Tons Of CO2 Equivalents Research Articles

Numerical Study of Integrated Solar Photovoltaic–Thermal Module with a Refrigeration System for Air-Conditioning and Hot Water Production under the Tropical Climate Conditions of Singapore

Thermal systems of buildings in the tropics are highly energy intensive. In this study, a novel integrated solar photovoltaic–thermal–refrigeration (PVTR) system used to produce hot water and air-conditioning in the tropical climate conditions of Singapore was analyzed. A dynamic simulation model was formulated for the analysis. Mathematical models were developed for the PV sandwich attached with a solar flat plate collector and for the main components of the refrigeration system. Thorough investigation of the electrical and thermal performances of the system were conducted through the analysis of coefficient of performance (COP), cooling capacity, water temperature and heat capacity in water heater, photovoltaic (PV) module temperature and PV efficiency. The results show that attractive electrical and thermal performance can be achieved with a maximum annual cooling COP of 9.8 and a heating COP of 11.3. The PV efficiency and power saving were 14% and 53%, respectively. The annual cooling, heating and PV energy produced were 9.7, 15.6 and 1.6[Formula: see text]MWh, respectively. The financial payback period of the system was 3.2 years and greenhouse gas (GHG) emission reduction annually was 12.6 tons of CO2 equivalents (tCO2e).

Smart cities – Thermal networks for London

This paper presents a feasibility study of the technical and economic viability of introducing combined heating and cooling networks in London, referred to collectively in this paper as “thermal networks”.The study begins with a review of the current and potential future demographic and energy trends for London. This is followed with detailed energy analysis of three different thermal network configurations to identify the most viable thermal network configuration for London. Future projection analysis was also carried based on a number of potential building mix scenarios.The study revealed that by using thermal network with heat recovery produced significant energy savings and subsequent carbon savings by upto 56%. The majority of the energy saving and equivalent CO2 emission savings resulted from the reduction of the heating energy required to cater for the loads due the viability of heat recovery from the cooling network into the return of the heating network. The study also revealed that by utilising thermal networks, with central energy centre approximately 1831 tonnes of CO2 equivalent could be saved per annum compared to traditional supply methods. With a minimum assumed system life of 25 years this equates to approximately 46,000 tonnes CO2.

Adoption and kitchen performance test of improved cook stove in the Bale Eco-Region of Ethiopia

This study was conducted to assess the determinants of households' decision for adoption of improved cook stoves (ICS), the performance of the stoves under real kitchen conditions and their potential in the reduction of greenhouse gas emission in Bale Eco-region, Southeastern Ethiopia. Data for this study were collected from 342 household heads that were randomly selected from four rural kebeles. For Kitchen Performance Test (KPT), 25 ICS and 30 traditional cook stove (TCS) user households were selected using stratified random sampling. The data gathered through questionnaire were analyzed using descriptive statistics and binary logistic regression. The data gathered from KPT were analyzed using independent t-test. Accordingly, the regression result revealed that higher education level of household head, larger family size and presence of separate kitchen house were significantly and positively related to the adoption of ICS. On the other hand, having men-headed household was related negatively to the decision of households adopting ICS in a significant manner. The KPT result showed that an average of 1.12 (SD = 0.3) kg of firewood is consumed per day for each Standard Adult Equivalent (SAE) for TCS users while an average of 0.79 (SD = 0.2) kg of firewood is consumed per day for each SAE for ICS. The KPT result also showed that using an ICS results in an annual emission reduction of 0.494 tons of CO2 equivalent.

Integrating Greenhouse gases (GHG) assessment for low carbon economy path: Live case study of Indian national oil company

