Slow pyrolysis of Spirulina platensis for the production of nitrogenous compounds and potential routes for their separation

• Published in: Bioresource technology Vol. 313; p. 123709
• Main Authors: Rocha, K.C., Alonso, C.G., Leal, W.G.O., Schultz, E.L., Andrade, L.A., Ostroski, I.C.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2020
• Subjects: Adsorption; Bio-oil; Extraction; Fine chemistry; Heterocyclic compounds; Fine chemistry; Extraction; Adsorption; Heterocyclic compounds; Bio-oil
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2020.123709

•Operational conditions for a bio-oil rich in nitrogenous compounds were investigated.•The potentials routes to separate the different nitrogenous compounds were evaluated.•An Optimization study to maximize liquid yield was performed.•Generation of 90.64% was nitrogenous compounds, which octadecanamide as the main compound.•Extraction with phosphoric acid showed a promising route for compounds separation. The potential of microalgae Spirulina platensis to the production of nitrogenous compounds in liquid fraction via slow pyrolysis was evaluated. Aiming to identify the best condition which maximized liquid yield, the effects of operational conditions mass load, temperature, and heating rate were evaluated using Experimental Design and Response Surface Methodology techniques and optimized with Differential Evolution methodology. The composition of liquid fraction was analyzed by GC–MS and the effect of the same operational conditions in nitrogenous compounds formation was analyzed. The separation of nitrogenous compounds was evaluated by extraction and adsorption techniques. The results indicated that the heating rate significantly impacted both the liquid yield and the formation of the nitrogenous compounds. At optimal conditions, a maximum liquid yield of 64.59% was obtained. The extraction and adsorption processes showed to be promising routes for the purification of nitrogenous compounds, however, extraction was more selective to separate them.