Abstract Spontaneous self-heating and off-gassing of wood pellets during storage is well-recognized problem. The reason for the phenomena is be autoxidation of fatty/resin acids in the pellets material. Two antioxidants, TBHQ (tert-Butylhydroquinone) and PG (propyl gallate), have been used as additives during pellets production in order to investigate how effective these antioxidants are in blocking autoxidation. Off-gassing of volatile aldehydes, CO and CO2 from wood-pellets and depletion of O2 during storage at room temperature in two different scales of closed storage systems were investigated and antioxidant fortified pellet batches and a reference batch without additive were compared. The results show that TBHQ is an efficient antioxidant at a low concentration (0.5%) in blocking autoxidation of fatty/resin acids in wood pellets. The CO emissions are reduced between 72 and 90% depending on the pellets temperature. Some of the fatty acids are almost intact in the samples with TBHQ compared to reference sample; showing that TBHQ blocking degradation by autoxidation of those fatty acids. For PG, autoxidation has not been blocked. The total amount of emitted aldehydes are 77% less than in pellets made with antioxidants as compared to the reference pellets, showing that TBHQ is acting as inhibitor in the autoxidation processes.

中文翻译：

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抗氧化剂作为木屑颗粒中的添加剂，作为减少储存过程中释放气体和自热风险的一种手段

摘要 木屑颗粒在储存过程中自热和放气是一个公认的问题。这种现象的原因是颗粒材料中脂肪酸/树脂酸的自动氧化。两种抗氧化剂 TBHQ（叔丁基氢醌）和 PG（没食子酸丙酯）已被用作颗粒生产过程中的添加剂，以研究这些抗氧化剂在阻止自氧化方面的效果。研究了木材颗粒中挥发性醛、CO 和 CO2 的排气以及在室温下储存期间在两种不同规模的封闭存储系统中的 O2 消耗，并比较了抗氧化剂强化颗粒批次和不含添加剂的参考批次。结果表明，TBHQ 在低浓度 (0.5%) 下是一种有效的抗氧化剂，可阻止木屑颗粒中脂肪酸/树脂酸的自氧化。根据颗粒温度，CO 排放量减少 72% 至 90%。与参考样品相比，含有 TBHQ 的样品中的一些脂肪酸几乎是完整的；表明 TBHQ 通过这些脂肪酸的自动氧化阻止降解。对于 PG，自氧化并未被阻断。与参考颗粒相比，释放的醛总量比使用抗氧化剂制成的颗粒少 77%，表明 TBHQ 在自氧化过程中起到抑制剂的作用。