A variety of approaches are available for transporting and storing hydrogen in energy carriers other than gaseous of liquid hydrogen. Examples include metal hydrides where the hydrogen is adsorbed and desorbed on a metal material or compounds where a chemical reaction liberates hydrogen. This paper describes the approach for analyzing the cost and energy impacts of hydrogen carrier options.

The project team expanded on DOE's existing H2A tools to consider hydrogen delivery options other than compressed or liquefied hydrogen. We investigated carrier options where the hydrogen is reacted with a carrier material at a central processing plant and delivered by truck to the retail forecourt. The carrier is either transferred to the hydrogen vehicle or the hydrogen is liberated from the carrier at the forecourt. Typically, a chemical reaction or desorption step is required to release hydrogen from the carrier. Spent carrier material is then returned from the forecourt to the reprocessing facility by truck.

Reprocessing plant costs and energy inputs were estimated for a variety of carrier systems. The key cost and energy input for chemical hydrides is electric power. Transportation by truck is limited by the gross vehicle weight of trucks (40 tons). The higher value of the mass of the carrier or spent material determines the amount of hydrogen that can eventually be delivered. Forecourt requirements include storage tanks for fresh and spent carrier material as well as reactors and hydrogen compression and storage equipment for systems where hydrogen is liberated at the forecourt.

A cash flow analysis for the reprocessing facility, delivery truck fleet, and forecourt was developed using the H2A framework. Capital and operating costs as well as energy inputs are estimated for each step of the delivery process. The model then calculates the required selling price in order to achieve rates of return that are consistent with other H2A analyses. This analysis tool can be used by developers and DOE to evaluate the cost of hydrogen delivery options including chemical carriers on a consistent basis. Example analyses for conventional and chemical hydride options are included in the paper.

The energy inputs for the delivery chain are also used to determine the greenhouse gas emissions from carrier options on a well to wheel basis.