scholarly journals Biogas Reforming Conversion Character on Microwave-heating Carbon Receptor

2020 ◽  
Vol 42 (2) ◽  
pp. 40-46
Author(s):  
Hee Gaen Song ◽  
Young Nam Chun
Keyword(s):  
Carbon Dioxide ◽  
Global Warming ◽  
Space Velocity ◽  
Quartz Tube ◽  
Carbon Adsorption ◽  
Product Gas ◽  
Decomposition Of Methane ◽  
Main Components ◽  
Gasification Reaction ◽  
Reforming Gas

Objectives:Methane (CH<sub>4</sub>) and carbon dioxide (CO<sub>2</sub>) are the main components of biogas and are produced from biomass gasification. These two gases are a by-product gases that can be used as an energy source and is known as a greenhouse gas that affects global warming. In order to convert the gas which is the main cause of global warming into high-quality fuel energy, the microwave reforming characteristic research was conducted. In this study, the reforming characteristics of microwave carbon receptor pyrolysis-gasification gas were investigated. In addition, reforming gas conversion characteristics according to the reforming temperature, flow rate, and CH<sub>4</sub> / CO<sub>2</sub> ratio, which are the main influence variables, were studied.Methods:Experiment was achieved in a microwave convertor which was installed a quartz tube reactor. The reactor was irritated by a microwave energy to heat carbon receptor in a sample basket which was placed at the center of the quartz tube. A simulated gas mixture of methane and carbon dioxide was fed into the carbon receptor in the reactor, and a reformed product gas was collected and analyzed using a GC-TCD.Results and Discussion:In the case of microwave reforming of a mixture gas of carbon dioxide and methane, hydrogen and carbon was produced by thermal decomposition of methane. The produced carbon was adsorbed to the receptor and interfered with the catalytic activity. The attached carbon was reacted with the carbon dioxide by gasification reaction to produce carbon monoxide, and was cleaned to maintain a constant reforming conversion.Conclusions:As a result, the conversion rate and the product gas yield were high when the receptor bad reforming temperature was high and the space velocity in the convertor was low. The increase in methane in the simulated gas resulted in low conversion due to carbon adsorption.

scholarly journals Conversion of Biogas to Renewable Energy by Microwave Reforming

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4093
Author(s):  
Ha Jin Kim ◽  
Young Nam Chun
Keyword(s):  
Carbon Dioxide ◽  
Renewable Energy ◽  
Catalytic Activity ◽  
Conversion Efficiency ◽  
Oxidation Reaction ◽  
Methane Reforming ◽  
Complete Oxidation ◽  
High Quality ◽  
Product Gas ◽  
Main Components

Biogas consists of methane and carbon dioxide, the main components, which are major greenhouse gases that affect global warming. As such, in order to convert greenhouse gas into renewable energy, which is a high-quality fuel, the biogas microwave reforming characteristics were studied and the results are as follows: In the main components of biogas, methane and carbon dioxide, the conversion efficiency of both methane and carbon dioxide increased as the amount of CO2 relatively increased. This is because the problem of active pore failure due to gasification of the attached carbon generated during methane reforming was overcome. When nitrogen, a biogas-containing component, was added, the activity of catalytic activity pores was enhanced by promoting the production of microplasma, resulting in increased conversion efficiency. When the concentration of oxygen, which is a biogas-containing component, increased, the conversion efficiency increased, but when the concentration is more than 10%, the fuel value of the product gas decreased due to the complete oxidation reaction.

scholarly journals Estimating Causal Effects When the Treatment Affects All Subjects Simultaneously: An Application

2021 ◽  
Vol 5 (2) ◽  
pp. 22
Author(s):  
Chiara Binelli
Keyword(s):  
Machine Learning ◽  
Carbon Dioxide ◽  
Global Warming ◽  
Carbon Dioxide Emissions ◽  
Control Group ◽  
Sources Of Information ◽  
Average Global Temperature ◽  
Causal Impact ◽  
The Impact ◽  
Robust Evidence

Several important questions cannot be answered with the standard toolkit of causal inference since all subjects are treated for a given period and thus there is no control group. One example of this type of questions is the impact of carbon dioxide emissions on global warming. In this paper, we address this question using a machine learning method, which allows estimating causal impacts in settings when a randomized experiment is not feasible. We discuss the conditions under which this method can identify a causal impact, and we find that carbon dioxide emissions are responsible for an increase in average global temperature of about 0.3 degrees Celsius between 1961 and 2011. We offer two main contributions. First, we provide one additional application of Machine Learning to answer causal questions of policy relevance. Second, by applying a methodology that relies on few directly testable assumptions and is easy to replicate, we provide robust evidence of the man-made nature of global warming, which could reduce incentives to turn to biased sources of information that fuels climate change skepticism.

scholarly journals Effect of Urban Heat Island and Global Warming Countermeasures on Heat Release and Carbon Dioxide Emissions from a Detached House

Atmosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 572
Author(s):  
Daisuke Narumi ◽  
Ronnen Levinson ◽  
Yoshiyuki Shimoda
Keyword(s):  
Carbon Dioxide ◽  
Global Warming ◽  
Heat Release ◽  
Urban Heat Island ◽  
Co2 Emissions ◽  
Heat Island ◽  
Sensible Heat ◽  
Heating Season ◽  
Urban Heat ◽  
Cooling Effects

Urban air temperature rises induced by the urban heat island (UHIE) effect or by global warming (GW) can be beneficial in winter but detrimental in summer. The SCIENCE-Outdoor model was used to simulate changes to sensible heat release and CO2 emissions from buildings yielded by four UHIE countermeasures and five GW countermeasures. This model can evaluate the thermal condition of building envelope surfaces, both inside and outside. The results showed that water-consuming UHIE countermeasures such as evaporative space cooling and roof water showering provided positive effects (decreasing sensible heat release and CO2 emissions related to space conditioning) in summer. Additionally, they had no negative (unwanted cooling) effects in winter since they can be turned off in the heating season. Roof greening can provide the greatest space- conditioning CO2 emissions reductions among four UHIE countermeasures, and it reduces the amount of heat release slightly in the heating season. Since the effect on reducing carbon dioxide (CO2) emissions by UHIE countermeasures is not very significant, it is desirable to introduce GW countermeasures in order to reduce CO2 emissions. The significance of this study is that it constructed the new simulation model SCIENCE-Outdoor and applied it to show the influence of countermeasures upon both heat release and CO2 emissions.

An overview of flow cell architectures design and optimization for electrochemical CO2 reduction

2021 ◽  
Author(s):  
Dui Ma ◽  
Ting Jin ◽  
Keyu Xie ◽  
Haitao Huang
Keyword(s):  
Carbon Dioxide ◽  
Global Warming ◽  
Electrochemical Reduction ◽  
Atmospheric Carbon Dioxide ◽  
Co2 Reduction ◽  
Value Added ◽  
Flow Cell ◽  
Design And Optimization ◽  
Electrochemical Co2 Reduction ◽  
Carbon Dioxide Levels

Converting CO2 into value-added fuels or chemical feedstocks through electrochemical reduction is one of the several promising avenues to reduce atmospheric carbon dioxide levels and alleviate global warming. This approach...

GLOBAL WARMING AS A CRITICAL FACTOR SUSTAINABLE DEVELOPMENT

2017 ◽  
Author(s):  
Nikolay Tymchenko ◽  
◽  
Nataliia Fialko ◽  
Keyword(s):  
Carbon Dioxide ◽  
Sustainable Development ◽  
Global Warming ◽  
Critical Factor ◽  
Annual Changes

Different aspects of the climate threat associated with global warming are considered. The limits of annual changes in the concentration of carbon dioxide in the atmosphere are analyzed. Climate danger assessments due to global warming are discussed.

scholarly journals Collateral transgression of planetary boundaries due to climate engineering by terrestrial carbon dioxide removal

2016 ◽  
Vol 7 (4) ◽  
pp. 783-796 ◽  
Author(s):  
Vera Heck ◽  
Jonathan F. Donges ◽  
Wolfgang Lucht
Keyword(s):  
Carbon Dioxide ◽  
Global Warming ◽  
Carbon Dioxide Removal ◽  
Small Range ◽  
Earth System ◽  
Planetary Boundaries ◽  
Climate Engineering ◽  
Terrestrial Carbon ◽  
The Earth ◽  
Atmospheric Carbon

Abstract. The planetary boundaries framework provides guidelines for defining thresholds in environmental variables. Their transgression is likely to result in a shift in Earth system functioning away from the relatively stable Holocene state. As the climate system is approaching critical thresholds of atmospheric carbon, several climate engineering methods are discussed, aiming at a reduction of atmospheric carbon concentrations to control the Earth's energy balance. Terrestrial carbon dioxide removal (tCDR) via afforestation or bioenergy production with carbon capture and storage are part of most climate change mitigation scenarios that limit global warming to less than 2 °C. We analyse the co-evolutionary interaction of societal interventions via tCDR and the natural dynamics of the Earth's carbon cycle. Applying a conceptual modelling framework, we analyse how the degree of anticipation of the climate problem and the intensity of tCDR efforts with the aim of staying within a "safe" level of global warming might influence the state of the Earth system with respect to other carbon-related planetary boundaries. Within the scope of our approach, we show that societal management of atmospheric carbon via tCDR can lead to a collateral transgression of the planetary boundary of land system change. Our analysis indicates that the opportunities to remain in a desirable region within carbon-related planetary boundaries only exist for a small range of anticipation levels and depend critically on the underlying emission pathway. While tCDR has the potential to ensure the Earth system's persistence within a carbon-safe operating space under low-emission pathways, it is unlikely to succeed in a business-as-usual scenario.

scholarly journals STEAM GASIFICATION OF SOME MONGOLIAN COALS

2017 ◽  
pp. 48-51
Author(s):  
Tungalagtamir B ◽  
Enkhtsetseg E ◽  
Chao Lumen ◽  
Narantsetseg M ◽  
Avid B ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Bituminous Coal ◽  
Steam Gasification ◽  
Coal Deposits ◽  
Gasification Rate ◽  
Product Gas ◽  
N2 Atmosphere ◽  
Carbon Dioxide Concentrations ◽  
Stainless Steel Reactor ◽  
Scale Reactor

