Thermodynamic guiding principles of high-capacity phase transformation materials for splitting H2O and CO2 by thermochemical looping

Author(s):  
Shang Zhai ◽  
Joonhyun Nam ◽  
Gopalakrishnan Sai Gautam ◽  
Kipil Lim ◽  
Jimmy Rojas ◽  
...  

Thermochemical looping splitting of water and carbon dioxide (CO2) with greenhouse-gas-free (GHG-free) energy has the potential to help address the Gt-scale GHG emissions challenge. Reaction thermodynamics largely contributes to the...

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xue Hao ◽  
Yu Ruihong ◽  
Zhang Zhuangzhuang ◽  
Qi Zhen ◽  
Lu Xixi ◽  
...  

AbstractGreenhouse gas (GHG) emissions from rivers and lakes have been shown to significantly contribute to global carbon and nitrogen cycling. In spatiotemporal-variable and human-impacted rivers in the grassland region, simultaneous carbon dioxide, methane and nitrous oxide emissions and their relationships under the different land use types are poorly documented. This research estimated greenhouse gas (CO2, CH4, N2O) emissions in the Xilin River of Inner Mongolia of China using direct measurements from 18 field campaigns under seven land use type (such as swamp, sand land, grassland, pond, reservoir, lake, waste water) conducted in 2018. The results showed that CO2 emissions were higher in June and August, mainly affected by pH and DO. Emissions of CH4 and N2O were higher in October, which were influenced by TN and TP. According to global warming potential, CO2 emissions accounted for 63.35% of the three GHG emissions, and CH4 and N2O emissions accounted for 35.98% and 0.66% in the Xilin river, respectively. Under the influence of different degrees of human-impact, the amount of CO2 emissions in the sand land type was very high, however, CH4 emissions and N2O emissions were very high in the artificial pond and the wastewater, respectively. For natural river, the greenhouse gas emissions from the reservoir and sand land were both low. The Xilin river was observed to be a source of carbon dioxide and methane, and the lake was a sink for nitrous oxide.


Author(s):  
E. A. Alabushev ◽  
I. S. Bersenev ◽  
V. V. Bragin ◽  
A. A. Stepanova

The Paris Agreement, adopted in December of 2015 at the 21st session of the UNFCCC Conference of the Parties and effected from November of 2016, coordinates the efforts of states to reduce greenhouse gas (GHG) emissions, including carbon dioxide. One of its largest emitters to the atmosphere is the metallurgical industry. Among the proposed ways to reduce carbon dioxide emissions is the widespread use of hydrogen in the ferrous metallurgy. An overview of the problems that the ferrous metallurgy will face when replacing carbon-containing fuels with hydrogen is presented. It was noted that the use of hydrogen in the ferrous metallurgy contains such technological risks as high cost in comparison with currently used fuels and reducing agents; explosion hazard and corrosion activity, the need for a radical reconstruction of thermal units when using hydrogen instead of traditional for the ferrous metallurgy natural, coke and blast furnace gases, as well as solid fuels. It is shown that minimizing these risks is not always possible or economically feasible, and the result of using hydrogen in the ferrous metallurgy instead of carbon-containing fuel from the point of view of reducing greenhouse gas emissions may be low with a significant increase of economic and social risks.


1999 ◽  
Vol 26 (3) ◽  
pp. 166-168 ◽  
Author(s):  
TIM NEWCOMB

Many nations have recognized the need to reduce the emissions of greenhouse gases (GHGs). The scientific assessments of climate change of the Intergovernmental Panel on Climate Change (IPCC) support the need to reduce GHG emissions. The 1997 Kyoto Protocol to the 1992 Convention on Climate Change (UNTS 30822) has now been signed by more than 65 countries, although that Protocol has not yet entered into force. Some 14 of the industrialized countries listed in the Protocol face reductions in carbon dioxide emissions of more than 10% compared to projected 1997 carbon dioxide emissions (Najam & Page 1998).


2020 ◽  
Author(s):  
Fallon Fowler ◽  
Christopher J. Gillespie ◽  
Steve Denning ◽  
Shuijin Hu ◽  
Wes Watson

AbstractBy mixing and potentially aerating dung, dung beetles may affect the microbes producing the greenhouse gases (GHGs): carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). Here, their sum-total global warming effect is described as the carbon dioxide equivalent (CO2e). Our literature analysis of reported GHG emissions and statistics suggests that most dung beetles do not, however, reduce CO2e even if they do affect individual GHGs. Here, we compare the GHG signature of homogenized (“premixed”) and unhomogenized (“unmixed”) dung with and without dung beetles to test whether mixing and burial influence GHGs. Mixing by hand or by dung beetles did not reduce any GHG – in fact, tunneling dung beetles increased N2O medians by ≥1.8x compared with dung-only. This suggests that either: 1) dung beetles do not meaningfully mitigate GHGs as a whole; 2) dung beetle burial activity affects GHGs more than mixing alone; or 3) greater dung beetle abundance and activity is required to produce an effect.


