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Abstract Transdisciplinary research often utilizes collaborative ways of knowledge production to enable deliberate transformations towards sustainability. Multiple concepts with varying definitions are applied, leading to confusio...
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Abstract Transdisciplinary research often utilizes collaborative ways of knowledge production to enable deliberate transformations towards sustainability. Multiple concepts with varying definitions are applied, leading to confusion in the aims and uses of these concepts. In this article, we review five concepts relevant to the current debate on the new collaborative ways of knowledge production in transdisciplinary research. We focus on the concepts of co‐creation, co‐production, co‐design, co‐learning, and adaptive co‐management in the context of natural resources management (NRM). This study couples a literature review and a conceptual analysis, and aims to clarify definitions, use, the interlinkages of these concepts and to shed light on their intertwined nature. We propose an integrative understanding of the concepts to facilitate collaborative modes and to enable the transformative aims of research processes. To this end, we discuss how to harvest the transformative potential of the “co‐concepts” by focusing on reflexivity, power analysis and process orientation.
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Purpose: In this study, we attempted to reduce the negative economic externalities related to Carbon Dioxide (CO2) emissions in the Yangtze River Delta region (YRD) and designed a cross-municipality responsibility-sharing mechanis...
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Purpose: In this study, we attempted to reduce the negative economic externalities related to Carbon Dioxide (CO2) emissions in the Yangtze River Delta region (YRD) and designed a cross-municipality responsibility-sharing mechanism. Methods: We estimated the municipal CO2 footprints in the YRD from 2000 to 2019 based on nighttime light data and measured CO2 emissions efficiency using a super slack-based measurement (super-SBM) model. Based on this, we designed a scenario of horizontal CO2 compensation among the YRD's municipalities from the perspectives of both CO2 footprints and CO2 trading (CO2 unit prices in trading were determined based on CO2 emissions efficiency). Results: The results showed the following: (1) The CO2 footprints evolution of the YRD municipalities could be divided into four categories, among which, eleven municipalities showed a decreasing trend. Thirteen municipalities stabilized their CO2 footprints. Thirteen municipalities exhibited strong growth in their CO2 footprints, whereas four municipalities maintained a low level of slow growth. (2) Spatially, CO2 emissions efficiency evolved from a broad distribution of low values to a mosaic distribution of multi-type zones. (3) After 2011, the ratio of CO2 footprint compensation amounts to local Gross Domestic Product (GDP) in most municipalities was less than 0.01%, with its center of gravity shifting cyclically. It was appropriate to start charging the CO2 footprint compensation amounts after 2011, with a dynamic adjustment of 3 years. (4) After 2007, the supply-demand relationship of CO2 trading continued to deteriorate, and it eased in 2016. However, its operational mechanism was still very fragile and highly dependent on a few pioneering municipalities. Innovations: In this study, we designed a horizontal CO2 compensation mechanism from the binary perspective of CO2 footprints and CO2 trading. In this mechanism, the former determines the CO2 footprint compensation amounts paid by each municipality based on whether the CO2 footprint exceeds its CO2 allowance. The latter determines the CO2 trading compensation amounts paid by the purchasing municipalities based on their CO2 emissions efficiency. This system balances equity and efficiency and provides new ideas for horizontal CO2 compensation.
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Ship transport and pipeline transport of CO2 are considered to be viable options for large scale CCS. While pipeline transport is usually recommended for shorter distances, ship transport might also be considered for these distanc...
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Ship transport and pipeline transport of CO2 are considered to be viable options for large scale CCS. While pipeline transport is usually recommended for shorter distances, ship transport might also be considered for these distances in the early stage of CCS due to its high flexibility and low capital expenses. Ship transport is usually carried out in liquefied state at a temperature around -50 degrees C and low pressures. Thus, an efficient liquefaction process is required. Unlike other works on CO2 liquefaction, it is assumed that the CO2 has been transported by pipeline before it is transported by ship. Consequently, the CO2 is expanded instead of being compressed and purification is not necessary as it has already been carried out before pipeline transport.
