Tonnes Of Greenhouse Gas Emissions Research Articles

Integrated climate change and air pollution mitigation assessment for Togo

Togo, in west Africa, is vulnerable to the impacts of climate change, but has made a negligible contribution to causing it. Togo ratified the Paris Agreement in 2017, committing to submit Nationally Determined Contributions (NDCs) that outline Togo's climate change mitigation commitment. Togo's capital, Lomé, as well as other areas of Togo have ambient air pollutant levels exceeding World Health Organisation guidelines for human health protection, and 91 % of Togolese households cook using solid biomass, elevating household air pollution exposure. In Togo's updated NDC, submitted in 2021, Togo acknowledges the importance and opportunity of achieving international climate change mitigation targets in ways that improve air quality and achieve health benefits for Togo's citizens. The aim of this work is to evaluate priority mitigation measures in an integrated assessment of air pollutant, Short-Lived Climate Pollutant (SLCP) and Greenhouse Gas (GHG) emissions to identify their effectiveness in simultaneously reducing air pollution and Togo's contribution to climate change. The mitigation assessment quantifies emissions for Togo and Grand Lomé from all major source sectors for historical years between 2010 and 2018, for a baseline projection to 2030 and for mitigation scenarios evaluating ten mitigation measures. The assessment estimates that Togo emitted ~21 million tonnes of GHG emissions in 2018, predominantly from the energy and Agriculture, Forestry and Other Land Use sectors. GHG emissions are projected to increase 42 % to 30 million tonnes in 2030 without implementation of mitigation policies and measures. The implementation of the ten identified priority mitigation measures could reduce GHG emissions by ~20 % in 2030 compared to the baseline, while SLCPs and air pollutants were estimated to be reduced more, with a more than 75 % reduction in black carbon emissions in 2030. This work therefore provides a clear pathway by which Togo can reduce its already small contribution to climate change while simultaneously achieving local benefits for air quality and human health in Togo and Grand Lomé.

Good for the Gut [food - waste

Researchers are finding innovative ways to recycle discarded food waste to create prebiotics. There is some evidence that pectin oligosaccharides, which have been produced from carbohydrates extracted from certain food waste such as potato peel, could be used to make a prebiotic - but so far it has only been done on a small scale within a lab setting. Food waste is a problem of supersized proportions. One third of the food we grow - 1.3 billion tonnes - is wasted. Not only is this shameful when 690 million people go to bed hungry every night, but it also produces an estimated 1.8 billion tonnes of greenhouse gas emissions. Turning our noses up at leftovers is part of the problem. The priority is to minimise waste, by eating wonky veg, for example, or redistributing surplus food to hungry people, or animals if it is of lesser quality. But the bulk of wasted food doesn't even reach our plates. Some food is inedible because it has gone off, become contaminated, or is an inedible by-product of the food industry such as onion skins. These products are then either recycled for fertiliser, burned for energy, or simply go to landfill. But thankfully, there's appetite for a new solution to address food waste: recycling that retains the value of food molecules so they can still provide nourishment.

A multi-objective optimization approach for supply chain design of alum sludge-derived supplementary cementitious material

Most alum sludge is disposed of in landfill sites in Australia, resulting in significant environmental pollution and management cost. Effective management of sludge in a more sustainable manner remains a critical social, environmental, and economic concern. To simultaneously solve the dilemma of sludge management, economic expenditure of disposal, greenhouse gas emissions, and social impacts, this study proposed a multi-objective model for supply chain design of alum sludge-derived supplementary cementitious material as a viable solution. This study identified and quantified the potential social benefit by considering different impacts of new working opportunities based on their type and location, optimized the greenhouse gas emission saving for the potential supply chain, and assessed the economic benefit of the optimal untapped supplementary cementitious material value chain. The viability and applicability of the model are demonstrated through a case study in Australia, where potential utilization paths for available alum sludge are valued. A set of Pareto-optimal solutions was generated using the ɛ-constraint method, and three compromise Pareto-optimal solutions showed a clear trade-off among three objectives. The result analysis of each single-objective optimization indicates that the maximum working opportunity brought by the proposed supply chain was over 3.6 million working hours. Besides, up to 5.5 billion tonnes of greenhouse gas emissions saving was reported when maximizing the environmental objective, and the maximum economic benefit in the form of net present value was over 200 million Australian dollars in simulated 20 years. The Pareto-optimal solutions report a trade-off among three objectives, and two compromised solutions are proposed based on the level of objective values.

