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Coal burning emits a significant amount of elemental mercury (Hgo) into the atmosphere, which can cause severe damage to the environment and human health. Here, magnetic FeS2 nanorods are facilely obtained via a low-temperature (200–350 °C) molten salt (KSCN) route. The annealing temperature is found to notably affect the structure and Hgo capture performance of FeS2, while precursors exert subtle effects on the mercury adsorption performance. The Hgo capture ability of FeS2 first increases and then decreases with increasing annealing temperature. The highest magnetism (12 emu/g) and optimal mercury capture performance (Hgo removal efficiency of 96.2%) are achieved over FeS2 nanorods synthesized at 250 °C. This material shows superior performance in the temperature range of 60–180 °C owing to its rod-like structure with ample number of exposed adsorption sites. NO and SO2 are found to only slightly intervene in the mercury removal process. Hgo vapor first adsorbs on the FeS2 surface via physical adsorption followed by conversion into mercury sulfide (HgS) and mercury oxide (HgO) by the oxidation of disulfide ions (S22–) and chemisorbed oxygen (O*) species, respectively. [ABSTRACT FROM AUTHOR]

Steam-CO2 reforming of biomass derived synthesis gas (bio-syngas) was investigated with regard to the steam concentration in the feed using Rh-loaded alumina foam monolith catalysts, which was also accompanied by thermodynamic equilibrium calculation. With 40 vol % steam addition, steam methane reforming and water gas shift reaction were prevailed at the temperature below 640 °C, above which methane dry reforming and reverse-water gas shift reaction were intensified. Substantial change of activation energy based on the methane conversion was observed at 640 °C, where the reaction seemed to be shifted from the kinetic controlled region to the mass transfer controlled region. At the reduced steam of 20 vol %, the increase in the gas velocity led to the increase in the contribution of steam reforming. Comparing to the absence of steam, the addition of steam (40 vol %) resulted in the increase in the production of H2 and CO2, which in turn increased the H2/CO ratio by 95% and decreased the CO/CO2 ratio by 60%. Rh-loaded alumina monolith was revealed to have a good stability in upgrading of the raw bio-syngas. [ABSTRACT FROM AUTHOR]

Biogas offers significant benefits as a renewable energy source, contributing to decarbonization, waste management, and economic development. This comprehensive review examines the historical, technological, economic, and global aspects of biomethane production, focusing on the key players such as China, the European Union, and North America, and associated opportunities and challenges as well as future prospects from an Australia perspective. The review begins with an introduction to biogas, detailing its composition, feedstock sources, historical development, and anaerobic digestion (AD) process. Subsequently, it delves into major biomethane production technologies, including physicochemical absorption, high-pressure water scrubbing (HPWS), amine scrubbing (AS), pressure swing adsorption (PSA), membrane permeation/separation (MP), and other technologies including organic solvent scrubbing and cryogenic separation. The study also discusses general guidelines of techno-economic assessments (TEAs) regarding biomethane production, outlining the methodologies, inventory analysis, environmental life cycle assessment (LCA), and estimated production costs. Challenges and opportunities of biogas utilization in Australia are explored, highlighting and referencing global projections, polarization in production approaches, circularity in waste management, and specific considerations for Australia. The review concludes discussing future perspectives for biomethane, emphasizing the importance of technological advancements, policy support, and investment in realizing its full potential for sustainable energy and waste management solutions., (© 2024 The Authors. ChemSusChem published by Wiley-VCH GmbH.)