Hemp Hurds and Processing By-Products
category
Hemp hurds (shives, woody core) constitute 65–70% of stem dry weight at 8–12 tonnes/ha, representing the most abundant hemp processing by-product. Hurd composition: cellulose 38–45%, hemicellulose 25–30%, lignin 21–26%, ash 1–3%. Bulk density of loose hurds is 100–130 kg/m³; compressed bale density 180–220 kg/m³. Primary valorisation pathways: animal bedding (45% of hurd market, €80–150/tonne), hempcrete aggregate (lime-hemp insulating construction material, €150–250/tonne), particleboard and MDF manufacturing (€100–180/tonne), activated carbon production (BET surface area 800–1,200 m²/g after KOH activation at 700–800°C), and paper pulp (yield 35–45% versus 40–50% for wood). Hemp seed (500–800 kg/ha) yields oil (30–35% oil content, omega-6:omega-3 ratio 3:1) valued at €2,000–4,000/tonne and protein-rich seed cake (€300–600/tonne animal feed). Full crop valorisation improves hemp fibre economics by €500–1,200/ha through by-product revenues.
Role
By-product valorisation of hurds, seeds, and tow converts hemp processing waste streams into revenue streams that subsidise bast fibre production economics, making the circular hemp biorefinery model competitive with conventional agricultural commodities on total farm income.