Can Digital Technologies Increase Consumer Acceptance of Circular Business Models? The Case of Second Hand Fashion

Experimentation with, and the implementation of, circular business models (CBMs) has gained rapid traction within the textiles and fashion industry over the last five years. Substitution of virgin materials with bioderived alternatives, extending the lifecycle of garments through resale, and rental services and the recycling or upcycling of garments are some of the strategies being used to reduce the 1.2 billion tonnes of greenhouse gas emissions and 92 million tonnes of waste associated with the sector in 2017. However, whilst CBMs demonstrate environmental and economic benefits, low consumer acceptance is considered by business professionals and policymakers to be one of the main barriers to the transition towards a circular economy. Digitisation is widely acknowledged as a catalyst for innovation in many sectors and digital technologies are driving new ways to exchange and share goods and services, enabling companies to match the supply, and demand for, otherwise underused assets and products. Online platforms, in particular, have played a crucial role in driving the growth of used goods and resale in other consumer goods markets, such as consumer technology. A mixed methods approach, including a review of 40 organisations operating second hand fashion models, a consumer survey of over 1200 respondents and in-depth interviews with 10 organisations operating second hand fashion models, is adopted to reveal (a) the barriers to consumer acceptance of reuse models in the fashion industry, and (b) how digital technologies can overcome these barriers. Findings highlight the significant progress that organisations have made in using digitalisation, including data analytics, algorithms, digital platforms, advanced product imagery and data informed customer communications, to address barriers associated with convenience, hygiene, trust and security. Furthermore, the study identifies opportunities for the development of more sophisticated digital technologies to support increased transparency and address concerns associated with the quality, authenticity and sourcing of materials. Positioned at the interface of digitisation and consumer acceptance of circular business models, this study makes an important contribution to understanding consumer barriers and how to address them and concludes with a set of recommendations for practitioners.

Environmental sustainability and footprints of global aquaculture

While aquaculture is critical to global food and nutrition security, the fast development of aquaculture production systems has recently increased concerns about resource overexploitation and associated environmental impacts. Understanding how sustainable is current global aquaculture practice is important given its potential impacts on key sustainable development goals (SDGs). Here, for the first time, we developed a food-energy-water-carbon (FEWC) composite sustainability index (0–100) to assess the sustainability of global aquaculture across countries. Results indicate that the overall sustainability of global aquaculture is low (average score = 26) with none achieving a high sustainability score (75–100) and almost all practicing aquaculture in a relatively low sustainable way (0–50). Considering the sub-sustainability at a sector level, 80% of countries had at least two sectors among FEWC falling into the low sustainable zone (score less than 25). Regarding the environmental impacts, global aquaculture production accounted for approximately 1765.2 × 103 TJ energy use, 122.6 km3 water consumption, and 261.3 million tonnes of greenhouse gas emissions in 2018. China led all countries by contributing to more than half of global aquaculture water consumption and greenhouse gas emissions, followed by India and Indonesia. This study highlights the significance of cross-sectoral management and policymaking to achieve global aquaculture sustainability.

Editorial and News

Editorial and News

Estimation of the sustainable production of gaseous biofuels, generation of electricity, and reduction of greenhouse gas emissions using food waste in anaerobic digesters

Food waste is a type of organic waste generated by restaurants, food processing plants, households, and commercial and institutions. This study aims to assess the sustainable biofuel, electricity production and greenhouse gas emission reduction potential of food waste using anaerobic digestion technology. Food waste data was collected from the Australian government database to estimate the biomethane and biogas yield and to evaluate the opportunities to convert the biomethane into electricity and heat. This study found that food waste can yield 47% biomethane and hence for Australia, an estimated total of 0.07 million m3 to 1.54 million m3 of biogas can be produced and up to 414,898 tonnes of greenhouse gas emissions reduced annually. The study also estimated that the generated biogas can replace fossil fuel-based electricity generation of up to 52.36 GW and 554.4 TJ heat per year. The environmental assessment indicated that the complete conversion of food waste can lower greenhouse gas emissions (GHG) by up to 5,07,434 tonnes per year and Australia can earn about $52.38 M revenue from electricity production. Therefore, conversion of food waste into biofuel through the anaerobic digestion process can play a significant role in generating electricity from non-fossil-based sources, reducing GHG emissions and earning revenue.

