CO2 Equivalent Research Articles

Technology Focus: EOR Operations (November 2024)

International agreements and national policies on environmental sustainability are changing the outlook for enhanced oil recovery (EOR) globally. These changes are highlighted by both monetary and intellectual commitments by oil companies around the world. Saudi Aramco has pledged $1.5 billion toward sustainable technology. In practice, members of Aramco’s EXPEC Advanced Research Center have collaborated with King Fahd University of Petroleum and Minerals to develop sustainable surfactants for use in high-temperature, high-pressure, and high-salinity carbonate reservoirs. They used no or only green solvents to produce soluble, stable surfactants with the potential for biodegradability. In Colombia, Ecopetrol is committed to reducing CO2 emission by 25% by 2030. As part of its efforts, it has been optimizing polymer injection in Chichimene, a heavy-oil field. By estimating life cycle greenhouse-gas emissions and energy consumption, it was able to show that polymer injection and its associated carbon intensity reduction could prevent the emission of 3,200 tons CO2 equivalent. To comply with the UK’s North Sea Transition Deal, which mandates a 50% reduction in offshore oil and gas emissions by 2030, Ithaca Energy and Energy Research Norway is using life-cycle assessment to guide more efficient heavy-oil recovery. By using low-dose polymer injection, instead of alternatives such as thermal EOR, it was able to increase exergy while also reducing CO2 emissions by 35%. In these studies, we already see the effect of the energy transition as companies turn away from traditionally effective but environmentally burdensome EOR methods such as steam injection and new polymers that show equal, if not greater, effectiveness with a reduced environmental cost. As we move forward with further regulation and innovation, it will be interesting to see how emerging technological developments in polymers, nanofluids, and even artificial intelligence can help producers meet both the economic and environmental criteria to maintain profitable fields. Recommended additional reading at OnePetro: www.onepetro.org. SPE 218653 Coinjection EOR Technology Increases Recovery and Reduces Greenhouse-Gas Emissions by G. Wasylchuk, GERI SPE 218690 Steam Generation Using Renewables Energy—An Integrated Approach for Enhanced Oil Recovery Applications by Mustafa Al Ajmi, Petroleum Development Oman, et al. SPE 218962 Reaching a Million Barrels in an Abu Dhabi Field by Focusing on Operations Efficiency by Masud J. Akhtar, Abu Dhabi National Oil Company, et al.

Investigation on the methane emissions from permeation of urban gas polyethylene pipes under the background of hydrogen-mixed natural gas transportation

Methane, a more potent greenhouse gas than carbon dioxide, aggravates the greenhouse effect of ecological environment through its emissions. When transporting hydrogen-mixed natural gas through urban polyethylene pipes, methane will be emitted due to the permeation characteristic of polyethylene pipe material. Therefore, it is crucial to pay attention to the methane emissions from permeation of polyethylene pipes for protecting the environment and climate. In this paper, the solubility and diffusion coefficients of methane within hydrogen-mixed natural gas in polyethylene pipe materials are calculated through the Monte Carlo method and molecular dynamics simulation to determine the permeation coefficient of methane. Simultaneously, the methane emissions and equivalent carbon dioxide emissions of the hydrogen-mixed natural gas in polyethylene pipes are investigated. Results indicate the methane solubility coefficient decreases with increasing temperature and hydrogen mixing ratio. The methane diffusion and permeation coefficients increase with the rising temperature and pressure, and decreasing hydrogen mixing ratio. The pressure exerts minor influence while the temperature and hydrogen mixing ratio have more significant impact. That is, the lower the temperature and the higher the hydrogen mixing ratio, the less methane emissions caused by permeation. Therefore, the effective reduction of methane emissions can be achieved by adding the insulation layer to mitigate the impact of high temperature and increasing the hydrogen mixing ratio. For example, for the polyethylene pipe with the operating pressure of 4 bar and the size specification of SDR11, when the temperature drops from 300 K to 260 K, the methane emissions of hydrogen-mixed natural gas with hydrogen mixing ratios of 0 vol%, 20 vol%, 50 vol% and 80 vol% will be drastically reduced by 73.3%, 74.4%, 77.2% and 78.5% respectively, and when 20 vol%∼80 vol% hydrogen are mixed in the natural gas at 260 K, 300 K and 310 K, the methane emissions will be effectively reduced by 26.7%∼85.6%, 23.3%∼82.1% and 23.9%∼82.4% respectively. The findings of this study can serve as guidance for reducing the methane emissions from permeation of polyethylene pipes transporting hydrogen-mixed natural gas.

