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Refuse Derived Fuel is energy derived from converting various wastes including municipal solid waste, industrial waste and other combustible components into alternative fuels as a coal substitute. This sustainable technology can significantly reduce the carbon footprint and provide additional environmental credentials, as, without these energy recovery techniques, the non-recyclable waste would be disposed of in landfills or incinerated. Therefore, this study aimed to estimate the carbon footprint of industrial wastes-based solid fuel (IWSF) using a life cycle assessment approach developed using a mixture of hazardous waste and biomass. The utilization of hazardous waste to produce solid fuel and its usage as a substitute fuel in cement kilns is relatively a novel approach. The simple and structured carbon footprint method used in this study has considered the greenhouse gas (GHG) emissions from the transportation of waste, manufacturing of IWSF, waste disposal, IWSF utilization in the cement manufacturing plant, and IWSF end of life. The feasibility of cofiring IWSF at a rate of 5 tons/h (10% of IWSF) with coal in the cement kiln and the GHG emissions associated with replacing the coal with IWSF are investigated. The overall carbon footprint of the IWSF is quantified in terms of greenhouse gas emissions and represented in carbon dioxide equivalents (CO2e). The evaluations estimated that the carbon footprint of using a mixture of IWSF and coal is equal to 0.185 kg CO2e. MJ−1. The findings indicate that replacing solar panels and 70% of conventional fluorescent lamps at the IWSF manufacturing plant with LED bulbs could reduce 24.8% and 45.5% of energy, respectively. In summary, the results showed that cofiring IWSF at a rate of 5 tonnes/h in cement kilns could help reduce CO2 emissions, lower clinker production costs due to the use of cheaper fuel, and promote sustainability. [ABSTRACT FROM AUTHOR]

A growing body of research has investigated the relationship between indoor air pollution from solid fuel and depression risk. Our study aimed to elucidate the relationship between indoor air pollution from solid fuel and depression in observational studies. The effect of indoor air pollution on depression was estimated using pooled odds ratios (ORs) with 95% confidence intervals (CIs). Heterogeneity was evaluated by the I-squared value (I2), and the random-effects model was adopted as the summary method. We finalized nine articles with 70,214 subjects. The results showed a statistically positive relationship between the use of household solid fuel and depression (OR = 1.22, 95% CI = 1.09–1.36). Subgroup analysis based on fuel type groups demonstrated that indoor air pollution from solid fuel was a higher risk to depression (OR = 1.24, 95% CI = 1. 10–1.39; I2 = 67.0%) than that from biomass (OR = 1.18, 95% CI = 0.96–1.45; I2 = 66.5%). In terms of fuel use, the use of solid fuel for cooking and heating increased depression risk, and the pooled ORs were 1.21 (95% CI = 1.08–1.36) and 1.23 (95% CI = 1.13–1.34). Exposure to indoor air pollution from solid fuel might increase depression risk. [ABSTRACT FROM AUTHOR]

Previous research found tobacco smoking and solid fuel use for cooking to increase the risk of chronic liver disease mortality, but previous cohort studies have not investigated their independent and joint associations with liver cancer incidence in contemporary China. The China Kadoorie Biobank (CKB) study recruited 0.5 million adults aged 30 to 79 years from 10 areas across China during 2004 to 2008. Participants reported detailed smoking and fuel use information at baseline. After an 11.1‐year median follow‐up via electronic record linkage, we recorded 2997 liver cancer cases. Overall, 29.4% participants were current smokers. Among those who cooked at least once per month, 48.8% always used solid fuels (ie, coal or wood) for cooking. Tobacco smoking and solid fuel use for cooking were independently associated with increased risks of liver cancer, with hazard ratios (95% confidence intervals [CIs]) of 1.28 (1.15‐1.42) and 1.25 (1.03‐1.52), respectively. The more cigarettes consumed each day, the earlier the age of starting smoking or the longer duration of solid fuels exposure, the higher the risk (Ptrend <.001, =.001, =.018, respectively). Compared with never smokers who had always used clean fuels (ie, gas or electricity), ever‐smokers who had always used solid fuels for cooking had a 67% (95% CIs: 1.29‐2.17) higher risk. Among Chinese adults, tobacco smoking and solid fuel use for cooking were independently associated with higher risk of liver cancer incidence. Stronger association was observed with higher number of daily cigarette consumption, the earlier age of starting smoking and longer duration of solid fuel use. [ABSTRACT FROM AUTHOR]

Spent coffee grounds (SCG) are industrial biowaste resulting from the coffee-brewing process, and they are often underutilized and end up in landfills, thereby leading to the emission of toxic gases and environmental damage. Hydrothermal carbonization (HTC) is an attractive approach to valorize wet biomass such as SCG to valuable bioproducts (i.e., hydrochar). Thus, in this work, the HTC of SCG was carried out in a 500 L stainless steel vessel at 150, 170, 190, 210, and 230 °C for 30 min, 60 min, 90 min, and 120 min and a feedstock to water weight ratio of 1:5, 1:10, and 1:15, and the use of the resulting hydrochar as a solid fuel was evaluated. The results showed that a high energy recovery (83.93%) and HHV (23.54 MJ/kg) of hydrochar was obtained at moderate conditions (150 °C, 30 min, and feedstock to water weight ratio of 1:5) when compared with conventional approaches such as torrefaction. Following this, the surface morphology, functionality, and combustion behavior of this hydrochar were characterized by SEM, FTIR, and TGA, respectively. In short, it can be concluded that HTC is an effective approach for producing solid fuel from SCG and the resulting hydrochar has the potential to be applied either in domestic heating or large-scale co-firing plants. [ABSTRACT FROM AUTHOR]

This paper presents an improved mathematical model for gasification of a solid porous fuel when hot gases are filtered through it. Gasification modes were studied at a constant pressure drop between the gasifier inlet and outlet and at a constant gas velocity at the gasifier inlet using polymethyl methacrylate as an example. In the case of a constant pressure drop, fuel gasification takes longer and the gas temperature at the outlet increases more slowly than in the case of a constant gas velocity at the inlet under comparable conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Co-HTC significantly improved the hydrochar quality as a solid fuel. • Co-HTC increased the fixed carbon but decreased the ash contents in the hydrochar. • Both HHV and fuel ratio increased as the proportions of rice straw increased. • The hydrochar combustibility index increased by 30% to 419% with co-HTC. • The synergistic effect of co-HTC is more significant at 180 °C and 220 °C. This study assessed the effects of mass mixing ratio and hydrothermal temperature on the co-hydrothermal carbonization (co-HTC) of sewage sludge and rice straw regarding the yield, chemical composition, fuel properties, surface functional groups, and combustion behavior of the hydrochar. The co-HTC increased the hydrochar yield at 180 °C but decreased it at 220 and 260 °C. The co-HTC increased the hydrochar organic matter contents, higher heating values, fuel ratios, and combustion behavior (combustibility index) by 16 % to 63 %, 15 % to 85 %, 51 % to 321 %, and 30 % to 419 %, respectively. The co-HTC also enhanced the formation of oxygen-containing functional groups on the hydrochar surface. The synergistic and anti-synergistic effects of the co-HTC were more positive at 180 and 220 °C but more negative at 260 °C. The co-HTC of municipal sludge and rice straw is promising in converting waste materials into high-quality hydrochar as a clean solid fuel. [ABSTRACT FROM AUTHOR]

• New numerical model for studying the gasification of multi-component porous fuels is developed. • Effect of the layering of solid porous fuels on their gasification is investigated. • During the gasification of multi-layer fuels, several gasification waves can occur simultaneously. • Operating time of the gasifier depends on the relative position of the fuel layers. • Relative sizes of the layers and their relative arrangement can be control parameters. The paper is aimed at investigating the influence of porous fuel layering on the operating regimes and performance of a low-temperature gas generator for high-speed flying vehicles equipped with a ramjet engine. The gas generator consists of a propellant and a porous fuel arranged sequentially to generate hydrocarbon gases that cool the engine before burning in the combustion chamber. In this paper, using a novel numerical model, gasification of multi-layer solid porous fuels consisting of polymethylmethacrylate (PMMA) and polyethylene (PE) is studied for various volume contents and relative arrangements of fuel parts. It is shown that during the gasification of the multi-layer fuels, several gasification waves can simultaneously occur in the gas generator. The operating time of the gas generator depends on the relative sizes and relative location of the PMMA and PE layers, and an increase in the number of layers leads to a decrease in the influence of their relative arrangement on the process. Thus, during the gasification of two-component multi-layer solid porous fuel, the composition of this fuel, i.e., the relative sizes of the layers and their relative arrangement, can be the control parameter that allows one to choose the desired characteristics of the gasification process. [ABSTRACT FROM AUTHOR]

