Exploring rice straw as substrate for hydrogen production: Critical challenges and opportunities

Due to the world's constant demand for rice as a main food crop, the quantity of rice straw produced pressurizing the waste management strategies of the countries. Rice straw is a big waste management issue in rice-producing nations such as China, India, Vietnam, Indonesia, Brazil, etc. Burning rice straw on the field is the most preferred option for farmers to get rid of the rice straw which creates an array of environmental issues. In addition to jeopardizing the environment by emitting a significant quantity of greenhouse gases (GHGs), the inappropriate utilization of rice straw and open crop burning in the field also tend to lose farmers a very profitable by-product. Benefits can be harnessed by utilizing the abundant rice straw as a raw material for valuable product generation. This work reviews the significant aspects of the use of rice straw as an imperative source of clean energy. The paper emphasizes some important background knowledge, such as the chemical, and physical properties that determine the caliber of rice straw. The different pretreatment methods that can make rice straw equipped for hydrogen production have also been discussed. The latest thermochemical and biochemical approaches for converting rice straw into hydrogen are vividly presented. Further studying the viability of producing hydrogen from rice straw in the context of modern agriculture becomes more crucial. The present review also discussed the policies and current situation of hydrogen production globally and provides a forecast on the state of hydrogen as a clean fuel for a sustainable future.