Alberto Abánades

Low Carbon Production of Hydrogen by Methane Decarbonization

Hydrogen is one of the energy vectors that is proposed to have an important role in the future. The implementation of the called “hydrogen economy” is a challenge that requires the development of sustainable production technologies for hydrogen. Such technologies are intended to be fed by renewable energy sources such as solar, wind, or biomass. Hydrogen generation from wind and solar photovoltaic cells will be done via water electrolysis. Direct thermal energy sources such as solar thermal are expected to use thermochemical methods, either from water or hydrocarbons as the main raw material. Biomass can be used in this context in two ways: as raw material, through the production of syngas or bio-methane to produce hydrogen by thermochemical processes, and as an electricity producer to generate hydrogen via electrolysis. In this chapter, techniques for hydrocarbon decarbonization will be discussed. The general chemical description of methane pyrolysis will be the starting point to describe concepts for its implementation, mainly applying solar technology. Other alternatives, such as the use bio-methane as raw material and the integration of methane pyrolysis with ammonia production or biofuel synthesis will be discussed. The scientific viability of methane decarbonization has been tested and proven, but viable industrial implementation of the technology still remains. The status of the implementation of this technology on an industrial scale will be discussed analyzing its main technological showstoppers and their potential solutions.

Natural Gas Decarbonization as Tool for Greenhouse Gases Emission Control

The reduction and control of carbon dioxide emissions of the energy system and other industrial processes using fossil resources is one of the main concerns of our society. Natural gas may contribute to reduce such emissions as it is the fossil with the highest H/C ratio. In addition, a deep reduction of emissions will require the development of technologies as carbon capture and sequestration (CCS) or utilization (CCU), or direct fossil decarbonization. Some practical approaches integrated in the Power-to-Gas scheme to the application of natural gas decarbonization are presented. The introduction of this technology in hydrogen mobility seems to be viable, providing a carbon-free production on site without hydrogen or carbon dioxide transport and storage. The integration of direct decarbonization into combined cycle plants for centralized electricity production is justified for carbon penalties above 50 €/kg.