Hydrogen production

Choose the route and define the boundary

Hydrogen can be produced by converting a hydrogen-containing feedstock or splitting water. A production route needs both a material balance and an energy balance. Calling the product clean without specifying the feed and energy supply leaves the main question unanswered.

Steam reforming produces a gas mixture. Electrolysis produces hydrogen and oxygen in separate compartments, but the hydrogen still needs conditioning suited to its user. The purification problem follows from the production chemistry.

Conventional methane reforming includes conversion with steam and subsequent water–gas shift chemistry. Ethanol has a different reaction network, including intermediates, methane and possible carbon deposits. The catalyst and steam ratio influence which products are formed.

Electrolysis uses electricity, and its system boundary includes power conversion, water treatment and gas handling. A stack electricity figure excludes some duties required by the complete installation. Electricity source and operating schedule also influence emissions and utilization.

Our detailed reforming coverage begins with bioethanol because it was the feedstock investigated by FluidCELL. Broader comparisons belong to the complete supply system: required hydrogen flow, purity, pressure and availability must be the same for each route.

Terminology is defined in the technical glossary. Source material is linked below.