Processes, methods, systems and devices for zero emission liquid hydrogen
production directly from a variety of methane sources, such as natural
gas and landfill gas, are disclosed. Five embodiments of plant designs
for liquid hydrogen production are presented. The embodiments combine
hydrogen production and liquefaction into a single process to produce
liquid hydrogen directly via methane containing gases; thus, eliminating
the conventional technology of pressure swing adsorption process for gas
mixture separation. The innovative process can be applied to produce high
purity liquid hydrogen with no carbon dioxide emission to the atmosphere;
and can also co-produce highly pure solid carbon and liquid carbon
dioxide as by-products for industrial application. The invention has
provided advantages over conventional approaches that result in up to
approximately 85% of first low efficiencies and approximately 56% of
second law efficiency, up to approximately 100% of hydrogen and methane
recovery, and a very high purity of liquid hydrogen (99.9999%).