Sewage sludge (SS) ashes, rich in iron and calcium, have been tested as a primary catalyst during air gasification of commercial wood pellets in a pre-pilot scale fluidized bed (FB) reactor. The shifting from a conventional fluidized bed to a spouted-fluidized bed configuration has been assessed on the catalyst performance. Specifically, at constant total air inlet flow rate, two different values of the air flow rate in a central spouting nozzle have been adopted, which correspond to 20% and 37.5% of the total inlet gas flow rate. Under the conventional fluidized bed configuration (i.e., bubbling regime), SS ashes exhibit good performance in term of tar reduction (about 20% decrease compared to a bed of inert silica sand), without significantly affecting the syngas composition. Concerning the transition to the spouted-fluid bed configuration, the gas-solid contact efficiency is enhanced at lower air flow rates through the central nozzle, with respect to the FB regime, leading to better gasification performance in terms of tar reduction (around 40% less) and syngas quality. A slightly worse gasification performance is obtained at high values of air flow rate in the central nozzle, due to a progressive increase of gas bed bypassing. Furthermore, moving from the conventional FB configuration to the spouted-fluid bed one dramatically boosts the elutriation rate of carbon fines as well as the attrition of catalyst particles.

中文翻译：

---

污水污泥灰烬作为减少生物质气化焦油的主要催化剂：鼓泡与喷射流化床配置

在中试规模的流化床 (FB) 反应器中，在商业木屑颗粒的空气气化过程中，测试了富含铁和钙的污水污泥 (SS) 灰烬作为主要催化剂。从传统流化床到喷射流化床配置的转变已经根据催化剂性能进行了评估。具体而言，在总进气流量不变的情况下，中心喷嘴采用了两个不同的空气流量值，分别对应于总进气流量的20%和37.5%。在传统的流化床配置（即鼓泡方式）下，SS 灰分在焦油减少方面表现出良好的性能（与惰性硅砂床相比减少约 20%），而不会显着影响合成气组成。关于向喷射流化床配置的过渡，相对于 FB 方案，在通过中央喷嘴的较低空气流速下，气固接触效率得到提高，从而在焦油减少（减少约 40%）和合成气质量方面获得更好的气化性能。由于气床旁通的逐渐增加，在中央喷嘴的高空气流速值下获得的气化性能稍差。此外，从传统的 FB 配置转移到喷射流化床可以显着提高碳粉的淘析率以及催化剂颗粒的磨损。由于气床旁通的逐渐增加，在中央喷嘴的高空气流速值下获得的气化性能稍差。此外，从传统的 FB 配置转移到喷射流化床可以显着提高碳粉的淘析率以及催化剂颗粒的磨损。由于气床旁通的逐渐增加，在中央喷嘴的高空气流速值下获得的气化性能稍差。此外，从传统的 FB 配置转移到喷射流化床可以显着提高碳粉的淘析率以及催化剂颗粒的磨损。