Dynamic performance analysis and optimization research on solar dual-stage evaporation multigeneration system

A novel solar dual-stage evaporation multigeneration system is proposed, with analysis on the impact of the parabolic trough collector area (APTC) and the volume of the heat storage tank (VHST) on performance under dynamic conditions. The particle swarm optimization- genetic algorithm and the minimum path method optimized the system’s overall performance. Results show that reducing APTC and increasing VHST can enhance energy performance within a certain range, but beyond specific thresholds, changes in APTC and VHST no longer affect it. As APTC and VHST increase, economic performance initially improves but then declines. The particle swarm optimization- genetic algorithm increased optimization efficiency and avoided local optima. When using the minimum path method, the dimensionless cumulative error was 0.63, balancing thermal and economic performance. Using toluene as the working fluid, the optimized system achieved thermal and exergy efficiencies of 56.06 % and 9.15 %, respectively, with a net present value of 58.12 M$, a payback period of 5.23 years, and an equivalent CO2 reduction of 24.8 kt, outperforming the solar organic Rankine cycle system in energy efficiency, economic performance, and carbon reduction potential. The solar dual-stage evaporation multigeneration system achieved the best performance with toluene as the working fluid, while heptane provided longer running time and greater carbon reduction potential. At low rated power generation, performance differences between toluene and heptane were minimal, while as the rated power generation increased, toluene showed significant advantages in thermal and economic performance.

Assessing the Environmental Impact of Municipal Waste on Energy Incineration Technology for Power Generation Using Life Cycle Assessment Methodology

The life cycle assessment methodology is a comprehensive environmental impact evaluation approach rooted in the “cradle-to-grave” concept. This study takes a municipal solid waste incineration power plant in central China as an example to comprehensively explore the potential ecological and environmental impacts of municipal solid waste incineration power generation through life cycle assessment methods. Burning one ton of waste can recover 7342 joules of thermal energy. Compared with traditional landfill, incineration can reduce greenhouse gas emissions by about 30%, with a potential global warming impact of −0.69 kg of carbon dioxide equivalent. Amongst environmental impacts, land, freshwater, and marine ecosystems possess the greatest potential toxicity, followed by the harmful effects on human health and the influence of ozone-producing photochemical pollution. Lastly, there comes terrestrial acidification, whereas other types of effects can be relatively disregarded in comparison. In the process of waste incineration power generation, the potential impacts of global warming, ionizing radiation, and fossil resource scarcity are less than zero, indicating that this is an environmentally friendly process. In response to the above-mentioned environmental impacts, it is necessary to pay attention to improving incineration efficiency, optimizing leachate treatment, reducing coal use, and controlling acidic gas emissions in the process of urban solid waste incineration power generation. This research offers insights into advancing environmentally sustainable technologies for utilizing waste as an energy resource.

