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Abstract To assess the electric power grid environment under the high penetration of photovoltaic (PV) generation, it is important to construct an accurate representation of PV power output for any location in the southwestern United States at resolutions down to 10-min time steps. Existing analyses, however, typically depend on sparsely spaced measurements and often include modeled data as a basis for extrapolation. Consequentially, analysts have been confronted with inaccurate analytic outcomes due to both the quality of the modeled data and the approximations introduced when combining data with differing space/time attributes and resolutions. This study proposes an accurate methodology for 10-min PV estimation based on the self-consistent combination of data with disparate spatial and temporal characteristics. Our Type I estimation uses the nearby locations of temporally detailed PV measurements, whereas our Type II estimation goes beyond the spatial range of the measured PV incorporating alternative data set(s) for areas with no PV measurements; those alternative data sets consist of: (1) modeled PV output and secondary cloud cover information around space/time estimation points, and (2) their associated uncertainty. The Type I estimation identifies a spatial range from existing PV sites (30–40 km), which is used to estimate accurately 10-min PV output performance. Beyond that spatial range, the data-quality-control estimation (Type II) demonstrates increasing improvement over the Type I estimation that does not assimilate the uncertainty of data sources. The methodology developed herein can assist the evaluation of the impact of PV generation on the electric power grid, quantify the value of measured data, and optimize the placement of new measurement sites.

Hot flue gas evaporation technology is an effective strategy for zero liquid discharge of desulfurization wastewater. However, there is a potential risk that heavy metals such as Hg may be released from the wastewater during evaporation, disrupting the original balance of the power plant or even exceeding the Hg emission standard. Wastewater evaporation and Hg release behavior were obtained using a single droplet drying system. At an evaporation temperature of 300 °C, approximately 18.5% of Hg was released in the constant wet-bulb temperature period, and the remaining was released in the following evaporation periods. Furthermore, a fixed-bed experiment, in combination with density functional theory calculations, was used to investigate the possible migration mechanisms of released Hg. The results revealed that high HCl concentration, introduced fly ash, and precipitated evaporation products play a crucial role in the fate of Hg, and 85.3% of Hg finally turned into less harmful particulate-bound Hg. This study provides a new and effective strategy for evaluating the migration process of pollutants in wastewater treatment. Moreover, it will serve as an essential reference for advanced wastewater treatment and heavy metals control technologies in the future.

Abstract A waste heat air drying system, including a top closed air drying cycle and a bottom organic Rankine cycle (ORC), is proposed, considering the temperature matches during the humid air sensible heat and latent heat recovery processes. In the top air cycle, the waste heat is used as heat source. In the bottom ORC, the sensible heat and latent heat in the humid air of the top cycle are recovered to generate power and get rid of the moisture. The results showed two key parameters, including the working composition and the evaporating pressure of the bottom ORC, influence thermal matching of the humid air waste heat recovering process, and then on overall energy saving performance of the proposed system significantly. Using the zeotropic mixtures as working fluids of the bottom ORC is a better way with the air relative moisture content lower than 0.2, compared to that of using pure working fluids. While, using the pure working fluid is better with the air relative moisture content over 0.2. The optimal evaporating pressure of the bottom ORC is obtained, to achieve the maximal specific net power output and total thermal efficiency of the drying system.

Abstract In world practice bioethanol is widely used as a component for standard motor gasolines, with concentration 5–15% by volume (E5, E10, E15 fuels) or as bioethanol fuels with ethanol content from 20% till 85% by volume (E20-E85 fuels). Currently in Russia the motor biofuel and its components are not used. At the same time, the development of biotechnologies and bioenergy is the priority task of the scientific and technical policy of the State. The complex program sets the goal to increase the consumption volume of motor biofuel up to 10% till 2020. It should be achieved primarily by bioethanol production, which will be used as a component of automotive gasolines or for production of bioethanol fuels. Bioethanol in Russia can be used in essentially different ways: 1) as a high-octane component in concentration not higher than by 5% by volume for the production of motor gasoline 2) as a high-octane component in concentration not higher than 10% by volume for benzanol (gasohol) production 3) for ethyl tertiary butyl ether (ETBE) production 4) as a component of bioethanol fuels in concentration up to 85% by volume. The final aspect is especially topical for production of high quality high-octane fuel from low-octane hydrocarbon fractions, as well as maximum utilization of bioethanol octane-increasing potential. Currently VNII NP JSC is conducting research work aimed to develop production technology of E30 and E85 bioethanol fuels. This technology will enable the essential expansion of the potential of bioethanol application and the efficient resolution of usage of low-octane fractions due to production of high-octane fuel with improved ecological characteristics with a minimum possible cost. This article presents the developed technical requirements for bioethanol fuels E30, E85.

