This article reviews the optimization of the selection of the final drying technology in conjunction with the upstream continuous solid-liquid filtration, cake washing, and dewatering technology selection. Most often when analyzing a new process development approach, engineers take a “silo” approach and look at each step independently. This article illustrates that by taking a holistic approach and looking at each step not individually but as a continuum, the process solution becomes much more efficient.

In the manufacturing of this specialty chemical, the crystals coming from the reactor in a methanol slurry must be filtered, washed and dewatered and then dried to a final moisture of less than 1.0 (<1.0 %). The standard approach would be to first look at the solid-liquid filtration step and optimize this step for the maximum washing and drying efficiency and then with this information optimize the downstream drying. The operating company, however, took a different approach and looked at the process as a continuum from solid-liquid filtration through cake washing and dewatering to final drying. The Continuum Approach” resulted in operational energy and nitrogen savings as well as lower capital and installation costs for a more efficient and reliable process.