The gasification tests for the Alagtolgoi and Ailbayan coal deposits were conducted in the temperature up to 850°C using bench scale reactor in order to evaluate product gas composition. Prior to the gasification experiments, the raw coal was pyrolysed in a stainless steel reactor under N2 atmosphere at a temperature of 500°C for 1 h. General behavior of the coal conversion was quite similar for both coals. The gasification tests show that an increase in temperature enhances the formation of hydrogen, carbon dioxide and carbon monoxide. The highest yield of hydrogen and carbon dioxide concentrations of the Ailbayan coal are achieved at temperature of 850°C, which were 2.859 mmol⋅g-1⋅min-1 and 1.054 mmol⋅g-1⋅min-1 respectively. However maximum rate of hydrogen for Alagtolgoi subbituminous coal reached around 800°C. Overall results show that the maximum gasification rate is reached earlier for subbituminous coal than for bituminous coal, but product gas evolution was higher for the investigated bituminous coal.

scholarly journals Carbon dioxide and methane exchange of a patterned subarctic fen during two contrasting growing seasons

2021 ◽  
Author(s):  
Lauri Heiskanen ◽  
Juha-Pekka Tuovinen ◽  
Aleksi Räsänen ◽  
Tarmo Virtanen ◽  
Sari Juutinen ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Global Warming ◽  
Plant Community ◽  
Carbon Balance ◽  
Growing Season ◽  
Drought Period ◽  
Annual Carbon ◽  
Ecosystem Level ◽  
Community Types ◽  
Annual Carbon Balance

&lt;p&gt;Abstract&lt;/p&gt;&lt;p&gt;Northern mires have sequestered substantial amounts of atmospheric carbon since the last glacial period forming one of the largest carbon pools in the biosphere (Hugelius et al., 2020). Current global warming is causing the subarctic and arctic regions warm rapidly, two to three times as fast as the rest of the world (Masson-Delmotte et al., 2018), which will affect the carbon balance of these mires.&lt;/p&gt;&lt;p&gt;In Kaamanen, northern Finland, we studied carbon dioxide (CO&lt;sub&gt;2&lt;/sub&gt;) and methane (CH&lt;sub&gt;4&lt;/sub&gt;) exchange between patterned mesotrophic fen and the atmosphere, both on ecosystem and plant community level. The ecosystem level measurements were conducted by utilizing eddy covariance method, while the fluxes on plant community scale were measured with flux chambers. The studied fen can be described as a mosaic of strings and flarks (or hummocks and hollows, respectively). The microtopography of the string-flark continuum form four main plant community types with varying water table conditions and vegetation composition. The measurements took place in 2017&amp;#8211;2018. The two years in question were contrasting in their meteorological and environmental conditions. The 2017 growing season had average temperature, but high precipitation sum, while 2018 growing season was warm and dry. In July 2018 a north-western Europe-wide heatwave caused a month-long drought period at the site. Compared to 2017, the annual carbon balance of the Kaamanen fen was affected by earlier onset of photosynthesis in spring and the drought event during summer 2018.&lt;/p&gt;&lt;p&gt;We found that the annual carbon balance of the fen did not differ markedly between the studied years, even though the meteorological and environmental conditions did. The earlier onset of growing season in 2018 strengthened the CO&lt;sub&gt;2&lt;/sub&gt; sink of the ecosystem, but this gain was counterbalanced by the later drought period. Additionally, we found strong spatial variation in CO&lt;sub&gt;2&lt;/sub&gt; and CH&lt;sub&gt;4&lt;/sub&gt; dynamics between the main plant communities. Most of the variation in ecosystem level carbon exchange could be explained by the variation in water table level, soil temperature and vegetation characteristics, which were also the environmental factors that varied between the plant community types.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;References&lt;/p&gt;&lt;p&gt;Hugelius, G., Loisel, J., Chadburn, S., Jackson, R. B., Jones, M., MacDonald, G., Marushchak, M., Olefeldt, D., Packalen, M., Siewert, M. B., Treat, C., Turetsky, M., Voigt, C. and Yu, Z.: Large stocks of peatland carbon and nitrogen are vulnerable to permafrost thaw, Proceedings of the National Academy of Sciences - PNAS, 117, 20438&amp;#8211;20446, doi:10.1073/pnas.1916387117, 2020.&lt;/p&gt;&lt;p&gt;Masson-Delmotte, V., Zhai, P., P&amp;#246;rtner, H.-O., Roberts, D., Skea, J., Shukla, P. R., Pirani, A., Moufouma-Okia, W., P&amp;#233;an, C., Pidcock, R., Connors, S., Matthews, J. B. R., Chen, Y., Zhou, X., Gomis, M. I., Lonnoy, E., Maycock, T., Tignor, M. and Waterfield T. (Eds.): Global Warming of 1.5&amp;#176;C. An IPCC Special Report on the impacts of global warming of 1.5&amp;#176;C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty, World Meteorological Organization, Geneva, Switzerland, 2018.&lt;/p&gt;

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