overcome information asymmetry and drive sustainable development. Grounded in organisational information‐processing theory (OIPT), we draw on data from the Carbon Disclosure Project's Climate Change Supply Chain initiative for a qualitative content analysis of a large sample of global firms. Consistent with OIPT, we find that although firms primarily engage their supply chain partners in a variety of ways to reduce information uncertainty around indirect emissions data, effectively interpreting and managing broader sustainability information equivocality becomes a growing priority. Our findings further suggest that firms engage suppliers, customers, and other supply chain partners through basic, transactional, and collaborative types of engagement. We contribute to literatures on interorganisational information processing and sustainable supply chain management by providing a more detailed understanding of how firms engage supply chain partners in the context of climate change.

Life cycle greenhouse gas emissions of China shale gas

Having the largest shale gas reserve in the world, China is vigorously developing its shale gas resources. In this work, a hybrid life cycle inventory is used to estimate upstream greenhouse gas (GHG) emissions and evaluate the atmospheric environmental effects of China’s shale gas development. A comprehensive GHG emission model of the preproduction phase is constructed by considering green completion, methane emission from flowback water, indirect emissions from materials upstream material manufacturing, and Monte Carlo simulation. Results indicate that the upstream GHG emission of 230 shale gas wells is 18.8 g CO2eq/MJ. During the preproduction phase (from well pad preparation to well completion), indirect GHG emissions from upstream material manufacturing are substantial and account for 78%. The estimation of GHG emissions in preproduction phase presents considerable uncertainty (39%–79%) due to the uncertainty of constructing the pad preparation process and the estimated ultimate recovery. In preproduction phase, the GHG emission of China shale gas is estimated to be approximately 4.18 g CO2eq/MJ (95% CI: 2.57 to 7.47 g CO2eq/MJ), which is higher than that of the US shale gas.

Carbon footprint accounts of Pakistan: an input-output life cycle assessment model.

The Paris agreement (2015) seems a significant achievement towards a global mitigation policy to climate change. However, implementing the promised Intended Nationally Determined Contribution (INDC) targets by the participating countries has become a real challenge. In this aspect, the input-output life cycle assessment (IO-LCA) model provides an important assessment mechanism to design suitable abatement policies limiting the rising greenhouse gas (GHG) emissions. The present paper develops an IO-LCA model for Pakistan and estimates all the direct and indirect GHG emissions caused by all the production activities during all the stages of production. This task is achieved in three phases. In phase 1, the Pakistan input-output table (IOT) is constructed. In phase 2, the GHG environmental satellite accounts are created for each sector in the economy. In phase 3, the GHG emissions are linked to different categories of final demand.

Buffering phosphate mitigates ammonia emission in sewage sludge composting: Enhanced organics removal coupled with microbial ammonium assimilation

Ammonia emission is a challenge for sewage sludge composting, causing odor issues, indirect greenhouse gas emission and nitrogen loss in the mature compost. This study investigated the effectiveness of applying K2HPO4KH2PO4 buffer to mitigate ammonia emission in sewage sludge composting. During the 34-day aerated composting experiment, adding 7.5 mg P·g−1 DM (dry matter) K2HPO4KH2PO4 buffer reduced the ammonia emission and total nitrogen loss by 45.4% and 41.8%, respectively. The enhanced nitrogen conservation by phosphate additive resulted from two complementary mechanisms: (1) phosphate buffering effect and (2) accelerated sludge extracellular polymeric substance (EPS) decomposition, thus improving microbial ammonium assimilation to convert ammonia-N to cell-protein. The extent of nitrogen conservation was found to be positively associated with activities of the key enzymes for microbial ammonium assimilation and relative abundance of the ammonium-assimilating Bacillus. In a summary, K2HPO4KH2PO4 addition was proved as an effective strategy to reduce ammonia emission, promote organics removal and conserve nitrogen nutrients in the final compost product.

