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Significant amounts of energy are used in the conventional methods for drying wet carbonaceous materials such as biomass, low-rank coals, sludge, and manure, because the latent heat for evaporating water is large. An innovative drying process, based on self-heat recuperation technology that recovers not only latent heat but also sensible heat, was developed to save drying energy. Water contained in a wet sample is heated to its boiling point, and the resulting steam is superheated. The superheated steam is compressed to provide a temperature difference for heat exchange. The condensation heat of the compressed steam is exchanged with the evaporation heat of the water from the wet sample. The sensible heat of the compressed steam is utilized to raise the temperature of both evaporated steam (superheating) and water contained in the wet sample (preheating). In addition, the sensible heat of the dried sample is recovered by gas to improve the overall energy efficiency. The amount of energy required for the p...

Significant amounts of energy are used in the conventional methods for drying wet carbonaceous materials such as biomass, low-rank coals, sludge, and manure, because the latent heat for evaporating water is large. An innovative drying process, based on self-heat recuperation technology that recovers not only latent heat but also sensible heat, was developed to save drying energy. Water contained in a wet sample is heated to its boiling point, and the resulting steam is superheated. The superheated steam is compressed to provide a temperature difference for heat exchange. The condensation heat of the compressed steam is exchanged with the evaporation heat of the water from the wet sample. The sensible heat of the compressed steam is utilized to raise the temperature of both evaporated steam (superheating) and water contained in the wet sample (preheating). In addition, the sensible heat of the dried sample is recovered by gas to improve the overall energy efficiency. The amount of energy required for the p...

Abstract Decarbonization of the energy system is a key goal of the Paris Agreements, in order to limit temperature rises to under 2° Celsius. Hydrogen has the potential to play a key role through its versatile production methods, end uses and as a storage medium for renewable energy, engendering the future low-carbon energy system. This research uses a global model cognizant of energy policy, technology learning curves and international carbon reduction targets to optimize the future energy system in terms of cost and carbon emissions to the year 2050. Exploring combinations of four exploratory scenarios incorporating hydrogen city gas blend levels, nuclear restrictions, regional emission reduction obligations and carbon capture and storage deployment timelines, it was identified that hydrogen has the potential to supply approximately two percent of global energy needs by 2050. Irrespective of the quantity of hydrogen produced, the transport sector and passenger fuel cell vehicles are consistently a preferential end use for future hydrogen across regions and modeled scenarios. In addition to the potential contribution of hydrogen, a shift toward renewable energy and a significant role for carbon capture and storage is identified to underpin carbon target achievement by 2050.

Abstract Decarbonization of the energy system is a key goal of the Paris Agreements, in order to limit temperature rises to under 2° Celsius. Hydrogen has the potential to play a key role through its versatile production methods, end uses and as a storage medium for renewable energy, engendering the future low-carbon energy system. This research uses a global model cognizant of energy policy, technology learning curves and international carbon reduction targets to optimize the future energy system in terms of cost and carbon emissions to the year 2050. Exploring combinations of four exploratory scenarios incorporating hydrogen city gas blend levels, nuclear restrictions, regional emission reduction obligations and carbon capture and storage deployment timelines, it was identified that hydrogen has the potential to supply approximately two percent of global energy needs by 2050. Irrespective of the quantity of hydrogen produced, the transport sector and passenger fuel cell vehicles are consistently a preferential end use for future hydrogen across regions and modeled scenarios. In addition to the potential contribution of hydrogen, a shift toward renewable energy and a significant role for carbon capture and storage is identified to underpin carbon target achievement by 2050.

Over the last decade, municipal solid waste generation in Phnom Penh has increased noticeably; however, the waste management system is far from satisfactory. Considerable amount of waste is left uncollected, as well as intentionally disposed of in public open spaces. External and internal factors can trigger these problems. Possible external factors are low collection frequency, low cleaning services, and insufficient facilities such as small dumpsters. Possible internal factors, which also play an important role in this issue, include low awareness, insufficient knowledge, and low responsibility for personal waste. To examine the influences of these internal and external factors on people’s waste disposal behaviors, we selected and conducted a questionnaire survey at four sites in Phnom Penh that differ in waste collection frequency and population density. A total of 413 valid responses were obtained. We developed a structural equation model to explain people’s intentions not to dispose of waste in public open spaces. The results showed that personal and social norms, such as perception of social pressure from friends and family and from the government, had significant influences on intention, whereas the influence of external factors was much smaller.

Over the last decade, municipal solid waste generation in Phnom Penh has increased noticeably; however, the waste management system is far from satisfactory. Considerable amount of waste is left uncollected, as well as intentionally disposed of in public open spaces. External and internal factors can trigger these problems. Possible external factors are low collection frequency, low cleaning services, and insufficient facilities such as small dumpsters. Possible internal factors, which also play an important role in this issue, include low awareness, insufficient knowledge, and low responsibility for personal waste. To examine the influences of these internal and external factors on people’s waste disposal behaviors, we selected and conducted a questionnaire survey at four sites in Phnom Penh that differ in waste collection frequency and population density. A total of 413 valid responses were obtained. We developed a structural equation model to explain people’s intentions not to dispose of waste in public open spaces. The results showed that personal and social norms, such as perception of social pressure from friends and family and from the government, had significant influences on intention, whereas the influence of external factors was much smaller.

The demand for novel, cost-effective, and environmentally friendly rare earth element and yttrium (REY) sources is essential. The recovery of REY and other valuable components from coal fly ash (CFA) may result in securing alternative resources, decreased disposal costs, and environmental protection, all of which may have positive effects. However, research on the recovery of REY from CFA is underway, and it is still necessary to assess its viability from an economic and environmental standpoint. The authors have reviewed some of the most recent advances in extracting rare earth elements from CFA. However, most techniques reported for the treatment of CFA are still at the laboratory scale. Nevertheless, there are several pathways for industrial-scale applications. Therefore, CFA treatment and the extraction of valuable products from it have considerable potential for reducing both its carbon footprint and environmental burden.

The demand for novel, cost-effective, and environmentally friendly rare earth element and yttrium (REY) sources is essential. The recovery of REY and other valuable components from coal fly ash (CFA) may result in securing alternative resources, decreased disposal costs, and environmental protection, all of which may have positive effects. However, research on the recovery of REY from CFA is underway, and it is still necessary to assess its viability from an economic and environmental standpoint. The authors have reviewed some of the most recent advances in extracting rare earth elements from CFA. However, most techniques reported for the treatment of CFA are still at the laboratory scale. Nevertheless, there are several pathways for industrial-scale applications. Therefore, CFA treatment and the extraction of valuable products from it have considerable potential for reducing both its carbon footprint and environmental burden.

Micellization of fluorocarbon and hydrocarbon surfactant mixtures in aqueous solution is reviewed. Simple fluorocarbon surfactant micelles can be characterized by growth from sphere to rod-and disk-like form, which is explained by packing constraint. Non-ideality of the mixed systems with head groups of same charge is summarized using interaction parameter calculated by Shinoda's equation. Examples of mixing of separate micelles in the concentrated solutions are given. The mixed systems with different head groups are described from the stand point of micellar growth and vesicle forming.