Effect of integrating high flow naturally driven dual solar air heaters with Trombe wall

Trombe wall is one of the sustainable architectural designs in the building that offers significant opportunities for energy saving and contribute to the low green-house emissions. Naturally or buoyancy driven dual solar air heaters (SAH) are barely used in building sector with Trombe wall due to its low mass flow rates and low efficiency. In this paper, a new concept of integrating high flow naturally driven dual heating system of Trombe wall integrated with SAH has been numerically investigated, optimized and an efficient design configuration is proposed. Total seven independent configurations namely type-1 to 7 have been investigated wherein type-1 and 2 is SAH coupled with a vertical chimney, type-3 has SAH coupled with Trombe wall, and type-4 to 7 are SAH coupled with Trombe wall having bell-mouth inlet opening for improved hydraulic performance for rapid space heating. It is observed that if Trombe wall is integrated suitably with bell-mouth inlet, SAH along with chimney, it can significantly increase the mass flow rates of heated air by about 2.5 times the convectional design. It is also observed that with increase in mass flow rates, system shows significant exergy gain of 142% when compared to conventional design. Time needed to heat a given space from a specific initial temperature are also calculated using first law of thermodynamics with mass flow values taken from the model and compared with conventional design. It was noted that to heat a given space to a desired temperature, new system of dual SAH takes about 70% less time. The proposed coupled Trombe wall-SAH device has shorter payback period and could save tons of greenhouse gas emissions annually compared to the conventional fossil fuel-based heating systems. Thermal comfort of the occupant can be enhanced with dual SAH-Trombe wall system resulting in significant energy saving.

Economic and Environmental Benefits from Municipal Solid Waste Recycling in the Murmansk Region

Most municipal solid waste (MSW) in Russia is disposed of in landfills, and only a relatively small fraction is recycled. The landfilling of waste leads to greenhouse gas (GHG) emissions, and air and groundwater pollution. However, recently, there have been some initiatives to improve waste management in the country. We assessed the economic and environmental benefits of waste recycling in the Murmansk region, in which a new waste recycling plant has been operating since 2019. We found that MSW recycling in the Murmansk region has induced a small, positive, job creation effect and could potentially lead to a non-negligible reduction in GHG emissions. Extrapolating the results from this case study to the country level, we found that recycling landfilled MSW in Russia could save approximately 154 million tons of GHG emissions in carbon dioxide equivalents annually, which is comparable to the total CO2 emissions from Algeria. The positive environmental and health-related impacts from the extensive implementation of MSW recycling in the country could be substantial. From this case study, we also learned that one of the biggest challenges for the waste recycling company in the Murmansk region is finding profitable markets for recycled materials. Moreover, due to the high investment and operational costs, recycling MSW led to a substantial increase in communal fees. However, there is potential to make waste recycling more cost effective. Most MSW in the Murmansk region is still separated at the recycling plant, while separating waste at the source could substantially reduce operational costs. Other challenges in the large-scale implementation of MSW recycling in Russia, such as a lack of investments and the population’s willingness to recycle waste, are also discussed.

Techno-Economic Analysis of Fast Pyrolysis of Date Palm Waste for Adoption in Saudi Arabia

Date palm trees, being an important source of nutrition, are grown at a large scale in Saudi Arabia. The biomass waste of date palm, discarded of in a non-environmentally-friendly manner at present, can be used for biofuel generation through the fast pyrolysis technique. This technique is considered viable for thermochemical conversion of solid biomass into biofuels in terms of the initial investment, production cost, and operational cost, as well as power consumption and thermal application cost. In this study, a techno-economic analysis has been performed to assess the feasibility of converting date palm waste into bio-oil, char, and burnable gases by defining the optimum reactor design and thermal profile. Previous studies concluded that at an optimum temperature of 525 °C, the maximum bio-oil, char and gases obtained from pyrolysis of date palm waste contributed 38.8, 37.2 and 24% of the used feed stock material (on weight basis), respectively, while fluidized bed reactor exhibited high suitability for fast pyrolysis. Based on the pyrolysis product percentage, the economic analysis estimated the net saving of USD 556.8 per ton of the date palm waste processed in the pyrolysis unit. It was further estimated that Saudi Arabia could earn USD 44.77 million per annum, approximately, if 50% of the total date palm waste were processed through fast pyrolysis, with a payback time of 2.57 years. Besides that, this intervention will reduce 2029 tons of greenhouse gas emissions annually, contributing towards a lower carbon footprint.