GHG evaluation and mitigation planning for low carbon city case study: Dan Sai Municipality

In the era of globalization, the economy has expanded, leading to an increase in population and the growth of the city dramatically. The municipalities as local administrators for the being and the quality of life of people in the city. However, the activities in the city such as fuel consumption of housing and transportation, electricity use, waste management like wastewater and waste produce both direct and indirect greenhouse gases, increasing many impacts of climate change. The concept of “low carbon city” has been applied to local government in Thailand. This research aims to evaluate city's greenhouse gas emissions in a case study of Dan Sai municipality based on the Global Protocol for Community-Scale Greenhouse Gas Emission Inventories guideline (GPC), divided into three scopes are scope 1, direct greenhouse gas emissions, scope 2, indirect greenhouse gas emissions from the electricity use and scope 3, other indirect greenhouse gas emissions. According to the study of the city's greenhouse gas emissions in year 2016, was found that Dan Sai municipality had a greenhouse gas emission of 22,925.66 tCO2eq, equivalent to 5.95 tCO2eq/person/year of the amount of greenhouse gas emissions per capita, The amount of greenhouse gas emissions per household is 11.84 tCO2eq/household/year and the amount of greenhouse gas emissions per area is 2,999.82 tCO2eq/square kilometer/year. And from the assessing results of the alternative options to reduce greenhouse gases by analyzing the final cost of the three options, that are increasing the number of solar rooftops, increasing the use of household LED bulbs and refining waste management using RDF technology, found that the final cost was −175.48, 87.53 and −61.72 Baht/kgCO2eq, respectively. This project model is a sustainable city developed into a low carbon city in the future.

A plant-wide wastewater treatment plant model for carbon and energy footprint: Model application and scenario analysis

A new model for accounting carbon and energy footprint of wastewater treatment plants (WWTPs) is proposed. The model quantifies direct and indirect greenhouse gas (GHG) emissions related to biological and physical processes of a WWTP. The model takes into account several innovative aspects with respect to already available literature models: i. kinetic/mass-balances; ii. nitrification as a two-step process; iii. nitrous oxide (N2O) formation during nitrification and denitrification both in dissolved and off-gas forms. A full-scale application has been performed by adopting the case study of a real WWTP. A scenario analysis was performed to quantify the influence of: composition of inflow wastewater (scenario 1), operating conditions (scenario 2), and oxygen transfer efficiency (scenario 3). Results have underlined the key role of the ratio between influent biodegradable carbon and nitrogen concentration on influencing direct and indirect GHG emissions. Direct GHG emissions increase from 0.49 to 0.63 kgCO2eq m−3 with the decrease of the influent ratio of the readily biodegradable carbon and organic and ammonia nitrogen. The increase of the influent organic and ammonia nitrogen favours the daily production of active ammonia oxidization biomass. The simultaneous variation of the investigated factors has amplified direct and indirect GHG emissions to a maximum value of 0.94 and 0.24 kgCO2eq m−3, respectively.

Idling fuel consumption and emissions of air pollutants at selected signalized intersections in Delhi

The present study was carried at eleven pre-timed signalized traffic intersections in Delhi (India) to estimate idling fuel losses and corresponding emissions. The estimates of idling fuel losses and corresponding emissions were expanded to ∼950 signalized intersections presently operational in Delhi city. In the study, idling fuel consumption tests were carried out using a fuel flow meter set-up on 341 test vehicles of different categories representing the traffic mix of Delhi. Direct greenhouse gases (viz., CO2, CH4, and N2O) and indirect greenhouse gases (viz., CO, NOx, and NMVOC) emissions were estimated using fuel-based IPCC emission factors. The results indicated that every day 9036 liters of petrol, diesel, LPG and 5461 kg of CNG losses occurred due to the idling of motor vehicles at these intersections which is equivalent to nearly 4.5million USD per year. GHG emissions (CO2, CH4, and N2O) estimated were ∼37 tonnes of CO2 eq/day. The present study highlights the methodology that can be used to estimate idling fuel losses and corresponding emission at signalized intersections. Finally, policy interventions and mitigation measures have been suggested to reduce idling emissions and corresponding emissions at these signalized intersections.