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Over the past century, the concentration of carbon dioxide (CO_(2)) has significantly increased in our atmosphere, creating numerous catastrophic effects and environmental impacts. There are three main CO_(2)capture methods: (a) p...
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Over the past century, the concentration of carbon dioxide (CO_(2)) has significantly increased in our atmosphere, creating numerous catastrophic effects and environmental impacts. There are three main CO_(2)capture methods: (a) post-combustion, (b) pre-combustion, and (c) oxy-fuel combustion implemented to capture CO_(2)from significant CO_(2)emitting sources. Further, the captured CO_(2)is utilized to convert it into value-added products. The current status of potential combined CO_(2)capture and CO_(2)utilization methods provide the solution to the issues of greenhouse-gas CO_(2)emissions from anthropogenic activities and the ever-growing energy demand challenges. These unique approaches dramatically reduce the overall energy penalty, cost-effective, and have a low environmental impact. As of now, carbon management is more intensively shifting toward the carbon utilization for minimizing energy consumption and replacing fossil fuel with the cleaner energy sources. This paper presents an idea of co-integration pathways for CO_(2)capture and CO_(2)utilization.
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Adsorption of CO2, N2, CH4 and H2 on triamine-grafted pore-expanded MCM-41 mesoporous silica (TRI-PE-MCM-41) was investigated at room temperature in a wide range of pressure (up to 25 bar) using gravimetric measurements. The mater...
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Adsorption of CO2, N2, CH4 and H2 on triamine-grafted pore-expanded MCM-41 mesoporous silica (TRI-PE-MCM-41) was investigated at room temperature in a wide range of pressure (up to 25 bar) using gravimetric measurements. The material was found to exhibit high affinity toward CO2 in comparison to the other species over the whole range of pressure. Column-breakthrough dynamic measurements of CO2-containing mixtures showed very high selectivity toward CO2 over N2, CH4 and H2 at CO2 concentrations within the range of 5 to 50%. These conditions are suitable for effective removal of CO2 at room temperature from syngas, flue gas and biogas using temperature swing (TS) or temperature-pressure swing (TPS) regeneration mode. Moreover, TRI-PE-MCM-41 was found to be highly stable over hundreds of adsorption-desorption cycles using TPS as regeneration mode.
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Abundant CO2 emissions from industries and the transportation sector cause an alarming threat to the planet due to overwhelming concerns over CO2 induced climate change. To resolve this tremendous environmental pollution, the long...
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Abundant CO2 emissions from industries and the transportation sector cause an alarming threat to the planet due to overwhelming concerns over CO2 induced climate change. To resolve this tremendous environmental pollution, the long-term solution for CO2 mitigation exists in the conversion of CO2 into value-added products through catalysis. Among several catalysts, metal organic frameworks (MOFs) are one of the remarkable candidates for CO2 conversion into fuels and chemicals. The MOFs are molded with robust structures, high porosity, high potential of CO2 adsorption, maximum atom utilization due to high dispersion and isolation of active sites of MOFs, tunability of the metal nodes, organic ligands, etc. MOFs have been implemented for several CO2 conversion processes such as cycloaddition of CO2 to epoxides, photocatalytic CO2 reduction, electrocatalytic CO2 reduction, hydrogenation, and others. These processes convert CO2 into products like cyclic carbonates, alkyl formate, formic acid, ethanol, methanol, methane, CO, and others. This study strived to explain elaborately the formation of fuels and chemicals through different catalytic processes using MOFs. Detailed reaction conditions, catalyst chemistry, reaction mechanisms, and formation rates for alkyl formate, formic acid, methanol, ethanol, CO, and methane have been critically analyzed in present study.
