Your choices so far:
1 Process heat/steam (50 - 150 °C); 2 Fuel: gaseous
| 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 | 2 Fuel: Gaseous | 1 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) | Transport |
| Residual oils/fats etc | Local heating (ind. house) |
To obtain the highest efficiency in the full chain from energy source to useful energy with the end user, the number of intermediate steps and conversions should be kept as low as possible.
Direct fuel firing is one of the shortest possible process chains and should be used if at all possible and if district cooling and/or heating is without reach. Direct fuel firing will not be able to provide chilling conditions, so if gaseous fuel is the main resource for the heating process and there is also a demand for cooling, then the cooling should be produced locally using cooling machines. Fuel-fired absorption cooling machines are available and may be considered but in most cases compressor cooling based on a supplementary supply of electricity from hydroelectric, wind-power or CHP/tri-generation plants would be the best solution.
Depending on availability, contracting biogas of sng-quality (substitute natural gas) from the gas grid is the easiest thing in the world.
Though it may be possible to use thermal gasification of solid biomass to obtain a gaseous fuel suitable for low-temperature processes, the complexity will hardly ever be motivated only because of the switch from a non-renewable to a renewable energy source. There will have to be something more, an extra added value, to make the process viable.