The Formation Of Microemulsion Systems For Solubilizing And Upgrading Sewage Sludge Liquefaction Bio-oil

The dual pressure of energy crisis and environmental concerns make it a global common goal to seek for an environmentally friendly and sustainable renewable energy which could substitute for fossil fuel.Biomass,the only renewable carbon source,is widely considered as a promising new energy resource.As one of the biomass,sewage sludge can be liquefied to bio-oil,which could not only considerably reduce the volume of sewage sludge but also make use of the energy contained in sewage sludge.When compared with traditional fossil fuel,liquefaction bio-oil contains some undesirable fuel properties such as high water content,high viscosity and poor cold flow properties.Consequently,upgrading bio-oil is essential before its utilization.Micro-emulsification is an easy and efficient bio-oil upgrading technology due to its simple procedure and mild reaction conditions.In this study,micro-emulsification was used to solubilize and upgrade sewage sludge liquefaction bio-oil,and the effects of micro-emulsion compositions on solubilization of bio-oil were analyzed.The micro-emulsion compositions studied here include the concentration of surfactant,the type and concentration of co-surfactant,the type of polar phase(water,hydrous ethanol and absolute ethanol)and its volume.According to the results of solubilization,the micro-emulsion had the best solubilization performance when the concentration of surfactant was 0.30 M,n-octanol was used as co-surfactant,C/S was 0.9,1.0 mL of absolute ethanol was considered as the polar phase.The physiochemical properties of micro-emulsified bio-oil,diesel and crude bio-oil were investigated and compared by elemental analysis,GC-MS analysis and thermogravimetric analysis.According to the results,the fuel properties of bio-oil could be improved by micro-emulsification.Additionally,the micro-emulsion which used absolute ethanol as polar phase had better solubilization performance and higher stability.In this study,absolute ethanol,as polar phase,was firstly used to form micro-emulsion for the sake of upgrading bio-oil.In this way,the solubilization content of bio-oil was higher than that of micro-emulsion without absolute ethanol.On the one hand,the solubilization of bio-oil could be facilitated by the usage of On the other hand,absolute ethanol as polar phase could reduce the viscosity of bio-oil,improve the cold flow properties and enhance the stability of bio-oil.As a result,the fuel properties of bio-oil were effectively improved.