This study investigated the effects of additives on reduction in ash deposit formation while co-firing straw pellets with pulverized coal. A pulverized-fuel-fired combustion system was used to co-combust sub-bituminous coal and herbaceous biomass. Kaolin (Al₂Si₂O₅(OH)₄) and ammonium sulfate ((NH₄)₂SO₄) were used to determine the influence of additives on ash deposit reduction. Experiments were performed in an 80 kW_th scale combustion system for various proportions of additives (proportions of 1 wt% and 4 wt% of fuel). Weight of deposited ash was measured concurrently. In the experimental results, different trends from several previous researches were observed regarding effectiveness of the additives: Addition of kaolin increased deposition by up to 19%, while ammonium sulfate increased deposition by up to 36%. Thermodynamic equilibrium of all experimental cases was calculated based on ash composition, and we reveal that in our experimental cases kaolin promotes formation of K-silicates of low melting temperature, while ammonium sulfate reacts with KCl to increase melting temperatures for K-Al-silicates. This demonstrates that the fuel-specific choice of additives is important to effectively reduce ash deposition.

本研究调查了添加剂对减少灰烬形成的影响，同时将秸秆颗粒与煤粉混烧。使用粉状燃料燃烧系统来混合燃烧次烟煤和草本生物质。高岭土 (Al ₂ Si ₂ O ₅ (OH) ₄ ) 和硫酸铵 ((NH ₄ ) ₂ SO ₄ ) 用于确定添加剂对减少灰分沉积的影响。实验在 80 kW _th中进行不同比例的添加剂（比例为 1 wt% 和 4 wt% 的燃料）的规模燃烧系统。同时测量沉积灰的重量。在实验结果中，在添加剂的有效性方面，观察到与之前几项研究不同的趋势：添加高岭土最多可增加 19% 的沉积，而硫酸铵最多可增加 36% 的沉积。所有实验案例的热力学平衡都是基于灰分组成计算的，我们发现在我们的实验案例中，高岭土促进了低熔融温度的 K-硅酸盐的形成，而硫酸铵与 KCl 反应以提高 K-Al-硅酸盐的熔融温度。这表明特定于燃料的添加剂选择对于有效减少灰分沉积很重要。