Greenhouse Gas Emissions from Cold Chains in Agrifood Systems

Cold chains are essential components of agrifood system activities, from storage and food processing to transport, retail, and household consumption. We devise a comprehensive methodology, validated against established data, to estimate both direct (due to refrigerant use) and indirect (from energy use) greenhouse gas emissions from agrifood system cold chains, expanding previous approaches, which had focused on direct emissions only. We found that in 2022, world-total indirect emissions from energy use in cold chains were more than twice the direct component from refrigerants. This resulted in a new estimate of world-total GHG emissions from agrifood system cold chains of 1.32 Gt CO2eq in 2022, with significant growth over the past two decades (0.52 Gt CO2eq in 2000). Household consumption and food processing represented the most significant contributors to agrifood system emissions from cold chains, together representing in 2022 three-fourths of the total. These results align well with known global patterns of energy use in the refrigeration sector and highlight the importance of targeting cold chains within agrifood system with GHG emission mitigation actions.

Carbon Emission Reduction Associated With Utilisation Of Telehealth In Outpatient Clinics In An Australian Quaternary Health Service

Objective: To assess the impact of implementing telehealth in outpatient clinics on the carbon emissions associated with the delivery of health care. Design & Setting: Retrospective cohort study in large metropolitan quaternary referral health service from January 2021- December 2022. Participants: All patients who attended an outpatient clinic appointment during the study period, either in-person, via telehealth or via telephone. Main outcome measures: The estimation of carbon emissions in tonnes (t) of CO2-equivalent (CO2-e) associated with in-person and telehealth appointments based on emissions associated with travel, telehealth platform usage and N95 mask usage. Results: There were 571,121 outpatient clinic appointments during the study period. Of the appointments, 251,458 (44%) were conducted remotely, resulting in an estimated reduction in 3,629t of CO2-e emissions in the two-year period. Telehealth consultations in this time contributed 4.5t of CO2-equivalent emissions. The total emission usage of telehealth clinic was only 0.12% of emissions generated from face-to-face clinic appointments. Conclusion: Telehealth offers the opportunity of substantial carbon emissions reduction within the healthcare sector, while also providing cost and time-saving benefits for healthcare services and patients. Limitations include generalisation of transportation modes and the retrospective nature of the data collection.

Circular Regenerative Agricultural Practices in Africa: Techniques and Their Potential for Soil Restoration and Sustainable Food Production

The conventional linear system of global food production and consumption is unsustainable as it is responsible for a substantial share of greenhouse gas emissions, biodiversity declines due land use change, agricultural water stress due resource-intensive water consumption patterns and land degradation. During the last decade (1994–2014), for example, the greenhouse emissions from agriculture in Africa were reported to increase at an average annual rate of between 2.9% and 3.1%, equivalent to 0.44 Gt and 0.54 Gt CO2 per annum, respectively. Between 2000 and 2020, the greenhouse gas emissions from agrifood systems were shown to decrease in all major regions of the world, except in Africa and Asia, where they grew by 35 and 20 percent, respectively. With most of the circular agricultural practices still central to food production in the developing African countries, the continent can spearhead a global return to circular agriculture. Using a descriptive review approach, we explore the literature to examine the extent to which African agriculture is deploying these practices, the potential areas for improvement and lessons for the world in embracing sustainable food production. We underscore that the farming communities in sub-Saharan Africa have, for decades, been using some of the most effective circular agricultural principles and practices in agricultural production. We further show that practices and strategies akin to sustainable agricultural production include agronomic practices, smart irrigation options, renewable energy harvesting and waste-to-fertilizer technologies. All of these technologies, which are central to sustainable agricultural production, are not new to Africa, although they may require packaging and advocacy to reach a wider community in sub-Saharan Africa.

