Physical and chemical stability of Bagasse biocrude from liquefaction stored in real conditions

The stability of biocrude produced from the liquefaction of sugarcane bagasse in ethanol was observed. The degradation characteristics of biocrude and reference fuels, such as diesel, waste cooking oil biodiesel, and their blends, were studied under three different storage environments and temperatures over 24 weeks, namely, hot (43 °C), cold (4 °C), and outdoor (variable temperature) conditions. Higher Heating Values of biocrude had only small changes for all storage conditions,and this was similar to the behavior of the reference fuels. Density changes were significant in hot conditions for biocrude oil compared with outdoor and cold conditions. The change in chemical composition reflects changes in densities. Upon different storage conditions, the chemical composition of waste cooking oil biodiesel and biocrude changed considerably over the time\ud period, whereas diesel and biodiesel blend B20 remained relatively stable. The instability of the biocrude was mainly due to oxygenated compounds, especially phenols forming cyclic and aromatic compounds. The degradation rate of biocrude was the slowest in cold conditions

Experimental investigations of physical and chemical properties for microalgae HTL bio-crude using a large batch reactor

As a biofuel feedstock, microalgae has good scalability and potential to supply a significant proportion of world energy compared to most types of biofuel feedstock. Hydrothermal liquefaction (HTL) is well-suited to wet biomass (such as microalgae) as it greatly reduces the energy requirements associated with dewatering and drying. This article presents experimental analyses of chemical and physical properties of bio-crude oil produced via HTL using a high growth-rate microalga Scenedesmus sp. in a large batch reactor. The overarching goal was to investigate the suitability of microalgae HTL bio-crude produced in a large batch reactor for direct application in marine diesel engines. To this end we characterized the chemical and physical properties of the bio-crudes produced. HTL literature mostly reports work using very small batch reactors which are preferred by researchers, so there are few experimental and parametric measurements for bio-crude physical properties, such as viscosity and density. In the course of this study, a difference between traditionally calculated values and measured values was noted. In the parametric study, the bio-crude viscosity was significantly closer to regular diesel and biodiesel standards than transesterified (FAME) microalgae biodiesel. Under optimised conditions, HTL bio-crude's high density (0.97'1.04 kg-1) and its high viscosity (70.77-73.89 mm2s-1) had enough similarity to marine heavy fuels. although the measured higher heating value, HHV, was lower (29.8 MJ-kg-1). The reaction temperature was explored in the range 280-350°C and bio-crude oil yield and HHV reached their maxima at the highest temperature. Slurry concentration was explored between 15% and 30% at this temperature and the best HHV, O:C, and N:C were found to occur at 25%. Two solvents (dichloromethane and n-hexane) were used to recover the bio-crude oil, affecting the yield and chemical composition of the bio-crude

Solvothermal Liquefaction of Corn Stalk: Physico-Chemical Properties of Bio-oil and Biochar

This study investigated the conversion of corn stalk to bio-oil by solvothermal liquefaction using ethanol as a solvent. Effect of reaction temperature, time and solvent to biomass ratio on the yield and the properties of bio-oil and biochar was studied. Analysis of corn stalk and bio-oil were done to determine the surface functional groups, existing bonds and molecular structure of specified compounds. Investigations were done to identify different compounds in bio-oil, the thermal stability, and weight loss kinetics of biochar. Study shows that percentage yield of bio-oil increases with increase in temperature and time, up to a specific level, and then starts declining. Further, the heating value, carbon content, and fixed carbon content of both bio-oil and biochar increased to 30.52, 22.8 MJ/kg, and 66.42 and 61.25%, 26.10 and 27.97% respectively from those (19.55 MJ/kg, 51.12 and 6.36%) of the corn stalk. This study suggests that the bio-oil contained mostly phenolic compounds and its derivatives. Two major DTG peaks were observed at 380 and 620 °C indicating the improvement in thermal stability of the biochar after solvolysis liquefaction process. Investigation results can be very useful in optimizing process parameters for solvothermal liquefaction