Preliminary Study Of Fast Pyrolysis And Liquefaction Of Algae Powder From Dianchi Lake For Bio-oil

Cyanobacterial bloom caused by eutrophication is one of the frequent environmental disasters all over the world. Algal bloom not only affects water landscape, but also releases algal toxins which may deteriorate human health and biosafety. With rapid pyrolysis and liquefaction technology, the collected blue-green algae from cyanobacterial blooms can be converted to bio-oil. The method helps reduce the nutrient load of water and prevent the deterioration of water quality. It blazes a new way for the utilization of blue-green algae.In this paper, the feasibility of converting cyanobacterial blooms into bio-oil with a fixed-bed reactor was investigated. And a technique route of transforming biomass char into hydrogen-rich gases by steam gasification process was introduced. Subsequently hydrogen was used as material for bio-oil upgrading and utilization efficiency was improved as a result.Fast pyrolysis characteristics of cyanobacterial blooms were investigated, while final pyrolysis temperature, heating rate, particle size and nitrogen flow rate on products distribution and composition were evaluated. The results showed that proper final pyrolysis temperature, higher heating rate, smaller particle size and proper nitrogen flow rate were beneficial for bio-oil production, and bio-oil yield obtained maximum at final pyrolysis temperature of 500℃, particle size of below 0.08mm and nitrogen flow of 100mL/min, reached 54.97%.Steam gasification characteristics of biomass char were explored, and effects of gasification temperature, steam flow rate, particle size of biomass char and solid residence time on dry gases yield and carbon conversion efficiency (CCE) were studied. The results suggested higher gasification temperature, proper steam flow rate and particle size, longer solid residence time were favored in gasification process. At gasification temperature of 850℃, steam flow rate of 1.24g/min, particle size of 0.45mm-0.9mm, and solid residence time of 15min, dry gas yield and carbon conversion efficiency reached 1.84Nm3/kg and 98.82% , respectively.