Greater Global Warming Potential Research Articles

Circularity of bulky waste: a case study of krško in Slovenia

Since waste is recognized as an excellent alternative for fresh raw materials substitution, the economy and society are striving for efficiently utilization of different waste fractions. Also bulky waste. To increase and accelerate the utilization of bulky waste the Circular Process Model (CPM) has been designed and applied in case study of Krško, Slovenia. The Material Flow Analysis (MFA) method was used to determine the quality and quantity of bulky waste which can be used at the highest levels of the waste management: 7 % of material was reused for the same or another purpose, 59 %recycled and 34 % energy generated. Besides, the Life Cycle Assessment (LCA) was applied to assess the different processes investigated. The LCA showed recovery has the greatest Global Warming Potential (GWP) impact among almost all of the processes considered. Using both MFA and LCA demonstrated valuing quality over quantity in bulky waste management can drastically reduce the effects of GWP.

Effects of straw mulching and nitrogen application rates on crop yields, fertilizer use efficiency, and greenhouse gas emissions of summer maize

Although straw mulching and nitrogen applications are extensively practiced in the agriculture sector, large uncertainties remain about their impacts on crop yields and especially the environment. The responses of summer maize yields, fertilizer use efficiency, and greenhouse gas (GHG) emissions including carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) in the North China Plain (NCP) to two straw management practices (S0: no straw and S1: straw mulching) and two nitrogen application rates (N1: 180 and N2: 210 kg N ha−1) were investigated in field tests in 2018, 2019, and 2020. The highest yields and partial factor productivity (PFP) were obtained by S1N1, followed by S1N2, S0N1, and S0N2. S1N2 had the highest CO2 emissions and greatest CH4 uptake, S0N1 had the lowest CO2 emissions, and S0N2 had the smallest CH4 uptake. The highest and lowest N2O emissions were found in S0N1 and S1N1, respectively. The S1N2 treatment, an extensively applied practice, had the greatest global warming potential (GWP), which was 70.3 % larger than S1N1 and two times more than S0N1 and S0N2. The largest GHG emission intensity (GHGI) of 19.4 was found in the S1N2 treatment, while the other three treatments, S0N1, S0N2, and S1N1, had a GHGI of 10.1, 10.7, and 10.7, respectively according to three tested results. In conclusion, S1N1 treatment achieved a better trade-off between crop yields and GHG emissions of summer maize in NCP.

Methane emissions along biomethane and biogas supply chains are underestimated

Methane emissions along biomethane and biogas supply chains are underestimated

Comparison of vegetable production, resource-use efficiency and environmental performance of high-technology and conventional farming systems for urban agriculture in the tropical city of Singapore

Urban farming can improve cities’ food security and resilience, but the performance of different farming systems with respect to land and investment constraints has not been systematically investigated. Here, we compared conventional soil-based farming, vertical farming with natural lighting (Vnat), and indoor vertical farming. This study aimed to compare (1) the dynamic production of leafy vegetables over time given the same amount of investment and land constraints, (2) the associated water and energy use, and (3) the global warming potential (GWP) of the urban farming sector if each of the three farming systems was solely used in the tropical city-state of Singapore. A system dynamics (SD) model was constructed to map the potential quantity of leafy vegetables produced, together with the water and energy use of each farming system. The land and monetary investment constraints were set at an additional 0.3% of the total land area of Singapore and an annual investment of SGD 10–20 million (0.001–0.005% of Singapore's annual GDP). Vnat farming was predicted to have the highest production level (110,000 t) and self-sufficiency (76.9% of total demand) by 2050 based on the SD model. This would be >3 times the self-sufficiency level achieved by indoor and soil-based farming systems given the same investment and land constraints. Indoor farming was simulated to use <14% the land area of Vnat while soil-based farming exhausted the additional 0.3% of the land allocated. Indoor farming was also the most energy intensive system, requiring 100 times more than Vnat farming. Comparison of the GHG emission rates showed that indoor farming had the greatest GWP—at 2.51 kg CO2-eq per kg of lettuce produced. Our results suggest that Vnat farming may be the best form of urban farming system to provide large amounts of food in Singapore, considering the production level, the amount of resources used, and the environmental impacts.

