Economic analysis of a continuous casein process using carbon dioxide as precipitant

Economic analyses are presented for two conceptual casein plants of commerc ial scale. For the first analysis, costs were estimated for a plant that us ed CO2 as precipitant to manufacture casein. The results were compared with estimated costs for Ca caseinate plants. In the second analysis, costs wer e estimated for the precipitation step only for a casein plant that used CO 2 as a precipitant. In the first case, the equipment was sized for a Ca caseinate plant with a flow rate of 10,000 L of milk/h and a caseinate output of 320 kg/h. Unit op erating costs for production of CO2-precipitated casein with recycling of C O2 were $0.038/kg less than for Ca caseinate manufactured from fresh casein and $0.103/kg less than for casein manufactured from dried casein. In the second case, operating costs for precipitation of casein with CO2 in a plant with a flow rate of 50,000 L of milk/h and a casein output of 1500 kg/h are $0.095/kg more than with lactic acid or HCl if CO2 was not recycl ed. If CO2 was recycled, capital costs were increased, but operating costs were significantly reduced. With recycling of CO2, the cost difference betw een CO2-precipitated casein and the other caseins was $0.021/kg.