Greenhouse gas mitigation potential in crop production with biochar soil amendment—a carbon footprint assessment for cross‐site field experiments from China

AbstractBiochar soil amendment (BSA) had been advocated as a promising approach to mitigate greenhouse gas (GHG) emissions in agriculture. However, the net GHG mitigation potential of BSA remained unquantified with regard to the manufacturing process and field application. Carbon footprint (CF) was employed to assess the mitigating potential of BSA by estimating all the direct and indirect GHG emissions in the full life cycles of crop production including production and field application of biochar. Data were obtained from 7 sites (4 sites for paddy rice production and 3 sites for maize production) under a single BSA at 20 t/ha−1 across mainland China. Considering soil organic carbon (SOC) sequestration and GHG emission reduction from syngas recycling, BSA reduced the CFs by 20.37–41.29 t carbon dioxide equivalent ha−1 (CO2‐eq ha−1) and 28.58–39.49 t CO2‐eq ha−1 for paddy rice and maize production, respectively, compared to no biochar application. Without considering SOC sequestration and syngas recycling, the net CF change by BSA was in a range of −25.06 to 9.82 t CO2‐eq ha−1 and −20.07 to 5.95 t CO2‐eq ha−1 for paddy rice and maize production, respectively, over no biochar application. As the largest contributors among the others, syngas recycling in the process of biochar manufacture contributed by 47% to total CF reductions under BSA for rice cultivation while SOC sequestration contributed by 57% for maize cultivation. There was a large variability of the CF reductions across the studied sites whether in paddy rice or maize production, due likely to the difference in GHG emission reductions and SOC increments under BSA across the sites. This study emphasized that SOC sequestration should be taken into account the CF calculation of BSA. Improved biochar manufacturing technique could achieve a remarkable carbon sink by recycling the biogas for traditional fossil‐fuel replacement.

Estimation of energy efficiency and greenhouse gas emission of cotton crop in South Punjab, Pakistan

The agricultural sector is a consumer as well as a producer of energy. This study explores the relationship between energy consumption and greenhouse gas emission of cotton crop in Punjab province of Pakistan. Standard energy equivalents megajoules (MJ) were used to measure energy from different inputs and output, similarly, a standard unit kilogram of carbon dioxide equivalent (kg CO2) was used to estimate direct and indirect greenhouse gas emissions from the use of farm inputs. A non-parametric data envelopment analysis was used to estimate the energy efficiency of cotton growers. Farm efficiency analysis tool (FEAT) was used to estimate greenhouse gas emission and its intensity. The results showed that a total of 58, 374.07 MJ ha−1 input energy was used in cotton production, and output energy was calculated as 33,134 MJ ha−1. The results of DEA showed that 33% and 61% farmers were technically and pure technically efficient, respectively. The technical, pure technical and scale efficiency score of the cotton growers were 0.77, 0.90 and 0.85, respectively. Optimum energy requirement was found to be 34,882.65 MJ ha−1 demonstrating that if recommendations are followed 22.65% of input energy can be saved. The total greenhouse gas (GHG) emission was calculated to be 1928 kg CO2 ha−1. GHG intensity a ratio of kg CO2eq emission per MJ of output energy produced was estimated to be 0.07 kg CO2/MJ in cotton production. As part of recommendations, energy management in term of efficient, sustainable and economic use of energy in cotton is highly recommended.

Carbon footprint calculation in telecommunications companies – The importance and relevance of scope 3 greenhouse gases emissions

Energy efficiency measures and climate policies are closely related to strategic concerns of companies, and reduction of greenhouse gas (GHG) emissions has become an important indicator of energy efficiency measures. This paper discusses the application aspects of organizational carbon footprint (CF) for telecommunications companies. In order to better understand the structure of overall (direct and indirect) GHG emission, the model for calculating the organizational CF was established for the case of a telecom operator in its initial stages of carbon policy. In order to understand the importance of scope 3 categories in the overall CF, calculated results were compared to CF results reported by three other European telecommunications operators. The results for a particular case based on Slovenian operator revealed that the largest contributor to GHG emissions is the consumption of purchased electricity. The employees’ commute to and from work, the use of company-owned vehicles, and heating represent the next major sources of GHG emissions. It was shown that the most contributive upstream scope 3 aspects are similar for various European telecommunication operators and that exclusion of some categories along the supply chain may give a distorted image of organizational CF. However, the comparative analysis revealed that using only the company's own-recorded in-house data can be far from sufficient to make conclusions which GHG emissions scope contributes the highest share to the overall organizational CF of telecommunications companies. In this context, this paper reveals new findings on the relevance of CF determination for telecommunications companies as a guideline for reconsidering their energy efficiency and sustainability plans.