Abstract Physical, Regulatory and Brand value risks due to climate change challenges are foreseen by businesses globally. This paper is oriented towards these challenges and prepared a comprehensive Greenhouse gases (GHG) footprint plan and identification of mitigation opportunities for ONGC, a fortune 500 and national oil company of India. Internationally recognized standards and guidelines like Greenhouse Gas Protocol, ISO-14064, and American Petroleum Institute compendium have been referred for quantifying carbon emissions in nearly real 400 + operation control facilities. The GHG inventory is based on Operational Control approach to identify the boundary for which emissions are to be quantified and two significant scopes of emissions viz Direct Emissions and Indirect Emissions are identified and quantified. The quantification concluded that GHG emission footprint for the year 2016–17 is in the range of 9 million tons of CO2equivalent. GHG emissions mainly account due to stationary combustion, fugitive emissions and wastewater treatment, which share the around 56% of total emissions. Another 24–26% of emissions are contributed due to flaring, processes by glycol dehydrator, acid gas removal units, and by electricity purchased from the grid. As a result, it has been found that ONGC emits 187 kg CO2e emissions per tonne throughput and also compared with its global peer organizations. At the organization level, “Key Industrial Sites” have been identified as contributing higher GHG emissions and accordingly key “hot-spots,” a list of 15 GHG mitigation opportunities have been proposed in the paper. Two GHG mitigation initiatives based on solar energy and bioenergy application undertaken at ONGC has also been briefed on case studies.

An integrated life cycle inventory and artificial neural network model for mining air pollution management

It is necessary to trade off environmental impact and mining performance, preferably using an integrated life cycle modeling approach, while quantifying the air emissions. An integrated framework comprises of a life cycle inventory, and artificial neural network model for mining (LCAMM) is developed and applied to the real case study of an open-pit gold mine. This study aims to develop the air pollution inventory using inverse matrix method and estimation of midpoint impact assessment using defined characterization methodologies. Furthermore, this paper explores the feasibility of back-propagation artificial neural networking model to develop the carbon footprints analysis for the mine in terms of CO2 equivalent by constructing different scenarios. The inventory result shows that TSP (49.6%), PM10 (20%), PM2.5 (14.7%), N2O (7.1%), CO (6.1%), SO2 (1.3%), HCN (0.6%), CH4 (0.4%), CaO (0.2%) and VOCs (0.06%) are responsible for the total environmental load in this gold mining. Subsequently, particulate matter formation (kg PM10 eq.) significantly contributes to the midpoint impact in contrast to the other environmental impacts, mainly because of hauling, handling of ore, milling/grinding, drilling and stockpiling. The study reveals that average 13,992.25–13,993.75 tons of CO2 equivalent is produced as the carbon footprints for this mine. This study confirms that LCAMM framework can serve the basis for further analysis of pollutant’s dispersion and assist decision makers to select an appropriate remedial technique in the mining industry.

The impact of surgery on global climate: a carbon footprinting study of operating theatres in three health systems

Climate change is a major global public health priority. The delivery of health-care services generates considerable greenhouse gas emissions. Operating theatres are a resource-intensive subsector of health care, with high energy demands, consumable throughput, and waste volumes. The environmental impacts of these activities are generally accepted as necessary for the provision of quality care, but have not been examined in detail. In this study, we estimate the carbon footprint of operating theatres in hospitals in three health systems. Surgical suites at three academic quaternary-care hospitals were studied over a 1-year period in Canada (Vancouver General Hospital, VGH), the USA (University of Minnesota Medical Center, UMMC), and the UK (John Radcliffe Hospital, JRH). Greenhouse gas emissions were estimated using primary activity data and applicable emissions factors, and reported according to the Greenhouse Gas Protocol. Site greenhouse gas evaluations were done between Jan 1 and Dec 31, 2011. The surgical suites studied were found to have annual carbon footprints of 5 187 936 kg of CO2 equivalents (CO2e) at JRH, 4 181 864 kg of CO2e at UMMC, and 3 218 907 kg of CO2e at VGH. On a per unit area basis, JRH had the lowest carbon intensity at 1702 kg CO2e/m2, compared with 1951 kg CO2e/m2 at VGH and 2284 kg CO2e/m2 at UMMC. Based on case volumes at all three sites, VGH had the lowest carbon intensity per operation at 146 kg CO2e per case compared with 173 kg CO2e per case at JRH and 232 kg CO2e per case at UMMC. Anaesthetic gases and energy consumption were the largest sources of greenhouse gas emissions. Preferential use of desflurane resulted in a ten-fold difference in anaesthetic gas emissions between hospitals. Theatres were found to be three to six times more energy-intense than the hospital as a whole, primarily due to heating, ventilation, and air conditioning requirements. Overall, the carbon footprint of surgery in the three countries studied is estimated to be 9·7 million tonnes of CO2e per year. Operating theatres are an appreciable source of greenhouse gas emissions. Emissions reduction strategies including avoidance of desflurane and occupancy-based ventilation have the potential to lessen the climate impact of surgical services without compromising patient safety. None.

