Fiber-first approach to isothermal calorimetry for quantification of self-heating reduction by antioxidants for the wood pelleting industry

Abstract

Self-heating has become a problematic issue for the wood pelleting industry as it continues to garner negative public scrutiny based on documented instances of injury and death. To counter this, manufacturers have turned toward modifying wood furnish through implementation of antioxidants into their processes. The antioxidants are intended to provide a reduction in finished product self-heating, in addition to other production benefits (e.g. pellet binding or dye lubrication). This work develops and demonstrates an antioxidant screening method that takes place in a laboratory setting, allowing for low-cost and low-risk evaluation of prospective antioxidant ingredients. Results showed that the method was robust towards different woody materials, and successfully demonstrated reduction to self-heating by a variety of lignins and a synthetic antioxidant. Ideally, the developed protocol will evolve into a practice where manufacturers first evaluate materials that lower self-heating using isothermal calorimetry in order to screen new pelleting reagents prior to committing to costly trials.