Pedro, Guilherme A.Amaral, Mateus S.Pereira, Felix M.Flumignan, Danilo Luiz [UNESP]Da Rós, Patrícia C. M.Reis, Cristiano E. R.Silva, Messias Borges [UNESP]2021-06-252021-06-252021-01-01Bioenergy Research.1939-12421939-1234http://hdl.handle.net/11449/208762This study evaluated the use of biomass of Chlorella minutissima grown in 40-L photobioreactors using a Guillard f/2 biomass at over 80% moisture content as feedstock to produce ethyl esters. The study design investigated the influence of acid catalyst type (HCl or H2SO4) and concentration (0.3 or 0.6 mol L−1), co-solvent to ethanol ratio (1:10 or 1:5 v/v), and acyl acceptor to biomass ratio (25 mL g−1 or 50 mL g−1) on ester yield and conversion. An L8 Taguchi design was used to evaluate the influence of the factors, demonstrating a range of conversion ranging from 37 to 98%. Furthermore, the effects of reaction conditions on the residual biomass were assessed by measuring the concentration of acid-labile carbohydrates, which could be utilized in integrated sugar- and lipid-based algal refineries. It was found that in situ transesterification using HCl can provide easily accessible and fermentable carbohydrates at concentrations of about 32 wt% in residual biomass. In this sense, the findings of this study demonstrate a further step in the integration of microalgae biomass in the development of liquid-fuel biorefineries. Graphical abstract: [Figure not available: see fulltext.]engChlorella minutissimaFatty acid ethyl esterIn situ transesterificationMicroalgaeArtigo10.1007/s12155-021-10295-z2-s2.0-85107746426