Citizens' Climate Lobby: Replacing natural gas with hydrogen

Whether you are a climate change believer or denier, it’s clear that our planet is in the throes of worsening storms, heat waves, and sea level rise. The Aug. 9 report from The Intergovernmental Panel on Climate Change (IPCC) adds context to these observations. Climate change is already affecting every region on earth in multiple ways (and) the changes we experience will increase with additional warming, they say. 

The IPCC calls this moment a “Code Red for humanity” and confirms that carbon dioxide (CO2) from burning fossil fuels is the main driver of climate change. Our goal should be to cease burning fossil fuels. We know how to break down the problem. The sources of atmospheric CO2 are: petroleum (42 percent), natural gas (34 percent), coal (11 percent), deforestation, forest fires (9 percent), and other (4 percent). 

Ninety percent of petroleum is used for transportation and changes are already underway. Auto manufacturers are planning a transition to electric vehicles within the next decade. Transition in the aviation sector is less clear, however. 

Coal is used primarily in the generation of electricity. Here too a major transition is underway. Coal-fired power plants are being decommissioned at a rapid rate in favor of natural gas. This fuel substitution, however, reduces but does not eliminate the emissions problem. Natural gas, mostly methane, still produces CO2 when combusted, albeit less than coal. 

In the natural gas sector, the potential to transition to hydrogen is an emerging option. University of Texas professor Michael Webber cites several possibilities. He says: “Turbines can burn hydrogen to generate electricity for the grid, and internal combustion engines can burn it in heavy duty vehicles. Hydrogen in fuel cells can produce electricity for cars, homes or offices. Burning it or reacting it in Fuel Cells does not produce CO2.”

There are engineering challenges yet to be faced in the construction of hydrogen pipelines. Replacing natural gas in a pipeline with pure hydrogen is problematic. Special pipeline alloys would be needed to transport gas with greater than 20 percent hydrogen to prevent embrittlement of the pipes. Also, leaked hydrogen does have a climate warming effect, but just a fraction of that of methane. 

There are multiple options to replace traditional natural gas. Biomethane is produced when sewage is treated with bacteria. The chemical reaction that occurs when water is injected into iron-bearing rock formations releases hydrogen. Most hydrogen today is produced by Steam Re-Forming of methane. 

Here methane and steam are heated and hydrogen is one of the bioproducts.  

Pure hydrogen is produced by electrolysis of water. When combined with alternative energy sources, this method produces no CO2 emissions. Prof. Webber cites an example from Delta, Utah where the coal-fired boilers in one of this county’s largest power plants are being replaced with turbines that can burn hydrogen. The process starts with a blend of 30 percent hydrogen in natural gas and shifts to 100 percent hydrogen later. The hydrogen will be generated onsite using wind and solar energy. The hydrogen is then stored in existing salt caverns, each about the size of the Empire State Building.

Transporting hydrogen offers some flexibility. Pipelines are not the only option.  Hydrogen could be transported in an alternative chemical form more easily and safely than raw hydrogen. For example, ammonia is already moved worldwide as a fertilizer ingredient, and ammonia can be burned without producing any CO2. Leading the way, a Finnish industrial builder, Wartsila, is constructing a ship named Viking Energy that will run on ammonia fuel cells avoiding greenhouse emissions and other pollutants.

Prof. Webber adds that one could transport natural gas as is, through gas pipes but decarbonize it at the end user’s location by splitting CH4 into hydrogen and solid carbon with a somewhat new process called methane pyrolysis. There is no combustion involved. A plasma process heats the methane decomposing it into carbon powder and hydrogen. The carbon powder byproduct can be bagged and sold for soil improvement in farming.

Transitioning from natural gas to hydrogen offers multiple climate and business advantages. By decarbonizing natural gas, we retain the gas infrastructure and with hydrogen we can reach the zero CO2 emissions goal.

— John Fulenwider is a resident of Holland and a member of the Holland chapter of Citizens' Climate Lobby.