This study introduces an experimental framework employing hydrothermal carbonization (HTC) for the valorisation of factory tea waste as a solid fuel. Employing a centre composite design and response surface methodology, the investigation systematically assesses the influence of two critical process parameters, temperature (180–220 °C) and time (0–240 min), on higher heating value (HHV), hydrochar yield, and energy yield. The study identifies an optimized HTC condition (220°C, 55 min) resulting in the recorded HHV of 22.26±1.10 Mj/Kg. Combustion characteristics and kinetics of the factory tea waste-derived hydrochar (TW-hydrochar) is analysed through TGA and DTG, complemented by structural elucidation via FTIR and FE-SEM. Concurrently, the study reports the observation of carbon dots (TW-CDs) generation during TW-hydrochar production, characterized comprehensively through UV–visible spectroscopy, TEM, XRD, XPS, Zeta potential, and fluorescence methods. Further, antimicrobial properties of TW-CDs are rigorously investigated against Bacillus subtilis and Escherichia coli , manifesting pronounced antibacterial activity against B. subtilis and E. coli as evidenced by a 12 mm and 11 mm inhibition zone, respectively. This research contributes to the scientific understanding of tea waste valorization through HTC, providing insights into cleaner fuel options and the emergence of carbon dots with potential antibacterial applications. [Display omitted] • Hydrochar and carbon dots were simultaneously prepared from factory tea waste. • Optimized HTC (220°C, 55 min) yields TW-hydrochar with HHV of 22.26±1.10 Mj/Kg. • Combustion kinetics of TW-hydrochar was analysed using DFM, KAS, STK, OFW, and DAEM. • TW-CDs possess effective antibacterial activity against B. subtilis and E. coli. [ABSTRACT FROM AUTHOR]

The complex and severe problem of energy poverty seriously affects the health and quality of life of residents and poses a significant challenge to the country’s macroeconomic development. The purpose of this paper is to analyze the spatial distribution of energy poverty and the characteristics of regional differences in 30 provinces in mainland China from 2008 to 2019 by constructing an energy poverty evaluation index system and explore the main reasons for the gap between energy poverty regions in China from the perspective of “relational data.” The results show that the spatial distribution of energy poverty in China is “high in the west and central area and low in the east,” and the spatial pattern is relatively stable. From the perspective of the time dimension, the problem of energy poverty in China has been alleviated during the sample period, and the overall gap in energy poverty has shown a decreasing trend. The difference in energy poverty between regions is the primary source of the overall gap, but its contribution is gradually decreasing. The empirical results suggest that reducing the imbalance of industrial structure, energy price, and energy investment among regions can effectively narrow the inter-regional energy poverty gap. Moreover, there are differences in the dominant factors that determine the difference in energy poverty within the eastern, central, and western regions. In this regard, it is recommended to further improve the relevant policies in developing new energy sources according to local conditions, reasonably increasing energy construction investment, strengthening technological innovation, establishing financial guarantee mechanisms, and guiding residents to consume modern, clean energy.

BackgroundHousehold solid fuel have been associated with changes of handgrip strength (HGS). However, no study has explored the longitudinal associations between household solid fuel use and HGS. Thus, the aim of our cohort study was to investigate the longitudinal associations between household fuel use and HGS.MethodsThe study was based on the China Health and Retirement Longitudinal Study. A handheld dynamometer was used to measure HGS. Household fuel use statuses were collected using questionnaires. Analyses of covariance were performed to examine the associations between household fuel use and HGS.ResultsThe study included 9,382 participants during a 4-year follow-up. The participants who used solid fuel for cooking had more decreases of HGS than those who used clean fuel (P < 0.0001). The least square means (95% CIs) of changes of HGS for participants who used solid fuel and those who used clean fuel for cooking were −1.67 (−2.15, −1.19) and−2.27 (−2.75, −1.79), respectively. The association between fuel use for heating and HGS was non-significant (P = 0.63). The interaction terms of sex to cooking fuel (P = 0.04) and smoking to cooking fuel (P < 0.001) were significant; men and participants who had ever smoked had higher decreases in HGS.ConclusionUsing household solid fuel for cooking but not heating was associated with more decreases in HGS. Proper ventilation and clean fuel should be promoted for public health.

• Incomplete solid fuel burning is the major source of atmospheric phenols and EPFRs. • Phenols emitted from incomplete solid fuel burning strongly correlates with EPFRs. • Higher levels of primary phenols and EPFRs present in China's agricultural regions. Environmentally persistent free radicals (EPFRs) bonded to fine particle matters (PMs) are known to cause adverse health impacts. This study comprehensively addressed their emission sources and major precursors including phenols, based on field measurements and inventory estimation. The emission characteristics of phenols and EPFRs were obtained through direct measurement of PM 2.5 and gaseous samples, collected from various real-world anthropogenic sources. The residential sector (coal and biomass combustion) was revealed to produce the highest level of EPFRs (0.66 to 3.21 × 1017 spins/g) and phenols (5.8 to 55.9 mg/g) per unit mass of emitted PM 2.5 amidst all estimated samples, including power plant, various industrial processes, and transportation sources. Additionally, the emission of phenols strongly correlates with that of EPFRs, indicating an EPFR transition pathway during the pyrolysis process of lignin. Furthermore, the residential sector contributed approximately 80.6 % of atmospheric EPFRs and 99.9 % of phenols as primary emitted PM 2.5 in mainland China in 2019. Much higher levels of primary phenols and EPFRs presented in agricultural regions, where biomass was commonly used as household fuel. The obtained results highlight that the pollution control of residential solid fuel burning can efficiently relieve the negative impacts associated with atmospheric phenols and EPFRs. [ABSTRACT FROM AUTHOR]

This study investigates the application of supercritical CO 2 (SC-CO 2) in acerola waste pretreatment for hydrothermal carbonization, examining the impact of ZnCl 2 as an additive. Quantified response variables included hydrochar yield, high heat value, energy yield and oxygenated functional groups. Four equations were proposed to correlate the independent variables-additive concentration (C), temperature (T) and residence time (t)-with each response. Subsequently, a multiple-response optimization study was conducted to determine the best conditions, considering all responses. Utilizing SC-CO 2 pretreatment and ZnCl 2 additive resulted in hydrochar with the highest values for all responses. The optimum conditions obtained were T = 161.4°C, t = 105.5 min, and C = 1.43%. The hydrochar obtained under optimal conditions demonstrated that the supercritical CO 2 pretreatment associated to the use of ZnCl 2 additive increased the process yield in 11.02% and the energy yield in 13.02%, confirming the potential application of the hydrochar as a solid fuel. [Display omitted] • The application Supercritical CO 2 pretreatment to hydrothermal carbonization was investigated. • The effect of using ZnCl2 solution in the process was analyzed. • Supercritical CO 2 enhance hydrochar and energy yield in, 9.58% and 10.58% respectively. • The supercritical CO 2 pretreatment with ZnCl 2 increased the hydrochar yield in 11.02%. • The combine treatment raised the energy yield in 13.02%. [ABSTRACT FROM AUTHOR]

