PNNL

Abstract

Hydrogen is a key feedstock in the chemical industry, with a demand of over 50 million metric tons/year and today over 90% of this hydrogen is made through coal degasification or methane reforming, releasing hundreds of millions of metric tons of carbon dioxide annually. Industrial decarbonization therefore requires hydrogen production to be addressed. In order to produce hydrogen with minimal carbon footprint, either the carbon dioxide from the above processes has to be captured, stored, and utilized, or the hydrogen has to be made from carbon free sources, such as by splitting water using renewable energy sources. Today, water electrolysis is gaining traction in large scale renewable energy applications, with production of multiple technologies scaling to hundreds to thousands of megawatts of new electrolyzer capacity annually. Each of these technologies has different advantages and disadvantages, and there will likely be applications for each in the overall deployment of renewable hydrogen, to be discussed in this paper.