Utilizing geothermal energy from enhanced geothermal systems as a heat source for oil sands separation: A numerical evaluation

Burning natural gas to heat water for oil sands separation is and energy and carbon-intensive process. This study presents a COMSOL Multiphysics simulation model that comprehensively investigates the feasibility of utilizing geothermal energy from enhanced geothermal systems (EGSs) as a heat source for oil sands separation. The simulation model was built with discrete fractures and was verified with analytical results. The results demonstrate that a doublet EGS performs better than a triplet EGS for heat production, because a doublet system has more uniform flow distribution and longer flow paths. The heat production performance of an EGS can be improved by decreasing the injection temperature or creating more fractures and wider fracture apertures to increase the injection flow rate in a deeper geothermal reservoir. By adjusting the parameters of water, fractures, and the geothermal reservoir, the theoretical model shows that a doublet EGS can provide hot water (≥60 °C) for 30 years, thus saving 957.35 × 106 m3 of natural gas and reducing 1.96 × 106 tonnes of greenhouse gas emissions. This study provides a rational approach for evaluating potential EGS projects in future to provide hot water for oil sands separation.

Optimal biomass allocation to the German bioeconomy based on conflicting economic and environmental objectives

While some studies have simultaneously modeled the competitiveness of biochemicals alongside bioenergy and biofuels for greenhouse gas abatement, this has never been done before for Germany. The findings on the potential greenhouse gas abatement from these previous studies cannot be replicated in the German context because of different frame conditions, such as biomass potentials, temporal horizon, climate targets and the evolution of demand from biomass end-use sectors. This, therefore, necessitates a country-specific assessment. In this study we use a bi-objective bottom-up optimization model to quantify the potential greenhouse abatement (i.e. from best compromise solutions between the cost-optimal and technical-optimal objectives) for biomass deployment to the bioenergy, biofuels and biochemical sectors of the German bioeconomy. Results show that, with a reference crude oil price development, biomass potentials (i.e. 300 PJ of forest residues and 2.7 million hectares of arable land) could save 69 million t CO2-eq by 2050, representing a 6% reduction over 1990 GHG emission levels in the energy, building, transport and industrial sectors. The cumulative abatement (i.e. for 2020–2050) of 1.72 billion tonnes of greenhouse gas emissions was found to be 8.5% higher than when the available biomass resources were exclusively used for bioenergy and biofuels.

A life cycle analysis techno-economic assessment framework for evaluating future technology pathways – The residential air-conditioning example

Clarity on cost and environmental benefits of individual technologies evaluated in a systemic and systematic manner is necessary in communicating the results at the policy level so as to enable effective decisions. Yet, the highly complex nature of many energy modelling tools makes it difficult for non-specialists to interpret and make sense of their results. An integrated life cycle analysis and techno-economic assessment framework is proposed in this study, as a first step towards developing an alternative and potentially more intuitive energy systems modelling tool. The residential air-conditioning sector in the Southeast Asian context is used as an example to demonstrate the advantages of the modelling methodology in profiling future technology pathways. The use of best available R32 technology can lead to cumulative savings of 2195 million tonnes of greenhouse gas emissions in the region by 2050; while the best available R407C technology has an average cost of $40.85 per tonne of greenhouse gas abatement. In addition, our modelling tool is capable of profiling energy outlooks for emerging economies and will be further integrated with hourly energy analysis frameworks in the next steps of development.

