170 likes | 248 Views
ERT 320 Bio-Separation Engineering. Product Formulation and Finishing Operations. Product Formulation and Finishing Operations. “ Ability to evaluate process and important parameters involved in purification and polishing steps of bio-products for selected bio-separation units ”.
E N D
Product Formulation and Finishing Operations “Ability to evaluate process and important parameters involved in purification and polishing steps of bio-products for selected bio-separation units”
Introduction Product Finishing Surface finishing is a broad range of industrial processes that alter the surface of a manufactured item to achieve a certain property. Finishing processes may be employed to: improve appearance, adhesion or wettability, solderability, corrosion resistance, tarnish resistance, chemical resistance, wear resistance, hardness, modify electrical conductivity, remove burrs and other surface flaws, and control the surface friction. In bio-separation principle, product finishing is the polishing process (normally the last stage in bio-separation scheme) to obtain a great surface structure of final product, for example in crystalline or powder form.
CRYSTALLIZATION • Crystallization is capable of producing bioproducts at very high purity (say, 99.9%), and is considered to be both a polishing step and purification step. • Polishing: a process needed to put the bioproduct in its final form for use. • Ex: Antibiotics; normally the final form must be in crystalline. • May replace other more expensive purification steps such as chromatography.
Crystallization Principle 1) Crystals • When allowed to form freely, crystals appear as polyhedrons, or solid formed by plane faces,. • Although the relative sizes of the faces differ, the angles made by the corresponding faces of the same material do not vary determine the characteristics of the substance. • Difference on crystal relatives sizes, results in a variety of crystal shapes called modification of habit.
Crystallization Principle 2) Nucleation • The generation of ultramicroscopic particles in the process of nucleation is the sum of contributions by primary nucleation and secondary nucleation. • Primary nucleation: occurs in the absence of crystals. • Secondary nucleation: is attributed to the influence of existing crystals.