Design optimization of a multi-temperature solar thermal heating system for an industrial process

Presently, great challenges are being faced by the industrial sector in terms of energy management and environmental protection. Utilization of solar energy to meet a portion of heat demand in various industries constitutes tremendous economic opportunities for developing countries such as Morocco. Therefore, this paper introduces an optimization procedure and simulation of a centralized solar heating system providing hot water to four processes with different temperature levels and load profiles. Asa case study, a Casablanca based Moroccan milk processing company is evaluated and the life cycle cost method is practiced to select the optimal size of the main design parameters for decision-making. It was found that 400m2 of evacuated tube collectors tilted at an angle of 30° and connected to a 2000l storage tank can lead to a maximum life cycle saving cost of 179kUSD for a total annual heat demand of 528.23MWh. In this optimal configuration, the overall annual solar fraction is found to be 41% and the payback period of 12.27years attained. The system has the potential to reduce around 77.23tons of CO2 equivalents of greenhouse gas emissions annually. The economic competitiveness of the solar thermal heating plant can be considerably improved with higher inflation rates and lower initial investments.

Calculations of environmental benefits from using geothermal energy must include the rebound effect

When considering the environmental benefits from converting to renewable energy sources, the rebound effect is often omitted. In this study, the aim is to investigate greenhouse gas emission reduction inclusive of the rebound effect. We use Iceland as a case study where alternative consumption and energy production patterns are simulated using data from countries with similar environmental conditions but do not use geothermal or hydropower to the same extent as Iceland. Because of the rapid shift towards renewable energy and exclusion of external energy provision, the country is considered suitable for such a study. It was found that real emission reductions are most likely overestimated by previous calculations. Results show that between 1969 and 2014 greenhouse gas emission savings are likely to be between 164 and 361 million tonnes of CO2 equivalents. Between 1994 and 2014 savings are likely to be between the range of 76 and 142 million tonnes of CO2 equivalent. This study sheds a stronger light on the real observed environmental benefits when changes in consumption pattern are included in calculations stating greenhouse gas emission reductions.

Energy and climate impact assessment of waste wood recovery in Switzerland

Waste wood represents as much a waste to dispose of as a secondary resource to exploit. Various studies have assessed the energy potential and/or climate impact of energy recovery from waste wood. This paper aims to assess the long-term potential of waste wood for energy production and greenhouse gas (GHG) emissions reduction in Switzerland. Material flow analysis (MFA) is applied for modelling the metabolism of wood and waste wood in the Swiss anthroposphere over one century. The energy and climate impacts are estimated for 32 scenarios which assume different forest harvesting variants and waste wood treatment options. The scenario analysis shows that waste wood treatment options are more beneficial in the long term in terms of energy production (by energy recovery from waste wood) and of GHG emission reduction than the increase in the quantities of waste wood generated in the future caused by the advocated strategies of increased forest harvesting. By using the Maximin criterion, the long-term optimal additional potential for energy recovery from waste wood is estimated at 2110 GWh/year of useful energy, which offers a reduction of 364 tonnes of CO2 equivalents per year. As prerequisites, the nominal installed capacity of the waste wood boilers needs to be raised and their efficiency and as well as those of incineration plants need to be increased. In addition, the sustainable potential of Swiss forests must be fully exploited. This study identifies various recommendations for the optimal exploitation of energy recovery from waste wood.

California proposes to cut methane releases from oil and gas operations

Oil and gas operations in California would have to reduce their emissions of methane, a major component of natural gas, under a regulation the state proposed last week. The California Air Resources Board says the proposal would limit intentional venting of the potent greenhouse gas and require facilities to monitor for and repair leaks. Under the proposal, emissions from the state’s oil and gas sector would drop by about 1.5 million metric tons of carbon dioxide equivalents from an estimated 2.5 million metric tons of CO2 equivalents per year, based on the 20-year climate change potential of methane. The state’s proposal is similar to a regulation EPA issued in May. Though the federal rule applies only to new and modified oil and gas facilities, the California proposal would apply to existing operations, too. Oil and gas facilities are responsible for about 15% of California’s methane emissions, notes the air resources

Excessive red and processed meat intake: relations with health and environment in Brazil.

