State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
Environ Res. 2022 Sep;212(Pt C):113389. doi: 10.1016/j.envres.2022.113389. Epub 2022 May 10.
Oxidative torrefaction is a promising way for biomass upgrading and solid biofuel production. Alkali metals are considered to be efficient activators for enhancing biofuel upgrading during the thermal reaction process. Herein, the microalga Nannochloropsis Oceanica is selected as the feedstock for assessing potassium carbonate activated effect on solid biofuel production through oxidative torrefaction. The potential of potassium carbonate on microalgal biofuel properties upgrading is deeply explored. SEM observation and BET analysis show that torrefied microalgae can be transformed from a spherical structure with wrinkles to smaller particles with larger surface areas and higher total pore volumes, implying that potassium carbonate is a promising porogen. Moreover, potassium carbonate can significantly change the DTG curve at the temperatures of 250 °C and 300 °C from one peak to two peaks, inferring that the activated effect of potassium carbonate occurs on the torrefied microalgae. C NMR analysis reveals that the microalgal components significantly change as the torrefaction severity increases, with the decomposition of carbohydrate and protein components. When the potassium carbonate ratio increases from 0:1 to 1:1, the graphitization degree increase from 3.065 to 1.262, along with the increase in the HHV of solid biofuel from 25.024 MJ kg to 31.890 MJ kg. In total, this study has comprehensively revealed the activated effect of potassium carbonate on improving the properties of microalgal solid biofuel.
氧化热解是生物质升级和固体生物燃料生产的一种很有前途的方法。碱金属被认为是在热反应过程中增强生物燃料升级的有效活化剂。在此，选择微藻 Nannochloropsis Oceanica 作为原料，通过氧化热解评估碳酸钾对固体生物燃料生产的活化效果。深入探讨了碳酸钾对微藻生物燃料性能升级的潜力。SEM 观察和 BET 分析表明，热解微藻可以从具有褶皱的球形结构转变为具有更大表面积和更高总孔体积的较小颗粒，这表明碳酸钾是一种有前途的造孔剂。此外，碳酸钾可以显著将 DTG 曲线在 250°C 和 300°C 的温度下从一个峰变为两个峰，这表明碳酸钾的活化作用发生在热解微藻上。C NMR 分析表明，随着热解程度的增加，微藻成分发生显著变化，碳水化合物和蛋白质成分分解。当碳酸钾的比例从 0:1 增加到 1:1 时，固体生物燃料的石墨化程度从 3.065 增加到 1.262，同时固体生物燃料的高位热值从 25.024 MJ kg 增加到 31.890 MJ kg。总的来说，本研究全面揭示了碳酸钾对改善微藻固体生物燃料性能的活化作用。