Hyperbaric oxygen rapidly produces intracellular bioenergetics dysfunction in human pulmonary cells

Hyperoxic exposure lasting days alters mitochondrial bioenergetic and dynamic functions in pulmonary cells as indices of oxygen toxicity. The aim of this study was to examine effects of short duration hyperbaric and hyperoxic exposures to induce oxygen toxicity similarly. Cultured human lung microvascular endothelial cells, human pulmonary artery endothelial cells and A549 cells were exposed to hyperoxia (∼5 % CO2 equivalent, balance O2) under hyperbaric conditions (4.8 ATA) for 1 and 4 h. Measures of mitochondrial dynamics, inner membrane potential, mitochondrial respiration, the intracellular distribution of bioenergetic capacity and respiration complex protein levels were then quantified. Exposures resulted in altered mitochondrial motility, presence of inhomogeneities in respiration parameters, loss of inner membrane potential, and changes in intracellular partitioning of ATP-linked respiration. Changes in the levels of respiration complex protein levels were also found. The combination of hyperoxic exposure with hyperbaric conditions rapidly produced changes in mitochondrial dynamics and bioenergetics in pulmonary cells. These changes are consistent with the onset of pulmonary oxygen toxicity previously known to result from long duration exposure to hyperoxia alone. These findings suggest health caution is warranted in environmental settings in which both hyperoxic and hyperbaric conditions are present. The synergism of hyperoxia and hyperbaria for rapid induction of oxygen toxicity in cellular models has utility for the study of mechanistic determinants of oxygen toxicity, testing of putative therapeutics, and associated investigations of mitochondrial dysfunction.

Global warming impacts of carbon dioxide, methane, and albedo in an island forest nature reserve

Abstract Forest ecosystems influence climate by sequestering carbon from the atmosphere and by altering the surface energy balance. However, the combined global warming impacts (GWIs), contribution from carbon dioxide (CO2) fluxes, methane (CH4) fluxes, and albedo changes (Δα) remain poorly understood. Here, we reported the combined GWIs of CO2, CH4, and albedo with eddy covariance (EC) measurements during 2020–2022 in a subtropical island forest located in the Nanji Islands National Marine Protected Area in Southern China. We suggested that the island forest acted as a significant carbon sink, with annual CO2 and CH4 fluxes of −548.6 ± 11.1 and −5.67 ± 1.1 g C m−2 yr−1, respectively, while the daily albedo varied within the range of 0.03–0.15. By converting the radiative forcing induced by CH4 and albedo change in the forest to CO2 equivalents, we analyzed the three contributors to the combined GWI. The annual averages GWI of CO2 uptake, CH4 uptake, and Δα were −2 011.6 ± 40.6, -211.3 ± 1.1, and 0.03 ± 4.5 g CO2-eq m−2 yr−1, respectively, with a mean combined GWI of −2 223 ± 40.8 g CO2-eq m−2 yr−1. During 2020–2022, the contributions of CO2 uptake, CH4 uptake, and Δα to the combined GWI were 89.7% to 91.4%, 9.4% to 9.6% and -1.0 to 0.9%, respectively. Nanji island forest had a strong positive effect on climate change mitigation, with CO2 and CH4 uptake greatly enhancing its cooling benefits. Using Pearson correlation and path analysis, we found photosynthetically active radiation, precipitation, soil water content were the primary factors controlling the GWI dynamics, mainly driving the changes in CO2 fluxes. This study provided novel insights into the establishment of the overall evaluation framework for ecosystem-scale GWIs of CO2 and CH4 fluxes, and albedo based on long-term EC measurements in an island forest.

The carbon crater: Comparing anthropogenic greenhouse gas emissions to historical planetary events

