As fossil fuel continues to negatively impact the environment, and the natural resources to meet the demand for it rapidly deplete, the search for a sustainable substitute grows ever more urgent.
What may come as a surprise to some (though not to us anymore) is that the solution to this pressing issue may just lie with the humble hemp plant.
For centuries industrial hemp has been grown throughout the world for its stalks and fibres, producing a variety of products including rope, textiles, paper products and building materials. And research has indicated that the farmers producing these materials are also already likely producing enough hemp to potentially create fuel to power their entire farm.
This claim lies with the hemp seed - the part of the plant that is often discarded in this kind of hemp farming. Back in 2010 researchers at the University of Connecticut found that the hemp seed oil from cannabis sativa (otherwise known as industrial hemp) is a viable source for biodiesel, a fuel derived from ‘biomass’ - that is, plant or algae material, or animal waste.
They tested hemp at the university’s specialised biofuel lab at its Environmental Science & Engineering centre, converting it into biodiesel through a process of transesterification - a chemical reaction between vegetable or animal fats and alcohol.
Hemp was discovered to have an encouragingly high efficiency of conversion, with 97% of the hemp oil converted to biodiesel, compatible for use in any conventional diesel engine. It also burned at a lower temperature than any other biodiesel currently on the market, the list of which includes soybeans, olives, peanuts and rapeseed.
The conversation around biofuels also often boils down to weighing up food against fuel - a debate around whether agricultural land should rather be reserved for producing food crops instead of fuel. But industrial hemp circumnavigates this debate by virtue of the fact that it has the ability to flourish on infertile soil, leaving primary crop land free for growing food .
Adding to its sustainability factor is that it requires minimal water and fertilisers and no pesticides to produce a high yield, is susceptible to only a few diseases and grows incredibly fast - “like a weed”. Hemp is also versatile in that it can be grown in any temperate to hot climate, and because the rest of the plant can be used to make various other materials, nothing is discarded and wasted in the process of production.
Most significantly for us and for the environment at large is the fact that hemp-based biodiesel presents a viable, low emission replacement to petroleum-based fuels.While typical diesel contains a high level of sulfur leading to the production of sulfur oxide emissions, biodiesels do not.
The hemp plant is a carbon-neutral resource that ingests carbon dioxide even faster than trees, while also reabsorbing or ‘scrubbing’ any CO2 produced from the burning of biodiesel from the air through the process of photosynthesis. It literally leaves the soil in a better condition than it found it in.
So, why the delay? None of these findings are recent, with the key study into hemp as a biodiesel having been done almost a decade ago now. Why isn’t the world already forging ahead and growing hemp en masse in an effort to minimise our impact on the planet?
Well, the USA usually leads the charge on this scale of industrial innovation. But the regulated growing of industrial hemp was only legalised in the country in 2018 with the passing of the Hemp Farming Act, in which hemp was legally recognised as distinct from other cannabis plants for the first time in 70 years. And embargos like this have resulted in a worldwide stunted evolution of cannabis.
The infrastructure for producing hemp biofuels has not yet been established, and more resources and time need to be put towards innovation and development of hemp as a biofuel to mitigate some of the snags that have surfaced. About 50% more biofuel is required to create the equivalent energy as fossil fuels, requiring pre-treatment of hemp and a longer, more costly process.
However, these are issues that are very likely to be overcome and solved with investment and technological development in the industry. And as hemp experiences its global renaissance thanks to amended legislation and enlightened attitudes, hopefully in years to come we will witness the scale of interest that is necessary to get the world into gear on the good leaf.