RESUMEN
Upgrading of bio-oil obtained from hydrothermal liquefaction (HTL) of algae is necessary for it to be used as a fuel. In this study, bio-oil obtained from HTL of Nannochloropsis sp. was upgraded using five different catalysts (Ni/C, ZSM-5, Ni/ZSM-5, Ru/C and Pt/C) at 300⯰C and 350⯰C. The upgraded bio-oil yields were higher at 300⯰C; however, higher quality upgraded bio-oils were obtained at 350⯰C. Ni/C gave the maximum upgraded bio-oil yield (61â¯wt%) at 350⯰C. However, noble metal catalysts (Ru/C and Pt/C) gave the better upgraded bio-oils in terms of acidity, heating values, and nitrogen values. The higher heating value of the upgraded bio-oils ranged from 40 to 44â¯MJ/kg, and the nitrogen content decreased from 5.37 to 1.29â¯wt%. Most of the upgraded bio-oils (35-40â¯wt%) were in the diesel range. The major components present in the gaseous products were CH4, CO, CO2 and lower alkanes.
Asunto(s)
Biocombustibles , Aceites de Plantas , Catálisis , Polifenoles , Temperatura , AguaRESUMEN
Hydrothermal liquefaction (HTL) of nine algae species were performed at two reaction temperatures (280 and 320°C) to compare the effect of their biomass composition on product yields and properties. Results obtained after HTL indicate large variations in terms of bio-oil yields and its properties. The maximum bio-oil yield (66wt%) was obtained at 320°C with a high lipid containing algae Nannochloropsis. The higher heating value of bio-oils ranged from 31 to 36MJ/kg and around 50% of the bio-oils was in the vacuum gas oil range while high lipid containing algae Nannochloropsis contained a significant portion (33-42%) in the diesel range. A predictive relationship between bio-oil yields and biochemical compositions was developed and showed a broad agreement between predictive and experimental yields. The aqueous phases obtained had high amount of TOC (12-43g/L), COD (35-160g/L), TN (1-18g/L), ammonium (0.34-12g/L) and phosphate (0.7-12g/L).