Equilibrium climate sensitivity modeling relies heavily on paleoclimate records that were affected by meteorite impacts and volcanic explosions. This paper conducts a thought experiment by re-assembling known data and theories to shed new light on anthropogenic carbon waste. Anthropogenic activity, meteorite impacts and volcanic explosions all extract material from the Earth’s crust and deposit it in the atmosphere. This thought experiment tests if the mass of anthropogenic greenhouse gas emissions from 1851 to 2021 is comparable to the mass of atmospheric emissions from historical planetary events. Approximately 3.60 trillion tons of anthropogenic carbon dioxide equivalents are converted into volume and then transformed into the shape of a meteorite impact structure named the “Carbon Crater.” The 35 km crater (bounded by 34%–68% confidence intervals of 25–45 km) would rank 23rd on the list of known impact structures. The 2.6 km projectile required to create the Crater would be a 10 on the 1–10 Torino hazard scale described as “. . .capable of causing global climatic catastrophe. . .” The estimated re-occurrence interval for a projectile of this size is 5.3 million years. An interval of this time in Earth’s recent history predates homo sapiens. The Crater’s volume is exponentially larger than the 1883 eruption of Krakatoa and ranks as an 8 (“mega-colossal”) on the 0–8 Volcanic Explosivity Index. The thought experiment indicates that the Carbon Crater’s scale is comparable with large historical biospheric events. These results likely confer few direct implications for the study of the paleoclimate in climate modeling but might change conceptual understandings of atmospheric human waste. Additional empirical research is required to understand the potential impact of the Carbon Crater on conceptual change.

From biogas to biomethane: Comparison of sustainable scenarios for upgrading plant location based on greenhouse gas emissions and cost assessments

Addressing the global energy crisis and achieving sustainable development goals (SDGs) necessitates shifting towards renewable energy sources, with biomethane emerging as a viable alternative. This study evaluated three scenarios for biomethane production from biogas: localized upgrading for biofuel use, district upgrading for biofuel use, and district upgrading with grid injection. By utilizing economic assessments and spatial and network analysis, the optimal locations for upgrading plants were identified to minimize transportation costs and GHG emissions (CO2 equivalents). Results indicate that Scenario 1 achieves the lowest emissions and operating costs (41 MEUR), while Scenarios 2 and 3, despite higher initial investments (152–173 MEUR), offer significant economies of scale (1187–1321 MEUR) and substantial annual production capacities (8.8 × 106 Sm³ of biomethane). Comparative and sensitivity analyses show renewable energy sources reduce GHG emissions by up to 83.7% and significantly lower operating costs. This research underscores the critical role of strategic planning and renewable energy integration in optimizing the biomethane value chain for environmental sustainability and economic viability while also emphasizing the need for further research to refine these findings.

Environmental impact of intravenous versus oral administration materials for acetaminophen and ketoprofen in a French university hospital: an eco-audit study using a life cycle analysis.

The combination of acetaminophen with a nonsteroidal anti-inflammatory drug is the cornerstone of perioperative multimodal analgesia. These drugs can be administered intravenously or orally as premedication, consistent with the concept of pre-emptive and preventive analgesia. We aimed to assess the environmental impact of their intravenous and oral administration in a French university hospital. We carried out a life cycle assessment to determine the amount of greenhouse gas emissions and depletion of water resources resulting from the oral vs intravenous administration of 1g acetaminophen and 50mg ketoprofen. We assessed two schemes of intravenous administration, depending on the use of the same or a different infusion set for each drug. At our centre, the intravenous administration of both drugs was associated with the emission of 444-556g CO2 equivalent (CO2e), and with 9.8-12.2 L of water waste. The oral administration of both drugs generated 8.36g of CO2e emissions and consumed 1.16 L of water. At a national level, the switch from intravenous to oral premedication of the drugs could avoid the emission of 2,900-3,700 tons of CO2e and the waste of 58,000-74,000 m3 of water each year. This eco-audit indicates that oral administration of acetaminophen and ketoprofen results in significantly lower carbon emissions and water consumption than intravenous administration. These findings highlight the importance of using the oral route for most patients, limiting intravenous administration for those with specific needs because of higher environmental impact and cost.

