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The development of renewable energy resources is strongly urged to recoup the shortage of fossil-based energy and its associated pollution issues. Energy production from carbohydrate materials has recently been of great interest due to the availability, reliability, and abundance of carbohydrate sources. Significantly, the catalytic transformation of waste carbohydrates into furanbased biofuels, specifically 2,5-dimethylfuran (DMF), appears to be an attractive solution to the aforementioned energy and environmental issues. The potential of DMF as a renewable fuel is prospective, with its physicochemical properties that are similar to those of fossil fuels. Therefore, the current work focuses on the production of DMF, with the important aspects for enhanced DMF yield being summarized herein. Notably, the significant catalysts derived from zeolite, noble-metal, non-noble-metal, metal− organic framework, and electrocatalytic materials are discussed, alongside their effects in deriving carbohydrates to DMF. Furthermore, the mechanisms of DMF production were clarified too, followed by the scrutinization of the effects from reaction conditions, solvents, and hydrogen donors onto the DMF yield. Finally, the purification process, commercialization potential, and economic feasibility of DMF production were incorporated too, with insightful future directions being identified at the end of our review. This review is expected to advocate DMF production from carbohydrate materials, which could alleviate the energy and environmental problems encountered presently.

Photocatalytic degradation of an odorous chemical, 2-mercaptobenzothiazole (MBT), in aqueous suspension was investigated using pure TiO2 and neodymium ion doped TiO2 (Nd3+−TiO2) catalysts. The photocatalytic activity of Nd3+−TiO2 was evaluated in the photocatalytic degradation of MBT in aqueous solution. The experimental results showed that the overall kinetic constant (k) of MBT degradation using Nd3+−TiO2 was significantly higher than that using TiO2 and an optimal content of neodymium ion doping was found to be 1.2% (molar ratio). The main intermediates during the MBT degradation were identified by LC/MS−MS, and the final products including sulfate ion, ammonium ion, and nitrate ion were also determined by ion chromatography. Only three main intermediates including benzothiazole, 2-hydroxybenzothiazole, and benzothiazole-2-sulfite were found during the MBT degradation using the TiO2 catalyst, while five main intermediates including benzothiazole, 2-hydroxybenzothiazole, benzothiazole-2-sulfonate, benzothiazole-2-sulfite, and anilinesulfonic acid were found during the MBT degradation using 1.2% Nd3+−TiO2. On the basis of analytical results, a possible pathway of MBT degradation in such a photocatalytic oxidation reaction was proposed and illustrated. It was concluded that the photodegradation of MBT and its intermediates can be enhanced owing to the neodymium ion doping.

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Climate change issues are calling for advanced methods to produce materials and fuels in a carbon–neutral and circular way. For instance, biomass pyrolysis has been intensely investigated during the last years. Here we review the pyrolysis of algal and lignocellulosic biomass with focus on pyrolysis products and mechanisms, oil upgrading, combining pyrolysis and anaerobic digestion, economy, and life cycle assessment. Products include oil, gas, and biochar. Upgrading techniques comprise hot vapor filtration, solvent addition, emulsification, esterification and transesterification, hydrotreatment, steam reforming, and the use of supercritical fluids. We examined the economic viability in terms of profitability, internal rate of return, return on investment, carbon removal service, product pricing, and net present value. We also reviewed 20 recent studies of life cycle assessment. We found that the pyrolysis method highly influenced product yield, ranging from 9.07 to 40.59% for oil, from 10.1 to 41.25% for biochar, and from 11.93 to 28.16% for syngas. Feedstock type, pyrolytic temperature, heating rate, and reaction retention time were the main factors controlling the distribution of pyrolysis products. Pyrolysis mechanisms include bond breaking, cracking, polymerization and re-polymerization, and fragmentation. Biochar from residual forestry could sequester 2.74 tons of carbon dioxide equivalent per ton biochar when applied to the soil and has thus the potential to remove 0.2–2.75 gigatons of atmospheric carbon dioxide annually. The generation of biochar and bio-oil from the pyrolysis process is estimated to be economically feasible.