Energy is the most important aspect in determining a country’s socioeconomic success. Due to persistent exhaustion of the nonrenewable assets of energy such as coal and petroleum, the advancement of renewable energy assets has emerged as a research hotspot. An increasing interest in biofuels from agricultural and other wastes has resulted in scientific advancements in recent years. Bioethanol, for example, is a biofuel made from green energy, which are clean, safe, and economically viable alternatives to nonrenewable energy fuels. Moreover, second generation bioethanol from the lignocellulosic biomass, is fascinating because of its abundant availability around the world. Biomass energy is considered as one of the endless sources of energy and a strategy not only to combat the fossil fuel energy problem but also prevent carbon emissions. Corn cobs and corn stovers, for example, are one of the most abundant, affordable, and readily available renewable cellulosic materials from corn, consisting about 50 times of the corn biomass. Many physicochemical structural and compositional characteristics in biomass prevent cellulose from being digested into sugars and other organic molecules that can then be converted to fuels. For this, researchers are exploring different thermochemical processes like pyrolysis, gasification, liquefaction, and torrefaction as well as green processes for modifying the physical and chemical structure of lignocellulosic biomass, boosting hydrolysis rates and thus, production of clean and green energy. The present chapter is devoted to the recent developments in different thermochemical and green processes for the production of biomass energy.