The stem makes up most of the biomass of the hemp plant and consists of an inner shiv (plant xylem) surrounded by external cortical fibres. The inner shiv and cortical fibres are separated using a decorticator and the outer fibres can be further refined and used in the making of textiles, rope, car dashboard mouldings and battery superconductors. The inner shiv may be used to create a hemp-based building material known as Hempcrete.
Hempcrete is now commonly used in the building industry due to its renewable nature, fast growing time, non-allergenic properties and superior insulating and thermal efficiency in comparison to traditional fibre insulation. Hempcrete is also recognised as a carbon sink with the organic matter of the plant being locked-up within the building. Other uses of hemp shiv include: insulation, particleboard, fibreboard, equine bedding, compost, bioplastics and oil spill clean-up.
Hemp is increasingly being recognised as a candidate for producing energy from biomass. The United States Food and Drug Administration (FDA) places hemp in the top ten of potential renewable biomass sources, due to its ability to grow quickly and in many soil types, including low quality soils. Hemp fibre has a high calorific value and a high ignition point, making it ideal for producing energy from biomass or waste production. Hemp can also be used for bioremediation of contaminated soils, with the resulting fibres and biomass burned using pyrolysis to safely decompose the chemicals absorbed from the soil throughout the growing season. All parts of the plant can be used for energy from biomass generation.