Lifecycle Assessment Analysis of Recycled Concrete Aggregate Incorporating Fly Ash and Hemp

The critical roles of recycling are increasing depending on depleted natural resources and its devastating consequences. Concrete has been one of the most used building materials for many years to response the basic need of human beings for shelter. The studies on the recycling of concrete are crucial to minimize negative effects of both the high amount of energy consumed during the production phase and the limited recycling opportunities after destruction. Considering the amount of construction and demolition waste (CDW) after the February 6, 2023 earthquakes in Türkiye, it is clear that recycling concrete (RC) may make a positive contribution to environmental sustainability and natural resources usage. In addition, as a result of the ongoing urban transformation projects throughout Türkiye, especially in Istanbul, there is a need to recycle CDW, the majority of which consists of concrete. This paper examines the equivalent CO2 emissions of recycled concrete aggregate (RCA) incorporation of various proportion fly ash and hemp based on previous studies by applying the Excel-based GreenConcrete LCA software developed at the University of California Berkeley Campus (UC Berkeley). As a result of the investigations, it is seen that the use of RCA, which is generated in large quantities both as a result of earthquakes and urban transformation projects, reflects positively on the environmental impacts in the LCA analysis. In addition, the use of concrete mixtures that contribute to the recycling of wastes such as fly ash and hemp used as admixtures contributes to reducing the environmental damage of these wastes and improving the concrete content.

A-198 ESG Opportunities Harnessed During Pathology Transformation

Abstract Background Synnovis (a SYNLAB business) is in the process of delivering one of the largest Pathology transformation programmes in the UK, moving to a seven-site hub and spoke model from 89 laboratories over a dispersed geography. This remit also presented an opportunity for SYNLAB to deliver on its Environmental Social Governance (ESG) ambitions, by embedding ESG principles into programme delivery. There are several examples within each ESG pillar that demonstrate the benefits to be leveraged during transformation. Methods SYNLAB’s vision is to deliver sustainable diagnostic services. The integration of ESG into both the decision-making process and transformation structure ties these ambitions into programme benefits realisation. As well as setting performance level targets, the delivery of ESG benefits provide measures of success throughout the transformation journey, motivating stakeholders and building confidence along the way. Results Environment: The efficient use of space and LEAN principle design has consolidated the fragmented laboratory services spanning 15,000m2 into a bespoke, cutting-edge Pathology Hub with 6 spokes (hospital based services). The new hub building was designed to achieve BREEAM Excellent standards which measure performance against criteria such as energy management and efficiency, sustainable design and materials. The hub’s energy is from renewable-backed sources, and we will achieve a 47% reduction in CO2 equivalent (CO2e) emissions by unifying a significant proportion of its legacy footprint in this way. Further energy savings will be achieved through the associated analytical equipment consolidation, including a decrease from 50 to 14 microtomes, a decrease of 29 to 15 ventilated benches and a reduction of over 200 fridges and freezers across the service. In addition, substantial CO2e emissions savings are also being delivered by moving to a greener logistics provider, utilising electric vehicles and bikes. 2023 saw such emissions fall by 60% across Synnovis, helping to keep London’s air cleaner. Social: The transformation programme enables the hand back of over 6,000m2 of real estate to Synnovis’ NHS partners to use for critical hospital services (the equivalent of over 150 operating theatres). Governance Both internally and externally, ESG is integrated within the Synnovis organisational culture. For example, internally it applies mandatory sustainability metrics to its solution selection processes. These influenced the selection of Abbott’s Indexor solution to support the transformation of Blood Sciences, delivering a saving of over 2.8 million plastic sample bags every year. Externally, SYNLAB works with its partners to manage this substantial and complex transformation programme. Risk management is assured through transparency, securing confidence in the good use of public funds, ensuring responsiveness to customer and partner feedback, and ensuring accountability for and the delivery of targeted healthcare outcomes. Conclusions The integration of SYNLAB’s ESG strategy within the transformation programme is delivering tangible benefits across all ESG pillars. It has highlighted that in addition to the core outcome of services transformation, there are many more opportunities that can be realised as a result of making ESG an integral part of the pathology transformation programme.

Climate impact of early-stage NSCLC treatment: A comparison between radiotherapy and surgery using Life Cycle Assessment.

