This book covers process design for cryogenic processes like air separation, natural gas liquefaction, and hydrogen and helium liquefaction. It offers an overview of the basics of cryogenics and information on process design for modern industrial plants. Throughout, the book helps readers visualize the theories of thermodynamics related to cryogenics in practice. A central concept in the book is the connection between the theoretical world of process design and the real limitations given by available hardware components and systems.