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Biochar is an engineered carbon-rich substance used for soil improvement, environmental management, and other diverse applications. To date, the understanding of how biomass affects biochar microstructure has been limited due to the complexity of analysis involved in tracing the changes in the physical structure of biomass as it undergoes thermochemical conversion. In this study, we used synchrotron x-ray micro-tomography to visualize changes in the internal structure of biochar from diverse feedstock (miscanthus straw pellets, wheat straw pellets, oilseed rape straw pellets, and rice husk) during pyrolysis by collecting a sequence of 3D scans at 50 °C intervals during progressive heating from 50 °C to 800 °C. The results show a strong dependence of biochar porosity on feedstock as well as pyrolysis temperature, with observed porosity in the range of 7.41–60.56%. Our results show that the porosity, total surface area, pore volume, and equivalent diameter of the largest pore increases with increasing pyrolysis temperature up to about 550 °C. The most dramatic development of pore structure occurred in the temperature range of 350–450 °C. This understanding is pivotal for optimizing biochar's properties for specific applications in soil improvement, environmental management, and beyond. By elucidating the nuanced variations in biochar's physical characteristics across different production temperatures and feedstocks, this research advances the practical application of biochar, offering significant benefits in agricultural, environmental, and engineering contexts. [ABSTRACT FROM AUTHOR]

Anaerobic fermentation (AF) is a widely used process for the transformation of organic waste into biogas. However, despite its ubiquitous use, it has several limiting factors, including low yield, redox imbalance, high concentration of inhibitors, and a long retention time. Integration of pyrolysis with AF improves efficiency and facilitates effective biomass utilization in a closed-loop approach. Research trends emphasize the inclusion of biochar derived from biomass to improve the stability and efficiency of AF and facilitate biogas up-gradation (H 2 S removal). However, there is a lack of consolidated scientific understanding regarding the complex interactions of biochar and AF microbial communities, in addition to its potential amendment advantages. Therefore, this review summarizes biomass utilization for biochar production using various pyrolysis methods and its use as an effective inclusion material to improve AF performance. Specifically, the influence of biochar amendments in AF is discussed in terms of microbial colonization, direct interspecies electron transfer, minimization of organic load, and buffering maintenance. Moreover, the role of AF digestate biochar in nutrient recycling and utilization as a soil conditioner is elaborated. The progressive integration of pyrolysis and AF offers the complete decoupling of biomass, enhances AF performance, and promotes the establishment of a sustainable bioprocess by inducing the circular bioeconomy. • Biochar amendments in anaerobic fermentation (AF) improve the process efficiency. • Biochar inclusion in AF offers DIET, microbial colonization, and maintain buffering. • Pyrolysis conditions and biomass type has a significant influence on biochar composition. • Progressive integration of pyrolysis and AF maximize the resource recovery in closed-loop. [ABSTRACT FROM AUTHOR]

• Biochar can be produced through pyrolysis (at temperatures of 600-700 °C). • Hydrothermal carbonization is performed at temperatures between 180-300 °C. • Activation can be performed in two ways (physical and chemical). • Activation temperature ranges between 600-800 °C. • Chemical activation has the advantage to lower the final activation temperature. Clean water is an essential resource for life, and its demand is continuously increasing with the rapid growth in population, while the freshwater reserves are also depleting. A large amount of wastewater is released by different industries, which is affecting the environment as well as polluting the freshwater reserves. Recycling and treatment of wastewater are highly essential to meet the demand for clean water and to protect the environment. Activated carbon can be used in primary, secondary and tertiary wastewater treatment steps. It can be used to capture pollutants which stop microbial activity or to produce clean water with high purity. About 3 million tons of activated carbon are produced per year and it is mainly used for fluid purification. The objective of this review is to investigate the preparation and production of biochar from lignin which is an important resource available in great quantities (about 100 Million tons per year) and the practical application of it for wastewater treatment. Biochar can be produced through pyrolysis (at temperatures of 600-700 °C) and hydrothermal carbonization (at temperature between 180-300 °C). Subsequent activation can be performed in two ways (physical and chemical), usually at temperatures between 600-800 °C. The quality of biochar and activated carbon produced from lignin-rich residue can be very high, even though the costs also are higher respect to other fossil derived materials (carbon black, lignite and pet coke). [ABSTRACT FROM AUTHOR]

