Your choices:
1 Biomass (digestible sludge); 2 Process heat; 3 Electricity
| What is your resource? | What do you want to deliver? | What is the service the customer wants? |
| 1 Biomass (digestible sludge) | District cooling | Comfortable indoor climate |
| Biomass (fermentable sludge) | District heating | Electricity |
| Biomass (solid) | 3 Electricity | Process cooling (< 0 °C) |
| Geothermal | Fuel: Gaseous | 2 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) |
In some cases it may be possible to integrate electricity production into the industrial process without interference.
Just a very simple example: Assume a biotechnical industry using saturated steam at 180 °C and 10 bar for a distillation process and further assume that the steam flow is 5 tonnes per hour. In case the steam boiler is classified at 16 bar, then a screw expander with the total efficiency 12% would be able to produce about 2.7 kW of electricity. This is certainly only a very small contribution to the electricity grid but the point is that a screw expander is a robust piece of equipment and that this production will cause very low marginal costs. Since the unit is assumed at an industrial site, one may assume 6000 hours of operation and then the annual production amounts to 16 MWhel. The electricity can be used internally or sold to the grid.
Provided the integration can be done with only very low marginal costs and provided the equipment chosen is robust so that it does not affect the availability of the process heat, this type of integrations can be done in very many processes.
The integration makes use either of pre-process energy carriers (like in the example above) or it may make use of post-process waste energy. In either case, the integration of electricity production with an industrial process will not depend on the fuel used in the process.
Hence, the fact that a steam boiler or a flame furnace is fired with biogas will not affect the potential for process integration.