This study investigated the potential of hydrothermal carbonization (HTC) using the inherent moisture (50% wet basis) of wheat straw for improving the undesirable characteristics of wheat straw and producing high-quality pellets. The material was treated at temperatures of 100, 140, 180, and 220 °C for 15 and 30 min. When compared to the untreated sample, the pellets produced from samples treated at 220 °C for 30 min showed the lowest water adsorption of 10%, the highest bulk density of 147.6 kg/m3, and the highest HHV of 22.2 MJ/kg, though the ash content increased to 8.9%, and the durability was reduced to 87.0%. Pellets produced from samples treated at 140 °C for 30 min showed the highest durability of 97.7% and hardness of 5.1 N/mm2 with enhanced HHV of 18.3 MJ/kg, and unchanged ash content. The treatment time showed significant effect (p < 0.05) on pellet durability, hardness and water adsorption at temperature of 100 and 140 °C. However, there was no obvious effect when the temperature was 180 and 220 °C. The kinetic analysis indicates that the activation energy drops from 89.9 kJ/mol (raw wheat straw pellet) to 44.4 kJ/mol (220–30 pellet) and from 162.2 kJ/mol to 93.8 kJ/mol using the reaction order model and the 3D diffusion model, respectively. Pellets produced by HTC at 140 °C for 30 min make high-quality pellets with lower energy and water consumption as compared to the more severe HTC conditions previously reported. [Display omitted] [ABSTRACT FROM AUTHOR]

Solid fuels are types of fuel that comprise coal, biomass, charcoal, wood, or straw and are used for cooking, heating, lighting, boiling water, and generating revenue at home. Globally, 3 billion of the world's poorest people continue to rely on inefficient solid fuels, which produce health-damaging contaminants. In Ethiopia, more than 90% of households rely on wood as their primary source of energy. The actual and potential determinants of solid fuel use have not been fully identified, particularly at the national level in Ethiopia. Therefore, this study aimed to determine the magnitude of solid fuel use and its associated factors in Ethiopia. We used the Ethiopian Demographic and Health Survey (EDHS), which was conducted in 2016. The data was conducted using a 2-stage stratified cluster sampling approach. A total of 16 650 weighted samples were taken. Multilevel logistic regression models were fitted to identify factors associated with solid fuel use, and a cluster-level random intercept was introduced in the mixed model. An adjusted odds ratio with a 95% confidence level was reported to show the strength of the association and its significance. The goodness of fit of the model was checked using proportional change deviance (PCV). The magnitude of solid fuel use among households in Ethiopia was 94.03% (95% CI = 93.66, 94.37). Household heads completed in primary school (AOR, 3.09, 95% CI = 2.44, 3.91), outdoor cooking places (AOR, 4.13, 95% CI = 2.96, 5.76), and small peripheral regions (AOR, 14.44, 95% CI = 6.12, 34.04) were all significantly associated with solid fuel use. The intra-cluster correlation coefficient (ICC) showed that about 81% of the variations in the use of solid fuel were attributed to the difference at the 643 cluster level, but the remaining 19% were attributed to individual household factors. The PCV was 90%, which showed that the variation in solid fuel use among study households was explained by factors at both the individual and community levels. The deviation test of the fourth model had the lowest value (3528) and was chosen as the best-fitted model. Due to different influencing factors, the use of solid fuel is still high in Ethiopia. Promoting access to education and raising awareness toward solid fuel impact is very important. [ABSTRACT FROM AUTHOR]

An updated systematic review was conducted to assessing on the association between indoor air pollution caused by household energy consumption and childhood pneumonia in low- and middle-income countries. We performed a meta-analysis from the electronic databases of PubMed, Cochrane library, Web of Science, EMBASE. Studies were selected when they reported childhood pneumonia or ALRI in relation to indoor air pollution resulted from solid fuel. Studies must provide results on exposure prevalence of children aged below 5 years from Asia or Africa. We devoted ourselves to identifying randomized controlled experiments and observational epidemiological researches, which revealed the relation between household usage of solid fuel and childhood pneumonia. Among 1954 articles, 276 were reviewed thoroughly and 16 conduced to such a meta-analysis. It was found that there is a significant relationship between the solid fuel combustion and increasing risk of childhood pneumonia (OR = 1.66, 95%CI 1.36–2.02). The summary odds ratios from biomass use and mixed fuel use were, respectively, 1.86 (95%CI 1.15–3.02) and 1.58 (95%CI 1.38–1.81), with substantial between study heterogeneity (I2 = 87.2% and 29.2%, respectively). According to the subgroup analysis along with the meta-regression analysis, the risk of using solid fuel in Asian regions is higher than that in African regions. Studies based on non-hospital participates (I2 = 49.5%) may also a source of heterogeneity. We found that indoor air pollution generated by the usage of solid fuel might be a significant risk factor for pneumonia in children and suggested improving the indoor air quality by promoting cleaner fuel will be important in undeveloped countries. [ABSTRACT FROM AUTHOR]

The article describes the experimental studies results of the use of barley brewer's spent grain (BSG) for the production of alternative solid fuels. A method of obtaining briquettes by pressing is described. The calorific values of the raw material and the obtained samples are defined. According to the research results, the highest calorific value of the dried brewer's spent grain is 20005 kJ/kg, and that of the created solid fuel samples - briquettes - is in the range from 20173 to 20298 kJ/kg. The residual moisture content of the dried brewer's spent grain was ~ 6.5 % wt., the ash content of the dried brewer's spent grain was in the range of 1.6 ÷ 2.3 % wt. The residual moisture content of the briquettes was in the range of 0.5 ÷ 1.5% wt., and the ash content was in the range of 1.5 ÷ 1.6 % wt. The obtained alternative solid fuel, which contains barley brewer's spent grain, has a high calorific value, does not contain harmful impuritiesor require additional cleaning or auxiliaries to form a solid form, provides additional disposal of industrial beer industry wastes, increases environmental friendliness by replacing traditional fuel resources with absence of large amounts of harmful emissions. Created samples do not require binders and precleaning before production. [ABSTRACT FROM AUTHOR]

The mathematical model and numerical method proposed in this study make it possible to study the regularities of gasification of solid porous fuel when hot gases are filtered through it and estimate the maximum operating time of the propulsion system. The features of gasification are studied for the case when polymethyl methacrylate is used as a solid fuel. It is shown that by changing the characteristics of the system and the process conditions, it is possible to change the flow rate of gaseous products from the gas generator, which will affect both the operating conditions of the cooling system for the materials of the combustion chamber structure and the value of the engine thrust. It is also shown that the operating time of a jet engine with a low-temperature gas generator increases with decreasing temperature and consumption of gaseous solid fuel combustion products, the interphase heat transfer coefficient, and the characteristic pore size of the fuel. [ABSTRACT FROM AUTHOR]

：Household air pollution（HAP）from the indoor burning of solid fuels, such as coal and biomass fuels, directly affects human health. Global exposure to HAP is estimated to cause millions of premature deaths. To better understand the research progress and hotspots of HAP studies, a bibliometric analysis was carried out using CiteSpace and papers searched from the Web of Science Core Collection. The number of publications per year, publication journals, and keywords was analyzed. The results showed that the number of publications in this field is growing exponentially, indicating that this issue is receiving more interest. These studies are mostly published in international journals such as Indoor Air, Science of the Total Environment, and Energy for Sustainable Development, with research teams from countries such as the United States and China. Clean energy, improved cookstoves, black carbon, and PM2.5 are the most widely mentioned keywords. Health outcomes of HAP exposure, clean intervention, and co-benefits in health and climate are important foci. It is suggested that sequential studies should be conducted on pollution characterization, exposure, and health risk assessment to protect human health. [ABSTRACT FROM AUTHOR]

Although solid fuel use for cooking is linked to an increased risk for depression, there is limited evidence on the effects of cooking duration and kitchen ventilation on these associations in rural areas. Among 29 903 participants from the Henan Rural Cohort, the independent and combined associations of cooking fuel type, cooking duration, and kitchen ventilation with depressive and anxiety symptoms were examined by logistic regression models and restricted cubic spline. The adjusted odds ratios (aORs) and 95% confidence intervals (CIs) of solid fuel use for depressive and anxiety symptoms were 1.237 (1.041, 1.469) and 1.384 (1.153, 1.662), respectively. Increased cooking duration was associated with an increased prevalence of depressive symptoms (aOR: 1.098, 95% CI: 1.033, 1.166) and anxiety symptoms (aOR: 1.074, 95% CI: 1.009, 1.144). Solid fuel use and long‐duration cooking associated with increased prevalence of depressive and anxiety symptoms were only observed in individuals without kitchen ventilation. Kitchen ventilation may attenuate the positive associations of solid fuel use and long‐duration cooking with the prevalence of depressive and anxiety symptoms, which suggested popularizing clean fuel and promoting kitchen ventilation may be effective strategies to improve mental health related to household air pollution sourced from solid fuel use and long‐duration cooking. [ABSTRACT FROM AUTHOR]

