Engineered biochar/hydrochar derived from organic wastes for energy, environmental, and agricultural applications

The pursuit of environmental sustainability and the harnessing of renewable energy sources pose significant challenges, compelling researchers to explore innovative solutions. Carbon materials have emerged as crucial players in both energy, environmental, and agricultural applications, owing to their exceptional properties. Biomass waste, abundant and often overlooked, has captured attention as a promising precursor for the development of carbon-based products. This is particularly evident in the creation of biochar and hydrochar, whose characteristics are intricately shaped by production methods, source materials, and process conditions. These variables collectively influence their suitability for diverse purposes, ranging from energy storage and conversion to soil and water restoration, making them invaluable tools in sustainable agriculture and environmental conservation, as well as in the capture of greenhouse gases. The versatility of biomass-based activated carbon is further enhanced by the diverse array of feedstocks and activation pathways employed. This adaptability renders it suitable for a multitude of applications, creating a symbiotic relationship between resource abundance and functional efficacy. This comprehensive review aims to evaluate contemporary thermochemical methods for converting organic waste into high-value carbon materials. Moreover, it delves into strategies that augment the functionality of these materials, including activation processes and surface modifications. The review also illuminates recent advancements in the realms of energy, agriculture, and environmental research. It consolidates existing literature on physicochemical characteristics and techno-economic assessments of engineered carbon materials, providing a nuanced understanding of their potential impact. While exploring challenges, prospects, and future research directions, this review outlines the synthesis of carbon compounds from biomass. It emphasises the capacity to produce distinct chars with unique properties through various production methods, tailoring them to the specific requirements of diverse environmental applications.