.4 Advantages and Disadvantages1.4.1 Advantages1.4.2 Disadvantages2. Conversion2.1 Thermochemical2.2 ... using biofuels4. Biofuels4.1 Ethanol4.2 methanol4.3 Charcoal4.4 Biodiesel4.5 Pyrolysis of biomass4.6 ... refining the gas, the more energy efficient it is.The sorbent or molecular sieve is mainly used and