Evaluating carbon footprint of municipal solid waste treatment: Methodological proposal and application to a case study

This paper applies the Life Cycle Assessment methodology to develop a simple method to calculate the carbon footprint of the municipal solid waste treatment stage. This simple and structured methodological procedure takes into account: i) direct greenhouse gas emissions produced in waste treatment, taking place within the city boundary (scope 1 of international carbon footprint standards); ii) indirect greenhouse gas emissions related to the use of grid-supplied electricity, as well as fuel production and distribution (scopes 2 and 3 emissions as per international carbon footprint standards); and iii) avoided greenhouse gas emissions as a result of the products obtained (if any) that can replace other products or the raw materials used to produce them. Madrid City (a representative European city), the capital of Spain, was used as a case study to prove the validity and usefulness of the proposed methodology. In this city, 344 kg of municipal solid wastes were produced per inhabitant in 2013. These wastes were collected separately in different fractions (packaging, glass, paper/cardboard and mixed waste, including organic material). Mixed waste and packaging fractions were processed at the Valdemingómez Technology Park. The current treatment stage was compared with several alternative scenarios which describe hypothetical management routes for the different waste fractions. The carbon footprint for the current situation is equal to 224 kg CO2 eq/twaste. In comparison to the worst situation, corresponding to the scenario in which municipal wastes were landfilled without energy recovery, the current scenario reduces its carbon footprint by 1597 kg CO2 eq/twaste (a reduction of 88%). Improvements in the material separation and recovery processes, along with the implementation of biological treatments for the organic fraction, clearly contribute to reducing the carbon footprint of the municipal solid wastes handled in the city of Madrid.According to the obtained results, the scenarios based on a total recovery of valuable materials and waste-to-energy or anaerobic digestion treatments present the lowest carbon footprint because burden avoided is more important than direct and indirect emissions from treatments. In addition, the consumption of electricity and the emissions derived from its generation (mix of generation), can increase the carbon footprint of power-intensive treatments.

Integrated fixed-film activated sludge membrane bioreactors versus membrane bioreactors for nutrient removal: A comprehensive comparison

This research elucidates the pollutants (nutrients and carbon) removal performance and nitrous oxide (N2O) emissions of two pilot plants. Specifically, a University of Cape Town (UCT) Membrane Bioreactor (MBR) plant and an Integrated Fixed Film Activated Sludge (IFAS)-UCT-MBR plant were investigated. The plants were fed with real wastewater augmented with acetate and glycerol in order to control the influent carbon nitrogen ratio (C/N). The short-term effect of the inlet C/N ratio variation (C/N = 5 mgCOD/mgN and C/N = 10 mgCOD/mgN) on the behaviour of both plants was investigated. The results showed that the IFAS-UCT-MBR configuration provided the best performance in terms of pollutants removal at the two investigated C/N ratios. Furthermore, the lowest N2O emission (with respect to the influent nitrogen) was observed in the IFAS-UCT-MBR configuration, thus suggesting a potential beneficial effect of the biofilm in the emission reduction. However, the membrane of the IFAS-UCT-MBR showed a greater fouling tendency compared to the UCT-MBR configuration. This result, likely related to the biofilm detached from carriers, could seriously affect the indirect GreenHouse Gas emissions due to the increase of the energy requirement for permeate extraction with the increase of membrane fouling.

Quantification of direct and indirect greenhouse gas emissions from rice field cultivation with different rice straw management practices – A study in the autumn - winter season in An Giang Province, Vietnam