Environmental Problem Shifting Analysis of Pollution Control Units in a Coal-Fired Powerplant Based on Multiple Regression and LCA Methodology

Coal-fired power generation leads to serious environmental pollution, such as air and water pollution; thus, pollution control or treatment is necessary. However, end-of-pipe treatments are still indispensable approaches to reducing environmental stress, and focusing on each in turn leads to pollutant-by-pollutant features. The present study applies the LCA method to reveal the total direct and indirect environmental impacts from increasing significant pollution control units for a coal-fired power plant. From the results, it was found that increasing the performance of CCS and FGD units may result in higher overall environmental impacts due to their energy costs. Greater energy requirements result in greater global warming potential, human toxicity, and terrestrial acidification effects. LNB &amp; OFA, SCR, and ESP units did not cause any other significant environmental impacts, while activated carbon used in the ACI unit is an additional source of indirect terrestrial acidification. Water depletion effects must be considered when increasing the use of CCS units. Policy makers can use the data from the present study to establish sustainable directions to resolve environmental problems at the macro-economic scale.

Boreal forest soil CO2 and CH4 fluxes following fire and their responses to experimental warming and drying

Boreal forests store large amounts of organic carbon and are susceptible to climate changes, particularly rising temperature, changed soil water and increased fire frequency. The young post-fire ecosystems might occupy larger proportions of the boreal forests region with the expected increases in fire frequency in the future and change the carbon (C) balance of this region. However, it is unclear how soil C fluxes in the post-fire boreal forest response to the climate changes. Therefore, a two-year field experiment was conducted in a boreal forest to investigate the effects of fire on the soil C (CO2 and CH4) fluxes and the responses of these fluxes to simulated warmer and drier climate conditions. The results showed that the boreal forest recovered form wildfire 7–8 years had higher soil CO2 flux than the mature forest. Furthermore, the treatments of warming, drying and the combination of warming and drying increased growing season cumulative soil CO2 flux in the post-fire forest by 15.8%, 20.4% and 34.2%, respectively. However, the boreal forest soil changed from a weak CH4 source to a weak CH4 sink after fire disturbance. Although CH4 absorption increased by warming and drying treatments, the interaction of warming and drying led to a decrease in soil CH4 uptake. The results indicated that the post-fire soil showed CO2 and CH4 fluxes with a greater global warming potential than before burning and that the global warming potential of the soil gas fluxes further increased by warming and drying. The predictive power of models of C cycle-climate feedbacks could be increased by incorporating the distinct ecosystem following fire with permafrost degradation and climate change across the boreal zone.

Electrochemical Reduction of Greenhouse Gas with Couette-Taylor Flow (CTF) Mixer

N2O, a greenhouse gas like CO2 or CH4, has 268 times greater global warming potential (GWP) than CO2. Even though the volumetric portion of N2O among the greenhouse gases is merely 6%, the potential of N2O to exert a greenhouse effect is equivalent to 3 billion ton of CO2, which is similar to 50% of total car emissions worldwide. In addition, N2O plays a significant role in depleting ozone layer. The concentration of such N2O has been increasing, due to manufacturing, transportation, and agricultural activities [1]. Various chemical methods such as a thermal decomposition, a high/medium temperature catalytic decomposition, and a selective catalytic reduction have been adopted in order to reduce N2O [2]. They have been applied to industrial fields: massive production of nitric acid, adipic acid, and caprolactam because wasted heat could be used to elevate temperature up to a point, whereupon thermal decomposition of N2O takes place. However, such high-temperature methods are inadequate for reduction of N2O, which is typically emitted from room-temperature process, such as biological or medical process. Furthermore, given that the high-temperature methods require an enormous amount of energy, the successful electrochemical reduction of N2O at room temperature with a simple apparatus could be an effective alternative. Although N2O is very stable in the atmosphere, it could be electrochemically reduced into N2 in an aqueous electrolyte solution [3]. The rate of electrochemical N2O reduction could be enhanced by adopting adequate catalysts and gas-dissolution system. In this study, Couette-Taylor flow (CTF) mixer with electrochemical system was developed for effective N2O reduction. It consists of a stationary outer cylinder and a rotating inner cylinder, which are working and counter electrodes used for an electrochemical reaction. The gas injected into the solution present between two cylinders could form micro bubbles with great gas pressure and gas-liquid interfacial area than bulk gas due to the Taylor vortices in the CTF mixer [4]. The application of the CTF mixer resulted in the enhanced N2O solubility and rapid dissolution. Based on the improved N2O dissolution, high N2O conversion over 90% was obtained. In this presentation, we will focus on the optimization of operating condition of CTF mixer such as catalyst, rotational speed of inner cylinder, gas flow rate, and liquid circulation rate for efficient N2O reduction. The optimized system was also applicable to electrochemical reduction of CO2 not only N2O.