• An easy-to-use GUI-based application program for multifractal analysis is presented. • It includes estimates and standard errors for the singularity and Rényi spectra. • The MFA program accepts various types of input and outputs with clear interpretation. • With it, it is possible to assess evidence of multifractality against monofractality. • Data on soil and plant structures (porosity, branching) are used in three examples. Multifractal systems are common in nature, and fractal theory has been applied to a large number of patterns for curves, surfaces and volumes in a variety of research domains. For instance, researchers in soil science recently applied multifractal analysis (MFA) to study porosity, which is linked to soil gas diffusion, water content and therefore, nutrient transportation for plants. The calculation of multifractal spectra (singularity, Rényi) is complex and the data can be 'big' and of various forms (graphical or numerical), yet the results are highly informative. An easy-to-use GUI-based (GUI: Graphical User Interface) application would allow researchers to concentrate on the results instead of having to deal with the technical aspects. This note fills the gap with the MFA application program, originally written in MATLAB and provided with a user's guide. Datasets on soil and plant structures (soil porosity, tree branching, biochar structure) are used in three examples, which help illustrate the variety of inputs with our MFA application, demonstrate its generality in performing the MFA method, and interpret the program outputs. [ABSTRACT FROM AUTHOR]

A series of new hybrid photocatalysts based on Fe 3 O 4 and standard biochar (biochar obtained by pyrolysis of Sewage Sludge (SS), Soft Wood Pellets (SWP), and Rice Husk (RH) at 700 °C) were successfully prepared using impregnation method. The biochar and resulting photocatalysts were characterized by wide range physicochemical techniques and investigated in hydrogen evolution under artificial solar irradiation. It can be noticed that when Fe 3 O 4 is supported on SWP700 and RH700, presented a superior photocatalytic activity. Our best hybrid photocatalyst (Fe 3 O 4 -2.5%/RH700) achieved hydrogen production of 4162 μmol/g. Comprehensive electrochemical measurements reveal that the superior performance of Fe 3 O 4 - 2.5%/RH700 may be attributed to the lower band gap energy (2.27 eV), higher photocurrent density, and lower charge transport resistance. In addition, SS700 showed extraordinarily high activity (3845 μmol/g) in the conversion of deionized water to hydrogen, which is comparable to those of iron oxide photocatalysts supported on SWP700 and RH700. Based on the ultimate and proximate analyses, unique structure, high electric conductivity, dense aromatic structure, and exclusive mineral composition account for the enhanced activity exhibited by the SS700. These encouraging results showed that biochar derived from SS could be a low-cost, renewable, environmentally friendly and metal-free photocatalyst in hydrogen generation. • Extraordinarily high activity of SS700 in the conversion of deionized water to hydrogen. • Low-cost, renewable, environmentally friendly and metal-free photocatalysts. • Iron oxide composites were synthesized for photocatalytic hydrogen generation. • Fe 3 O 4 /biochar supports promises an excellent alternative to nanocarbons for H 2 generation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pyrolysis of post-consumption food waste has been conducted in an auger reactor. • Pyrolysis yield was 37.2% bio-oil, 27.6% char, 21.0% gas, and 14.2% aqueous phase. • Bio-oil has low water content, is nearly alkaline, and has HHV = 28.2 MJ kg−1. • Bio-oil consisted of fatty acids commonly found in dairy, meat, and vegetable oils. • Food wase pyrolysis is predicted to contribute 30% to the world's renewables by 2026. Food waste produced in households, public restaurants, and hospitality sectors is causing serious concerns due to its negative environmental impact and the associated cost of disposal in landfills. This paper presents a comprehensive experimental assessment of post-consumption food waste characteristics, its conversion to added-value products through pyrolysis, and its potentials for worldwide large-scale processing. Analysis of the food waste samples revealed highly desirable features (e.g., volatile = 75.2%, lipid = 15.4%, and HHV = 20.1 MJ kg−1). The overall pyrolysis yield was 37.2% bio-oil, 14.2% aqueous phase, 27.6% biochar, and 21.0% non-condensable gas. The bio-oil showed attractive fuel characteristics (HHV = 28.2 MJ kg−1, water content = 4.6%, and pH = 6), however, the viscosity was high (136 cSt). The most abundant compounds in the bio-oil were major fatty acids commonly found in dairy fats, meat, and hydrogenated vegetable oils. The biochar has an improved characteristic (HHV = 26.3 MJ kg−1 and O/C = 0.065), which makes it potentially useful for energy applications as well as for long-term carbon sequestration if used in soil amendment. The non-condensable gas has an energy content of 15.8 MJ kg−1, nearly 30% that of natural gas. In assessing the worldwide potential implementation of food waste pyrolysis, the calculations indicate that Eastern and Southern Asia, followed by sub-Saharan Africa, respectively, are of the highest potential for large-scale processing. The estimated world's energy output is 1376.2 GW and this is predicted to contribute to around 30% to the world's demand of renewable energies by 2026, if this feedstock is fully utilized. Most importantly, the outcome of this study is highly encouraging for the development of bioenergy technology in regions where conventional biomass resources are limited, such as arid and semi-arid regions. [ABSTRACT FROM AUTHOR]

