Your choices so far:
1 Fuel: gaseous; 2 Transport
| What is your resource? | What do you want to deliver? | What is the service the customer wants? |
| Biomass (digestible sludge) | District cooling | Comfortable indoor climate |
| Biomass (fermentable sludge) | District heating | Electricity |
| Biomass (solid) | Electricity | Process cooling (< 0 °C) |
| Geothermal | 1 Fuel: Gaseous | Process heat/steam (50 - 150 °C) |
| Sunshine | Fuel: Liquid | Process heat (150 - 1000 °C) |
| Water | Fuel: Solid | Process heat (> 1000 °C) |
| Wind | Local cooling (ind. house) | 2 Transport |
| Residual oils/fats etc | Local heating (ind. house) |
Biogas can easily be up-graded either by pressurised scrubbing where water is used to wash out the contaminants and to raise the methane content to 90-95% or in a pressure-swing-absorption (PSA) process yielding a similar quality. Since the fossil gas distributed throughout Europe in pipelines (natural gas) consists to the main part of methane but with a bit of heavier hydrocarbons (3-5%) in it, the addition of a little bit of LPG to the upgraded biogas makes it a copy of the fossil gas and it may then be injected into the pipeline system for distribution or sold as a car fuel. Obviously a strict quality control will be necessary but given that, there will be no major problems.
The upgrading of gasifier gas is a much more complicated process since the gas composition is much more complex and singe the starting point is a hot gas still containing complex hydrocarbons and inorganic ash components. The bottleneck for thermal gasification has been – and still is – to clean the gas from its contaminants without having to cool it down. If the gas is cooled down from process temperature to ambient for cleaning, this will represent a very significant heat loss and loss of total efficiency. Once this problem is solved, however, there will be multiple options for a subsequent processing and upgrading of the gasifier gas for numerous purposes including transportation fuels. This is known as the "biorefinery concept" but has so far not been realized on a commercial basis.