The paper presents main trends in growth and generation of waste, depending on increase of world GDP and the population of the planet. The main directions in extending the concept of national strategies for sustainable development have been considered with due account of energy and resource conservation problems, as well as the need for the rational use of natural and secondary resources in all countries of the world community. The energy potential use of combustible waste that has not found technological application is considered by many countries as one of the priority areas in the field of unconventional energy. The paper describes the main directions in application of the technology for briquetting multicomponent compositions into solid fuel. The developed production technology makes it possible to process waste products by briquetting them with the addition of various binders, and on the example of a binder component in the form of viscous hydrocarbon-containing waste, the main technological features of obtaining solid multicomponent fuel are presented in the paper. The paper describes the equipment for electrohydraulic treatment, which operates as a part of the preparation line for briquetting of the applied oily waste and that allows to reduce the sulphur content in the waste used, and such approach in general permits to regulate the environmental characteristics of harmful substance emissions at the maximum acceptable level. Taking into account the application aspects of the technology for wet briquetting of materials, the paper reflects the main results of the obtained dependences of humidity on productivity according to the content of the binder component. The proposed algorithm for solving the problem makes it possible to rationally use of substandard combustible industrial waste to obtain a multicomponent solid fuel, while at the production stage, the energy and environmental aspects of the resulting fuel are taken into account with due consideration of the component composition of the fuel.

A simulation was needed to simulate generating energy from Jatropha plants’ solid wastes in combined cycle power plants. In this study, a simulation was built to simulate energy generation from gasified Jatropha solid wastes. Solid wastes from Jatropha plants' were generated from biodiesel production to produce 1.53 kg/s biodiesel. An assumption was made these solid wastes were gasified to generate energy. Energy production was simulated using DWSIM software. Solid wastes were classified into three categories; cake, shell, and husk. The amount of cake was calculated to be 1.62 kg/s, the shell calculated to be 3.6 kg/s, and the husk was calculated to be 2.16 kg/s. Therefore, the producer gas for each Jatropha solid waste was estimated according to the literature to be 3.65 m3/s for the cake, 4.86 m3/s for husk, and 8.1 m3/s for the shell. The simulation of generating energy from the syngas was validated using experimental data from the literature. Sensitivity analysis was conducted to find the optimum conditions. The results showed that the energy produced from Jatropha waste was higher than that produced from biodiesel. From the simulation, the net energy generated in the gas turbine section was 21.34 MW and from HRSG 12.472 MW. The water flow rate in the compression section of syngas was found to be 10.18 kg/s, which was converted to steam and added more power to the power plant.

Background Limited data suggest that household air pollution from cooking and heating with solid fuel (i.e. coal and biomass) stoves may contribute to the development of hypertension and vascular damage. Methods Using mixed-effects regression models, we investigated the associations of household air pollution with blood pressure (BP) and vascular function in 753 adults (ages 40–79 years) from 3 diverse provinces in China. We conducted repeated measures of participants' household fuel use, personal exposure to fine particulate air pollution (PM2.5), BP, brachial–femoral pulse wave velocity (bfPWV), and augmentation index. Ultrasound images of the carotid arteries were obtained to assess intima–media thickness (CIMT) and plaques. Covariate information on sociodemographics, health behaviors, 24-h urinary sodium, and blood lipids was also obtained. Results Average estimated yearly personal exposure to PM2.5 was 97.5 µg/m3 (SD: 79.2; range: 3.5–1241), and 65% of participants cooked with solid fuel. In multivariable models, current solid fuel use was associated with higher systolic (2.4 mm Hg, 95% CI: −0.4, 4.9) and diastolic BP (1.4 mm Hg, 95% CI: −0.1, 3.0) and greater total area of plaques (1.7 mm2, 95% CI: −6.5, 9.8) compared with exclusive use of electricity or gas stoves. A 1 − ln(µg/m3) increase in PM2.5 exposure was associated with higher systolic (1.5 mm Hg, 95% CI: 0.2, 2.7) and diastolic BP (1.0 mm Hg, 95% CI: 0.4, 1.7) and with greater CIMT (0.02 mm, 95% CI: 0.00, 0.04) and total area of plaques (4.7 mm2, 95% CI: −2.0, 11.5). We did not find associations with arterial stiffness, except for a lower bfPWV (−1.5 m/s, 95% CI: −3.0, −0.0) among users of solid fuel heaters. Conclusions These findings add to limited evidence that household air pollution is associated with higher BP and with greater CIMT and total plaque area. [ABSTRACT FROM AUTHOR]

Hydrothermal carbonization (HTC) has emerged as a promising technology for sustainable use and waste valorization. One major challenge of HTC technology is the process water (PW) disposal or reuse, which is rich in dissolved organic carbon. This study evaluated the (i) potential of HTC to transform sugarcane industry by-products (sugarcane bagasse and vinasse) into useful materials for energy purposes, after, (ii) carry out the PW reuse in a novel HTC process with sugarcane bagasse. Relationships among composition, structure and morphology with fuel properties of hydrochars were evaluated. All hydrochars had lower volatile matter and higher fixed carbon content compared to the raw biomass. In addition, the decrease of H/C and O/C atomic ratios indicated an enhancement of the dehydration and deoxygenation reactions. Furthermore, the higher heating values (HHV) of hydrochars were in the range of 21.10–23.78 MJ kg-1, compared to 15.43 MJ kg-1 of the sugarcane bagasse. This result added to those from the van Krevelen diagram showed that the hydrochars presented fuel properties similar to conventional non-renewable energy sources, such as bituminous coal. Overall, the PW reuse did not promote great differences in the hydrochar properties and, consequently, no big changes on their fuel properties. Further, the hydrochar produced with sugarcane bagasse, vinasse, and sulfuric acid showed the highest heating value, and it was the most hydrophobic hydrochar among the others investigated. Therefore, the present study showed HTC and PW reuse as promising methods to treat the sugarcane industry by-products for solid fuel production. [ABSTRACT FROM AUTHOR]

The article describes preparation of an alternative solid fuel from corn alcohol distillery stillage, which is the waste of the alcohol industry. We determined the calorific values of the dried alcohol distillery stillage and experimental briquettes, which were made of it by pressing at high pressure and temperature. The average value of the higher calorific value of the dried alcohol distillery stillage is 19545 kJ kg-1, while this value for the produced briquettes is in the range of 22445 to 26594 kJ kg-1. The established calorific values exceed those of analogues, which are widely used for the producing of alternative solid fuels (miscanthus and energy willow). Solid fuel prepared from corn alcohol distillery stillage can be used both in a solid form and in a dried one. The proposed method for preparation of the solid fuel allows providing additional utilization of alcohol distillery stillage and rational use of secondary raw materials of alcohol production. [ABSTRACT FROM AUTHOR]

The influence of the inlet swirling flow on the regression rate of the fuel in the combustion chamber of the solid fuel ramjet is investigated in this study using numerical simulations. The finite-volume solver of the compressible turbulent reacting flow is developed to study the flow field where the burning rate is computed using the conjugate heat transfer method for the solid fuel. The correlation is found for the maximum regression rate versus an imposed inlet swirl when the linear distribution of the circumferential velocity is applied at the inlet stream. Although the regression rate augmentation is considerable due to the swirling flow field in the combustor, it is shown that the swirl is effective if is applied near the shear layer of the backstep flow in the combustor. The modified swirler with short blades is suggested to be used in solid fuel ramjets to increase the regression rate of the fuel and improve the performance, but with lower pressure loss. [ABSTRACT FROM AUTHOR]

