Biomass as a sustainable resource for value-added modern materials: a review

Over the past century, the world's population has increased greatly. The growth in the population has increased the global food demand, so the food sector has increased its production. As a result of the increased production and consumption, a huge amount of agro-food waste is being generated yearly. Rice husk, wheat straw, sugarcane bagasse, corn husk, peanut shell, eggshell, are just a few examples of agro-food wastes. As these agro-food wastes and their by-products are left unused and unattended, their amount is increasing globally. It is imperative to find ways to put these wastes to environmentally viable use. These wastes find direct uses in biofertilizers, mud houses, animal feed, biofuel, and heat generation in small-scale industries, etc. After heat generation, ashes are considered as a secondary by-product, which can be used as a sustainable and renewable resource for synthesizing value-added products for various applications. This article presents a review of the traditional and advanced methods of utilizing these wastes in household applications, animal feed, fertilizers, fuel generation, pyrolysis, and for the removal of toxic metals from polluted water. These secondary resources can also be used in construction materials and for the synthesis of glasses and glass-ceramics, which can be used in bioengineering, optical, and dielectric materials. Agro-food wastes can be used as resource materials to develop modern materials with better properties instead of using minerals. This not only reduces the environment- and management-related problem of the wastes but also provides a sustainable alternative way to produce cost-effective value-added materials for the benefit of society. (c) 2020 Society of Chemical Industry and John Wiley & Sons, Ltd