Hydrogen production carbon capture from coal

Today s rapidly increasing activities on hydrogen focus mostly on vehicle applications and less on stationary applications. For fuel cells, stationary applications are also relevant, but natural gas will be the dominant fuel here. The dominance of the transport sector is also reflected in the hydrogen roadmaps developed, among others, in the EU, the USA, Japan, or at an international level. Whereas in the beginning, onsite or decentralised production options based on fossil fuels or electricity are seen as the major option for hydrogen production, later on central production options will dominate the market. Here, several options could play a role, from coal, with carbon capture and sequestration, through natural gas and renewables (wind, biomass) to nuclear. A C02-free or lean vision can be identified in every roadmap. The cost... 

Carbon capture and storage is the key to avoiding an overall increase of C02 emissions through fossil hydrogen production, primarily from coal. Except for biomass, renewable hydrogen is only an economic choice under certain circumstances, unless renewable targets are set. 

The alternative fuels and drive systems available only seem to be viable on the mass market, if the oil price stays above 60 to 70 /bbl for a sustained period. Oil prices peaked above 140 /bbl in summer 2008 and many experts believe that stable oil prices over 100 /bbl could be reached in the next one or two decades. The higher the market prices of fossil fuels, the more competitive low-carbon alternatives will become The principal choice here is between biofuels, electricity and hydrogen, provided that they are produced either from low/zero-carbon feedstock or that the C02 generated during their production is captured and stored. But higher priced conventional oil resources, on the other hand, can also be replaced by high-carbon alternatives such as oil sands, oil shale or synthetic fuels from coal and gas. 

Both the production of hydrogen from coal and the production of oil from unconventional resources (oil sands, oil shale, CTL, GTL) result in high C02 emissions and substantially increase the carbon footprint of fuel supply, unless the C02 is captured and stored. While the capture of C02 at a central point source is equally possible for unconventionals and centralised hydrogen production, in the case of hydrogen, a C02-free fuel results, unlike in the case of liquid hydrocarbon fuels. This is all the more important, as around 80% of the WTW C02 emissions result from the fuel use in the vehicles. If CCS were applied to hydrogen production from biomass, a net C02 removal from the atmosphere would even be achievable. 

Hydrogen can be produced from most fossil fuels (e.g. coal, natural gas, oil, etc.). The complexity of the processes varies. Since carbon dioxide is produced as a byproduct, C02 should be captured and stored to ensure a sustainable (zero-emission) process. The feasibility and viability of the processes will vary with respect to a centralised or distributed hydrogen production plant. 

Carbon sequestration is employed to capture carbon dioxide generated in combustion, fossil fuel gasification, and fermentation (such as in the production of bioethanol) and to place the carbon dioxide where it cannot be released into the atmosphere." Carbon sequestration works best with concentrated sources of carbon dioxide. The carbon dioxide from conventional sources where fossil fuels are burned in air is so dilute that its capture for sequestration is challenging and expensive. In coal gasification to produce elemental hydrogen, however, carbon in coal is reacted at high temperatures with oxygen and steam in several reactions for which the overall process is... 

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