Caragana is potentially an alternative biomass feedstock in China. The influences of different torrefaction conditions on the physical characteristics and fuel properties of pellets made from Caragana were investigated. The Caragana pellets were torrefied under the temperature of 225, 250, and 275 °C with the residence time of 10, 15, and 20 min, respectively. The results showed that the density of torrefied pellet reduced by 24.07 to 35.20%. Compression strength decreased to 7.62 N/mm2 for treated pellets under the condition of 275 °C and 20 min with the maximum weight loss of 29.93%, and the higher heating value increased to 20.95~22.93 MJ/kg. The equilibrium moisture content of the torrefied pellets decreased by 46.17% compared with raw materials. The mass yield and energy yield of torrefied pellet were 70.07 to 88.54% and 70.93 to 90.79%, respectively. With the increase of the torrefaction severity, the mechanical and physical properties of the pellets decreased, while the storage performance and fuel properties enhanced. Simultaneously, the torrefaction temperature had more influence on the fuel properties of Caragana pellets than the residence time. The Caragana pellets torrefied at 250 °C for 20 min maintained not only almost the same mechanical and physical properties as the untreated pellets but performed better storage and fuel properties. [ABSTRACT FROM AUTHOR]

Abstract Background Household air pollution (HAP) is a significant source of the global burden of disease. Our objective was to evaluate the association between environmental health literacy (EHL), a domain of health literacy (HL) that describes the ability to use environmental health information to reduce health risks, and symptoms associated with HAP. Methods We performed a cross-sectional population-based study of 353 households in Kasarani, Kenya. One individual from each household was surveyed using our novel EHL survey tool. Baseline characteristics were compared between individuals who were symptomatic (i.e., experiencing cough, shortness of breath, phlegm production, wheeze, chest tightness, headache, eye irritation, or burns from cooking at least 5 times per month) versus individuals who were asymptomatic (i.e., experiencing none or symptoms no more than once per month). Multivariate logistic regression was used to determine the odds ratios (OR) of self-reported symptoms associated with HL, stratified by median EHL, adjusting for education, self-perceived health and solid fuel use. Results A total of 100 individuals (28%) reported experiencing one or more symptoms at least 5 times per month, including 31.2% of solid fuel users and 30.3% of non-solid fuel users. Among individuals with high EHL, higher HL was associated with lower risk of experiencing symptoms (OR = 0.26; 95% CI 0.10–0.67), however, there was no association among individuals with low EHL (OR = 0.85; 95% CI 0.34–2.13). Among solid fuel users, the association between HL and risk of experiencing symptoms was driven by individuals with high EHL (OR = 0.30; 95% CI 0.05–1.84), rather than those with low EHL (OR = 1.22; 95% CI 0.36–4.16). Conclusions To the best of our knowledge, this was the first study to assess the association between EHL, HL, and HAP-associated symptoms. Our findings highlight the potential importance of EHL in promoting sustainable interventions to reduce symptoms associated with HAP from solid fuel use among communities in Kenya.

Hydrothermal carbonization (HTC) of Agave Salmiana bagasse was investigated to assess the potential of hydrochar as an energy resource. The effect of operating conditions on the mass yield and the energy quality of hydrochar was examined by varying the temperature and the holding time over the ranges of 180–250 ℃ (T) and 0–60 min (t), respectively. These parameters were screened using the response surface methodology through a Doehlert design. Performances of HTC were assessed on the basis of the hydrochar mass yield higher heating value ultimate and proximate analyses. In the studied domain, the modeling results indicated that the hydrochar mass yield varies between 45% and 86% and higher heating valuesfrom18 to 23 MJ.kg-1, which is similar to that of peat. In addition, the volatile matter and fixed carbon fractions of hydrochars ranged from 54 to 80% and between 12 and 36%, respectively. Energy yield modeling indicated that the mass yield is the most influent parameter. The maximal energy yield value was obtained at 180 ℃ with time equal to 0 min. Globally, the evolution of H/C ratio is amplified for temperatures greater than 215 ℃ by increasing the holding time from 30 to 60 min. For O/C ratio the maximal variation is below these conditions. It is concluded that increased hydrothermal carbonization conditions favor dehydration reactions, while decarboxylation reactions are favored in mild HTC conditions. The combustion characteristics such as ignition peak and burnout temperatures were significantly modified for hydrochars. The model results indicated that lowest ignition and peak temperature values are obtained at both low-temperature and low-holding time, and high-temperature and high-holding time zones. An increase in the burnout temperature was correlated with the increase of the fixed carbon content in hydrochars.

With the development of the iron and steel industry, the amount of NOx emissions is increasing year by year, and this causes environmental pollution in forms such as acidic rain and photochemical smog, which greatly threatens human health and social development. The iron and steel industry is one of the major sources of NOx emissions, accounting for more than 10% of the total NOx emissions, and the iron ore sintering process is one of the major sources of NOx emissions in the iron and steel industry, as it accounts for more than 50% of the total emissions of iron and steel plants. Hence, it is extremely urgent to reduce NOx emissions under the current high requirements of environmental protection. Since sintering gas is characterized by large volume, high dust and oxygen content, low NOx concentration, and the presence of SO2, available technologies used in De-NOx have the disadvantages of low efficiency and high investment and cost. Presently, how to cost-effectively reduce the NOx emission of the iron ore sintering process is a new challenge in the iron and steel industry. In the sintering process, NOx is mainly generated in the combustion of solid fuels, which is affected by the existing states of coarse solid fuels. Hence, the combustion behaviors of uncovered and coated coarse coke breeze and the effects of their addition methods on the NOx emission and the bonding strength of the sinter were investigated by the visible micro sintering and combustion equipment. Then, the optimal existing state of coarse coke breeze was explored by sinter pot tests. The results show that compared with the uncovered coarse coke breeze, the NOx emission decreases by 56% when coarse coke breeze is coated with calcium ferrite fines. As the coarse coke breeze is separated and controlled to be in an uncovered state, then it is added into the sintering materials after first mixing process, NOx emission increases by about 56% and the strength of the sinter decreases. The maximum concentration of NOx and conversion rate of N element decrease by 8% and 27%, respectively, when the coke breeze is a coated state by controlling in the size of 0.50−3.15 mm, respectively. The sinter indexes are also improved.

The World health organization (WHO) is particularly concerned about the ambient concentrations of Particulate Matter (PM10, PM2.5), Sulfur dioxide (SO2), Nitrogen dioxide (NO2), and Ozone (O3). This paper investigates the contributions of both the coal-fired plants and the coal-burning households to these critical pollutants. Using twelve months’ data, the annual concentrations of these pollutants were 60, 34, 39, 14, and 64 μg/m3 respectively with PM10, and PM2.5 exceeding the annual National Ambient Air Quality Standard (NAAQS). The diurnal pattern of PM10 and PM2.5 have double maxima corresponding to the cooking pattern of the community dwellers while O3 concentration peaks at noon which can result from photochemical reactions. Seasonally, all pollutants have their maximum concentrations during the winter except O3 that has high concentrations during the spring and summer. During the period, PM10 and PM2.5 concentrations exceeded the 24 h NAAQS for 104, 190 (55, 30%) days, and the World Health Organization (WHO) 24 h standard for 125, 225 (66, 36%) days respectively. The 8 h rolling mean of O3 also exceeded the NAAQS 490 times far above the allowable limit. The study indicates that PM10 and PM2.5 were mainly generated within the community. NO2 seems to receive significant contributions from biogenic emissions from the wetland area of the community while SO2 and O3 may be receiving significant contributions from the coal-fired plants as shown by the air mass backward trajectory modeling.

Air pollutants are common modifiable risk factors for arthritis. To explore the longitudinal effects of air pollution on arthritis based on a cohort study in middle-aged and elder people of China. Data was obtained from the China Health and Retirement Longitudinal Study (CHARLS) from 2011 to 2018. A total of 7449 participants aged 45 years and older were involved in our study. The generalized linear mixed models were conducted to examine the separate and joint effects of household air pollution and outdoor air pollution on arthritis, respectively. We found a strong significant association between air pollution and arthritis incidence. Individuals cooking primarily with solid fuel were more likely in higher risk of arthritis compared with cleaner fuel (OR= 1.15; 95% CI: 1.08–1.23). The group-based trajectory model identified four trajectory groups, compared with group “High-Decreasing rapidly”, adjusted ORs of incident arthritis for group “Middle-Decreasing moderately”, “Low-Decreasing slowly” and “Low-Stably” were 1.36 (95% CI, 1.03–1.79), 1.36 (95% CI, 1.01–1.83) and 1.81 (95% CI, 1.30–2.52), respectively. These associations were generally higher in participants younger than 65 years. In addition, solid fuel use and PM2.5 exposure had additive and multiplicative effects on arthritis. The results suggested that solid fuel use and long-term PM2.5 exposure were associated with a higher incidence of arthritis. Therefore, it is necessary to restrict solid fuel use to reduce household air pollution and make stronger environmental protection policies to reduce PM2.5 concentration.

