Biomaterials-based concrete composites: A review on biochar, cellulose and lignin

In recent years, a discernible surge in greenhouse gas emissions has precipitated severe global warming, with the construction industry identified as a notable contributor, particularly through carbon dioxide emissions from cement production. As concrete stands as the second most extensively utilized material globally, its pervasive use amplifies the release of potent greenhouse gases. This paper introduces a novel approach to carbon capture in concrete materials by employing CO₂ adsorbents that synergistically enhance the carbonization reaction, thereby augmenting capture efficiency. Biochar emerges as a promising candidate for carbon capture due to its robust CO₂ adsorption capacity and its eco-friendly, cost-effective, and low-carbon production process. For instance, typically 1 ton of biochar has potential to sequester 3 ton of carbon dioxide from the environment. Various studies have explored the integration of biochar into concrete materials, aiming to improve mechanical, durability, and thermal properties, as well as the overall functionality of formed concrete composites. Beyond its role in enhancing concrete properties, biochar presents itself as an effective carbon sequestering agent with or without modification which is also reviewed in this paper. Concurrently, research efforts are underway to investigate the reinforcement properties and selective CO₂ sorption capabilities of cellulose-based materials in concrete composites. Noteworthy attributes such as abundance, biodegradability, renewability, and cost-effectiveness position cellulose-based materials as promising alternatives to traditional reinforcing agents. This paper provides a comprehensive review of the latest advancements in the utilization of biochar and cellulose materials in concrete composite applications. Emphasis is placed on evaluating the durability, mechanical properties, and carbon capture potential of concrete composites augmented with biochar and cellulose. The synthesis of research progress in this domain serves to elucidate the current state of knowledge and offers insights into the future prospects of biochar and cellulose-enhanced concrete composites in the context of sustainable construction practices.