Ultrasonic Preparation of Emulsions Derived from Aqueous Bio-oil Fraction and 0# Diesel and Combustion Characteristics in Diesel Generator

Abstract

Preparation of emulsions from aqueous fractions of biomass pyrolysis liquid (bio-oil) and 0# diesel was studied under ultrasonic power. The thermogravimetric analysis and combustion characteristics of the optimized emulsions in a particular diesel generator were also investigated. The results show that the mass ratio of aqueous bio-oil fraction to 0# diesel affected the emulsion stability greatly, by factor analysis method, and the optimized emulsion was not stratified for 30 days when the ratio was 1:9 under the following conditions: water:bio-oil mass ratio, 2:1; ultrasonic time, 120 min; formula emulsifier addition (Span-80:Tween-80:Tween-20:n-octanol ratio = 72:9:9:10, wt %), 3 wt % (which was longer than that prepared by mechanical agitation). The density and heat value of the nonstratified emulsions (after 30 days) were similar with those of 0# diesel, because of the low aqueous bio-oil fraction content and 0# diesel dilution; however, an increase of more than 38.4% in the dynamic viscosity and a decrease in pH from 5.26 to <3 may result from the concentrated polar oxygenates and carbohydrates in aqueous bio-oil fraction, which were further solubilized in water-in-oil (W/O) emulsion droplets. In addition, ultrasonic emulsification resulted in entropy augmentation and equilibrium tendencies (by thermodynamic analysis). Thermogravimetric analysis of the emulsion shows that there is a weight loss peak that is attributed to residual carbon combustion above 400°C, in addition to a similar hydrocarbon vaporization peak at 180°C with diesel. The existence of residual carbon and the high viscosity of the emulsion might have caused inefficient combustion when the output power of diesel generator was above 1400 W with high feeding amount, which also resulted in higher exhaust gas temperature than diesel feedstock, although microexplosion may have occurred. Moreover, when the output power increased to 1600 W with the emulsion used, the O 2 and NO X emissions decreased 21% and 87.2%, respectively, the CO 2 emission increased 13.3%, and the CO and SO 2 emissions increased quickly to 5124 ppm and 59 ppm, respectively, compared with pure diesel. The corrosion and blockage caused by coking of the injector were obvious.

Extract Nitrogen-Containing Compounds in Biocrude Oil Converted from Wet Biowaste via Hydrothermal Liquefaction

“…This may be attributed to the fact that the ultrasonic-assisted extraction with water can more effectively extract oxygenated compounds (e.g., phenolic compounds) from algal biocrude oil. 31,47 The effect of the mixing ratio of the toluene-soluble fraction (liquid phase) and water during the ultrasonic-assisted extraction was also investigated. An ultrasonication time of 15 min was selected because the nitrogen content of algal biocrude oil can be effectively reduced under this condition.…”

“…To conduct an efficient emulsification, certain amounts of water and the toluenesoluble phase would be needed to create a stable micelle and reach the critical micelle concentration. 31,44,47,48…”

“…For pyrolysis-derived bio-oil, water has also been used to separate relatively polar compounds (e.g., carboxylic acids) from nonpolar hydrocarbons. 30,31 Figure 2 also shows that the biocrude oil yield is 16.9−26.8% when using water as a solvent for HTL raw oil converted from swine manure and low-lipid algae. Chakraborty et al have explored using water, ethanol, and dichloromethane as solvents in a sequential HTL and multistep extraction process to obtain value-added products, including polysaccharide, bio-oil, and biochar, from Chlorella.…”

Synthesis of Ni base nanoparticles by W/O emulsion combustion

“…It is supposed that the solid phase may play a role in promoting evaporation such as boiling stone. Therefore, the water phase in the emulsion may explosively evaporate and cause secondary atomization both the emulsion and the water phase [21,22] with increase in the concentration. As a result, the higher the concentration of the solution was, the smaller both primary and agglomerated particle would become.…”

Review of Bio-oil Upgrading Technologies and Experimental Study on Emulsification of Bio-oil and Diesel

“…Yuping Li [17] has studied the emulsification of the aqueous fractions of bio-oil (ABF) and 0# diesel under ultrasonic power. It reported that the mass ratio of ABF to 0# diesel affected the emulsion stability greatly, by factor analysis method, and the optimized emulsion was not stratified for 30 days when the ratio was 1:9 under the following conditions: water: bio-oil mass ratio, 2:1; ultrasonic time, 120 min; formula emulsifier addition (Span-80:Tween-80:Tween-20:n-octanol ratio= 72:9:9:10, wt%), 3wt%.…”