Thermal Hydrogen: A Formula for Efficient, Emissions-Free Coal Use

By Jared Moore, Ph.D.

With abundant natural gas supply available for the foreseeable future, coal must find new ways to compete. Though coal is still much cheaper, natural gas has fundamental advantages that enhance its competitiveness in the electricity sector: capital costs, efficiency and emissions.  For coal to remain competitive under increasing emissions constraints, a bold new strategy may be necessary to create new energy carriers.

The economic motivation for new energy carriers is a compelling combination of supply-side economics (energy dominance), and energy and capital efficiency (“small is beautiful”).  Energy dominance because cheaper local energy suppliers displace oil.  “Small is beautiful” because of improved energy efficiency and reduced excess electricity capacity.

The thermal hydrogen system enables these advantages to be pollution free using hydrocarbons without carbon capture.  All hydrogen is distributed using the existing infrastructure system.  Here’s how:

In our modern economy, hydrocarbons are almost always combusted with air.  Since air is ~80 percent nitrogen, the products of combustion (exhaust) are similarly diluted with nitrogen.  Carbon capture is the technical term for separating the nitrogen and it is required to isolate CO2 for sequestration. The capture process makes up the vast majority of the costs for carbon capture and sequestration (CCS).  In fact, the commodity value of CO2 might be greater than the sequestration costs (~$5/t CO2).

Thermal hydrogen is an energy system engineered to enable emissions-free hydrocarbons without carbon capture.  This is accomplished by taking advantage of the chemical separation inherent to electrolysers and fuel cells.  In both instances, chemicals are isolated when they cross an electrolyte, and with some clever engineering, these opportunities negate the need for carbon capture.

Electrolysis is the separation of H2O (or CO2) and is powered by excess electricity (and heat).  The pure oxygen created from electrolysis is typically dumped. However, the pure oxygen is an opportunity to enable hydrocarbon oxidation in the absence of nitrogen – thus pre-empting the need for carbon capture.

The pure oxygen enables the simplest and most efficient thermodynamic cycles possible: the Allam cycle for electricity generation and auto-thermal reforming for hydrogen/syngas generation.  Therefore, a source of pure oxygen can make hydrocarbons more competitive with decarbonization – not less.