Carbon-free production of hydrogen with molten salt nuclear reactors

Molten salt nuclear reactor developer Terrestrial Energy has partnered with Southern Company and several U.S. Department of Energy National Laboratories to develop a more efficient and cleaner method for producing hydrogen using nuclear heat and power.

The two-year research and development project will examine the efficiency, design and economics of the IMSR® power plant to produce carbon-free, industrial-scale hydrogen using the hybrid sulfur process. This carbon-free method of generating hydrogen from water may be more efficient than high-temperature steam electrolysis.

The project intends to demonstrate the commercial and industrial-scale viability of pairing the hybrid sulfur process with an IMSR® power plant for large-scale production of hydrogen with zero greenhouse-gas emissions.

This work builds on two decades of research at Savannah River National Laboratory, which will continue to lead the technology development along with Sandia National Laboratories and Idaho National Laboratory.

Besides current uses of hydrogen in ammonia production, petroleum refining, chemicals production and other industrial applications, hydrogen is expected to grow significantly as a storable energy carrier. Future applications include all forms of transportation, thermal energy and energy storage, as well as growth in conventional uses of hydrogen. By 2020, the hydrogen market is expected to reach $200 billion.

Today, most hydrogen is made from fossil energy using steam methane reforming (SMR) of natural gas, followed by partial oxidation (POX) and autothermal reforming (ATR), which combines SMR and POX processes.

Removing carbon from the production of hydrogen helps bring deep decarbonization into reach. It points the way to the production of carbon-neutral transport fuels and zero-emissions fertilizers.

Hydrogen could play a bigger role in a carbon-free economy

Hydrogen is already very important for industrial applications.

Hydrogen could be better than electrical batteries for industrial equipment, planes and drones.

Both alkaline and PEM water electrolyzers are available in Megawatt (MW) scale. In April 2017, a 3 MW PEM electroylzer stack was unveiled at Hannover Messe. A large-scale (400 MW) alkaline system consisting of 187 electrolyzer stacks is currently available at $450/kW USD plus housing. High temperature electrolysis splits water at between 700-1000°C. The solid oxide electrolyer (SOEC) is the most commonly used high temperature electrolyzer.

According to the U.S. Department of Energy (DOE), the cost of distributed (as opposed to centralized) hydrogen production via electrolysis using off-peak electricity was $3.90 USD/kilogram (kg) H2 in 2015, while the 2020 cost target for distributed hydrogen production is $2.30/kg H2.

The DOE estimates the hydrogen threshold cost – the sweet spot for competition of Fuel Cell Electric Vehicles (FCEVs) with hybrid electric vehicles (HEVs) – to be $2.00-$4.00/gge (gallon gasoline equivalent) on a cost per mile basis in 2020.

Sale of forklifts for industrial uses is increasing: this market segment is the “low hanging fruit” of hydrogen applications. In the U.S., some 11,600 forklifts (logistics vehicles) were sold as of October 2016. Hydrogen powered forklifts are more cost effective than battery powered forklifts due to low refueling times that are a tenth of that required to swap out a fully charged battery. The CAPEX for hydrogen powered forklifts is competitive with battery-powered forklifts.

Easy Jet has partnered with French Aerospace giant Safran to test hydrogen fuel cells on their planes. Fuel cells will collect energy through solar panels and kinetic energy as the planes brake on the runway through “regenerative braking”, which will in turn power the planes taxiing capabilities. (If applied across their entire 279 plane fleet, they estimate savings of 55,000 tonnes of fuel per year).

Hydrogen is being used to power certain drones.