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The current status and challenges associated with the production and utilization of cellulosic ethanol in Korea are reviewed in this paper. Cellulosic ethanol has emerged as a promising option for mitigating Korea's CO(2) emissions and enhancing its energy security. Korea's limited biomass resources is the most critical barrier to achieving its implementation targets for cellulosic ethanol. Efforts to identify new suitable biomass resources for cellulosic ethanol production are ongoing and intensive. Aquatic biomasses including macroalgae and plantation wastes collected in the Southeast Asia region have been found to have great potential as feedstocks for the production of cellulosic ethanol. R&D explorations into the development of technologies that can convert biomass materials to ethanol more efficiently also are underway. It is expected that cellulosic ethanol will be in supply from 2020 and that, by 2030, its use will have effectively reduced Korea's total gasoline consumption by 10%.

Abstract Transportation de-carbonization is a complex problem involving the economy, population, technology and environment. Implementing the pathway simulation based on systematic methods will help to optimize the transportation sustainability plan. This study’s key motivation is that earlier research ignored the relationship between driving factors and the transmission process. To quantitatively identify the path and process of emission reduction, a hybrid system dynamics STIRPAT-SD model is proposed to explore the transportation optimization’s de-carbonization ability. This study fully considers the composition of elements and subsystems based on the STIRPAT theoretical model and visually shows the system’s feedback relationship. Transportation structural and technical optimization scenarios are set to identify the threshold reduction paths. It is found these optimization strategies have significant de-carbonization effects. And transportation structure policy has the highest de-carbonization efficiency, the emission intensity decreased by 9.1% under the TSS2 scenario (Transportation structure scenario). This study proposes a novelty model combining dynamic simulating processes with a significantly theoretical model to improve simulation and factor composition accuracy. And the joint scenario setting identifies the most effective de-carbonization pathway and clarifies the threshold of all possible pathways. Research findings can effectively track, test, predict the achievement of policy goals, and provide policy optimization references for the sustainable development related to the transportation system in practice.

Abstract The Chinese government has taken measures to realize energy-savings and emission reductions, such as promoting innovations, adjusting the industrial structure, balancing regional development, and reforming markets. The aim of this paper is to assess the effects of these measures on China's CO2 emissions by using a newly proposed decomposition approach, which identified eight new factors related to the above realistic measures, i.e., energy saving and production technologies, industrial energy and production efficiencies, regional energy and production efficiencies, and pure energy and production efficiencies. The main findings indicate benefits from considerable technological progress in energy-saving and production during 2000–2016 period, and two technological factors contributed the most to emissions abatement and cumulatively reduced 5372.43 Mt and 1291.72 Mt CO2 emissions. The efforts of industrial restructuring promoted energy and production efficiency improvement, which further facilitated emission reduction. In contrast, the pure energy and production efficiency changes cumulatively led to 1080.26 Mt and 1135.85 Mt CO2 emissions growth during the whole sample period, suggesting that severe resource misallocation problems may exist in both the energy market and output market. Additionally, the Chinese government failed to narrow the technology gap between developed regions and underdeveloped regions, further restricting emission reduction.

Yard waste is either dumped or is being openly burned to get rid of it, instead of using it as a valuable renewable energy source. In this study, hydrothermal carbonization of yard waste was conducted to valorize it as a solid bio fuel, using a batch reactor. The effect of process parameter on yield, energy and physicochemical properties of the valorized solid bio fuel (hydrochar) was examined in this study by varying reaction temperature (160-200 °C for 2 h) and reaction time (2-24 h at 200 °C). The calorific value of hydrochar was within a range of 17.72-24.59 MJ/kg as compared to 15.37 MJ/kg for untreated yard waste. Hydrochar mass yield decreased from 78.6% at operating temperature - time of 160 °C -2 h to 45.6% at 200 °C -24 h. The plot of atomic ratios (H/C and O/C) demonstrates improvement in the coalification process which was mainly governed by decarboxylation and dehydration reactions. The grindability of the prepared hydrochar was comparable to that of coal. Hydrochar produced at lower reaction condition (160-200 °C at 2 h) have better flowability as compared to that produced at higher reaction condition (4-24 h at 200 °C). The reaction time longer than 12 h has a minimal effect on the yield, energy and physicochemical properties of hydrochar. Increasing reaction time and temperature improved the ignition and burnt temperature of hydrochar. All reaction condition has an energy ratio (energy output to energy input) of more than one making HTC process a net energy producer.

Biogas is a viable alternative for supplying clean and sustainable energy. Despite all manner of policy measures introduced by the Government of India, biogas is not widely used in India. This article tries to identify factors that influence the decision to adopt biogas at household level. We examine a conceptual framework empirically in which a household wants to maximize utility from biogas by using the India Human Development Survey (IHDS) I, which is a nationally representative, multi-topic survey. By applying both maximum likelihood and penalized likelihood methods (Firthlogit) of logistic regression on a sample size of almost 10,384 households, it has been found that wealthy people are more likely to adopt biogas compared to the marginalized section of the society. We recommend more inclusive policy measures for the weaker section of the society to create an enabling environment to make it a self-promoting technology.

