Abstract:Energy is the base of economic and social development. As a kind of renewable new energy, biological energy has been recognized as a major energy in future world. Pyrolysis is a kind of important method for biomass energy conversion and utilization, and how to effectively condense and separate the gas produced in the process of biomass pyrolysis to yield refined biooil has received widespread attention. Preliminary separation and refinement of biooil can be achieved by fractional condensation in the process of pyrolysis, which provides the possibility for further comprehensive utility of biooil and has been proved to be the best economic method. Focusing on the latest research on fractional condensation of biooil, various relatively efficient fractional condensation devices were compared and analyzed, and the physicochemical properties of the product were analyzed and summarized. Seen from the current research results, by controlling reasonable temperature and selecting appropriate condensing medium, multistage condensation device has achieved preliminary hierarchical collection of biooil. As for heavy components of fractional condensation, their low water content and high heating value and less small organic molecules make biooil more stable, and lead to its physical and chemical properties and components are similar to fossil fuel. So heavy components obtained by multistage condensation can be used as industrial combustion directly or crude biooil after further refinement, which is the main alternative to traditional energy. The light components of fractional condensation can be used to agricultural production. Both heavy and light components can be used to extract chemical raw materials with high quality. Meanwhile, due to the complexity of biooil components, the mechanism of the condensation is very intricate and there is no consistent discussion and recognition, so the mechanisms of the condensation deserve further study. Furthermore, the components and physicochemical properties of biooil obtained by fractional condensation can also be influenced by other factors such as the type of material, the reaction devices and the reaction conditions. So far, the research on fractional condensation is confined only to experimental stage and still far from widespread application. Biooil with different components obtained by fractional condensation can’t be utilized until further refinement, so the research of fractional condensation has a long way to go.