Mathematical simulation for optimization of tanning processes; deliming of white hide

Abstract

In this paper, the authors show the usefulness of theoretical tools of chemical engineering in natural polymer processing, namely on the example of white hide deliming. White hide is a consequent product in the processes in which raw hide is transformed into leather. It is produced in the de-hairing stage which follows the soaking operation. For next operation, tanning, it is necessary to remove calcium hydroxide from white hide. Mathematical descriptions of both non-chemical and chemical deliming are presented, concentration fields of the reacting chemicals described and the importance of the acido-basic boundary inside the white hide shown. Experimental determination of the effective diffusion coefficient is also included. The presented mathematical models can serve as a very good basis for rationalization of the deliming process, save considerable amounts of energies, deliming chemicals and technological water, and make the whole process more environmentally friendly.