Hemp in Sustainable Technologies
Hemp (Cannabis sativa) has been cultivated for thousands of years. With the recent passage of the Farm Bill and the Hemp Farming Act, hemp is growing in popularity and possibilities. Industrial hemp is cultivated for many uses and when extracted, has demonstrated numerous health benefits.
As the global population expands and consumption grows, there are increased strains on our natural resources. These strains prompt the consideration for sustainable methods to satisfy resource needs. Hemp presents an excellent opportunity to develop new sustainability technologies.
Here are just a few of the potential ways hemp can have a positive impact on the future.
General environmental implications
What’s triggering the growing interest in hemp? An increased awareness of our struggling environment is a major factor. Nonrenewable resources are being depleted at an unsustainable rate, leading to reduced quality of our water and air.1 The quest to develop environmental solutions for climate change is of top priority.
Enter hemp. Rapidly spreading in popularity, this “alternative crop” has sustainability possibilities we’re just beginning to consider.
Quick-to-yield crop: Hemp is much faster growing than comparable materials. How fast? In as little as two months it can be harvested for its fiber content.2 Compare that to the length of time to yield a cotton crop (6 months) or trees used to produce paper (up to 20 years).2,3 Plus, hemp offers more flexibility in climate options, growing easily in different soil types and temperatures.4 And since it thrives in tight spaces, farmers can grow more hemp in less space in shorter times, increasing both their yield and profits.2,5
Water usage: Where cultivating traditional crops is heavily dependent on significant water usage, hemp requires very little. In fact, growing hemp uses less than one-third of the water required to grow cotton.6
Fewer pesticides and herbicides: Many people are becoming aware of the detriments associated with excessive pesticide use on crops. Foods and fabrics may be washed before we come into contact with them, but there are still environmental dangers from dusting crops or releasing poisons into the air. Luckily, unlike most crops, hemp is naturally resistant to many pests, fungi, and diseases, so farmers aren’t compelled to saturate hemp in chemicals as a protective measure.2
Rotational crop: Hemp can actually improve the quality of the soil, which is ideal when it’s being used as a rotational crop. It does this in a few different ways. First, hemp can absorb heavy metals directly from soil, which doesn’t put human consumption at risk when the crop is being used for products like paper or building materials (although hemp grown in heavy metal-rich soil should not be used for hemp extract or textiles).1 This soil-clearing leaves the land healthy and immediately available for food crops.4
Second, farmers rotate their crops in order to allow depleted nutrients to replenish. But hemp actually returns many of its nutrients to the soil, leaving healthier ground and also benefitting the subsequent crop.1,2,7
Finally, since hemp can be grown in small areas, it has the added benefit of choking out weeds, reducing the need for herbicides and leaving a healthier crop.1
No, we won’t all be living in hemp huts in the future. But as a composite of building materials, hemp shows promise as a sustainable option. Builders testing characteristics like strength, durability, water absorption, and thermal conductivity discovered that the hemp options were comparable to commercially available building materials.8
Additional studies are being done combining hemp with other materials to determine the possibility of its use in construction materials.9 For instance, older brick homes that struggle to retain heat can be retrofitted with a combination of hemp and lime or polyester insulation materials to improve air transmittance. This insulation has the added benefit of easing energy demands, as well.10,11
Unlike coal, a limited resource that can be dangerous to mine, and wood, which has significantly longer growth time requirements, hemp can be used as alternative fuel for energy and heating. In countries with colder climates, such as in Sweden and Moldova, people have begun using hemp in briquette form as a heating source.1,12 Hemp briquettes have been shown to be comparable to wood in small-scale heating units, and have the potential to be fermented or otherwise distilled to produce gaseous fuels, such as ethanol or even gasoline.1,12 Production of biofuels on a larger scale has not yet become feasible, but it’s a promising possibility for the future.
Deforestation has catastrophic effects on our environment. Could hemp be the solution we so desperately need? Consider the time and space required to turn trees into paper. Hemp, on the other hand needs little space to grow, and as mentioned earlier, can produce crops in a matter of months, not years.4 In addition, this biodegradable crop “produces more pulp per acre than trees,” and it has a higher cellulose concentration, which can result in sturdier paper products.2
In Europe, the bast fiber in hemp is already being used for products such as cigarette paper, currency, and thin book paper, such as that used in bibles and other dense books.1 This particular kind of paper, which is made of fibers with low lignin content, isn’t as processed as that used in large-scale operations.1
Yet while the environmental benefits of using hemp to create paper abound, the economic factors involved in processing the plant make it cost-prohibitive. Still, processes are being refined; perhaps in the future there will be a substantial shift away from deforestation for paper production.