Lignocellulosic biomass from rice husk (RH) is a renewable resource for fuel production, but it could pose ash-related challenges. This work focused on investigating the effects of pretreatment at different sodium hydroxide (NaOH) concentrations (i.e., 0.0, 0.25, 0.50, 0.75 and 1.00 M) on the calorific values and ash contents of treated RH products, and also finding the optimal torrefaction conditions. The results showed that alkaline pretreatment by sodium hydroxide (NaOH) reduced the ash content in the RH samples by over 85 wt%. Due to its relatively excellent calorific values and low ash content, the RH sample with 0.25 M NaOH pretreatment (i.e., RH-25) was chosen as a starting feedstock in the subsequent torrefaction experiments as a function of 240–360 °C for holding time of 0–90 min. In addition, the surface properties by scanning electron microscopy—energy dispersive X-ray spectroscopy (SEM-EDS) and Fourier-transform infrared spectroscopy (FTIR) were also used to observe the elemental compositions preliminarily. Based on the fuel properties of the torrefied RH products, the optimal torrefaction conditions can be found at around 280 °C for holding 30 min. As compared to the calorific value of the RH-25 (i.e., 18.74 MJ/kg) and its mass yield (i.e., 0.588), the calorific value, enhancement factor and energy yield of the optimal product were 28.97 MJ/kg, 1.55 and 0.91, respectively. Although the resulting product has a high calorific value like coal, it could have slight potential for slagging and fouling tendency and particulate matter emissions due to the relatively high contents of silicon (Si) and sodium (Na), based on the results of EDS and FTIR.

A large population does not have access to modern household energy and relies on solid fuels such as coal and biomass fuels. Burning of these solid fuels in low-efficiency home stoves produces high amounts of multiple air pollutants, causing severe air pollution and adverse health outcomes. In evaluating impacts on human health and climate, it is critical to understand the formation and emission processes of air pollutants from these combustion sources. Air pollutant emission factors (EFs) from indoor solid fuel combustion usually highly vary among different testing protocols, fuel-stove systems, sampling and analysis instruments, and environmental conditions. In this critical review, we focus on the latest developments in pollutant emission factor studies, with emphases on the difference between lab and field studies, fugitive emission quantification, and factors that contribute to variabilities in EFs. Field studies are expected to provide more realistic EFs for emission inventories since lab studies typically do not simulate real-world burning conditions well. However, the latter has considerable advantages in evaluating formation mechanisms and variational influencing factors in observed pollutant EFs. One main challenge in field emission measurement is the suitable emission sampling system. Reasons for the field and lab differences have yet to be fully elucidated, and operator behavior can have a significant impact on such differences. Fuel properties and stove designs affect emissions, and the variations are complexly affected by several factors. Stove classification is a challenge in the comparison of EF results from different studies. Lab- and field-based methods for quantifying fugitive emissions, as an important contributor to indoor air pollution, have been developed, and priority work is to develop a database covering different fuel-stove combinations. Studies on the dynamics of the combustion process and evolution of air pollutant formation and emissions are scarce, and these factors should be an important aspect of future work.

Background: Chronic obstructive pulmonary disease (COPD) is a public health challenge globally. The burden of COPD is high in never-smokers but little is known about its causes. We aimed to find the prevalence and correlates of COPD in never-smokers, with a special focus on solid fuel exposure.Methods: We conducted a cross-sectional study in Western China. COPD was defined by FEV1/FVC < lower limits of normal (LLN). Descriptive statistics and multivariable logistic regression were used for analyses.Results: Six thousand two hundred and seventy one patients were enrolled between June 2015 and August 2016. The prevalence of COPD in never-smokers was 15.0% (95% confidence interval 14.1–15.9). The common independent predictors of COPD in never-smokers included age ≥60 years, exposure to solid fuel, living in a rural area and a history of tuberculosis. Participants with solid fuel exposure were 69% more likely to have COPD (adjusted odds ratio 1.69, 95% CI 1.41–2.04) than those without such exposure. In addition, we found a positive association between small airway dysfunction and solid fuel exposure (OR 1.35, 95% CI 1.18–1.53).Conclusions: This study confirmed the substantial burden of COPD among never-smokers and also defined the risk factors for COPD in never-smokers. Furthermore, we found a positive association between solid fuel exposure and COPD or small airway dysfunction.

The authors discuss a study which analyzed a large database of nonsmokers from different geographical areas of China to report on the association of household air pollution (HAP) and secondhand cigarette smoke (SHS) with lung cancer mortality. Topics include increase in lung cancer-related death for every five years of follow-up, proportions of the age-standardized mortality rate of lung cancer attributable to HAP from solid fuels, and the lack of association between SHS and lung cancer.

A cross‐sectional study was conducted to investigate the impact of solid fuel use for heating and cooking on blood pressure (BP) and hypertension, using data from the China Health and Retirement Longitudinal Study (CHARLS). The primary fuels used for indoor heating and cooking were collected by questionnaires, respectively. Hypertension was defined based on self‐report of physician's diagnosis, and/or measured BP, and/or anti‐hypertensive medication use. Multivariate logistic regression models were constructed to assess the associations. Among 10 450 eligible participants, 68.2% and 57.2% used indoor solid fuel for heating and cooking, respectively. Compared with none/clean fuel users, solid fuel for heating was associated with elevated BP (adjusted β: 2.02, 95% CI: 1.04–3.01 for systolic BP; adjusted β: 1.36, 95% CI: 0.78–1.94 for diastolic BP) and increased risk of hypertension (adjusted odds ratio: 1.15, 95% CI: 1.03–1.29). The impact of indoor solid fuel for heating on BP was more evident in rural and north residents, and hypertensive patients. We did not detect any significant associations between solid fuel use for cooking and BP/hypertension. Indoor solid fuel use is prevalent in China, especially in the rural areas. Its negative impact on BP suggested that modernization of household fuel use may help to reduce the burden of hypertension in China. [ABSTRACT FROM AUTHOR]

Aim The association of air pollution with prevalence of undernutrition indices (namely, anaemia, stunting, wasting and underweight) among under-five children in India was investigated. Methods Estimates of population weighted annual average gridded PM2.5 concentrations and proportion of households using solid cooking fuel (HSCF usage percent) during 2017 in India, reflecting the magnitude of ambient and household air pollution respectively, were extracted in a state-wise manner from India State Level Disease Burden Initiative (ISLDBI) reports. Their relationships with the corresponding prevalence of anaemia, underweight, wasting and stunting in under-five children were analysed. Results The state-level PM2.5 concentrations (mean: 65.5 µg/m3; median: 49.2 µg/m3; range: 17.3–209.0 µg/m3) correlated significantly (P < 0.01) with anaemia (r = 0.65), stunting (r = 0.58) and underweight (r = 0.50) prevalence; while HSCF usage (mean: 49.3%; median: 46.0%; range: 1.9–81.5%) correlated significantly (P < 0.01) with stunting (r = 0.69) and underweight (r = 0.58) prevalence. When examined across median cut-offs and after adjusting for socio-demographic index, the association of anaemia prevalence with PM2.5 concentrations persisted. This association was maintained even after controlling for the coverage of anaemia-specific interventions (namely, iron supplements and deworming medications). The mean difference in PM2.5 concentrations between the high and low PM2.5 states was 58.6 µg/m3, which accounted for 11.8% higher anaemia prevalence in the former as compared to the latter. Conclusion The burden of childhood undernutrition, particularly anaemia, in India may be linked to PM2.5 levels. To mitigate this burden, it may be necessary to complement the ongoing nutritional interventions with air pollution control measures. [ABSTRACT FROM AUTHOR]