The aims of the present study were to verify the proportion of population that consumed more red and processed meat than the World Cancer Research Fund (WCRF) dietary recommendation, to estimate the environmental impact of beef intake and the possible reduction of greenhouse gas emissions if the dietary recommendation was followed. We used the largest, cross-sectional, population-based survey entitled the National Dietary Survey (34 003 participants aged 10-104 years). The usual meat intake was obtained by two food records completed on 2 non-consecutive days. The usual intake was estimated by the multiple source method. The environmental impact was analysed according to estimates of CO2 equivalent emissions from beef intake as a proxy for beef production in Brazil. The red and processed meat intake mean was 88 g/d. More than 80 % of the population consumed more red and processed meat than the WCRF recommendation. Beef was the type of meat most consumed, accounting to almost 50 %. Each person contributed 1005 kg of CO2 equivalents from beef intake in 2008, the same quantity of CO2 produced if a car travelled a distance between the extreme north and south of Brazil (5370 km). The entire Brazilian population contributed more than 191 million tons of CO2 equivalents, which could have been reduced to more than 131 million tons if the dietary recommendation was followed. The present study shows that the magnitude of the excessive red and processed meat intake in Brazil can impact on health and the environment, pointing to the urgency of promoting a sustainable diet.

Neutralização compensatória de carbono - estudo de caso: indústria do setor metal mecânico, Rio de Janeiro (RJ)

RESUMO Este trabalho visa quantificar as emissões de gases do efeito estufa por uma empresa do setor metal-mecânico, situada no Rio de Janeiro (RJ). Foi feito um levantamento das atividades que influenciam as emissões dos GEE da empresa Metal Master. O cálculo das emissões de gases do efeito estufa foi através das metodologias desenvolvidas pelo Painel Intergovernamental de Mudanças Climáticas (IPCC) para o consumo de combustíveis, consumo de energia elétrica, resíduos dispostos em aterros, esgotos domésticos e efluentes industriais. Do total de emissões lançadas na atmosfera pela empresa em estudo, foi obtido um valor de 439 toneladas de CO2 equivalente, sendo 76,3 toneladas pelo consumo de combustíveis dos meios de transporte, 89 toneladas pelos resíduos gerados, 2,2 toneladas pelos efluentes gerados, 8,8 toneladas por consumo de energia elétrica e 148 toneladas por processos industriais internos. No cenário onde se contempla as medidas mitigadoras, tais emissões são reduzidas a 397 toneladas de CO2 equivalente. Caso seja empregado o reflorestamento como única forma de neutralização total de emissões da empresa em estudo, faz-se necessária a recuperação vegetal de uma área com 1,37 hectares de extensão.

Greening Industrial Production through Waste Recovery: "Comprehensive Utilization of Resources" in China.

Using nonhazardous wastes as inputs to production creates environmental benefits by avoiding disposal impacts, mitigating manufacturing impacts, and conserving virgin resources. China has incentivized reuse since the 1980s through the "Comprehensive Utilization of Resources (CUR)" policy. To test whether and to what extent environmental benefits are generated, 862 instances in Jiangsu, China are analyzed, representing eight industrial sectors and 25 products that qualified for tax relief through CUR. Benefits are determined by comparing life cycle inventories for the same product from baseline and CUR-certified production, adjusted for any difference in the use phase. More than 50 million tonnes of solid wastes were reused, equivalent to 51% of the provincial industrial total. Benefits included reduction of 161 petajoules of energy, 23 million tonnes of CO2 equivalent, 75 000 tonnes of SO2 equivalent, 33 000 tonnes of NOX, and 28 000 tonnes of PM10 equivalent, which were 2.5%-7.3% of the provincial industrial consumption and emissions. The benefits vary substantially across industries, among products within the same industry, and when comparing alternative reuse processes for the same waste. This first assessment of CUR results shows that CUR has established a firm foundation for a circular economy, but also suggest additional opportunities to refine incentives under CUR to increase environmental gain.

