Catalytic valorization of glycerol for producing biodiesel-compatible biofuel blends

ABSTRACT

Crude glycerol from biodiesel production is not of high quality due to catalyst and alcohol contamination. A product that could utilize glycerol, excess alcohol and catalysts could enhance the value proposition for the biodiesel industry. Here, we show that glycerol can be reacted with methanol and tert-butanol in the presence of common transesterification catalysts to produce an ether-rich mixture that is miscible with biodiesel. Our studies cover the impact of type and concentration of catalysts, molar ratio of reactants, temperature, and reaction time on alcohol conversion, product yield, selectivity and select fuel properties. Results show both NaOH and H₂SO₄ are capable of producing etherified blends from glycerol that are miscible with biodiesel. We anticipate the results to be a starting point for the development of an effective fuel additive to recycle the byproduct glycerol and excess alcohol resulting from biodiesel production.

KEYWORDS:

• Etherification
• glycerol
• biodiesel
• sodium hydroxide
• sulfuric acid
• biofuel blends

Disclosure statement

No potential conflict of interest was reported by the authors.