Hemp biomass, once a thrown away by-product of Hemp cultivated for fibre, seeds and flowers. However, recent research suggests that Hemp biomass is, in fact, a highly desirable resource in its own right. So, what is Hemp biomass? And what is it used for?

Hemp, known the world over as a multipurpose crop, is an annually reproductive plant that has been cultivated across the world for many centuries (1). In addition to its more traditional uses for fabric and paper, Hemp is used as a bedding for animals and livestock, in the automotive industry, the construction industry as well as the pharmaceutical and nutraceutical industries (2).

This incredibly diverse, and highly desirable, crop has been grown for thousands of years. Currently, due to the recently increased demand for hemp, especially hemp fibre, the cultivated area of hemp has increased remarkably. This is especially so in Europe, China, Canada and in the USA. In China, the expected increase in cultivated areas will hit 670 thousand hectares by the end of 2020 (3).

In the processing of Hemp fibres, seeds and shivs, the hemp stem becomes an underutilised by-product, termed Hemp biomass. The woody core, accounting for 70% of the hemp stem, has abundant characteristics making it valuable for use in many industries (4).

With this in mind, there are two questions that need to be answered; What is Hemp biomass? And, what are the uses of Hemp biomass?

What Is Hemp Biomass?

Hemp biomass is the component of the Hemp plant that remains after the flowers, seed and bast fibre has been harvested from the plant. In a conventional sense, this would be considered the waste of Hemp farming; however, Hemp biomass has its own, very valuable, uses in its own right.

Hemp biomass is an attractive resource for a number of products and industries. It is abundant in very beneficial characteristics, including, availability, renewability, biodegradability, reduced weight, increased flexibility, greater moldability, reduced cost and strong sound insulation properties (5).

The chemical composition of Hemp biomass is incredibly important, especially for its use as a biofuel. Hemp biomass contains higher levels of cellulose than corn fibre, corn stover and sorghum bagasse (6). Because of this, Hemp biomass is an attractive source of bioethanol fuel (7).

Hemp biomass has major advantages over other biomass crops, this is especially so considering its advanced mechanical and chemical properties. So what can we do with this valuable Hemp by-product?

Uses of Hemp Biomass

There are a range of industries Hemp biomass is able to be applied in. This includes being used as a biofuel, to help absorb nitrogen, carbon dioxide and hydrogen and plastic biocomposites.

Hemp Biomass as a Biofuel

Many investigations have looked at whether Hemp biomass would be a valuable bioenergy crop, especially when compared to other potential sources, such as kenaf, switchgrass and sorghum (8). Firstly, Hemp has been shown to have higher yields with reduced input, even when compared to switchgrass and sorghum. The predicted yield from the hemp of bioethanol is around 310 litres per tonne of Hemp biomass (9). Hemp is also expected to have a higher per-hectare profit than all other crops. Combined, these show Hemp biomass is a promising regional commodity crop for producing biofuels (10).

Several other studies have looked at the potential of Hemp biomass in bioethanol production, particularly considering its chemical composition. Hemp biomass has superior chemical composition favouring the production of bioethanol, and this is especially so in comparison to corn fibre, corn stover and sorghum. Overall, these investigations suggest that Hemp biomass is an excellent candidate for bioethanol production (11).

Hemp Biomass to Absorb Nitrogen, Carbon Dioxide and Hydrogen

There has been much attention recently on the ability of Hemp biomass to assist with the control of air pollution, this is through chemically and temperature-induced Activated Carbons (ACs). ACs are chemically induced carbons in Hemp biomass which are highly porous, that are incredibly useful as an absorbent for air pollution control and wastewater treatment (12). Research has demonstrated that Hemp biomass originated ACs works incredibly well in absorbing nitrogen and carbon dioxide and works remarkably well in absorbing hydrogen (13). This suggests Hemp biomass is incredibly valuable as a source of Activated Carbons in alleviating air pollution across the world (14).

Hemp Biomass In Plastic Biocomposites

We all know that in recent years there has been a resurgence of interest for the use of renewable materials in many products, especially plastics. The use of renewable materials, including plant fibres, offers the advantage of fewer health hazards and lower costs. The use of Hemp biomass as a source of biocomposites unlocks the potential of this underutilised material to help with the war on pollution (15).

The cellulose fibres obtained from Hemp biomass is used in the preparation of micro- and nano-cellulose fibres. As Hemp micro- and nano-cellulose fibres are very rigid, it is able to be used as a reinforcement in a wide range of polymeric matrices. These biocomposites have major applications in the automotive industry as well as for consumer goods, such as composite packaging and agricultural films (16).

The Bottom Line

Hemp biomass, a common by-product of Hemp cultivated for fibre and seeds, was once an under-utilised, but highly beneficial, resource. Recently, Hemp biomass has been used in numerous applications, such as biofuels, as a source of Activated Carbons and as biocomposites. These applications are highly beneficial, making this highly sustainable crop even more attractive.