Assessing the Benefits of Direct Isolation Processes

Direct isolation processes are often used in pilot-plant and manufacturing operations. The primary benefit of a direct isolation process over a process using a conventional extractive workup and crystallization is the decreased cost of goods (COG) due to decreased processing time. Direct isolation processes may be beneficial even when the yield is 5−15% below the yield from a conventional extractive workup and crystallization. The costs of scaling up both direct isolation and extraction processes can be calculated by a mathematical model, and the proportional costs of raw materials, labor, and waste disposal can be assessed. Although direct isolation processes are generally more economical than extraction processes, the direct isolation option is not suitable for all strategies. A perspective is offered on when to develop a direct isolation process over an extractive workup and crystallization process.