Published January 2023
Hydrogen is regarded as one of the most important chemicals manufactured and used globally in key applications, like petroleum refining, fertilizers industry (e.g., ammonia production), methanol manufacture, besides its uses across multiple sectors of other chemicals. Another unique point about hydrogen is that it can be used as a clean fuel. For example, when used in a fuel cell, hydrogen produces (electric) energy and water without carbon dioxide (CO2) emissions. Hence, the gas can be used as an energy source in integrated clean energy systems and auto transportation. A remarkable thing about hydrogen is that it has a very high energy density (energy per unit weight) and, like other fuels, can be stored and carried from one place to another as a chemical or energy source. Those qualities make hydrogen an attractive fuel for transportation and electricity generation.
Nevertheless, complete implementation of the plans to commercialize hydrogen as an energy source requires costly investments in hydrogen gas supply infrastructure (transport, distribution, and fueling systems) on an one-time investment as well as recurring-costs (operating costs) basis. Such infrastructure is currently scarce. Costly storage, transportation, and distribution of hydrogen to its customers result from the fact that hydrogen volumetric energy density is the lowest among fuels. The high volume to mass ratio of hydrogen is a major bottleneck and cost challenge to its large-scale commercialization, as the gas needs either to be compressed to extremely high pressures, hence requiring bulky storage and transportation equipment, or liquefied, which requires highly sophisticated and expensive apparatus. Other hydrogen storage techniques such as storing as metal hydrides are novel at this moment and require more extensive work before being ready for commercialization. The net result of all above is that hydrogen, delivered as a chemical commodity or fuel, has a much higher overall cost to customers on per pound basis than other fuels. In addition to high buying cost, safety in storing of compressed gas, particularly on board, are some other major concerns needing a thorough remedy.
For the above reasons, other means of hydrogen transportation are being considered among which hydrogen transportation in the form of methanol or ammonia are the most notable. A complete transportation route for hydrogen, in that case, would consist of producing methanol (or ammonia) from a hydrogen source at one place (region), and then transporting it (methanol for this review) to another place where hydrogen is required, and finally converting the transported methanol to hydrogen. Production of methanol from a hydrogen and carbon source is studied in other Process Economics Program (PEP) reports (e.g., PEP Report 43F). In this review, we present a technoeconomic evaluation of the last phase of the hydrogen transportation process that involves conversion of methanol (produced and transported from one region) back into the hydrogen in another region.
Lastly, the iPEP Navigator PO tool is attached to the electronic version of this review. The iPEP navigator interactive module provides an economic snapshot for the process, allowing the user to select and compare the processes, units, and regions of interest.