生物油重质油醇类添加剂提质研究

通过加入不同质量分数(5%~25%)的甲醇、乙醇、辛醇及其混合醇对松子壳热解重质油进行提质研究,考察醇添加剂对重质油理化特性影响及其存储稳定性。研究发现加入醇添加剂超声处理后能显著降低重质油的粘度、含水率和p H值,并提高其热值;同时使多环芳烃、酮类等物质含量降低,脂肪烃、芳香烃等含量增加。混合醇处理重质油的品质更好,存储56 d后性质仍较稳定,粘度和含水率随储存时间延长稍有增加。加入甲辛醇56 d后重质油的粘度为980 m Pa·s,含水率为21.02%,增长速率仅均为原始重质油的一半;且添加量越高,油的热值越高,添加量25%时热值为32.66 MJ/kg。但从热重分析发现甲辛醇添加量为20%时燃烧性能最好,其燃烧段的失重速率最大并且燃烧后的灰分最少。

Heavy Composition of Bio-oil Upgrading by Alcohol Additives

Bio-oil is the main product of biomass pyrolysis, which is considered as a promising replacing fuel for fossil oil. But the high oxygen, high viscosity, low heat value and poor stability of bio-oil make it difficult to apply directly. Thus study on the improvement of bio-oil quality is very necessary. Different mass fractions (5%~25%) of methanol, ethanol, octanol and its two mixed alcohols were used to improve the heavy oil quality which was pyrolysed from pine nut. The physical and chemical properties and storage time of heavy oil with alcohol additive were investigated. The results showed that the addition of alcohol additives could significantly reduce the viscosity, water content and pH value of heavy oil, and enhance its heat value. Simultaneously, the contents of phenols, polycyclic aromatic hydrocarbons and ketones in the heavy oil were decreased, and the contents of aliphatic hydrocarbons, aromatic hydrocarbons and alcohols were increased. The heavy oil adding mixed alcohol showed a better stability, and its viscosity and water content were only increased slightly after 56d. After adding methyl-octanol mixture and stored for 56d, the viscosity of the heavy oil was 980mPa·s, and water content was 21.02%. The growth rate was only a half of the original heavy oil. With the increase of methyl-octanol mixture additive amount, the heat value of heavy oil was increased. When the addition amount was 25%, the heat value was 32.66MJ/kg. However, it was found that the combustion performance was the best when adding 20% of methyl-octanol mixture;the weight loss rate of combustion section was the largest and the amount of ash after combustion was minimal.