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Summary: Microalgae is an excellent type of biomass for bio‐energy production due to its high calorific value and fast growth. However, a large amount of ash would be generated during microalgae utilization. In this work, MCM41 was prepared from microalgae ash. The materials were calcined at different temperatures (450°C, 500°C, 550°C, and 600°C), and the effect of calcination temperature was investigated. Polyethyleneimine (PEI) was loaded in MCM41 by the impregnation method at different loading amounts (30%, 40%, 50%, and 60%). The CO2 capturing capacity was measured. The results showed that the MCM41 calcined at 450°C was the optimal material, which performed the most developed pore structure. Amine loading enhanced the CO2 capturing capacity of MCM41. The CO2 capturing capacity increased as PEI loading amount increased. The highest CO2 adsorption amount was 2.275 mmol/g with 60% amine loading at 25°C and 1 bar. Adsorption temperature had a mild impact on CO2 capture, and its CO2 adsorption amount decreased slightly with an increase in the adsorption temperature. It was considered that the CO2 uptake of amine‐impregnated MCM41 kept stable at different temperatures below 100°C. Also, it showed good cyclic stability. After 10 cycles, the CO2 capturing capacity of 1.6 mmol/g was exhibited. [ABSTRACT FROM AUTHOR]

Summary: The iron industry is an energy‐intensive sector and a major contributor to global carbon dioxide emissions. With the projected increase in the demand for iron as raw material, the industry seeks ways to improve sustainability. The incorporation of a biomass‐based polygeneration system (BBPS) is a sustainable approach to generate the needed utilities of the iron plant. Biomass can be converted thermochemically into fuel gas for use in the plant, while the resulting biochar can be utilized for carbon sequestration. A multiobjective optimization model using fuzzy linear programming (FLP) is developed to seamlessly integrate a BBPS in an iron plant while obtaining negative carbon emissions. The FLP model simultaneously satisfied the product demands while maximizing the annual profit and minimizing the carbon footprint of the iron manufacturing plant. A sensitivity study is performed to gauge the effects of uncertainties of the prices of product streams and capital costs together. The best configuration of the integrated BBPS and the iron production plant are determined using this approach, resulting in 2.7 million tons CO2 y−1 of negative carbon emission. The reduction of the carbon footprint upper threshold target by 80% has shown a 34.15% improvement on the negative carbon footprint and 1.81% enhancement on the annualized capital cost of the plant. The change in the biomass price had a significant effect on the Pareto frontier of the level of satisfaction compared with the change in the coal and iron ore prices. The varied capital cost of the gasification had a relatively significant influence to the annualized profit of the plant compared with the varied capital cost of the other polygeneration processes. [ABSTRACT FROM AUTHOR]

Summary: Research on utilization of abundant rice residue for valuable bioenergy products is still not explored completely. A simple, robust, cheap, and one‐step fast pyrolysis reactor is still a key demand for production of bioenergy products, ie, high quality bio‐oil and biochar. Bio‐oil extracted from fast pyrolysis does not have adequate quality (eg, acidic and highly oxygenated). Catalytic fast pyrolysis using zeolites in the fast pyrolysis process effectively reduces the oxygen content (no H2 required). In this paper, the zeolites with different pore sizes and shapes (small pore, SAPO‐34 (0.56) and ferrierite (30); medium pore, ZSM‐5 (30), MCM‐22 (30), and ITQ‐2 (30); and large pore zeolite, mordenite (30)) were tested in a drop‐type fixed‐bed pyrolyzer. Catalytic deoxygenation is conducted at 450°C at the catalyst/biomass ratio of 0.1. Zeolite catalysts, its pore size and shape, could influence largely on deoxygenation. It was found that the small pore zeolites did not produce aromatics as compared to higher amount of aromatics formed in case of medium pore zeolites. ZSM‐5 and ITQ‐2 zeolites were especially efficient for the higher deoxygenation of biomass pyrolysis vapors due to better pore dimension and higher acidity. [ABSTRACT FROM AUTHOR]