Author(s):  
Marian PROOROCU ◽  
Sorin DEACONU ◽  
Mihaela SMARANDACHE

As a Party to the United Nations Framework Convention on Climate Change (UNFCCC), and its Kyoto Protocol, Romania is required to elaborate, regularly update and submit the national GHG Inventory. In compliance with the reporting requirements, Romania submitted in 2010 its ninth version of the National Inventory Report (NIR) covering the national inventories of GHG emissions/removals for the period 1989-2008. The inventories cover all sectors: Energy, Industrial Processes, Solvent and other product use, Agriculture, LULUCF and Waste. The direct GHGs included in the national inventory are: Carbon dioxide (CO2); Methane (CH4); Nitrous oxide (N2O); Hydrofluorocarbons (HFCs); Perfluorocarbons (PFCs); Sulphur hexafluoride (SF6). The emissions trend over the 1989-2008 period reflects the changes characterized by a process of transition to a market economy. With the entire economy in transition, some energy intensive industries reduced their activities and this is reflected in the GHG emissions reduction. Energy represents the most important sector in Romania, accounting for about 69% of the total national GHG emissions in 2008. The most significant anthropogenic greenhouse gas is the carbon dioxide. The decrease of CO2 emissions is caused by the decline of the amount of fossil fuels burnt in the energy sector, as a consequence of activity decline. According to the figures, there is a great probability for Romania to meet the Kyoto Protocol commitments on the limitation of the GHG emissions in the 2008-2012 commitment period.


2020 ◽  
Vol 2 ◽  
Author(s):  
Astley Hastings ◽  
Pete Smith

The challenge facing society in the 21st century is to improve the quality of life for all citizens in an egalitarian way, providing sufficient food, shelter, energy, and other resources for a healthy meaningful life, while at the same time decarbonizing anthropogenic activity to provide a safe global climate, limiting temperature rise to well-below 2°C with the aim of limiting the temperature increase to no more than 1.5°C. To do this, the world must achieve net zero greenhouse gas (GHG) emissions by 2050. Currently spreading wealth and health across the globe is dependent on growing the GDP of all countries, driven by the use of energy, which until recently has mostly been derived from fossil fuel. Recently, some countries have decoupled their GDP growth and greenhouse gas emissions through a rapid increase in low carbon energy generation. Considering the current level of energy consumption and projected implementation rates of low carbon energy production, a considerable quantity of fossil fuels is projected to be used to fill the gap, and to avoid emissions of GHG and close the gap between the 1.5°C carbon budget and projected emissions, carbon capture and storage (CCS) on an industrial scale will be required. In addition, the IPCC estimate that large-scale GHG removal from the atmosphere is required to limit warming to below 2°C using technologies such as Bioenergy CCS and direct carbon capture with CCS to achieve climate safety. In this paper, we estimate the amount of carbon dioxide that will have to be captured and stored, the storage volume, technology, and infrastructure required to achieve the energy consumption projections with net zero GHG emissions by 2050. We conclude that the oil and gas production industry alone has the geological and engineering expertise and global reach to find the geological storage structures and build the facilities, pipelines, and wells required. Here, we consider why and how oil and gas companies will need to morph from hydrocarbon production enterprises into net zero emission energy and carbon dioxide storage enterprises, decommission facilities only after CCS, and thus be economically sustainable businesses in the long term, by diversifying in and developing this new industry.


2012 ◽  
Vol 66 (9) ◽  
pp. 1930-1940 ◽  
Author(s):  
Juan P. Silva ◽  
José L. Ruiz ◽  
Miguel R. Peña ◽  
Henk Lubberding ◽  
Huub Gijzen

Greenhouse gas (GHG) emissions (CO2, CH4) from pilot-scale algal and duckweed-based ponds (ABP and DBP) were measured using the static chamber methodology. Daylight and nocturnal variations of GHG and wastewater characteristics (e.g. chemical oxygen demand (COD), pH) were determined via sampling campaigns during midday (12:30–15:30) and midnight (00:30–03:30) periods. The results showed that under daylight conditions in ABP median emissions were −232 mg CO2 m−2 d−1 and 9.9 mg CH4 m−2 d−1, and in DBP median emissions were −1,654.5 mg CO2 m−2 d−1 and 71.4 mg CH4 m−2 d−1, respectively. During nocturnal conditions ABP median emissions were 3,949.9 mg CO2 m−2 d−1, 12.7 mg CH4 m−2 d−1, and DBP median emissions were 5,116 mg CO2 m−2 d−1, 195.2 mg CH4 m−2 d−1, respectively. Once data measured during daylight were averaged together with nocturnal data the median emissions for ABP were 1,566.8 mg CO2 m−2 d−1 and 72.1 mg CH4 m−2 d−1, whilst for DBP they were 3,016.9 mg CO2 m−2 d− and 178.9 mg CH4 m−2 d−1, respectively. These figures suggest that there were significant differences between CO2 emissions measured during daylight and nocturnal periods (p < 0.05). This shows a sink-like behaviour for both ABP and DBP in the presence of solar light, which indicates the influence of photosynthesis in CO2 emissions. On the other hand, the fluxes of CH4 indicated that DBP and ABP behave as net sources of CH4 during day and night, although higher emissions were observed from DBP. Overall, according to the compound average (daylight and nocturnal emissions) both ABP and DBP systems might be considered as net sources of GHG.