Waste to Energy: Management of Biodegradable Healthcare Waste through Anaerobic Digestion

This research was carried out in 21m3 Technology for Economic Development (TED) model biogas plant constructed and operated at Bir Hospital, Kathmandu. The digester was fed with 95 kg of mixed waste per day in average generated at Bir Hospital. Average biogas production recorded per day was 5.78 m3 which increased to 8.09m3 per day after the feeding reached 15 tons after five months of regular feeding. The recorded burning time for this volume of gas was 12-14 hours per day in a stove of 0.22m3. Methane content in the gas reached up to 54% of the total volume and pH in the biodigester was maintained in a range of 6-7. The retention time of the biodigester was 147 days and the average energy content of biogas has been found as 4.38 Kwhth/m3. The payback period of the biodigester installed is 4 years when compared with LPG, since most of the hospitals use LPG as their cooking fuel it was only analyzed with the LPG. The total reduction of the GHGs was found to be 75.8 tons of CO2 equivalents per annum and the total reduction in terms of monetary benefits was 531.18 USD per annum. Except in one case the presence of E.coli was identified, beside its presence none of other harmful pathogens were detected in the slurry obtained.Nepal Journal of Science and Technology Vol. 16, No.1 (2015) pp. 41-48

Small-scale technology solutions to eliminate flaring

Five percent of the world’s gas supply is wasted by being flared or vented into the atmosphere, leading to a huge loss of potential revenue, not to mention a significant impact on the environment. This is equivalent to 150 billion cubic metres of natural gas per year and the release of 400 million metric tons of CO2 equivalent. The industry does this for a variety of valid reasons, including well testing, emergencies, commissioning, maintenance, or simply because an economic solution for capturing and using the gas has not been discovered. Capture of flared gas, therefore, presents an economic and environmentally beneficial opportunity to create new value chains that can benefit not only the industry but also people’s quality of life. This extended abstract draws on a recent DNV GL project to assess existing and future technologies and concepts for capturing small volumes of associated gas that are normally flared from oil fields, both onshore and offshore. The following four technology options that can be used to capture associated gas, convert it, and either utilise the product onsite or transport it to market for consumption are considered. Using more cost-effective ways of transporting natural gas where there is no existing pipeline. Converting gas into products with a higher economic value through chemical processes. Novel concepts—bringing the solution closer to the source of gas flaring. Other solutions. The extended abstract then focuses on cost-effective ways of transporting gas, in particular the use of micro-LNG solutions

Global mitigation of non-CO2 greenhouse gases: marginal abatement costs curves and abatement potential through 2030

Greenhouse gases (GHGs) other than carbon dioxide (CO2) play an important role in the effort to understand and address global climate change. Approximately 25% of Global warming potential-weighted GHG emissions in the year 2005 comprise the non-CO2 GHGs. The report, Global Mitigation of Non-CO2 Greenhouse Gases: 2010–2030 provides a comprehensive global analysis and resulting data-set of marginal abatement cost curves that illustrate the abatement potential of non-CO2 GHGs by sector and by region. The basic methodology – a bottom-up, engineering cost approach – builds on the baseline non-CO2 emissions projections published by EPA, applying abatement options to the emissions baseline in each sector. The results of the analysis are MAC curves that reflect aggregated breakeven prices for implementing abatement options in a given sector and region. Among the key findings of the report is that significant, cost-effective abatement exists from non-CO2 sources with abatement options that are available today. Without a price signal (i.e. at $0/tCO2e), the global abatement potential is greater than 1800 million metric tons of CO2 equivalent. Globally, the energy and agriculture sectors have the greatest potential for abatement. Among the non-CO2 GHGs, methane has the largest abatement potential. Despite the potential for project level cost savings and environmental benefits, barriers to mitigating non-CO2 emissions continue to exist. This paper will provide an overview of the methods and key findings of the report.

