Techno-economic modelling of biogas infrastructures
Biogas is produced from biomass by means of digestion. Treated to so-called ‘green gas’, it can replace natural gas. Alternatively, biogas can be used to produce electrical power and heat in a combined heat power (CHP) installation. In 2014 global biogas production was only 1% of natural gas production. In the future, biogas is expected to play a role in specific applications, e.g. to provide flexibility in electricity supply.
Biogas from several small scale production units can be collected at a hub; the biogas is upgraded to green gas or used in a CHP. A larger scale at the hub induces lower costs per unit and higher energy efficiency. But the collection also adds to the overall costs and reduces energy efficiency. Transport of biogas can be done using a grid with dedicated pipelines and decouples location of production from the location of use; it facilitates production at an agricultural site and use at a town or industrial area where power and heat may be needed. Moreover, biogas can be stored in pipelines.
For the biogas network as presented above, a numerical model was developed. The model calculates biogas transport cost, storage costs and energy use. Biogas is transported through direct pipelines or in a network of smaller pipelines connecting to a main. Calculations are done at farm scale and at a regional scale. The results show that the implementation of a biogas pipeline infrastructure may, under preconditions, make sense. Storage in the grid adds to flexibility in the energy system. Environmentally, decentralized biogas production reduces biomass transport.
The research reported in this thesis was part of the Flexigas project, which was part financed by the municipality of Groningen, province of Groningen, the European Union, European Regional Development Fund, the Ministry of Economic Affairs, ‘Pieken in de Delta’ and the ‘Samenwerkingsverband Noord Nederland'.