Your choices:
1 Biomass (solid); 2 Process heat; 3 Electricity
| 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 |
| 1 Biomass (solid) | Electricity | Process cooling (< 0 °C) |
| Geothermal | Fuel: Gaseous | Process heat/steam (50 - 150 °C) |
| Sunshine | Fuel: Liquid | 2 Process heat (150 - 1000 °C) |
| Water | Fuel: Solid | 2 Process heat (> 1000 °C) |
| Wind | Local cooling (ind. house) | Transport |
| Residual oils/fats etc | Local heating (ind. house) |
Depending on the total power demanded by the process and on the needs for other types of energy in the process industry, the supply of electricity for industrial processes on local basis opens up for two major solutions:
- The first is that the manufacturing company simply contracts electricity from the (local), biofuel-fired CHP plant.
- The second option is to set up a small-scale electricity production unit on-site, supplying the industrial company not only with at least part of their electricity but also supplying the main part of their heat needs.
In the second case there will again be two major alternatives:
- If the power demand and the heat demand is big enough, then a common steam boiler with a steam turbine or a screw expander might be the best solution.
- Another possibility is to install a small and simple fixed-bed gasifier and then to use the gas in a small IC-engine, a setup similar to what is used for farm-scale anaerobic digesters. In this case, the steam boiler will be replaced with the gasifier which might in some cases prove to be a cheaper investment. However, the operation of the gasifier will probably prove more complicated than the operation of the steam boiler and also will the flexibility with respect to fuel quality be less.
Generally speaking, small-scale electricity production is an expensive solution and this route should be chosen only in such cases when the process actually demands electricity.
Systems like these might be applicable for example in joineries or smaller saw-mills where the need of heat for drying and gluing is relatively large as compared to the need of electricity for the saws and planers.