GREENHOUSE GAS EMISSION REDUCTION IN FROZEN FOOD PACKAGING

This study evaluates the environmental impacts of four types of frozen food packages throughout their lifecycle and suggests strategies for reducing their related environmental impacts. The four most widely used frozen food packaging materials were chosen for this study: (1) pouches composed of low-density polyethylene (LDPE) film; (2) pouches composed of polyethylene terephthalate (PET) and LDPE film laminate; (3) cardboard boxes coated with LDPE; and (4) multipackage composed of cardboard boxes and LDPE film pouches. The packages are processed by a company located in Europe (Lithuania). The assessed environmental impact category was global warming. The global warming potential of packages expressed as greenhouse gas emissions (kg CO2 eq.) was evaluated using the CCaLC software package based on a life cycle assessment (LCA), which constitutes a quantitative methodology. The mechanical properties of the various types of packaging were examined, and the optimization of plastic film thickness was verified using polymer tension tests. The multipackage consisting of a cardboard box and an LDPE film pouch has the greatest global warming potential (98 kg CO2 eq./f.u.) followed by packages composed of cardboard and packages composed of laminated film. Production and raw material extraction stages account for most (up to 75%) of the environmental impact. Data from the polymer tension tests indicate that the environmental impact could be reduced by 36% (from 35 to 22 kg CO2 eq./f. u.) by decreasing the plastic film thickness as well as by reducing the package size by 10%.

Characterization of Methane Emissions From Rice Production on a Clay Soil in Arkansas

AbstractRice (Oryza sativa L.) production systems have a greater global warming potential than upland crops because of methane (CH4) emissions resulting from anaerobic conditions of the flooded soils. Differences in cultural practices, cultivar choice, previous crop/crop rotation, and in particular

Factors affecting mitigation of methane emission from ruminants: Microbiology and biotechnology strategies

Climate change is a subject of global environmental concern. Increased anthropogenic Greenhouse Gas (GHG) emissions have increased the global temperature the last 100 to 200 years. Carbon dioxide and methane are the main greenhouse gases related to animal nutrition and methane has greater global warming potential than carbon dioxide. Among greenhouse gases, methane is considered a potent greenhouse gas with 21 times more global warming potential than carbon dioxide. Worldwide, ruminant livestock produce about 80 million metric tons of methane each year, accounting for about 28% of global emissions from human related activities. Therefore it is impelling animal scientists to finding solutions to mitigate methane emission from ruminants. It seems that solutions can be discussed in four topics including: nutrition (feeding), biotechnology, microbiology and management strategies. We have already published the first and second review articles on feeding strategies and management strategies. In the current review, Microbiology and biotechnology such as emphasizing on animal breeding, genetic merit, bovine somatotropin (BST), unproductive animals, vaccination, immunisation and biological control (bacteriophage, acetogenesis reductive), chemical defaunation that can be leads to decreasing methane production from ruminant animal production are discussed.

Influence of urban land development and soil rehabilitation on soil–atmosphere greenhouse gas fluxes

Urban landscapes often have altered soil–atmosphere fluxes of major greenhouse gases (GHGs) including carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) when compared to their rural counterparts. It is unclear to what degree soil disturbance during urbanization contributes to these altered emissions. In addition, rehabilitation of degraded urban soils through deep tillage and organic amendment may improve the soil's ability to support vegetation, but its effect on subsequent soil GHG emissions is unknown. In 2007, twenty-four plots were either left undisturbed or subjected to topsoil stripping, grading and compacting to mimic typical land development followed by one of three treatments: 10cm topsoil replaced (typical practice); typical practice plus tilling; or compost incorporation to 60-cm depth, followed by typical practice plus tilling (rehabilitation). Soil–atmosphere CO2, N2O, and CH4 fluxes were measured seasonally from fall 2011 to summer 2013. Typical land development practices did not increase global warming potential (GWP) when compared to undeveloped land. Post-development soil rehabilitation, however, resulted in greater GWP (CO2eq ranging from 0.7 to 12.1gCm−2d−1) than both undisturbed soils and those subjected to typical development practices (CO2eq ranging from 0.1 to 5.6gCm−2d−1) driven primarily by increased CO2 efflux (ranging from 0.8 to 12.0gCm−2d−1 compared to 0.2 to 5.5gCm−2d−1 in other treatments). All soils were CH4 sinks (ranging from −0.8 to −0.2mgCm−2d−1) but CH4 consumption was too variable to demonstrate treatment effects. Likewise, N2O fluxes were largely consistent across treatments. Although greater GHG emissions in rehabilitated soil may be offset by increased plant biomass production, our study only assessed soil–atmosphere fluxes. Results suggest that soil disturbance history and management should be considered when assessing the impact of urban land development on GHG emissions.

