By Emily Ledger
It’s time to revisit the thousands of uses of hemp, and how some of these uses could benefit our environment. This time, we’re looking at hemp fuel. We know the damaging effects that some fuels can have on the natural world, but could hemp help?
What is Hemp Fuel?
Hemp can be used to make biofuels (the term given to fuels made from plants), called bioethanol and biodiesel. It can also be used as a fuel in a biomass power plant. Biofuels can be made by using both the fruit and grain of a plant or the fibres of the plants (cellulosic ethanol). Hemp is primarily used to produce cellulosic ethanol.
The process of converting hemp plants into fuel involves a number of steps. First of all, the harvested plant is shredded and heated with chemicals, so that the cellulose is released. Enzymes are then used to break down the cellulose into sugars.
Microbes are then introduced, to aid the fermenting process of the sugars – turning them into ethanol. Finally, the ethanol is purified and distilled, leaving the final biofuel.
Effects of Traditional Fuels
Traditional fuels – or fossil fuels – have become the main focus of international environmental concern. Fossil fuels can take thousands of years to form, and in the short time that we have been harvesting them, they have had a devastating effect on the environment.
Fuels like coal, natural gas, and oil are harvested from the earth and burnt. Petrol and diesel, are made using crude oil, which consists of hydrocarbons. When burnt, the fuel creates energy – but it also causes the release of toxic chemicals.
The hydrocarbons in the oil are converted to carbon dioxide, and other harmful by-products when burned. Many countries around the world have now agreed to cut their use of fossil fuels for more environmentally friendly, and renewable alternatives.
In addition, fossil fuels are limited by their lengthy formation time. We have been consuming fossil fuels at an unsustainable rate (faster than the earth can create them) since the industrial revolution.
Benefits of Hemp Fuel
Biofuels have the advantage of being much more sustainable. This is because we can continue to grow and harvest the materials to make biofuel at a sustainable rate. But what makes hemp particularly suited to being used for fuel?
The majority of biofuel is currently made from corn or sugarcane. These are great sources of ethanol, as they contain a lot of sugar. However, the downside to using these crops is that it creates competition with food production. To create fuel from these plants, you are using material which could otherwise be valuable food.
In comparison, the leaves and cellulose fibres from the hemp plant are not valuable food sources. Having said this, the seed by-products from the plants can be used to make nutrient-rich food products.
Hemp can also be grown fairly easily, in most climates (unlike corn and sugarcane). This means that most countries around the world would have the ability to grow their own fuel. The crops also don’t usually require pesticides and herbicides, and reach maturity within four months – meaning that more biofuel can be produced more quickly.
What are the Setbacks?
Of course, it’s not all plain sailing when it comes to hemp biofuel or biofuel as a whole. When compared to traditional fossil fuels, around 50% more biofuel is required to create the same amount of energy. However, the renewable and sustainable qualities of biofuel largely offset this inconvenience.
When comparing hemp fuel production to that of other biofuels, the cost is the main setback. This is down to the number of processes required to convert hemp fibres into fuel. Unlike sugarcane, which only requires fermentation – and even corn which requires hydrolysis and fermentation – hemp material needs to be pre-treated before these processes can take place.
The longer process involved in converting hemp, and other cellulose-high plants, into fuel, has restricted the industry. In order to take off, the cellulosic ethanol industry requires investment. This investment would aid the development of new technology and equipment, which in turn would make for a more viable fuel sector.