The high contents of nitrogen-containing organic compounds in biocrude obtained from hydrothermal liquefaction of microalgae are one of the most concerned issues on the applications and environment. In the project, Chlorella sp. and Spirulina sp. were selected as raw materials to investigate the influence of different reaction conditions (i.e., reaction temperature, residence time, solid loading rate) on the distribution of nitrogen in the oil phase and aqueous phase. Three main forms of nitrogen-containing organic compounds including nitrogen-heterocyclic compounds, amide, and amine were detected in biocrudes. The contents of nitrogen-heterocyclic compounds decreased with temperature while amide kept increasing. The effect of residence time on the components of nitrogen-containing organic compounds was similar with that of temperature. However, the influence of solid loading rate was insignificant. Moreover, it was also found that the differences of amino acids in the protein components in the two microalgae might affect the nitrogen distribution in products. For example, nitrogen in basic amino acids of Spirulina sp. preferred to go into the aqueous phase comparing with the nitrogen in neutral amino acids of Chlorella sp. In summary, a brief reaction map was proposed to describe the nitrogen pathway during microalgae hydrothermal liquefaction.

微藻水热液化得到的生物原油中高含量的含氮有机化合物是应用和环境中最受关注的问题之一。在该项目中，小球藻sp。和螺旋藻sp。选取不同的反应条件（即反应温度、停留时间、固相负载率）为原料，考察了不同反应条件对油相和水相中氮分布的影响。在生物原油中检测到三种主要形式的含氮有机化合物，包括氮杂环化合物、酰胺和胺。氮杂环化合物的含量随着温度的升高而降低，而酰胺则不断增加。停留时间对含氮有机化合物组分的影响与温度相似。然而，固体加载速率的影响是微不足道的。此外，还发现两种微藻蛋白质成分中氨基酸的差异可能会影响产品中的氮分布。例如，螺旋藻_ 与小球藻的中性氨基酸中的氮相比，优选进入水相。总之，提出了一个简短的反应图来描述微藻水热液化过程中的氮途径。