Having selected EFB, a compatible pretreatment method needs to be identified in accordance with aim (c). There exists a variety of processes for waste treatment, as mentioned in the introduction. While physical treatment (e.g. milling, freezing, extrusion) is commonly used for size reduction, chemical treatment (e.g. with acids, alkaline, or by organosolv process), physico-chemical (e.g. steam explosion, ultrasonic, liquid hot water), biological treatment (e.g. enzymatic, fungal, bacterial), or combined methods can fractionate and extract diverse sets of molecules. The ideal pre-treatment process is cheap, energy-efficient, suitable for different material types/compositions, and aids recovery of all feedstocks of interest at high qualities. Comprehensive advantages and disadvantages for treatment of lignocellulosic materials are provided in ref. 18.