Master mass transfer principles with ‘Principles of Mass Transfer,’ a comprehensive textbook from The Bookish Owl. Tailored for undergraduate chemical engineering students studying Mass Transfer I and II, and ideal for biotechnology students in Downstream Processing. This self-contained volume covers essential chemical separation techniques including distillation, adsorption, extraction, drying, and advanced membrane processes like reverse osmosis and electrodialysis. Explore emerging applications in drug delivery and chromatography. With practical worked examples from chemical and biotech industries, review questions for critical thinking, and end-of-chapter problems, this book ensures a thorough understanding of mass transfer fundamentals and their real-world applications. Equipment selection and industrial applications are also detailed, making it an indispensable resource for students and professionals.