This study presents the conception and development of a microwave (MW) applicator based on a TM010 cavity and a pulsed MW source, both custom-designed for evaluation of MW disruption of microalgae. The objective is the selective heating of microalgae immersed in their environment. The applicator enables exposing microalgae suspension to MW in continuous flow mode and monitoring the energy absorbed by the sample. The design was based on dielectric characteristics of microalgae in water, but other solvents might be considered. A tuning element ensures efficient MW coupling into the samples whose relative permittivity ranges from 10 to 80. The applicator includes a customized power supply operating a commercial magnetron source in pulse mode. The MW pulses are in the range of multiple kilowatts with adjustable duration in the microseconds range. The applicator enables to reach a power density in the microalgae sample beyond 10 ¹⁰ W/m ³ . Preliminary proof-of-principle experiments of MW disruption on fresh microalgae biomass Auxenochlorella protothecoides followed by lipid extraction enabled almost complete lipid recovery, while yields were negligible on untreated samples. Total energy consumption was below 4.2 MJ per kg of dry microalgae. Finally, the applicator characteristics are promising for future upscaling and deployment in the industry.

中文翻译：

---

用于暴露新鲜微藻生物质的脉冲微波施用器的构思和开发


本研究介绍了基于 TM010 腔和脉冲 MW 源的微波 (MW) 施加器的概念和开发，这两种施加器都是为评估微藻的 MW 破坏而定制设计的。目的是选择性加热沉浸在其环境中的微藻。该施加器能够以连续流模式将微藻悬浮液暴露于微波并监测样品吸收的能量。该设计基于水中微藻的介电特性，但也可以考虑其他溶剂。调谐元件确保有效的 MW 耦合到相对介电常数范围为 10 至 80 的样品中。该施加器包括一个定制电源，以脉冲模式操作商用磁控管源。 MW 脉冲的功率范围为数千瓦，持续时间可在微秒范围内调节。该施加器能够使微藻样品中的功率密度达到超过10 ¹⁰ W/m ³ 。对新鲜微藻生物质 Auxenolorella protothecoides 进行微波破坏，然后进行脂质提取的初步原理验证实验几乎可以完全回收脂质，而未经处理的样品的产量可以忽略不计。每公斤干微藻的总能耗低于 4.2 MJ。最后，涂抹器的特性有望在未来的行业升级和部署中发挥作用。