Cleaning waste minimization for multiproduct plants: transferring macro batch to micro conti manufacturing

The large specific amount of waste generated during cleaning is a serious environmental disadvantage of traditional batch processes. To overcome this, a transfer to a continuous production scheme employing micro components is investigated using the example of writing ink. Proper choice and design of micro structured equipment led to an agglomerate-free process and thus to the inhibition of fouling. Based on experimental results on pilot plant stage, the amount of detergent needed for cleaning can be reduced by 95% compared to batch production. This is mainly due to the small hold-up of the equipment and to improved premix stability. Product change procedures can even be carried out without in-between cleaning adhering to the optimum production sequence and adequate lot sizes.

► We follow a three-step approach to minimize cleaning waste on a micro conti plant. ► Micro equipment for agglomerate-free and stable production. ► Optimum product sequence and lot sizes allow to omit cleaning step at product change. ► Cleaning frequency can thus be reduced to one step per week before plant shut-down. ► Low hold-up of micro equipment leads to decrease of detergent amount needed.