Healthcare systems contribute significantly to CO2 emissions, accounting for 7 % of emissions in the Netherlands. Understanding the environmental footprint of medical treatments can help identify opportunities for reducing climate impact. We evaluated the climate impact of stereotactic body radiotherapy (SBRT) and Video-Assisted Thoracic Surgery VATS) when treating T1-2N0M0 Non-Small Cell Lung Cancer (NSCLC). We used life cycle assessment(LCA) to evaluate climate impact in emissions of kilograms of CO2 equivalent. Care trajectories were inventoried for both VATS and SBRT with the same entry and end point of the paths. We analyzed a range of factors contributing to climate impact, such as patient and staff travel, energy consumption, disposables and medication using direct measurements: questionnaires and waste audits, or retrospective record analysis. As is common in LCA, existing infrastructure was excluded from the analysis. Reductions that can be influenced by individual departments were also modeled. Using LCA we calculated the impact of all categorized contributions for two treatments for NSCLC. In total, VATS generates approximately 547 kg CO2 equivalent (CO2e), whereas SBRT generates 172 kg CO2e per treatment. For SBRT, the largest contributors were energy use in the hospital (52 % of total), of which 22 % is from the linac, and patient travel (23 %). For VATS, major contributions were hospital energy use (52 %) and disposables (23 %). Climate impact could be reduced by 20 % (SBRT) by hypofractionation, reduced linac idle time and patient travel impact, and 13 % (VATS) with fast track recovery and a reduction of disposables. When treating T1-2N0M0 NSCLC, surgery has a larger climate impact than SBRT. For both modalities reductions are possible.

Impact of COVID-19 led transition of work culture and travel to work patterns on society and environment in Delhi

Globally, COVID-19 has led to changes in daily lifestyle and travel behavior. There was a shift from in-person physical jobs to work-from-home culture, even for those jobs that required in-person presence at the job location. However, this was not true for everyone, and a majority continued to travel to work. The limited capacity of public transport services and the fear of exposure to the virus restrained people from practicing their conventional mobility choices. We explore the impact of COVID-19 on the nature of jobs and related changes in work travel patterns by population groups for Delhi using in-person surveys conducted during 2021 in six localities of Delhi. We also estimated the short- and long-term impacts of altered behavior on expenditures and equivalent CO2 emissions.As per the analysis, lower income groups, having no vehicles, with lesser qualifications, and employed as daily wagers, had limited capacity to change to work-from-home during COVID-19. We observed an increased dependency on personal motorized vehicles, leading to increased expenditures and reduced affordability. Adopting work-from-home during COVID-19 helped reduce equivalent CO2 emissions per working member by 39%. However, as the work at the site resumes, the emissions are expected to increase. The study shows that COVID-19 led to short-term benefits, but in the long term, the externalities will likely increase. Working from home during the pandemic provides short-term benefits; the social benefits are not equally distributed, and the transport emissions shall increase in the long term.

Development of a sustainable stabilized macadam road base using steel slag as supplementary cementitious material

As the main waste product of iron and steel industry, steel slag possesses considerable cementitious activity, making it a promising alternative to cement in Cement Stabilized Macadam (CSM). However, CSM was inevitably exposed to groundwater and rainwater when served as the pavement base course, leading to concerns over poor early strength and potential pollutant leakage, which are the main factors that may hinder the widespread utilization of steel slag in CSM base. To address these issues, this study investigated the feasibility of using steel slag powder to produce CSM. Steel Slag Powder-Cement Stabilized Macadam (SSCSM) samples were prepared and the hydration products, microstructure, mechanical properties, water damage resistance and heavy metal ions leaching behavior were investigated. The results show that the nucleation effect of steel slag powder accelerates the early hydration, but the C-S-H produced by hydration is not sufficient to form a stable hydration product network, so the microstructure of SSCSM is looser than that of CSM. The addition of steel slag powder improved the shrinkage performance of SSCSM, and the mechanical properties and heavy metal ion leaching concentration of SSCSM meet the engineering application requirements when the steel slag powder replacement level does not exceed 30 %. It was also found that the addition of steel slag powder promoted the development of pores in SSCSM samples after dry-wet cycles, resulting in the reduction of water damage resistance. Compared with conventional CSM, the use of SSCSM can not only reduce 4 % of raw material cost and 23.5 % of equivalent CO2 emission, but also mitigate the heavy metal ions leaching risk associated with steel slag, making it an effective and sustainable solution for steel slag recycling.

