This article reviews biochar production and its potential applications across various sectors, including agriculture, environmental remediation, and energy storage. It emphasizes the critical role of feedstock source and process parameters, such as residence time, heating rate, and temperature, in determining biochar’s properties. Although extensive research has been conducted on the physical and chemical properties of biochar, there remains a significant gap in evaluating its practical applications. This paper emphasizes the role of Multi-Criteria Decision Analysis (MCDA) as a valuable tool for optimizing both biochar production and its application strategies. By exploring scholarly articles and patents, it offers insights into biochar production techniques, characterization methods, and the importance of process optimization for sustainable and efficient biochar use in real-world scenarios.

Brewers’ spent grain (BSG) is an important waste produced by beer companies and has a high potential to be transformed into commercial by-products. The present paper reports a forecasting technology study with the aid of bibliographic review and patent analysis tools aiming to investigate the maturity of certain technologies, considering the use of BSG on a closed-loop biorefinery and circular bioeconomy concept integrated into a brewery. To evaluate the possibilities of production of high-added-value products in Brazil, we present an overview of BSG’s scientific, technological, and marketing products and applications. The comparison between the numbers of articles versus patents shows that the solutions proposed by research articles are not being transformed into maturated viable technologies. The results suggest that there is a gap between the scientific research in the institutions and their applications in the industry, which lead to the destination of BSG for more economically attractive investments when compared with research in Brazil. Ultimately, from the carried-out analysis, it is possible to propose a brewing process connected to the biorefinery system, showing its possibility in the newly arising brewery industries.

Brazil is one of the most powerful agro-industrial countries in the world impacting important chains of food, energy, and materials supplies. Residues resulting from this manufacture attract environmental and economic concerns for those producers. Aiming to focus on decentralized bioenergy production for local communities of the Midwest region, this work reports the physicochemical characterization of fruit peels of Baru (FPB), barks of Jatoba-do-cerrado tree (BJC), and their potential as raw materials for energy generation by gasification. FPB and BJC were analyzed by proximate analysis (12.0 and 11.6% of moisture, 71.2 and 75.4% of volatiles, 2.6 and 1.1% of ashes, and 26.2 and 23.5% of fixed carbon content), lignocellulosic analysis (21.7 and 13.3% of extractives, 65.8 and 60.7% of holocellulose, and 31.8 and 38.1% of lignin), and higher heating value (HHV), 19.7 kJ g⁻¹ and 20.4 kJ g⁻¹ for FPB and BJC, respectively. Both were used as fuel in a countercurrent gasifier (updraft) for the production of synthesis gas to generate energy, achieving satisfactory results, 25% and 15% of H₂, 33% and 36% of CO, and 14% and 4% of CO₂ for FPB and BJC, respectively. These results were similar or better than other biomasses reported in the literature. Since FPB and BJC are agricultural residues without a specific purpose, this work showed that decentralized bioenergy conversion by thermochemical process can benefit local producers. Graphical abstract

O lúpulo é o insumo utilizado na fabricação de cerveja responsável por aromas e pelo amargor da bebida. No Brasil, essa matéria-prima é importada quase que em sua totalidade. Essa planta, habituada a regiões de clima específico, está sendo cultivada em solo brasileiro e obtendo resultados promissores. Em função disso, o presente artigo buscou realizar uma prospecção tecnológica, por meio de uma metodologia qualitativa exploratória, sobre o que está sendo estudado e desenvolvido sobre lúpulo e sua utilização no processo cervejeiro nos últimos 20 anos. Sabe-se que, a partir do momento em que houver a comercialização de lúpulo nacional, novas tecnologias e processos serão necessários para sua manufatura. A pesquisa revelou uma tendência de países com maior produção de lúpulo ou cerveja a investirem mais em pesquisa e desenvolvimento no setor. Além do mais, foram identificados entraves para a inserção apropriada do lúpulo cultivado em território nacional para ser utilizado pelas cervejarias.

This work reports the characterization of a vegetable oil extracted from pequi seeds, an agroindustrial residue, and its biodiesel production using ethanol and heterogeneous catalysis. The pequi seeds showed 40.73 wt.% of extractive content, which represents a large amount of the biomass composition. The crude oil extracted from the pequi seeds with ethanol as solvent presented a high content of free fatty acids (FFAs), mainly oleic (54.14%) and palmitic (36.71%) acids, resulting in an acidity value of 13.8 ± 0.1 mg KOH g-1. The esterification/transesterification process was performed using two ion exchange resins as heterogeneous catalysts, a commercial protonic form (assigned as PR) and a zirconium-exchanged (assigned as PRZr). Conversions of 87.1 and 91.4% were achieved for PR and PRZr as catalysts, respectively, at optimal conditions (1:6 oil-to-alcohol molar ratio, 25 wt.% of catalyst, 100 ºC and 1 h). These results indicated that heterogeneous acid catalysts can be successfully applied in biodiesel production from fatty acidrich oils, such as the one extracted from pequi seeds. Also, a simultaneous process involving both oil extraction and biodiesel production was tested using PRZr as catalyst (25 wt.% of catalyst and 100 ºC), but due to the greater amount of ethanol necessary for the oil extraction (1:16 oil to alcohol mass ratio) the conversion reached only 51.5% after 5 h. For that reason, this work proposes a two stage system for biodiesel production that integrates oil extraction (stage one) and the esterification/transesterification reaction (stage two) to achieve a greener process, waste-to-bioenergy.