A comparative estimate of life cycle greenhouse gas emissions from two types of constructed wetlands in Tianjin, China

Constructed wetlands (CWs) are widely used for wastewater treatment, but may also be sources of greenhouse gas (GHG). This study focuses on comparing the GHG emissions from a vertical flow constructed wetland (VFCW) and a horizontal flow constructed wetland (HFCW) in the city of Tianjin, China. Two methods are used in this paper to estimate the indirect and direct GHG emissions. It is found that the VFCW emits 0.09, 1.34, and 3.31 kg equivalent CO2 (CO2 Eq.) to remove 1.00 m3 wastewater, 1.00 kg COD, and 1.00 kg BOD in the studied life cycle, respectively, in contrast to 0.18, 2.10, and 5.42 kg CO2 Eq. for the HFCW. The results indicate that the adoption of VFCW is a more effective option with respect to GHG emissions when treating the same amount of pollutants. In addition, the operation phase which includes GHG emissions from water treatment process and energy consumption for pump dominates the GHG emissions. For different kinds of GHG from CWs, CO2 dominates the influence on climate change. The CH4 and N2O emissions should also deserve more attention due to their greater global warming potential. This paper further suggests that GHG emissions can be mitigated in the design, construction, and operation stages through some feasible measures. It would reduce GHG emissions in CWs by adopting hybrid CW system (e.g. HF–VF or VF–HF) or choosing suitable plant species which can mitigate GHG emissions. In addition, aeration could contribute to the control of GHG emissions from CWs.

아디픽산 제조공정으로부터 발생되는 N2O에 대한 배출제어기술

Abstract Nitrous oxide (N 2 O) is one of six greenhouse gases listed up in the Kyoto Protocol, and it effects a strong global warming because of its much greater global warming potential (GWP), by 310 times over a 100-year time horizon, than CO 2 . Although such N 2 O emissions from both natural and anthropogenic sources occur, the latter can be controlled using suitable abatement technologies, depending on them, to reduce N 2 O below acceptable or feasible levels. This paper has extensively reviewed the anthropogenic N 2 O emission sources and their related compositions, and the state-of-the-art non-catalytic and catalytic technologies of the emissions controls available currently to representative, large N 2 O emission sources, such as adipic acid production plants. Challengeable approaches to this source are discussed to promote establishment of advanced N 2 O emission control technologies. Key Words : Nitrous oxide (N 2 O), Global warming, Anthropogenic sources, Adipic acid, Catalytic emission controls

The application of an life cycle inventory (LCI) model for solid waste disposal systems in malaysia

This paper discusses the application of an LCt model for solid waste management systems in Malaysia. The model was used to analyze the environmental and economic impacts of municipal waste management systems in Malaysia. In the first part of the study, the LCI model was adapted to analyze waste management systems of four selected cities: Kuala Lumpur and Penang to represent urban areas; Seremban to represent moderately urban areas and Muar to represent rural areas. The results have shown that Kuala Lumpur and Penang had greater Global Warming Potential (GWP) and the costs spent on the solid waste management were also higher as compared to that in suburban areas. In the second part of the study, a detailed evaluation was carried out by analyzing the implication of introducing incineration and composting into the solid waste management system, and the results were compared with the current system, i.e. 100 % landfilled. The relative GWP was lower for incineration, but the cost was extremely high. The results also showed that the final solid waste to be disposed to landfills and the impact due to water emissions could be reduced significantly when incineration and composting were introduced.