Decentralized biogas plant with heat pumps, heat storage and automation
ComBigaS will develop a biogas plant where the slurry is being produced so the flow of energy is being minimized. The systems are developed with an eye to the standardization and thus facilitate makes the establishment and subsequent operation kindness. The plant is developed for a project where the gas is exported, to use in district heating systems or upgrading to natural gas
To minimize the total energy consumption for process heating in smaller biogas plants where traditional heat exchangers are non-profitable, because of the relatively large capital investment and the need for supplementary heating, newly developed concept for the supply of extra energy is being used.
To ensure flexibility the plant receiver/mixing tank for thermal storage will be used. Since heating of the tank leads to the development of biogas, the tank will be covered with gas-tight cover. The biogas plant is being established with a primary thermophilic digester (approximately 52° C) and a secondary mesophilic digester (approximately 37° C).
The two-step process is to ensure optimum digestion of the biomass and thus optimize the gas production. The thermophilic digestion also ensures that the injected slurry sanitized according to veterinary requirements for reduction of bacteria and viruses, so that manure from several farms can be treated. The new development consists of:
- New concept for the supply of biogas plant with processing heat.
- Absorption of the uptake of the heat from the digested biomass for heat pump (this heat is typically not utilized): - Absorption of the heat from the secondary digester via cooling from approximately 52° C to approximately 37° C. - Absorption of the heat from biomass is pumped from the secondary digester to the storage via cooling in heat exchanger, from ca. 37° C to approximately 10° C
- Use of the receiving/mixing tank as heat storage. This enables this tank to being used as heat storage during periods when electricity costs are low. By heating the tank, electricity consumption for mixing and shredding will be reduced.
- The control system for controlling the heats transfer/cooling enables the transfer of process heat, depending on electricity prices.
- Reduction of capital investment and operating costs through standardization - many plants in the same organizational framework
- Lower heat consumption than in the known installation design.
- Reading of the gas quality in relation to the payment system and quality requirement from the customers
In addition, a new ingest system for solid biomass has been developed and tested in the project, which aims to streamline the mixing of solid biomass with pig manure. It is demonstrated that deep litter, etc. can be mixed with slurry to a homogeneous pumpable biomass.
Commercially, there is great interest for the demonstration plant from potential customers from both Denmark and internationally. There is an offer on multiple sites in Denmark, and entered into agreements with a number of partners in different countries, which will sell biogas plants based on this design under license. There are already realized sales of two plants in France and South Africa.
Key figures
Category
Participants
| Partner | Subsidy | Auto financing |
|---|---|---|
| COMBIGAS ApS | 6,21 mio. DKK | 6,21 mio. DKK |
Contact
ComBigaS ApS
Tinghøjvej 13
DK-6893 Hemmet
www.combigas.dk
Høgh, Klaus , 96808060, kh@combigas.dk
Øvr. Partnere:
