Extraction and puri®cation of lactic acid from silages

Various silages with di€erent contents of organic acids were used to evaluate the possibilities of recovery of lactic acid from grass silages. Press extraction yields of lactic acid from silage preparations ranged from 31 to 96 g lactate per kg silage dry matter (g LA/kg DM). The crude liquid press extract was pre-treated with ultra®ltration membranes followed by puri®cation with mono-polar electrodialysis (ED). Low current densities, high energy consumption at 1.47±1.76 kWh/kg lactate and the high levels of organics and minerals (8 g/l) limit the possible applications of the resulting product to low-grade applications such as animal feed additive or road-de-icers.