This study resulted in a comparative analysis of greenhouse gas emissions (GHGE) for rice production with different in-field rice straw management practices based on an experiment conducted in An Giang Province of Vietnam, during the autumn - winter season of 2016. Direct field GHGE was analyzed based on in-situ measurement and the total direct and indirect GHGE were estimated by applying the life cycle assessment using Ecoinvent3 database which is incorporated in SIMAPRO software. The experiment was conducted based on a completely random design with three treatments and three replications. The three treatments are [T1] Incorporation of straw and stubbles treated with Trichoderma; [T2] Incorporation of stubbles and removal of straw; and [T3] In-field burning straw. Closed chamber protocol and gas chromatography (SRI 8610C) was used to measure and analyse CH4 and N2O. CH4 emission rate was not significantly different (p>0.05) among the three treatments during sampling dates except on the days 17 and 24 after sowing (DAS). N2O emission rate was not significantly different (p>0.05) either. However, there were high variations of N2O emission after the dates of urea applied. Direct field emissions of CH4, N2O and CO2 equivalent (CO2eq) are not significantly different among the three treatments, but the amount of CO2eq per kg straw in T1 of incorporating rice straw treated with Trichoderma is significantly higher than in T3 of in-field burning straw. LCA based analysis resulted in total GHGE in the range of 1.93-2.46 kg CO2-eq kg-1 paddy produced consisting of 53-66% from direct soil emissions. Incorporation of straw treated with Trichoderma did not indicate the improvement of paddy yield. However, the organic matter, N-NH4+, and N-NO3- of this treatment was higher than those of the other researched treatments. This research was just conducted in one crop season, however, the results have initial implications for the other crop seasons.
 Nghiên cứu này phân tích phát thải khí nhà kính từ sản xuất lúa theo các biện pháp quản lý rơm rạ khác nhau dựa vào thí nghiệm được thực hiện ở vụ Thu Đông năm 2016 tại tỉnh An Giang, Việt Nam. Lượng phát thải khí nhà kính từ đất đã được phân tích dựa vào kết quả đo đạt tại ruộng và tổng lượng phát thải khí nhà kính trực tiếp và gián tiếp được ước tính bằng phương pháp vòng đời sử dụng cơ sở dữ liệu Ecoinvent3 gắn kết với phần mềm SIMAPRO. Thí nghiệm được bố trí hoàn toàn ngẫu nhiên gồm 3 nghiệm thức và 3 lần lặp lại. Các nghiệm thức gồm [T1] vùi rơm và rạ với Trichoderma, [T2] lấy rơm ra khỏi ruộng và vùi rạ và [T3] đốt rơm. Kỹ thuật buồng kín (closed chamber protocol) và máy sắc ký khí (SRI8610C) được sử dụng để đo đạt và phân tích khí CH4 và N2O. Tốc độ phát thải khí CH4 không khác biệt giữa ba nghiệm thức, ngoại trừ kết quả ở lần lấy mẫu 17 và 24 ngày sau sạ. Tốc độ phát thải N2O cũng không có sự khác biệt giữa các nghiệm thức. Tuy nhiên, tốc độ phát thải biến động rất lớn sau các ngày bón phân đạm. Lượng phát thải trực tiếp từ ruộng của CH4, N2O và CO2 tương đương (CO2-eq) không có sự khác biệt giữa ba nghiệm thức, nhưng lượng CO2-eq/kg rơm ở nghiệm thức vùi rơm và rạ với Trichoderma (T1) cao hơn nghiệm thức đốt rơm (T3). Kết quả phân tích LCA cho thấy lượng phát thải khí nhà kính dao động trong khoảng 1,93 – 2,46 kg CO2-eq/kg lúa với 53 – 66% lượng phát thải trực tiếp từ trong đất. Vùi rơm rạ với Trichoderma chưa cải thiện được năng suất lúa. Tuy nhiên, phần trăm chất hữu cơ và hàm lượng đạm hữu dụng trong đất của nghiệm thức này cao hơn so với hai nghiệm thức còn lại của thí nghiệm. Nghiên cứu này chỉ mới được thực hiện một vụ, nhưng đã mang lại nhiều kết quả có thể ứng dụng cho các vụ sau.

Variable speed liquid chiller drop-in modeling for predicting energy performance of R1234yf as low-GWP refrigerant

