Biosurfactant Rhamnolipid Enhanced Microemulsification Of Synthetic Bio-oil In Diesel

Recently, with the increasing concerns over environmental pollution and the growing demand for fossil fuel, biomass energy has received more extensive attention. Bio-oil, which mostly produced from biomass fast pyrolysis, has been known as one kind of promising energy as its low-carbon ability, renewability and environmental friendliness. However, the bio-oil is still needed to be upgraded as the shortage of bio-oil in fuel properties, including high water content, high corrosiveness, and high oxygen content, etc. And microemulsion is an effective way of upgrading bio-oil.In this present work, the quality of model bio-oil from pyrolysis biomass was improved by forming the diesel microemulsion with rhamnolipid(RL) as the surfactant. The optimum RL and n-heptanol dosage system were collected for forming microemulsion. The microemulsification of the bio-oil/diesel/RL system was evaluated by solubilization, the thermogravimetric and Fourier Transform Infrared spectrometry analysis. It was found that the optimum RL dosage was 5 g L-1 and the addition of n-heptanol had few positive effect on the solubilization performance. In fact, the microemulsification procedure was the process of breaking/rebuilding the equilibrium state of diesel and bio-oil phases by addition of RL. After microemulsification, synthetic bio-oil components were solubilized into the hydrophilic core(water, methanol and acetol), the palisade layer(glyoxal and vanillin) and the diesel continuous phase(guaiacol, acetaldehyde and furfural), respectively. In addition, the degradation rates of microemulsion system might be affected by the species and locations of synthetic bio-oil components in diesel.In order to upgrading biomass energy efficiently and precisely in future, evaluating the formulation and microemulsification of bio-oil/diesel/RL system would be of great theoretical guiding significance.