Study on the Concentration Process of Glutamic Acid Neutralizer by Vaccum Membrane Distillation Method and the Reuse of Product Water

Abstract

This paper uses orthogonal experiment for optimizing technological conditions of decolorization, and draws the conclusion that the best combination is A3C3B1E1D3, namely H2SO4：1.5%；HCl：5% and sepiolite: 1.5 g/l; speed 100 r/min; time: 1.5 h. Membrane distillation technology replaces the dryer to enrich the glutamic acid neutralizer, and improves the concentration of sodium glutamate in the glutamic acid neutralizer. The membrane distillation flux of glutamic acid neutralizer changes along the concentration multiple curve. It shows that with concentration up to 60%，the glutamic acid neutralizer will supersaturate when crystal comes up and the membrane distillation can't go on. The color and conductivity of product water suggest that some volatile substances are formed. Peak time difference between glutamate filtrate gas chromatography and product water of the membrane distillated glutamic acid neutralizer does not exceed 0.1min, and thus indicates that four volatile substances from product water are derived from glutamic acid filtrate. Product water can be recollected to glutamic acid ferment tank and recycled. Scanned by FT-IR, the main ingredients in the neutralizer indicate the existence of amino acid kind materials. When replacing dryer with membrane distillation process in industrialization, glutamic acid neutralizer can be concentrated from 50% to 59%, thus greatly improves economic benefit.