A quantitative assessment of greenhouse gas (GHG) emissions from conventional and modular construction: A case of developing country

Building construction serves a vital purpose from a social and economic perspective by meeting the housing needs of society and contributing to the economic growth of a country. However, from an environmental perspective, this sector contributes negatively by releasing tons of greenhouse gas emissions (GHG) in the atmosphere, which consequently gives rise to other environmental hazards such as global warming and ozone depletion. The use of off-site modular construction practices in developed countries is increasing due to its environmental benefits over conventional cast-in-situ method. However, the environmental performance of a construction method may vary across various geographical regions, which is why environmental assessment of construction methods specific to a region is required. This study provides a calculation of GHG emissions in modular and conventional construction methods utilized in Pakistan, considering two single-family single-storey buildings with similar characteristics. The study also provides recommendations to homebuilders for the improvements in low-performance areas in both modular and conventional building methods. The results of the study show that modular building accounts for a total of 3449.73 kgCO2-equivalent GHG emissions whereas conventional building resulted in a total of 6501.91 kgCO2-equivalent GHG emissions. Modular building results in a reduction of 3052.19 kgCO2-equivalent GHG emissions (46.9%) as compared to a conventional site-built building. This implies that the modular construction method is a more environmentally viable option than conventional construction, which needs to be adopted on a large scale to reduce GHG emissions.

Impact of PV system orientation angle accuracy on greenhouse gases mitigation

Sun, a free source of energy, has moved the world to consider photovoltaic (PV) system as green renewable energy since fossil fuel power plant accounts for a significant share of greenhouse gas (GHG) emissions across the globe. The output of the PV system is limited to many factors; however, the acute accuracy of orientation (tilt and azimuth) angles exposes the PV surfaces to high doses of solar radiations. Which increases the PV system output; in turn GHG mitigation potential. This paper draws a relationship between accuracy of orientation angles impact on PV system's GHG mitigation potential. For reference, the accuracy of orientation angles in Pakistan's Capital increases the annual average daily solar radiations level from 4.02 (horizontal surface) to 4.39 (−33.6 tilt and 180 azimuth) kWh/m2/d. Accuracy of orientation angles on multiple end energy users (equivalent to 1 MW) PV system has potential to avoid additional 65.1 and 22.6 tonnes of CO2 equivalent and production of 158987.13 and 55,120.1 kW h compared with a same size PV system with horizontal surface and 33.6 tilt angle (equivalent to location's latitude), respectively. PV system orientation angles accuracy has the potential to avoid tonnes of GHG emissions without any investment, operation and maintenance costs.

Field tests and real-world exhaust gas emissions of a pure rapeseed oil-fuelled harvester in forestry: Testing a solution for combined water, soil, and climate protection

Using pure rapeseed oil fuel (R100) in forest machinery could be a measure that contributes to climate, water, and soil protection in forestry. However, forest machinery that is compatible with R100 is not currently available. The target of this research was to operate forest machinery with R100 in a field-test, to collect and evaluate the operational and real-world emission behaviour and to assess the environmental impact. Therefore, a modern forest harvester was modified to operate with R100 and was monitored from August 2017 until December 2018, under Bavarian working conditions. The behaviour during 2100 h of operation was mainly evaluated using information on productivity and operating fluid consumption compared to diesel fuel operation before the modifications were made. Compared to diesel fuel operation, no significant differences in the productivity of the harvester and the energy efficiency of the engine could be detected. With the fuel tempering system installed, the engine could be started at an ambient temperature as low as −20 °C. The results of the engine oil analysis and technical engine inspection after the field test indicate a failure-free operation of the engine and exhaust gas after-treatment system. Furthermore, a functional diagnosis of the harvester indicates that all of the additionally installed components were functioning and the engine, as well as the exhaust gas after-treatment system, were in an appropriate condition. The real driving emissions of nitrogen oxides, hydrocarbons, and carbon monoxide were measured at the beginning of and close to the end of the field test and compared to that of the harvester operating with diesel fuel. Statistical analysis showed no significant influence of the fuel type or the operation time with R100 on the emission behaviour. The emission results were well below the legal requirements for engine test stand measurements. Within the lifetime of the harvester it can be estimated that a turnover of 350,000 L of diesel fuel and 700 to 1050 tonnes of greenhouse gas emissions can be avoided. For the first time, the results indicate that it is technically possible to operate a modern forest harvester with R100 (even during hard winter conditions), and this is in compliance with emission requirements and can contribute to climate, soil, and water protection.

