Catalytic filters are a novel technology for tar conversion in biomass gasification processes. Both particle elimination and tar abatement can be achieved in a single step at high temperatures minimizing energy efficiency penalties. This paper analyses the performance of a fixed bed catalytic filter candle in the reduction of biomass tar generated in situ in a dual fluidized bed gasifier (DFBG). In this study, the temperature of the filter was limited to 800 °C. Several variables affecting the performance of the filter were tested. Experiments at different gasification temperatures in the range 750–850 °C were performed so that the amount of tar reaching the catalytic filter was varied. The amount of tar at the catalytic filter inlet did not affect the tar conversion achieved which was around 75%. The major tar compound in the gasification gas at the outlet of the catalytic filter was naphthalene. At the highest temperature tested (850 °C), the tar content in the clean gas was 0.65 g/Nm3. The effect of the face velocity in the filter on the tar conversion reached was evaluated. Tar conversion decreased when the face velocity increased from 40 to 90 m/h as the residence time of the gas in the catalytic filter was lower. The ratio H2O to dry biomass was also varied (0.5–0.9) in order to produce tars of different nature. Higher conversions were achieved for higher values of this ratio.
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机译：催化过滤器是一种用于生物质气化过程中焦油转化的新技术。在高温下，只需一步即可消除颗粒和减少焦油，从而将能效损失最小化。本文分析了固定床催化滤烛在双流化床气化炉（DFBG）中减少原位产生的生物质焦油的性能。在这项研究中，过滤器的温度限制为800°C。测试了影响滤波器性能的几个变量。在750–850°C范围内的不同气化温度下进行了实验，以便改变到达催化过滤器的焦油量。催化过滤器入口处的焦油量不影响焦油转化率，后者约为75％。催化过滤器出口处的气化气中的主要焦油化合物为萘。在最高测试温度（850°C）下，清洁气体中的焦油含量为0.65 g / Nm3。评估了过滤器中表面速度对达到的焦油转化率的影响。当表面速度从40增至90 m / h时，随着气体在催化过滤器中的停留时间降低，焦油转化率降低。为了产生不同性质的焦油，水与干生物质的比率也有所不同（0.5-0.9）。对于该比率的更高值，可以实现更高的转化率。
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