Alkali species present in biomass pose significant challenges in chemical looping combustion (CLC) processes and other thermal conversion applications. The interactions between different alkali species and three common oxygen carrier (OC) materials that are considered to be state of the art in CLC applications have been investigated. A dedicated fluidized bed laboratory reactor was used to study interactions of KCl, NaCl, KOH, NaOH, K₂SO₄ and Na₂SO₄ with manganese oxide, calcium manganite and ilmenite. Alkali vapor was generated by injecting alkali salts under reducing, oxidizing and inert conditions at 900 °C. Gaseous species were measured online downstream of the reactor, and the efficiency of alkali uptake was determined under different conditions. The result show significant alkali uptake by all OCs under the studied conditions. Ilmenite shows near complete alkali uptake in reducing conditions, while manganese oxide and calcium manganite exhibited less effective alkali uptake, but have advantages in terms of fuel conversion and oxidizing efficiency. Alkali chlorides, sulfates and hydroxides show distinctly different behavior, with alkali hydroxides being efficiently captured all three investigate OC materials. The findings contribute to a deeper understanding of alkali behavior and offer valuable guidance for the design and optimization of CLC with biomass.

生物质中存在的碱物质对化学循环燃烧 (CLC) 过程和其他热转化应用提出了重大挑战。不同碱金属物质与三种常见氧载体 (OC) 材料之间的相互作用已被研究，这些材料被认为是 CLC 应用中最先进的技术。使用专用的流化床实验室反应器研究了KCl、NaCl、KOH、NaOH、K ₂ SO ₄和Na ₂ SO ₄与氧化锰、亚锰酸钙和钛铁矿的相互作用。碱蒸气是通过在900℃的还原、氧化和惰性条件下注入碱金属盐而产生的。在反应器下游在线测量气态物质，并确定不同条件下的碱吸收效率。结果表明，在研究条件下，所有 OC 都会显着吸收碱。钛铁矿在还原条件下表现出接近完全的碱吸收，而氧化锰和亚锰酸钙的碱吸收效果较差，但在燃料转化和氧化效率方面具有优势。碱金属氯化物、硫酸盐和氢氧化物表现出明显不同的行为，碱金属氢氧化物均被有效捕获，这三种研究的 OC 材料均被有效捕获。这些发现有助于更深入地了解碱行为，并为生物质 CLC 的设计和优化提供有价值的指导。