Application of extracted marine Chlorella sp. residue for bio-oil production as the biomass feedstock and microwave absorber

摘要

The extracted marine Chlorella sp. residue (EMCR) was used as a feedstock for biochar and bio-oil production. The biochar was prepared by slow pyrolysis at 450 degrees C for 60 min in a tube furnace and employed as a microwave absorber (MA). The bio-oil was produced by microwave pyrolysis (MWP) with investigation of temperature (350-450 degrees C), time (20-40 min) and MA loading (10-30 wt%) at fixed microwave power of 850 W. The pyrolysis condition was optimized to obtain maximum bio-oil yield using the Response Surface Methodology (RSM) based on Central Composite Design (CCD). The optimum condition was 350 degrees C, 15% MA loading and 40 min, which yielded 46% bio-oil. Characterization of Chlorella sp. biomass, EMCR, biochar and bio-oil was performed by proximate and ultimate analysis, FTIR, TGA and GC-MS. The higher heating values of biomass, EMCR and biochar were 22.43, 15.49 and 10.79 MJ/kg, respectively. The results showed a high feasibility of applying EMCR as the feedstock for biochar and bio-oil production. The EMCR derived biochar presented great efficiency as the MA with high surface area of 266 m(2)/g. The bio-oil consisted of a mixture of chemicals, which requires further processes before using in many applications.