This book on 'Protein Separation by Ultrafiltration' provides highly intuitive and practical understanding of the topics by emphasizing the physics and the underlying physical phenomena involved. The concepts have been substantiated by adequate experimental data and mathematical analysis. The book deals with the ultrafiltration of natural and simulated protein mixtures that has been conducted in three different modules like continuous single stirred cell, rotating disc membrane (RDM) module and cross-flow module. The experiments have been conducted in three different phases with primary aims given as under: 1)Isolation of ovalbumin from Chicken Egg White by two stage ultrafiltration in continuous single stirred module. 2)Study of permeate flux, concentration and rejection behavior of Bovine Serum Albumin (BSA) in high shear membrane module like RDM fitted with 30 kD Polyethersulfone (PES) membrane. The process has been simulated with surface renewal theory proposed by Dankwerts. 3)Study of permeate flux, concentration and rejection behavior of BSA in a standard cross-flow module fitted with PES membrane in order to quantify the fouling phenomena with a suitable adsorption isoth