Process for making granular l-lysine

Abstract

Process for the efficient production of a substantially dust-free, free flowing granular L-Lysine in which the L-Lysine content is adjustable. Cells are removed from a fermentation broth containing L-Lysine to make a substantially cell free L-Lysine broth. Water is removed from the L-Lysine broth to form a concentrated L-Lysine broth. The L-Lysine content of the concentrated L-Lysine broth may be adjusted to be between about 35% and 76%, measured as a percent of freebase per kg, by adding material containing L-Lysine to provide an enriched L-Lysine broth. The enriched L-Lysine broth is agglomerated by means of an atomized spray of the enriched L-Lysine broth directed onto a fluidized bed of percolating L-Lysine particles. The L-Lysine particulates act as seeds for the agglomeration process wherein the L-Lysine particulates grow in size to provide a substantially dust-free, free flowing granular L-Lysine. Granules in the size range between about 177 micron and 1190 micron, and preferably between about 177 micron and 420 micron, are selected by means of a sieving process and bagged. Granules which are larger than about 1190 micron are ground down and combined with particles which are less than about 177 micron and recycled back to the fluidized bed to act as seeds in order to sustain the agglomeration process.