Lanxess exiting chrome mine

Lanxess has agreed to sell its 74% ownership stake in a chrome ore mine in Rustenburg, South Africa, operated by 500 staff and 1,000 contractors, to South African chrome ores supplier Clover Alloys for an undisclosed sum. Lanxess expects to close the deal by the end of 2020. It sold a chrome chemicals unit to Brother Enterprises in August. Separately, Lanxess aims to eliminate 3.2 million metric tons of greenhouse gas emissions to become climate neutral by 2040.

An evaluation of the potential of waste to energy technologies for residual solid waste in New South Wales, Australia

The state of New South Wales (NSW) accommodates the largest population in Australia and is responsible for more than one-third of all waste generated in the country. An effective and economical waste management can be achieved by using waste to energy (WtE) technologies to manage residual wastes and produce energy. The aim of this study was to investigate the potential of the WtE technologies for energy recovery and greenhouse gas (GHG) emission reduction in NSW. In this study, major streams of wastes (municipal solid waste, commercial & industrial waste, construction & demolition waste) in NSW were classified into combustible, non-combustible and food organic waste. Four waste management scenarios using different combinations of WtE technologies, such as landfilling with energy recovery, incineration and anaerobic digestion (AD) were applied to evaluate electricity generation and GHG emission potentials from all these wastes. The results indicated that by employing a combination of incineration and AD for combustible and food parts of residual waste in NSW about 4165 GWh of electricity could be generated annually, which is equivalent to about 5.9% of the total electricity generation in NSW. This conversion of WtE leads to a reduction of about 1.7 million tonnes of GHG emissions annually. In this way, about 3 million tonnes of residual waste could be diverted from landfills in NSW annually which would offer approximately 50% reduction in landfilled waste by weight. Findings of the study showed that employing incineration and AD technologies could exploit a considerable amount of energy from residual waste and mitigate GHG emissions. Furthermore, employing efficient WtE technologies would divert organic waste out of landfills, avoiding emissions from landfills and will contribute to a greater share of renewable energy production, thereby reducing emissions from fossil fuel power plants.

ENVIRONMENTAL CONSUMPTION TAXES ON ANIMAL FOOD PRODUCTS TO MITIGATE GREENHOUSE GAS EMISSIONS FROM THE EUROPEAN UNION

Livestock cause around 10% of total greenhouse gas (GHG) emissions in the European Union. Despite the large quantities, no economic policy is in place to reduce emissions from the sector. In this paper, we introduce consumption taxes on animal products in the European Union to reduce GHG emissions. Impacts are simulated using the CAPRI model, which was created to analyze the impacts of agricultural policy reforms within the EU. Tax levels of 16, 60 and 290 Euro per ton of GHG emissions are used in the estimations. Our results show that consumption taxes have small mitigation effects, up to 4.9% of total agricultural emissions from the EU-27, mainly due to inelastic demand. The main source of reductions is beef and France is the country where most reductions would take place, given high levels of production and consumption in the country, combined with a large demand elasticity of beef.

GHG mitigation potential of solar industrial process heating in producing cotton based textiles in India

A preliminary attempt to estimate the potential of solar process heating in producing cotton based textiles in India as well as the amount of greenhouse gases likely to be mitigated consequently has been made. To begin with, all the processes involved in the production of cotton based textiles (yarn and cloth) that require thermal energy have been identified. Also an assessment of availability of solar radiation as well as the ambient conditions at various locations with clusters of cotton based textile units in the country has been made. Subsequently, the solar collector area required for meeting the process heating demand has been estimated. Further, corresponding useful thermal energy delivery of solar industrial process heating systems at identified locations has been estimated. The process heating potential in term of useful thermal energy requirements in cotton based textile production is estimated at 191 PJ annually. The estimated values of annual solar fractions for the identified locations with clusters of cotton based textile units range between 0.22 and 0.32 for systems without storage and in between 0.20 and 0.60 for SIPH system having provision of thermal storage for collection of energy that would otherwise be dumped. Solar process heating in cotton based textile industry in India have a potential to mitigate 2457–7648 thousand tonnes of greenhouse gas emissions annually depending on the location and the provision of a storage component or otherwise.