Numerical simulation of carbon dioxide flooding in fractured reservoirs using generic projection-based embedded discrete fracture model

This paper, for the first time, integrates the generic projection-based embedded discrete fracture model (pEDFM) with the commercial reservoir simulator ECLIPSE for carbon dioxide (CO2) flooding in fractured reservoirs. The integrated method first obtains inter-grid connections and corresponding transmissibilities within the reservoir model based on the generic pEDFM. It then constructs an equivalent CO2 flooding ECLIPSE model to the original pEDFM reservoir model, thereby calculating the global equations of the compositional flow model to obtain distributions of pressure, saturation, component concentrations, and well performance data. We implemented three numerical examples to verify that the proposed method can achieve significantly higher computational accuracy compared to the widely used embedded discrete fracture model in both high and low permeability fracture scenarios, while also avoiding the difficulties associated with generating matching grids for complex fracture networks. Furthermore, the proposed integrated method uses the solver within ECLIPSE to solve the global equations, thus avoiding the high cost of developing a robust nonlinear solver for complex compositional model of CO2 flooding. This demonstrates the practicality of the method and its significant potential for subsequent application to various reservoir models.

Lure Monitoring for Mediterranean Fruit Fly Traps Using Air Quality Sensors.

Effective pest population monitoring is crucial in precision agriculture, which integrates various technologies and data analysis techniques for enhanced decision-making. This study introduces a novel approach for monitoring lures in traps targeting the Mediterranean fruit fly, utilizing air quality sensors to detect total volatile organic compounds (TVOC) and equivalent carbon dioxide (eCO2). Our results indicate that air quality sensors, specifically the SGP30 and ENS160 models, can reliably detect the presence of lures, reducing the need for frequent physical trap inspections and associated maintenance costs. The ENS160 sensor demonstrated superior performance, with stable detection capabilities at a predefined distance from the lure, suggesting its potential for integration into smart trap designs. This is the first study to apply TVOC and eCO2 sensors in this context, paving the way for more efficient and cost-effective pest monitoring solutions in smart agriculture environments.

Conservation value and carbon sequestration potential of urban green spaces in a growing city: Case of the city of Bouaflé

Faced with the effects of climate change, green spaces are very determining in the provision of ecosystem services, particularly in carbon sequestration. This is why, from a perspective of sustainable management of these high-value spaces, this study was carried out. Surface and itinerant survey methods were combined to collect floristic data. At the end of the inventories, 99 species distributed between 33 families and 75 genera including 24 species with special status were recorded in eight (08) types of development. The total biomass of all the species inventoried at Bouaflé is 4385.78 t, corresponding to a carbon rate of 2192.91 t for a CO2 equivalent of 8047.99 t. The economic value of the rate of CO2 sequestered by all types of development varies from 24143.97 Euros, or 15814274 FCFA according to the CDM carbon price to 112671.86 Euros, or 73800068 FCFA according to the REDD+ carbon price. Social and educational establishments recorded the highest biomass (1841.88 t) while the lowest biomass (5.53 t) was estimated in sports equipment. The average biomass estimated in all types of development is of the order of 232.02±185.64 t/ha, which corresponds to a carbon rate of 116.01±92.82 t/ha and an equivalent CO2 of 425.76±340.65 t/ha. Considering each type of development, the average value of biomass varies between 24.83 t/ha in sports facilities and 468.79 t/ha in cemeteries.