The raw walnut shell was converted to hydrochar fuel through hydrothermal carbonization. The structural, morphological, and compositional analyses were carried out using Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric and basic elemental analyses. The effect of the processing parameters including reaction temperature, residence time, and water:biomass ratio on the hydrothermal treatment was studied. The selected hydrochar has been produced at the optimized condition of T = 250 °C, t = 5 h, and water:biomass ratio = 6.0 mL/g. The H:C and O:C atomic ratios decreased from 1.51 and 0.73 to 0.91 and 0.26 for walnut shell and the selected hydrochar, respectively. The elemental reduction occurred through the carbonization process, which mainly includes dehydration, decarboxylation, and depolymerization reactions in liquid phase. The higher heating value increased from 18.85 for walnut shell to 27.95 for the selected hydrochar. The obtained walnut shell–based hydrochar presents a relatively homogenized structure consisting of microspherical particles with a mean diameter of 6 μm. This lignin-like material with high carbon content and low ash content shows high thermal stability. These promising results are relevant to the development of hydrochar products from waste biomass for fuel applications. [ABSTRACT FROM AUTHOR]

Biomass has been the only renewable energy that can be directly converted into fuel. The full utilization of biomass can effectively alleviate energy needs in an eco-friendly way. It is also an important path for China to achieve the goal of "carbon neutrality". Therefore, this study aims to focus mainly on the general goal of clean energy production and high-value utilization for straw-based biomass resources in recent years. A systematic analysis was made to evaluate the comprehensive utilization technology and mode of producing gas, liquid, and solid clean energy in the biological or thermo-chemical way. The development status and research progress were concentrated upon the anaerobic digestion for biogas, hydrothermal catalysis for alcohol and hydrocarbon fuel, pyrolysis liquefaction and bio-oil upgrading, and solid fuel production. Particularly, an attempt was addressed on the prospect of biogas, liquid fuel, and solid fuel. More importantly, no matter what biomass conversion technology was adopted, biomass resources utilization should be comprehensive and of high value. Correspondingly, the large-scale application required at least three basic elements. The first was the scale collection and disposal of biomass raw materials at a low cost. The second was the efficient and stable transformation, as well as quality improvement technology. The last was that the terminal fuel products needed to connect smoothly with the current application. Among them, anaerobic digestion for biogas presented the highest level of industrialization in recent years, due mainly to effectively solving raw materials collection in large breeding farms. It infers that the anaerobic digestion and biogas purification technology were relatively mature during this time. As such, biogas was directly used as a source of fuel, power, and thermal production. By contrast, hydrothermal catalysis for alcohol and hydrocarbon fuel, together with pyrolysis liquefaction for bio-oil was relatively difficult to connect with the current application, due mainly to the high conversion cost, difficult product separation, low-quality improvement efficiency, and unstable products. Therefore, the large-scale development level of the two technologies was relatively low during this time. Nevertheless, the technology of biomass preparation was relatively mature for solid fuels. The research and development of supporting stoves also effectively implemented the application of molding fuel. But the biggest difficulty in the scale application lay in the collection and storage of raw materials. Finally, the development prospects were proposed for the biomass conversion technologies. In terms of biogas, the anaerobic digestion was enhanced by multi-ingredients and bio-strengthen to improve biogas production efficiency. A precise control system should be established for the high concentration anaerobic digestion for better stability. Particularly, the comprehensive utilization of biogas slurry was carried out to realize the nutrient recycling, and biological organic fertilizer, or carbon-based fertilizer for nitrogen and carbon fixation, with emphasis on the efficiency of desulfurization and decarbonization. In terms of liquid fuel, the unpolluted depolymerization can be explored from lignocellulose to platform compounds, especially how to realize the efficient separation and quality improvement of platform compounds. During the quality upgrading process, the multi-step reaction combined catalyzer can be used to shorten the process and improve the reaction efficiency. In addition, the efficient conversion of biomass resources into fuel, chemicals, and materials should be developed synchronously for higher-value products. In terms of solid fuel, the heat transfer and bonding mechanism of torrefaction straw should be studied during the molding process, further to realize the low energy consumption and high quality. New efficient molding and combustion equipment needed to be improved the reliability of solid fuel production, particularly on the standardization, series, and package of torrefaction, molding, and combustion equipment. Consequently, the standard production of biomass collection, storage, and combustion should be improved to form biomass solid fuel industry chain from collection, storage, transportation, molding, and distribution. This research can provide a strong reference for the efficient preparation of clean energy and high-value utilization in rural biomass. [ABSTRACT FROM AUTHOR]

Background: Tuberculosis (TB) and indoor air pollution (IAP) are equally critical public health issues in the developing world. Mongolia is experiencing the double burden of TB and IAP due to solid fuel combustion. However, no study has assessed the relationship between household solid fuel use and TB in Mongolia. The present study aimed to assess the association between household solid fuel use and TB based on data from the Mongolian National Tuberculosis Prevalence Survey (MNTP Survey). Method: The MNTP Survey was a nationally representative population-based cross-sectional survey targeting households in Mongolia from 2014 to 2015, with the aim of evaluating the prevalence of TB. The survey adopted a multistage cluster sampling design in accordance with the World Health Organization prevalence survey guidelines. Clusters with at least 500 residents were selected by random sampling. A sample size of 98 clusters with 54,100 participants was estimated to be required for the survey, and 41,450 participants were included in the final analysis of the present study. A structured questionnaire was used to collect information on environmental and individual factors related to TB. Physical examination, chest X-ray, and sputum examinations were also performed to diagnose TB. Results: The use of solid fuels for heating (adjusted odds ratio (aOR): 1.5; 95% confidence interval (CI): 1.1–2.1), male gender (aOR: 2.2; 95% CI: 1.6–3.2), divorced or widowed (aOR: 2.6; 95% CI: 1.7–3.8), daily smoker (aOR: 1.8; 95% CI: 1.3–2.5), contact with an active TB case (aOR: 1.7; 95% CI: 1.2–2.3), being underweight (aOR: 3.7; 95% CI: 2.4–5.7), and previous history of TB (aOR: 4.3; 95% CI: 3.0–6.1) were significantly associated with bacteriologically confirmed TB after adjusting for confounding variables. Conclusion: The use of solid fuels for heating was significantly associated with active TB in Mongolian adults. Increased public awareness is needed on the use of household solid fuels, a source of IAP. [ABSTRACT FROM AUTHOR]

The article presents methods and a system of assessments for estimating the technical feasibility of shifting the boilers of thermal power plants (TPPs) operating on solid fuel for burning alternative coal. A basic arrangement of carrying out works at the preliminary stage is proposed, which includes an analysis of experience gained from combustion of alternative coal at other TPPs and the characteristics (properties) of the design and alternative coals burned at a TPP. Based on field experience, the correspondence of coal grades to each other in regard to combustion stability is determined. In the course of a comparative analysis into the characteristics of the design coal burned at a TPP and alternative coal, the thermal performance indicators of the fuels, their characteristics influencing the harmful emissions and ash and slag removal, slagging and fouling properties, fuel and ash abrasive properties, explosion hazard properties, indicators characterizing the proneness to oxidation and self-ignition, and fuel flowability and congelation are estimated. The specific features of carrying out assessments in burning mixtures of solid fuels are considered. The conditions determining the technical feasibility of using alternative fuel without performing its mandatory experimental combustion are presented. Programs of organizational and technical measures for preparing and performing experimental combustion of alternative coal are given. Based on the results of works carried out at the preliminary stage, the conditions for obtaining substantiated assessments of technical feasibility and advisability of using alternative coal are determined more exactly, including the need to perform experimental combustion of alternative coal and the required scope of equipment's modifications. [ABSTRACT FROM AUTHOR]

The energy efficiency of the gasification of various solid fuels in the filtration combustion mode is evaluated. The modes of gasification of carbon and organic fuels with the moisture content of up to 70% and ash content of up to 90% are considered. The efficiency of air gasification of low-moisture carbon fuels does not exceed 70%; and of organic fuels, 85%. The efficiency of the air gasification of high-moisture fuels can reach 85–90%. The addition of steam to the gaseous oxidizer increases the efficiency of the process. The efficiency of steam-air the gasification of low-moisture low-ash carbon fuels reaches 85%. In the case of organic fuels, the maximum efficiency of steam-air gasification is observed for fuels with an ash content of 20 to 40%. For highly reactive fuels, the maximum efficiency is observed for ashless fuels. If the reactivity of the fuel is low, the highest gasification efficiency will be for high ash fuels. [ABSTRACT FROM AUTHOR]

