Lignocellulosic biomass as sustainable feedstock and materials for power generation and energy storage

Lignocellulosic biomass has attracted great interest in recent years for energy production due to its renewability and carbon–neutral nature. There are various ways to convert lignocellulose to gaseous, liquid and solid fuels via thermochemical, chemical or biological approaches. Typical biomass derived fuels include syngas, bio-gas, bio-oil, bioethanol and biochar, all of which could be used as fuels for furnace, engine, turbine or fuel cells. Direct biomass fuel cells mediated by various electron carriers provide a new direction of lignocellulose conversion. Various metal and non-metal based carriers have been screened for mediating the electron transfer from biomass to oxygen thus generating electricity. The power density of direct biomass fuel cells can be over 100 mW cm−2, which shows promise for practical applications. Lignocellulose and its isolated components, primarily cellulose and lignin, have also been paid considerable attention as sustainable carbonaceous materials for preparation of electrodes for supercapacitors, lithium-ion batteries and lithium-sulfur batteries. In this paper, we have provided a state-of-the-art review on the research progress of lignocellulosic biomass as feedstock and materials for power generation and energy storage focusing on the chemistry aspects of the processes. It was recommended that process integration should be performed to reduce the cost for thermochemical and biological conversion of lignocellulose to biofuels, while efforts should be made to increase efficiency and improve the properties for biomass fuelled fuel cells and biomass derived electrodes for energy storage.