2020 ◽  
Vol 31 (4) ◽  
pp. 945-960 ◽  
Author(s):  
Tariq Umar

PurposeThe Gulf Cooperation Council member countries not only generate the highest quantity of municipal solid waste (MSW) per capita when compared globally, but also in most of these countries, such waste is just dumped at different landfill stations. In Oman, the total quantity of MSW stood at 2.0 million tons per year. The emission from this waste is estimated at 2,181,034 tons/year (carbon dioxide equivalent). This article attempts to develop frameworks that considered landfilling, composting and recycling of MSW.Design/methodology/approachTo know the composition of the municipal solid waste in Oman, a quantitative research method was employed. The greenhouse gas (GHG) emissions from MSWM in this study focus on three major gases, CO2, CH4 and N2O. The Intergovernmental Panel on Climate Change (IPCC) 2006 model is used to calculate GHG emissions from landfills and composting (IPCC, 2006). Four frameworks – baseline F0, framework F1, framework F2 and framework F3 – are outlined in this paper. The F0 represents the current situation of the MSW in which most of the waste goes to landfills and dumpsites. In F1, improved MSW collection service and landfilling are incorporated and open burning is restricted. The F2 considered landfilling and composting, while F3 is based on landfilling, composting and recycling.FindingsThe framework F2, which proposes the composting process for the organic waste which normally goes to landfills, results in the reduction of emissions by 40% as compared to landfill practice. Similarly, the samples of MSW collected in Oman show a good amount of recycling waste. The framework F3, which considers the landfill, composting and recycling, reduced the total GHG emissions from 2,181,034 tons/year to 1,427,998 tons/year (carbon dioxide equivalent), representing a total reduction of 35% in emissions.Research limitations/implicationsDifferent values such as CH4 correction factor, the fraction of degradable organic carbon and the fraction of DOC used to determine the GHG emissions from MSW considering landfilling, composting and recycling based on the IPPC model and existing literature review. The actual determination of these values based on the Oman conditions may result in more accurate emissions from MSW in Oman.Practical implicationsDifferent frameworks suggested in this research have different practical implications; however, the final framework F3, which produces fewer emissions, required a material recovery facility to recycle the MSW in Oman. For framework F3, it is important that the residents in Oman have enough knowledge and willingness to do the waste segregation at the household level. Apparently, such knowledge and willingness need to be determined through a separate study.Originality/valueThe frameworks F2 and F3 are considered to be more suitable solutions compared to the current practices for Oman and other gulf countries to reduce its per capita emissions from MSW and protect its local environment. There is a potential for further work that needs to explore the possible solutions to implement the suggested frameworks.


2018 ◽  
Vol 10 (11) ◽  
pp. 3995 ◽  
Author(s):  
André Lopes Toledo ◽  
Emílio Lèbre La Rovere

This study aims to deepen the understanding of the role of the urban mobility sector in the current and future greenhouse gas (GHG) emissions of a middle-sized city of Brazil, which is also a developing economy. With the cross-reference between road and rail mobility data, governmental mobility planning, the Global Protocol for Community-Scale Greenhouse Gas Emission Inventories (GPC) of the Intergovernmental Panel on Climate Change (IPCC) emission quantification methodology, and the creation of scenarios for up to 10 subsequent years, it is possible to verify that individual motorized transport accounts for 60% of the total emissions from the urban transportation sector, with the largest amount of carbon dioxide equivalent (CO2eq) emissions per passenger among all of the forms of mobility. However, in the case of this study, government mobility planning, by not encouraging more energy-efficient transport and non-motorized modes, ends up aggravating GHG emissions in the scenarios considered for 2020 and 2025. In turn, the mitigation scenarios proposed herein integrate public transport and non-motorized transport solutions that would reduce the total of equivalent carbon dioxide (tCO2eq) by at least 45,000 tCO2eq per year by 2025. This cross-referencing of the environmental impact of government mobility policies can be replicated in other cities in developing countries that do not yet present municipal inventories or emission monitoring.


2021 ◽  
Vol 896 (1) ◽  
pp. 012015
Author(s):  
MS A P Permata ◽  
I Buchori ◽  
R Kurniati

Abstract Green Open Space (GOS) is one of the efforts to deal with increasing greenhouse gas (GHG) emissions because it can absorb CO2 emissions. Transportation activities cause high CO2 emissions, and the lack of public green open space, which results in the ability of green open space to absorb emissions, is not optimal. The intensity of traffic activity is getting more and more crowded, which will impact the surrounding community. This study aims to determine the level of adequacy of public green open space (GOS) in absorbing carbon dioxide (CO2) emissions from transportation activities. This study uses a literature review approach. The results obtained are the adequacy of public green open space in absorbing emissions from transportation and so that solutions are obtained to carry out policies in reducing air pollution produced by vehicles, and the importance of green open spaces (GOS).


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