TY - JOUR
T1 - Characterization of biocrudes recovered with and without solvent after hydrothermal liquefaction of algae
AU - Xu, Donghai
AU - Savage, Phillip E.
N1 - Publisher Copyright:
© 2014 Elsevier B.V.
PY - 2014/10/1
Y1 - 2014/10/1
N2 - Bench-scale, batch experiments exploring algae hydrothermal liquefaction typically use organic solvents such as dichloromethane (DCM) to recover biocrude from the reactor contents. Commercial-scale, continuous processes, however, may separate biocrude and the aqueous phase co-product without solvent use. Herein, we provide the first thorough examination of the influence of DCM extraction on biocrude yield and composition from microalgae liquefaction in hot compressed water (350. °C, 20. min). We provide gravimetric biocrude yields and biocrude characterization via elemental analysis, GC-MS, NMR, and IR spectroscopies. The application of DCM increases the biocrude yield because it extracts water-soluble compounds from the aqueous phase co-product. Indeed, the biocrude recovered from the aqueous phase accounted for about 8. wt% of the total amount of biocrude. The addition of these molecules diminishes the biocrude quality, however, by decreasing the C and H content, increasing the O and N content, and thereby decreasing the higher heating value of the biocrude. The biocrude extracted from the aqueous phase had a remarkably different elemental composition than did the biocrude recovered without solvent. The O and N contents were more than twice as high, and the higher heating value was 20% lower. The biocrudes recovered directly from hydrothermal liquefaction (e.g., without water and DCM coming into contact) were 87%-88% C and H, and possessed a higher heating value of >. 39. MJ/kg.
AB - Bench-scale, batch experiments exploring algae hydrothermal liquefaction typically use organic solvents such as dichloromethane (DCM) to recover biocrude from the reactor contents. Commercial-scale, continuous processes, however, may separate biocrude and the aqueous phase co-product without solvent use. Herein, we provide the first thorough examination of the influence of DCM extraction on biocrude yield and composition from microalgae liquefaction in hot compressed water (350. °C, 20. min). We provide gravimetric biocrude yields and biocrude characterization via elemental analysis, GC-MS, NMR, and IR spectroscopies. The application of DCM increases the biocrude yield because it extracts water-soluble compounds from the aqueous phase co-product. Indeed, the biocrude recovered from the aqueous phase accounted for about 8. wt% of the total amount of biocrude. The addition of these molecules diminishes the biocrude quality, however, by decreasing the C and H content, increasing the O and N content, and thereby decreasing the higher heating value of the biocrude. The biocrude extracted from the aqueous phase had a remarkably different elemental composition than did the biocrude recovered without solvent. The O and N contents were more than twice as high, and the higher heating value was 20% lower. The biocrudes recovered directly from hydrothermal liquefaction (e.g., without water and DCM coming into contact) were 87%-88% C and H, and possessed a higher heating value of >. 39. MJ/kg.
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U2 - 10.1016/j.algal.2014.08.007
DO - 10.1016/j.algal.2014.08.007
M3 - Article
AN - SCOPUS:84908360946
SN - 2211-9264
VL - 6
SP - 1
EP - 7
JO - Algal Research
JF - Algal Research
IS - PA
ER -