Unlike in biodiesel applications, the whole hemp plant can be used in ethanol or methanol production. As with biodiesel, ethanol and methanol can be used as a fuel for vehicles. When derived from industrial hemp, these alcohols are sometimes referred to as hempanol.
Ethanol is made from the sugars and starches of plants. To create ethanol from hemp, it requires a process called cellulolysis that consists of a number of stages.
Pre-treatment to make the cellulose content in hemp suitable for hydrolysis.
Breaking down the molecules into sugars using an enzyme that converts cellulose into glucose (cellulase).
Separation of sugar materials from the lignin.
Fermentation of the sugar solution.
Distillation to extract the ethanol.
The use of molecular sieves to increase ethanol concentration.
The use of food crops as fuel is always controversial, but as we’ve learned with hemp, the seed doesn’t have to be used as biofuel. One of the many benefits of using industrial hemp for biofuels is that practically the whole plant can be used.
Another benefit of using hemp compared to other food crops is that it can be grown on marginal lands, requires no pesticides or fertilizers and little water. Industrial hemp can also help remediate contaminated soils.
With the renaissance of hemp in the developed world under way as governments finally update archaic and ill-conceived regulations related to its cultivation, we can perhaps look forward to seeing cheap industrial hemp biofuels more widely available in the future.