Hydrothermal Liquefaction of Enteromorpha prolifera for Bio-Crude Production: An Experimental Study on Aqueous Phase Recirculation

Abstract

Abstract. In this study, catalytic hydrothermal liquefaction (HTL) of with aqueous phase recirculation (APR) was tested in order to improve bio-crude yield and reduce catalyst dosage. Bio-crude yields of 17.0% and 18.5% were obtained at 300°C in 30 min of non-catalytic HTL and catalytic HTL with 5.0% NaOH, respectively. Determination of alkali metals showed that 76.7% of the Na was recovered in the aqueous phase, indicating that APR provided the possibility for catalyst recycling. Bio-crude yields were increased to 20.0% and 22.7% when performing APR for non-catalytic and catalytic HTL, respectively. To investigate the effects of recycled catalyst and volatile aqueous products (VAPs), a different APR experiment with VAPs removal for catalytic HTL was conducted, and a bio-crude yield of 17.8% was achieved. It was concluded that bio-crude yield increased with APR, mainly due to the effects of VAPs. Keywords: Alkali metal, Aqueous phase recirculation, Hydrothermal liquefaction.

A review on bio-crude production from algal biomass using catalytic hydrothermal liquefaction process

“…For the other catalyst spirulina bio-crude yield is lower and similar to each other. In the case of nanochloropsis, the bio-crude yield is maximum for the catalyst of KOH and the bio-crude yield for other catalysts is lower [73][74][75][76]. The bio-crude yield of four algal biomass in presence of an organic and inorganic catalyst is given in Fig.…”