In recent years, marine auxiliary diesel engine has been widely used to produce electricity in the large ocean-going ship. One of the main technical challenges for ocean-going ship is to reduce pollutant emissions from marine auxiliary diesel engine and to meet the criteria of disposal on ships pollutants of IMO (International Maritime Organization). Different technical changes have been introduced in marine auxiliary diesel engine to apply clean fuels to reduce pollutant emissions. The ultralow sulfur light fuel will be applied in diesel engine for emission reductions in China. This study is aimed to investigate the impact of fuel (ultralow sulfur light fuel) on the combustion characteristic, NOx and green house gas emissions in a marine auxiliary diesel engine, under the 50%-90% engine speeds and the 25%-100% engine torques. The experimental results show that, in the marine auxiliary diesel engine, the cylinder pressure and peak heat release rate increase slightly with the increase of engine torques, while the ignition advances and combustion duration become longer. With the increases of the engine speed and torque, the fuel consumption decreases significantly, while the temperature of the exhaust manifold increases. The NOx emissions increase significantly with the increases of the engine speed and torque. The NO emission increases with the increases of the engine speed and torque, while the NO2 emission decreases. Meanwhile, the ratio of NO2 and NO is about 1:1 when the diesel engine operated in the low speed and load, while the ratio increases significantly with the increases of engine speed and torque, due to the increase of the cylinder temperature in the diffusive combustion mode. Moreover, the CO2 emission increases with the increases of engine speed and torque by the use of ultralow sulfur light fuel.

Bioenergy is considered a sustainable substitute to fossil-fuel resources and the development of a prudent combination of renewable and innovative conversion technologies are essential for the valorization and effective conversion of biowaste to value-added commodities. Here, a negative pressure-induced carbonization process was proposed for the valorization of lignin-enriched biowaste precursor to bio-oil and environmental materials (biochar) at various temperatures. The high heating values (HHV) of the as-prepared biochars from the lignin enriched precursor under negative pressure (low-medium vacuum) were within 25.9-31.5 MJ/kg, which matched satisfactorily to the commercial charcoal. Whereas, the bio-oils produced from the lignin enriched precursor under vacuum conditions was a blend of complex aromatic and straight-chain hydro-carbons, including aldehyde, ketone, phenol, and furans, exhibiting ability as potential heating-oil with HHV within 21.2-28.2 MJ/kg. Moreover, the biochars produced under vacuum environments at higher temperature showed greater stability (22.5-35.9%) than those produced under N2 atmosphere.

Abstract With the ever-growing need for lithium-ion batteries, particularly from the electric transportation industry, a large amount of lithium-ion batteries is bound to retire in the near future, thereby leading to serious disposal problems and detrimental impacts on environment and energy conservation. Currently, commercial lithium-ion batteries are composed of transition metal oxides or phosphates, aluminum, copper, graphite, organic electrolytes with harmful lithium salts, polymer separators, and plastic or metallic cases. The lack of proper disposal of spent lithium-ion batteries probably results in grave consequences, such as environmental pollution and waste of resources. Thus, recycling of spent lithium-ion batteries starts to receive attentions in recent years. However, owing to the pursuit of lithium-ion batteries with higher energy density, higher safety and more affordable price, the materials used in lithium-ion batteries are of a wide diversity and ever-evolving, consequently bringing difficulties to the recycling of spent lithium-ion batteries. To address this issue, both technological innovations and the participation of governments are required. This article provides a review of recent advances in recycling technologies of spent lithium-ion batteries, including the development of recycling processes, the products obtained from recycling, and the effects of recycling on environmental burdens. In addition, the remaining challenges and future perspectives are also highlighted.

Abstract Domestic wind turbine manufacturing sector in China has experienced development stages starting from scratch to mass production. During the 11th FYP period (2006–2010), the main goal of wind power policy in China is to promote the commercialization of wind power by large-scale deployment of wind farms. This goal has been realized to a great extent and now the cost of wind power generation is nearly comparable to coal-fired power generation in China. The industry policy, which devotes to mass production of domestic wind turbines, is also largely successful. The purpose of the paper is to provide an overview on wind turbine manufacturing sector in China. The policy evolution in different stages, achievements and challenges pertinent to the sector are addressed in the paper. Key findings are that the misleading industry policy, which provides strong incentive to blind entrance and “competition for scale and price” and restrains innovation as well, is the key obstacle for the sustainable development of the sector. Deficient technology standard and qualification system and the misplaced franchise bidding system also indulge vicious competition and oversupply. Creating a level playground for all turbine supplies, providing strong incentive to innovative manufacturers, establishing thorough and practicable standard and qualification system, and fine-tuning the directive of the franchise bidding system towards technology and service are the primary policy implications proposed by our study.