This paper presents a model for a variable-speed liquid chiller integrating a compressor model based on Buckingham π-theorem to accurately predict the system performance when R134a is replaced with R1234yf, using a wide range of data obtained from an experimental setup. Relevant variables such as temperature, pressure, mass and volumetric flow rates, compressor power consumption and rotation speed were measured at several positions along the refrigeration and secondary circuits and were used to validate the developed model. Model results show that cooling capacity and power consumption predicted values are in good agreement with experimental data, within ±5%, being slightly higher for the deviation obtained for R134a than for R1234yf. Moreover, model results indicate that R1234yf has a reduction of coefficient of performance (COP) compared with R134a (between 2 and 11.3%), and that R1234yf COP reduction is diminished at intermediate volumetric flow rate and higher inlet temperature for the evaporator secondary fluid, respectively. On the other hand, an environmental analysis based on TEWI (total equivalent warming impact) method showed that direct emissions are almost negligible for R1234yf. However, there are no environmental benefits in terms of indirect greenhouse gas emissions using R1234yf without system modifications (as for instance the addition of internal heat exchanger or R1234yf new design components), which are required to reduce the liquid chiller climate change contribution using it as low GWP alternative in comparison with the typically used R134a refrigerant.

The Role of Industrial Parks in Mitigating Greenhouse Gas Emissions from China.

This study uncovered the direct and indirect energy-related greenhouse gas (GHG) emissions of 213 Chinese national-level industrial parks, providing 11% of China's gross domestic product, from a life-cycle perspective. Direct emissions are sourced from fuel combustion, and indirect emissions are embodied in energy production. The results indicated that in 2015, the direct and indirect GHG emissions of the parks were 1042 and 181 million tonne CO2 equiv, respectively, totally accounting for 11% of national GHG emissions. The total energy consumption of the parks accounted for 10% of national energy consumption. Coal constituted 74% of total energy consumption in these parks. Baseline and low-carbon scenarios are established for 2030, and five GHG mitigation measures targeting energy consumption are modeled. The GHG mitigation potential for these parks in 2030 is quantified as 111 million tonne, equivalent to 9.1% of the parks' total emission in 2015. The measures that increase the share of natural gas consumption, reduce the GHG emission factor of electricity grid, and improve the average efficiency of industrial coal-fired boilers, will totally contribute 94% and 98% in direct and indirect GHG emissions reductions, respectively. These findings will provide a solid foundation for the low carbon development of Chinese industrial parks.

Low-ILUC-risk rapeseed biodiesel: potential and indirect GHG emission effects in Eastern Romania

ABSTRACTIndirect land-use change (ILUC) can have a severe impact on the greenhouse gas (GHG) balance of biofuels. Mitigating ILUC risk is important to avoid additional GHG emissions compared to fossil fuels. This is possible by making surplus land available through land demand reduction and using this for low-ILUC-risk biodiesel production. For a case study in Eastern Romania, we calculated the rapeseed biodiesel potential and the GHG emissions of four measures to make surplus land available in 2020. Four scenarios varying in assumptions on productivity and sustainability in the agricultural sector show the variation in the potential of these measures. We find that using surplus land to produce low-ILUC-risk rapeseed biodiesel has a potential of 3-64 PJ, 1-28% of the projected Romanian transport diesel consumption. The main contribution to this potential comes from yield improvements in crop and livestock production. Average GHG emissions of the ILUC mitigation measures are -11 to 22 g CO2-eq MJ−1 (maximum total lifecycle emissions are 34 g CO2-eq MJ−1; 60% reduction from fossil fuel reference). This means ILUC mitigation is possible without necessarily missing the GHG emission reduction target, provided that the entire agricultural sector is sustainably intensified, going beyond a focus on biofuel production alone.

Impact of greenhouse gases on surface coal mining in Brazil

Abstract This paper presents the first inventory and environmental impact study of the life cycle of coal obtained from a surface mine in Brazil. Significant reserves of coal in Brazil have attracted the attention of investors interested in building chemical and power generation plants. This inventory was developed to serve as a database for Life Cycle Assessment (LCA) studies, considering especially the impact of greenhouse gases, since there is no such information in the literature. The inventory collected data in situ, regarding the main pieces of equipment, inputs to the plant, and the direct emissions of greenhouse gases (GHG), covering different stages of the coal mining and processing, as well as the indirect emissions of GHG from the production and transportation of inputs. The coal life cycle emissions were equal to 3.29 × 10−2 kg CO2eq per kg of coal, of which direct emissions accounted for 98.3% of GHG, in which the major part was due to fugitive methane emissions from surface mining and post-mining coal crushing and handling operations. Additionally, the results of a sensitivity analysis showed that the diesel oil consumption was the most influential parameter of life cycle emission in terms of the inputs regarded.