Subcooling application in cooling processes leads to increasing of cooling performance and energy efficiency within defined limits. This study examines subcooling effects of refrigerants on the coefficient of performance (COP), exergy efficiency and environmental performances based on total equivalent warming impact (TEWI) and human health damage (HDD), which are considered environmental parameters, by considering different refrigerants. In the analyses, direct expansion (DX) system, which is used commonly in supermarkets, and the evaporator temperatures of the system 238 and 273 K are taken as reference. In addition, current refrigerants R-22, R-404A and R-507 and the alternative refrigerant R-407C are examined separately. The results of analyses show that the subcooling of 5 K in condenser causes energy saving between 4% and 8% as depending on the refrigerants and provides an increase as the exergy efficiency between 3% and 25%. Besides, HDD and TEWI values also decrease with increasing of subcooling temperature. At the end of the study, effect on system performance of subcooling processes was emphasised as related to exergy and TEWI analyses.

Abstract In recent years, the government and community have focused extensive attention on food waste recycling to achieve sustainable waste management. However, the motivation of stakeholders from the commercial and industrial sector to change recycling behaviour has not received enough attention. This study aimed to identify, prioritise, and quantify the relationships between key latent variables that affect the food waste recycling behaviour of relevant industries in Hong Kong (i.e. representatives from the hotel, food and beverages, and property management industries). This study integrated semi-structured interviews and a survey questionnaire on the basis of the Theory of Planned Behaviour, setting it apart from conventional studies on food waste behavioural factors. Qualitative content analysis and quantitative structural equation modelling were performed to analyse the interview and questionnaire responses, followed by correlation analysis to quantify the relationships between variables. The results demonstrate that food waste recycling behaviour is determined by three latent variables—administrative incentives and corporate support, logistics and management incentives, and economic incentives. Administrative incentives and corporate support demonstrate significant effects on recycling behaviour. Moral attitudes show a strong positive correlation with administrative incentives and corporate support. Similarly, there is a significant positive correlation between moral attitudes and logistics and management incentives. Administrative incentives and corporate support is the determining variable for the hotel and food and beverages industries, whereas logistics and management incentives are of the highest concern to property management representatives. These findings can facilitate the development of stakeholder-oriented policy to encourage corporate behavioural change towards food waste recycling for sustainable resource circulation.

Abstract Lithium-ion batteries (LIBs) have driven the industry of rechargeable batteries in recent years due to their advantages such as high energy and power density and relatively long lifespan. Nevertheless, the dispose of spent LIBs has harmful impacts on the environment which needs to be addressed by recycling LIBs. However, none of the currently developed recycling processes is economical. The physical recycling process of LIBs may be economical if the cathode active materials can be separated, regenerated, and reused to make new LIBs. However, the first barrier for regeneration and reusing is the separation of different types of spent cathode active materials in the filter cake that are mixed with each other and come in the form of very fine powders with various sizes (< 30 μm) from the physical recycling process. The aim of this study is to separate the mixture of cathode active materials by adopting Stokes’ law. The focus will be only on mechanical separation with no thermal or chemical separation methods. For the validation, an experiment was designed and successfully performed where different types of spent cathode materials (e.g., LiCoO2, LiFePO4, and LiMn2O4) were separated from the spent anode materials (e.g., graphite) with high efficiency and reasonable time.

Abstract Detailed estimates of carbon dioxide emissions at fine spatial scales are critical to both modelers and decision makers dealing with global warming and climate change. Globally, traffic-related emissions of carbon dioxide are growing rapidly. This paper presents a new method based on a multiple linear regression model to disaggregate traffic-related CO2 emission estimates from the parish-level scale to a 1 × 1 km grid scale. Considering the allocation factors (population density, urban area, income, road density) together, we used a correlation and regression analysis to determine the relationship between these factors and traffic-related CO2 emissions, and developed the best-fit model. The method was applied to downscale the traffic-related CO2 emission values by parish (i.e. county) for the State of Louisiana into 1-km2 grid cells. In the four highest parishes in traffic-related CO2 emissions, the biggest area that has above average CO2 emissions is found in East Baton Rouge, and the smallest area with no CO2 emissions is also in East Baton Rouge, but Orleans has the most CO2 emissions per unit area. The result reveals that high CO2 emissions are concentrated in dense road network of urban areas with high population density and low CO2 emissions are distributed in rural areas with low population density, sparse road network. The proposed method can be used to identify the emission “hot spots” at fine scale and is considered more accurate and less time-consuming than the previous methods.