The use of biomass pellets as a source of renewable energy has increased in recent times. However, pellet storage during transportation can compromise their properties, due to fluctuating temperature and humid environments. Here, we show that extended storage of one month at 40 °C and 85% relative humidity causes significant biomass pellet degradation. This was evidenced by higher pellet porosity, weight gain, increased inclusion body formation and creation of an internal network of cracks. We quantify the inclusion and pore growth processes at the surface and within the pellets, which has implications for subsequent thermochemical conversion. The global bioenergy transition may depend upon biomass pellets, and this study shows that storage conditions are critical in the supply chain, so to maintain their quality. Without the development of stronger policies to avoid premature degradation of biomass pellets, they may not realize their full potential as a bioenergy source.

近年来，越来越多地使用生物质颗粒作为可再生能源。但是，由于温度和潮湿环境的波动，运输过程中储存的颗粒会损害其性能。在这里，我们表明在40°C和相对湿度85％的条件下延长存储一个月会导致生物质颗粒的降解。较高的颗粒孔隙率，重量增加，包涵体形成增加以及内部裂纹的产生证明了这一点。我们对颗粒表面和颗粒内部的包裹体和孔洞生长过程进行了量化，这对后续的热化学转化具有重要意义。全球生物能源转型可能取决于生物质颗粒，并且这项研究表明存储条件在供应链中至关重要，因此要保持其质量。