Domestic Heating: Can Hemp-Hurd Derived Pellet Be an Alternative?

Abstract
Among the renewable sources, residual woody biomass from agricultural crops is becoming of great interest due to its lower environmental impact and one of the most growing agricultural sector, of the last decade, is the hemp industry which generates several kind of byproducts. In this paper, a blend of 50% of hemp-hurd and 50% of fir sawdust was pulverized and pelletized. The pellets were burned into a domestic pellet stove (9 kWth maximum nominal thermal power output) at different biomass flowrates. To compare results with a commercial-grade pellet, the tests were repeated by fueling the same stove with A2-grade pellets. Results shown that the pellet mixture 50/50 of fir sawdust and hemp-hurd is suitable for the commercial pellet stove used and that the slightly higher amount of ashes (2.7%), compared to pellet A2 (<1.2%), can be handled by the self-cleaning fire chamber. Comparable results were also obtained in regards with the stove global efficiency which ranged from 90.8-92.3% for the hemp pellets and 91-94% for the A2. A significant difference was noted in the biomass flowrate where, during the tests with hemp-hurd pellets a lower value was obtained (-20%) compared to A2. This resulted into lower power input in the stove and lower performances at the same nominal power output.
Funding Information
  • Italian MIUR project UNIHEMP (ars01_00668)