Economic Analysis of a Continuous Casein Process Using Carbon Dioxide as Precipitant

¹ US Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 E. Mermaid Lane, Wyndmoor, PA 19038

Economic analyses are presented for two conceptual casein plants of commercial scale. For the first analysis, costs were estimated for a plant that used CO₂ as precipitant to manufacture casein. The results were compared with estimated costs for Ca caseinate plants. In the second analysis, costs were estimated for the precipitation step only for a casein plant that used CO₂ 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 operating costs for production of CO₂-precipitated casein with recycling of CO₂ 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 recycled. If CO₂ was recycled, capital costs were increased, but operating costs were significantly reduced. With recycling of CO₂, the cost difference between CO₂-precipitated casein and the other caseins was $0.021/kg.

Key Words: economic analysis • carbon dioxide • casein • precipitation

Submitted on December 18, 1997
Accepted on July 27, 1998