Small-scale solids production plant with cooling crystallization, washing, and drying in a modular, continuous plant

Abstract

Small-scale continuous apparatuses for solid product manufacturing are receiving increasing interest due to the demand for the fast market availability of specialty chemical products manufactured in integrated and modular processing plants. Relevant unit operations span from crystallization over solid–liquid separation and filter cake washing to drying. For this purpose, the quasi-continuous filter belt crystallizer (QCFBC) was developed and is presented here. The newly integrated unit operations with positive pressure filtration (Δ𝑝max = 0.8 bar), filter cake washing (𝑉˙wash = 55 mL·min−1), and convection drying (𝑇dry = 60 °C) have been individually characterized and integrated into the filter apparatus that has been modified for continuous operation. They were synchronized with the flexible cooling crystallization, enabling for a seamless production process. Sucrose in water was used as model substance system. Long-term operations of up to 14 h were successfully performed with dry product filter cakes (22.64 g ± 1.64 g·h−1) of constant quality attributes (𝑥50,3 = 216.095 ± 14.766, 𝑠𝑝𝑎𝑛 = 0.347 ± 0.109, 𝑌rel. = 69.9% ± 5%, 𝑋RM = 1.64 mg·g−1 ± 1.38 mg·g−1).