Wood pellets have become a flagship biofuel in transitioning from coal-based heat and power generation to renewable energy. However, the hygroscopic nature of wood pellets is a long-standing challenge in storing and transporting this commodity. The heat of moisture sorption contributes to the self-heating and spontaneous combustion of wood pellets. The objective of this paper is to investigate the evolution of heat in moistened pellets and to compare them to that of wood chips. Wood pellets at several moisture content levels were immersed in liquid water and the rise in the pellets’ temperature was recorded. The calorimetric method was used to calculate the heat of wetting for the immersed pellets. The heat of wetting was at its maximum for completely dry pellets. The heat of wetting decreased linearly as the moisture content increased towards a fiber saturation point of about 0.17 (decimal dry basis). Statistically, the maximum heat of wetting of pellets is the same as that of wood chips. However, the rate of heat release of pellets is twice of that of chips.

木质颗粒已成为从煤炭供热和发电过渡到可再生能源的旗舰生物燃料。然而，木质颗粒的吸湿性是储存和运输这种商品的长期挑战。水分吸收的热量有助于木屑颗粒的自热和自燃。本文的目的是研究潮湿颗粒中热量的散发并将其与木屑进行比较。将几种水分含量较高的木质颗粒浸入液态水中，并记录颗粒温度的升高。量热法用于计算浸没颗粒的湿热。对于完全干燥的粒料，湿热最大。湿热随着水分含量朝着约0.17（十进制干基）的纤维饱和点增加而线性降低。从统计学上讲，颗粒的最大润湿热与木片的最大热相同。但是，丸粒的放热速率是碎屑的两倍。