Scientific American April 2021 pp28-37 |Energy| “What To Do About Natural Gas” “The massive gas infrastructure could pose a barrier to decarbonizing our energy system, but it doesn’t have to. Here’s how” By Michael E. Webber
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Summary of the article
Good news we have been gradually replacing coal- and oil-burning with methods for fueling power generation that are less of a burden on air quality. Bad news, even in America, our carbon footprint for U.S. Energy, power generation and other uses, is too high as we currently use Petroleum 37%, Natural Gas 32%, Coal 11% with only carbon-free Renewable 11% and Nuclear 8%. A clue to potential solutions lies in how we use energy with 37% for Transportation (91% is Petroleum-Based) , 35% Industrial (40% Natural Gas, 34% Petroleum), 16% Residential (44% Natural Gas, and 12% Commercial (39% Natural Gas). Little known but producing and delivering energy is highly inefficient with 65% lost and 35% actually delivered.
With a natural gas infrastructure valued at “several trillion dollars” one can imagine plenty of commercial and political resistance to changing what was considered to be a “bridge” to green energy. The author, Michael E. Webber an energy expert (UT Austin/Webber Energy Group/ENGIE) writes “If we can clean emissions out of the natural gas system, it could be part of a carbon-neutral future instead of a bridge.” How to do that? Extract carbon dioxide being produced, improve efficiency of energy use, conservation, electrify-cars-space heaters-water heaters and cooktops “using renewable sources” and “replace as much natural gas as possible with low-carbon alternatives such as biogas, hydrogen and synthesized methane or use a process called pyrolysis at the end of the natural gas pipes to get the carbon out.” Some of these alternatives can still leverage the huge infrastructure of natural gas pipelines lowering investment.
Six methods. 1) “Replace Gas with Biomethane”. Bacteria digest “organic matter” creating methane while capturing waste carbon dioxide. 2) React water with “rock containing iron to create silicates and hydrogen.” With some maneuvers, hydrogen gas can travel in natural gas pipelines and can be safely used as energy. 3) Heat natural gas and steam to produce hydrogen while capturing the carbon dioxide. 4) Electrolysis creates hydrogen when water is treated with electricity 5) “Transport hydrogen in other chemical forms. Add carbon dioxide to hydrogen to create water and methane” for transport in pipelines. This option has lower net emissions of carbon dioxide “because the fuel was made with carbon dioxide extracted from the atmosphere.” 6) “Extract carbon at consumer locations” by adding heat to natural gas to create hydrogen and small volumes of solid carbon waste can be discarded with household trash. Another method, scantly mentioned in this article, is pumping carbon dioxide captured underground.
Getting to-green never seemed more complicated but ultimately “Reining in climate change requires many solutions” but leveraging existing natural gas infrastructure can be key to creating a “low-carbon future.”