生物沥青-木屑混合成型行为和成型燃料品质分析

Co-pelletization of bio-asphalt and sawdust: densification behavior and qualities of pellet fuel

针对生物质成型产业现存的成型能耗较高和产品质量不佳的问题,采用生物柴油生产工艺的副产物生物沥青作为添加剂,按不同配比分别与樟木屑和杉木屑混合,制备成型燃料。考察生物沥青掺加量对木屑的成型能耗(挤压和推动能耗)和木屑成型燃料性质(密度、吸水性和燃烧特性)的影响规律。研究结果表明:当物料中生物沥青掺加量由0提高至20%时,挤压能耗依次降低,而推动能耗在0~5%处降低较为显著。木屑成型燃料的密度随着生物沥青掺加量的提高呈现先升高后降低的趋势,并在5%处取得最大值。成型燃料的吸水能力随着生物沥青掺加量的提高而持续降低。添加生物沥青能够降低成型燃料的着火温度,并扩大有效燃烧温度区间,从而提高成型燃料燃烧的稳定性和持续性。

Bio-asphalt, obtained from the production of biodiesel via transesterification method, was applied as an additive to be mixed with camphor wood sawdust and Chinese fir sawdust with setting ratios, respectively. The blends were further compressed into pellets. The effect of bio-asphalt dosage on compression properties （compaction and extrusion energy consumption）, and properties （density, moisture uptake and combustion characteristics） of pellets were investigated. The results show that the compaction energy consumption decreases with bio-asphalt dosage increasing from 0 to 20%, while a marked decrement of extrusion energy consumption is obtained in the range of 0-5%. The maximum densities of pellets are also obtained around bio-asphalt dosage of 5%. The moisture uptake of pellet decreases with the increment of bio-asphalt dosage, while the higher heating value of pellet is identified as an opposite trend. Furthermore, pellet fuel＇s ignition temperature is reduced with the addition of bio-asphalt, which can improve the stability and continuity of pellet＇s combustion.