Liquefaction

Abstract The primary challenge for cryogenic hydrogen technologies is the need for more efficient cooling and liquefaction cycles. This chapter begins with the fundamentals of refrigeration cycles, and how the efficiency is connected directly to thermophysical properties, particularly the exergy and associated exergy destruction of the hydrogen during cooling. The most common recuperator cycles for hydrogen liquefaction are discussed and exergy analysis reveals the causes of the major losses of energy efficiency. Next, regenerative and novel refrigeration cycles for hydrogen liquefaction are presented.