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Carbon monoxide is a conventional contaminant in the fuel obtained from reforming processes with an important influence on the performance of a proton exchange membrane fuel cell (PEMFC). The studies of transient and continuous in...
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Carbon monoxide is a conventional contaminant in the fuel obtained from reforming processes with an important influence on the performance of a proton exchange membrane fuel cell (PEMFC). The studies of transient and continuous injection of CO presented here give information about poisoning and recovery processes, and recommend strategies for fuel cell operation. Pulsing study shows that up to 100 ppm CO, has no significant effect on the performance. Constant current demand experiments show an oscillatory effect due to CO electro-oxidation at high over-potentials. In continuous poisoning process, kinetic and mass transfer affect the rate of CO removal. To recover the performance for continuous fuel cell operation, we propose cyclic feeding of hydrogen containing traces of CO (i.e. supplied by a reforming process) and pure hydrogen streams.
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Carbon dioxide (CO2) is an environmentally harmful "greenhouse gas" that is present in abundant quantities in the Earth's atmosphere. Due to the stability of its structure, it is notoriously regarded as an inert molecule that will...
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Carbon dioxide (CO2) is an environmentally harmful "greenhouse gas" that is present in abundant quantities in the Earth's atmosphere. Due to the stability of its structure, it is notoriously regarded as an inert molecule that will only react under harsh conditions such as high temperature or pressure. Electrochemical reduction of CO2 to value-added materials is a sustainable and potentially profitable way to curb greenhouse gas emissions; however, the challenge of amassing a sizable CO2 concentration in the active medium persists. Here, we find that various amines, already known to be effective absorbents for CO2 through the formation of carbamates, can be used directly as substrates for selectively reducing CO2 to carbon monoxide (CO) at room temperature and ambient pressure. Several primary amines were evaluated using glassy carbon and copper working electrodes for systematic comparison. Here, we demonstrated that use of copper electrodes dramatically enhances current density (up to -18.4 mA/cm(2) at -0.76 V vs RHE) compared to glassy carbon electrodes (-0.63 mA/cm(2)) using ethylenediamine (EDA) as the catalyst. Moreover, the faradic efficiency was significantly increased from 2.3% to 58%. This concrete finding shows potential to enhance amine catalytic activity for efficient CO2 reduction. This research has introduced a potentially more sustainable and green method for carbon capture and reduction systems.
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CO2 capture from flue gas using a potassium carbonate supported on alumina (K2CO3/Al2O3) solid sorbent was investigated in different flow patterns/regimes in fluidized bed/semi circulating fluidized bed made from glass reactor at ...
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CO2 capture from flue gas using a potassium carbonate supported on alumina (K2CO3/Al2O3) solid sorbent was investigated in different flow patterns/regimes in fluidized bed/semi circulating fluidized bed made from glass reactor at low temperature 60 °C. The semi-circulating fluidized bed reactor has 0.025 m of inner diameter and 0.80 m of height. The CO2 capture capacity were measured in the presence of H2O for five different flow patterns/regimes including fixed bed, multiple bubbling, slugging, turbulent and fast fluidization. It can be found that the fixed bed and multiple-bubbling bed could adsorb all CO2 in flue gas (CO2 removal fraction = 1) during 17 min and 10 min, respectively. The slugging, turbulent and fast fluidization could not remove 100% of CO2 in feed gas. Maximum CO2 removal fractions for slugging, turbulent and fast fluidization were 0.98, 0.94 and 0.72, respectively. However, the turbulent regime provided the best CO2 capture capacity at about 90% of stoichiometric theoretical value. The CO2 capture capacity for the multiple-bubbling and fast fluidization regimes were lower with about 66-72% of stoichiometric theoretical value. The fixed bed and slugging regimes provided the poorest CO2 capture capacity at about 53-60% of stoichiometric theoretical value. From all the obtained results, the CO2 capture capacity of the sorbent changed dramatically depending on the flow patterns/regimes in fluidized bed/ circulating fluidized bed.
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