Hemp clothing isn’t just a novelty souvenir from a music festival. Hemp fibers are being used to create everything from clothing to ropes to sails to sacks.13 Due to its easy cultivation and minimal water requirements, hemp is beginning to make a dent in cotton’s global popularity. While currently 36% of the world’s textiles are produced from cotton, hemp is rapidly becoming a preferable, more sustainable option.6 Research still needs to be conducted on optimal harvest time, as there have been wide discrepancies in quality based on growth time.7
Just one word: Plastics
When we discuss global warming and human impact on the environment, one topic that frequently arises is our use of plastic. It litters our beaches and can spend eternity in our landfills. But plastics are cheap to make and have numerous uses, so we continue to rely on this environmentally unsound substance. Environmental entrepreneurs have been seeking sustainable or biodegradable alternatives to petroleum-based plastics for years. Could hemp be their holy grail?
While a 100% hemp-based plastic is unlikely to be developed anytime soon, innovators have learned that hemp cellulose fiber is a viable source for alternative compounds. When extracted from the hemp plant, hemp cellulose fiber has been used in the production of rayon, cellophane, and other plastic materials.14 Other options currently in use include “composite bioplastics,” in which hemp combined with other plant sources to create strong, rigid materials for the manufacture of cars, boats, and other products.14
Not so fast
If hemp can replace more expensive and environmentally damaging crops, why haven’t more companies and industries made the switch? One of the main detriments is cost. Hemp has demonstrated tremendous potential as a replacement to our depleting natural resources, but it still has a long way to go in order to move from a niche sustainable crop to the plant of the future. Stay tuned!
- Young E. Revival of industrial hemp. https://www.lumes.lu.se/sites/lumes.lu.se/files/erin_young.pdf. Accessed October 1, 2019.
- Parletta N. Could hemp be the next big thing in sustainable cotton, fuel, wood, and plastic?https://www.forbes.com/sites/natalieparletta/2019/06/28/could-hemp-be-the-next-big-thing-in-sustainable-cotton-fuel-wood-and-plastic/#1d46d10b21c2. Accessed October 1, 2019.
- Cotton growing cycle. https://cottonaustralia.com.au/cotton-library/fact-sheets/cotton-growing-cycle. Accessed October 3, 2019.
- Qureshi A. All about hemp: the sustainable miracle crop. https://blueandgreentomorrow.com/sustainability/all-about-hemp-sustainable-miracle-crop/. Accessed October 1, 2019.
- Potential U.S. Production and Processing. https://www.ers.usda.gov/webdocs/publications/41740/15859_ages001ei_1_.pdf?v=0. Accessed October 3, 2019.
- Averink J. Global water footprint of industrial hemp textile. https://essay.utwente.nl/68219/1/Averink,%20J.%200198501%20openbaar.pdf. Accessed October 1, 2019.
- Bengtsson E. Obtaining high quality textile fibre from industrial hemp through organic cultivation. https://www.researchgate.net/publication/41793282_Obtaining_high_quality_textile_fibre_from_industrial_hemp_through_organic_cultivation. Accessed October 1, 2019.
- Manzi et al. New composite panels with hemp hurds for sustainable buildings. Environmental Engineering and Management Journal. 2013;12(S11 Supp 31-34).
- Asprone D et al. Potential of structural pozzolanic matrix–hemp fiber grid composites. Construction and Building Materials. 2011;25(6):2867-2874.
- Griffiths R et al. Sustainability of solid brick walls with retrofitted external hemp-lime insulation (Structural Survey). https://www.emerald.com/insight/content/doi/10.1108/02630801211256661/full/html. Accessed October 1, 2019.
- Zampori L et al. Life Cycle assessment of hemp cultivation and use of hemp-based thermal insulator materials in buildings. Environ Sci Technol. 2013;47(13):7413-7420.
- Kolarikova M et al. Evaluation of sustainability aspect – energy balance of briquettes made of hemp biomass cultivated in Moldova. Agronomy Research. January 2014.
- Carus M et al. The European hemp industry: cultivation, processing and applications for fibres, shivs and seeds. https://www.votehemp.com/wp-content/uploads/2018/09/13-03_European_Hemp_Industry.pdf. Accessed October 1, 2019.
- O’Connell K. Hemp makes great plastic, so why isn’t hemp plastic everywhere? https://ministryofhemp.com/blog/why-isnt-hemp-plastic-everywhere/. Accessed October 1, 2019.
Submitted by the Metagenics Marketing Team