Background: The adverse health effects of air pollutants are widely reported, and the elderly are susceptible to toxic environments. This study aimed to evaluate the association between use of solid fuels for cooking and mortality among the elderly.Methods: A total of 5,732 and 3,869 participants from the Chinese Longitudinal Healthy Longevity Survey were enrolled in two (2014 and 2018) and three surveys (2011, 2014, and 2018) of survey. Cooking fuel was divided into clean and solid fuel. Cox proportional hazards models were used to estimate the mortality hazard ratio (HR). Subgroup analyses were performed to assess the potential interaction effect.Results: Among the participants in the 2011–2018 survey, 53% reported using solid fuel. Such group was associated with a 9% increase in mortality risk relative to clean fuel users (HR = 1.09, 95% CI = 1.01–1.18). Among participants in the 2014–2018 survey, 339 reported a switch from solid to clean fuels and they were not at increased mortality risk relative to the 488 people that reported a stable use of clean fuels (HR = 1.14, 95% CI = 0.99–1.31) although the estimated HR was similar to the one for stable solid fuel users (HR = 1.19, 95%CI = 1.04–1.36 n = 509). Interaction and stratified analyses showed that solid fuel use had an impact on mortality in participants who were non-current smokers, had low dietary diversity scores, and were living in areas with high PM2.5 concentrations (>50 μg/m3) and city population below 8 million (P for interaction < 0.05). The association was robust in the three sensitivity analyses.Conclusion: The finding showed a clear association between solid fuel use and mortality among older Chinese, and an even stronger association between risk of mortality and solid fuel use among individuals exposed to high levels of PM2.5.

Microwave (MW)-assisted torrefaction and pelleting could enhance biomass fuel properties and energy applications. Plastic wastes are considered as a replacement source binder in pellets to minimize their effect on the environment as pollutants. High-density polyethylene (HDPE), an extractable plastic from recycling waste, was investigated as a binder for torrefied wheat and barley straw pellets. Fuel pellet characteristics, such as durability, density, tensile strength, and water absorption, were used to evaluate the pellets produced from a single pelleting test. The results showed that the addition of HDPE as a binder significantly increased the pellet quality in terms of density (686.12–982.93 kg/m3), tensile strength (3.68 and 4.53 MPa) for wheat and barley straw, and reduced ash content of the pellet from 10.34 to 4.59% for barley straw pellet and 10.66 to 3.88% for wheat straw pellets. The higher heating value (HHV) increased with increasing biochar mix and HDPE binder blend. The highest HHV value observed for barley straw was 28.34 MJ/kg, while wheat straw was 29.78 MJ/kg. The study further indicated that MW torrefaction of biomass-biochar mix with HDPE binder reduced the moisture adsorption of wheat and barley straw pellets, which can significantly improve their storage capability in humid locations. The moisture uptake ratio for MW-torrefied barley straw pellets was 0.10–0.25 and wheat straw pellets 0.11–0.25 against a moisture uptake ratio of 1.0 for untreated biomass. MW torrefaction of wheat and barley straw with biochar and HDPE binder addition during pelleting is a promising technique to improve biomass fuel pellet properties.

Background: Women bear a large share of disease burden caused by household air pollution due to their great involvement in domestic activities. Pollutant emissions are believed to vary by exposure patterns such as cooking and space heating. Little is known about the independent effect of solid cooking fuel combustion on breast cancer risk. We aimed to examine the association of indoor coal and wood combustion for cooking with breast cancer risk.Methods: During June 2004–July 2008, participants aged 30–79 from 10 diverse regions across China were enrolled in the China Kadoorie Biobank. Primary cooking fuel use information in up to three residences was self-reported at baseline. Multivariable logistic regression models yielded adjusted odds ratios (ORs) and 95% confidence intervals (CIs).Results: A total of 290,396 female participants aged 30–79 were included in the main analysis. Compared with long-term clean fuel users, the fully adjusted ORs were 2.07 (95%CI: 1.37–3.13) for long-term coal users, 1.12 (95% CI: 0.72–1.76) for long-term wood users, and 0.98 (95% CI: 0.55–1.74) for those who used mixed solid fuels to cook. Those who had switched from solid to clean fuels did not have an excess risk of breast cancer (OR: 0.88, 95%CI 0.71–1.10).Conclusion: Long-term solid fuel combustion for cooking may increase the risk of breast cancer. The strength of association is stronger among coal users than wood users. Targeted interventions are needed to accelerate the access to clean and affordable energy.

The heat release kinetics in thermally initiated polymerization of 1,4-diethynylbenzene suggested as fuel dispersant in gas generator engines was studied under isothermal conditions in the temperature interval 90–150°С in the melt–vapor two-phase closed system. The enthalpies and entropies of melting, vaporization, and sublimation of 1,4-diethynylbenzene and the kinetics of a decrease in its vapor pressure in the course of polymerization in the melt were determined. Specific features of pressure and temperature variation in the course of propagation of the 1,4-diethynylbenzene combustion front in a cylindrical specimen in a Crawford bomb at the initial pressure of 2 MPa were studied. [ABSTRACT FROM AUTHOR]

The aciculated dry branches of Araucaria angustifolia, which fall throughout the year by the natural pruning of the species, can be a renewable and sustainable alternative for energy generation and income for rural producers inserted in the Mixed Ombrophilous Forest. This research aimed to energetically characterize these dry branches produced by free-growing trees throughout the year in the Santa Catarina's Plateau Region. Also, it aimed to determine the influence of weather conditions on the energetic quality of the aciculated dry branches. To that end, we demarcated 37 trees by choosing a quadrant according to the radius of the crowns in which the dry branches were collected. Collections happened monthly between June 2018 and May 2019. Subsequently, the biomass's physical, chemical, and energetic properties were determined. A simple correlation between climatic variables and properties was obtained. The main advantage of aciculated dry branches as an energy resource was their low moisture content (18%) and the disadvantages were the high ash content and the low basic density (220 kg.m-3 ). Except for the moisture content, all the properties of the aciculated dry branches varied throughout the year, and they were influenced by the weather variables. The correlations between the climatic variables and the properties analyzed indicated that the energetic quality of the dry branches was better in the months with the highest values of average temperatures and solar radiation. [ABSTRACT FROM AUTHOR]

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In order to fully understand the carbon emission from different fuels in rural villages of China, especially in the typical atmospheric pollution areas. The characteristics of carbonaceous aerosols and carbon dioxide (CO 2) with its stable carbon isotope (δ13C) were investigated in six households, which two households used coal, two households used wood as well as two households used biogas and liquefied petroleum gas (LPG), from two rural villages in Fenwei Plain from March to April 2021. It showed that the fine particulate matter (PM 2.5) emitted from biogas and LPG couldn't be as lower as expected in this area. However, the clean fuels could relatively reduce the emissions of organic carbon (OC) and element carbon (EC) in PM 2.5 compare to the solid fuels. The pyrolyzed carbon (OP) accounted more total carbon (TC) in coal than the other fuels use households, indicating that more water-soluble OC existed, and it still had the highest secondary organic carbon (SOC) than the other fuels. Meantime, the coal combustions in the two villages had the highest CO 2 concentration of 527.6 ppm and 1120.6 ppm, respectively, while the clean fuels could effectively reduce it. The average δ13C values (−26.9‰) was much lighter than almost all the outdoor monitoring and similar to the δ13C values for coal combustion and vehicle emission, showing that they might be the main contributors of the regional atmospheric aerosol in this area. During the sandstorm, the indoor PM 2.5 mass and CO 2 were increasing obviously. The indoor cancer risk of PAHs for adults and children were greater than 1 × 10−6, exert a potential carcinogenic risk to human of solid fuels combustion in rural northern China. It is important to continue concern the solid fuel combustion and its health impact in rural areas. [Display omitted] • Biogas and liquefied petroleum gas (LPG) emitted high PM 2.5 as unexpected. • Biogas and LPG emitted lower PM 2.5 bounded PAHs and CO 2. • The CO 2 produced by coal burning was greater than other fuels, with lighter δ13C. • Sandstorm could aggravate the accumulation of indoor atmospheric CO 2. • Solid fuel users might face more serious cancer risks than biogas and LPG. [ABSTRACT FROM AUTHOR]