Carbon footprint of dairy goat milk production in New Zealand

The aim of this study was to assess the cradle-to-farm gate carbon footprint of indoor and outdoor dairy goat farming systems in New Zealand, identifying hotspots and discussing variability and methodology. Our study was based on the International Organization for Standardization standards for life cycle assessment, although only results for greenhouse gas emissions are presented. Two functional units were included: tonnes of CO2-equivalents (CO2e) per hectare (ha) and kilograms of CO2e per kilogram of fat- and protein-corrected milk (FPCM). The study covered 5 farms, 2 farming systems, and 3yr. Two methods for the calculation of enteric methane emissions were assessed. The Lassey method, as used in the New Zealand greenhouse gas inventory, provided a more robust estimate of emissions from enteric fermentation and was used in the final calculations. The alternative dry matter intake method was shown to overestimate emissions due to use of anecdotal assumptions around actual consumption of feed. Economic allocation was applied to milk and co-products. Scenario analysis was performed on the allocation method, nitrogen content of manure, manure management, and supplementary feed choice. The average carbon footprint for the indoor farms (n=3) was 11.05 t of CO2e/ha and 0.81kg of CO2e/kg of FPCM. For the outdoor farms (n=2), the average was 5.38 t of CO2e/ha and 1.03kg of CO2e/kg of FPCM. The average for all 5 farms was 8.78 t of CO2e/ha and 0.90kg of CO2e/kg of FPCM. The results showed relatively high variability due to differences in management practices between farms. The 5 farms covered 10% of the total dairy goat farms but may not be representative of an average farm. Methane from enteric fermentation was a major emission source. The use of supplementary feed was highly variable but an important contributor to the carbon footprint. Nitrous oxide can contribute up to 18% of emissions. Indoor goat farming systems produced milk with a significantly higher carbon footprint per area of land farmed compared with outdoor farming systems, although the 2 systems were not significantly different when results were expressed per kilogram of FPCM, at 0.81kg CO2e and 1.03kg CO2e per kg of FPCM, respectively. Both systems had footprints less than other reported dairy goat carbon footprints and on par with those for New Zealand dairy cows. The methodology used to determine enteric methane is important for an accurate and meaningful assessment. The choice of manure management system and supplementary feed can substantially affect the carbon footprint.

Energy savings across EU domestic building stock by optimizing hydraulic distribution in domestic space heating systems

The objective of this work is to quantify the resultant savings across the EU from the optimization of existing system components in domestic space heating distribution systems to maintain comfort levels. Heat energy savings are shown to range from 1% to 19% depending on dwelling type, age, location and initial specific heat energy consumption. Total potential savings across the sector amount 22.6Mtoe, a reduction of 7.3%; 53% of these from a reduction in pumping power required by heating distribution systems and 47% of these from a reduction in the heat energy consumed by heating systems. The carbon abatement potential is estimated to be 496 million tonnes of CO2 equivalent. Regulatory changes to the domestic replacement and maintenance industry are required for these low-cost, high impact and highly applicable energy saving measures to be adopted more extensively.

Impacto ambiental de un hospital público en la ciudad de Lima, Perú

The operation of hospitals produces negative effects on the environment which contributes to air pollution and climate change. The institution in this study is a category III health care facility located in the city of Lima. It generates 4.89 kg/bed/day of solid waste, and consumes 1.36 m3/bed/day of water; 25.22 kWh/bed/day of electricity, and 2.76 liters/bed/day of fuel. The level of PM10 and measured parameters of disposal to the public network are within legal limits, while mobile source noise exceeds the maximum allowable limit. The institution releases into the atmosphere 2,291 tons of CO2 equivalents per year. In conclusion, the institution studied generates a negative impact on the environment.

Is obesity associated with global warming?

ObjectivesObesity is a national epidemic that imposes direct medical and indirect economic costs on society. Recent scholarly inquiries contend that obesity also contributes to global warming. The paper investigates the relationship between greenhouse gas emissions and obesity. Study designCross-sectional state-level data for the year 2010. MethodsMultiple regression analysis using least squares with bootstrapped standard errors and quantile regression. ResultsStates with higher rates of obesity are associated with higher CO2 and CH4 emissions (p < 0.05) and marginally associated with higher N2O emissions (p < 0.10), net of other factors. Reverting to the obesity rates of the year 2000 across the entire United States could decrease greenhouse gas emissions by about two percent, representing more than 136 million metric tons of CO2 equivalent. ConclusionsFuture studies should establish clear causality between obesity and emissions by using longitudinal data while controlling for other relevant factors. They should also consider identifying means to net out the potential effects of carbon sinks, conversion of CH4 to energy, cross-state diversion, disposal, and transfer of municipal solid waste, and potentially lower energy consumption from increased sedentariness.