Engineered biochar derived from wood waste pyrolysis in molten salts were developed for effective CO 2 /N 2 separation. The production conditions were customized to obtain the biochar with high CO 2 capture capacity and CO 2 /N 2 selectivity by tuning the type of molten salts (MgCl 2 -KCl, ZnCl 2 -KCl, ZnCl 2 -NaCl-KCl, and K 2 CO 3 -Na 2 CO 3 -Li 2 CO 3), salt/feedstock ratios (1:1 and 3:1) and pyrolysis temperatures (600 and 800 °C). High temperature (800 °C) and moderate salt loading (salt/feedstock ratio of 1:1) benefited the CO 2 adsorption by providing an increased surface area and highly dispersed metal species as adsorption sites. PSL-3-800 and PSL-3-600 (K 2 CO 3 -Na 2 CO 3 -Li 2 CO 3 biochar) showed the highest CO 2 capacity (4.5 mmol g−1, 0 °C, 100 kPa) and the highest CO 2 /N 2 selectivity (28.5), respectively, among the engineered biochar developed in this study. In addition, ZP-3-600 showed the highest selection parameter (S) in both PSA and VSA processes, indicating the promising CO 2 capture performance under PSA/VSA conditions. A high recovery rate (89%) of molten salts was achieved. These results suggest a new pathway for upcycling biowaste as eco-friendly and effective adsorbents for gas adsorption and separation. [Display omitted] • Molten salt-assisted biochars were prepared for CO 2 capture from N 2. • K 2 CO 3 -Na 2 CO 3 -Li 2 CO 3 engineered biochar showed the highest CO 2 capacity. • A high pyrolysis temperature (800 °C) facilitated the formation of large surface area. • Separation potential was evaluated under pressure/vacuum swing adsorption conditions. • Recovery rate of soluble molten salt in the biochar was up to 89%. [ABSTRACT FROM AUTHOR]

[Display omitted] • Non-catalytic co-HTC of FWD and YW marginally increased energy potential of hydrochar. • Co-HTC with 0.5 M HCl exhibited the highest carbon utilization efficiency. • Co-HTC with citric acid provided ∼3-fold increase in pressure with ∼74% C loss. • Catalytic system of 0.5 M HCl had better overall energy and nutrient recovery performance. • Ash content and mineral constituents were the decisive factors for combustion behaviour. Hydrothermal carbonization (HTC) provides a promising alternative to valorize food waste digestate (FWD) and avoid disposal issues. Although hydrochar derived from FWD alone had a low calorific content (HHV of 13.9 MJ kg−1), catalytic co-HTC of FWD with wet lignocellulosic biomass (e.g. , wet yard waste; YW) and 0.5 M HCl exhibited overall superior attributes in terms of energy recovery (22.7 MJ kg−1), stable and comprehensive combustion behaviour, potential nutrient recovery from process water (2-fold higher N retention and 129-fold higher P extraction), and a high C utilization efficiency (only 2.4% C loss). In contrast, co-HTC with citric acid provided ∼3-fold higher autogenous pressure, resulting in a superior energy content of 25.0 MJ kg−1, but the high C loss (∼74%) compromised the overall environmental benefits. The results of this study established a foundation to fully utilize FWD and YW hydrochar for bioenergy application and resource recovery from the process water. [ABSTRACT FROM AUTHOR]

This paper mainly studies the multi-objective optimization of load dispatch of power systems including renewable energy and CO2 capture and storage (CCS) technologies. The improved environmental/economic load dispatch model for the power system is constructed, considering the renewable energy utilization and CCS technologies. A novel singular weighted method (SWM) has been proposed in this paper for solving this kind of multi-objective and multi-constraint optimization problem. A power system with five generators has been applied in one case study to test the model and SWM. It was concluded that the share that each unit takes is not linear; however, the optimal results are largely relevant to the characteristics of the units. In addition, the research results showed that with the increment of the weight coefficient for a certain objective function, the optimization result was closer to the single optimization result for that objective function; and with the increase of forecast demand load, a 35 MW wind energy unit and a 200 MW water energy unit should be built. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]