februari 18, 2021

No pipeline, no problem

Colony Farm – First virtual pipeline of this scale

Key words: biogas, biomethane, biogas upgrading, power, predicable source of income, renewable energy, remote areas, pipeline connection

Authors: Marjolein Overbosch, Stephen McCulloch, Phil Greenaway

No pipeline, no problem

Upgraded biogas makes a very efficient source of renewable energy, biomethane. Biogas can be produced from various organic resources of which the most common are agricultural waste, municipal waste, landfills, and wastewater treatment facilities. Some of these sites are in very remote areas that do not have access to a national grid to inject the produced biomethane into. Virtual Pipeline offers the solution.

A virtual pipeline is an alternative method to transport natural gas, or biomethane, to remote places or places that are not connected to the national gas grid network. It replicates the continuous flow of a fixed physical pipeline, working where physical pipelines are not able and to monetise gas in regions with changing supply and demand centers. It offers flexibility to produce biogas and still be able to inject it into the national grid. It can also provide a bridge for injection until new pipelines become available.

The technology

The process of biogas upgrading remains the same, DMT uses the Carborex®MS a high selective membrane technology. After the biogas upgrading step, the produced biomethane is compressed to 250bar, similar to the process of the production of CNG. After the compression step the biomethane is transported using a trailer to a communal grid injection point. Virtual pipeline is a flexible and diverse approach, based on a scalable and modular system and stored on a mobile unit at the production site.

DMT is currently working on several projects from biogas from agricultural waste that utilize the virtual pipeline approach. All projects use DMT’ s technology, Carborex®MS, to separate CO2 from the CH4 stream.

Colony Farms

A perfect example of a virtual pipeline project is the Cambridge Biopower project at Colony Farm in Cambridgeshire. DMT has delivered the biogas upgrading technology for the plant at Colony Farm, a Carborex®MS 710. The facility converts 710 Nm³ biogas to produce more than 99,5% pure biomethane after which the gas is compressed and stored. The Carborex®MS will be able to recover the methane with an uptime of 98%.

Cambridge Biopower was developed as a 5MW on farm AD project as an integral part of A&EG Heading’s farming organisation to provide diversity of income from a predictable and maintainable farm-based source. A&EG Heading Limited farms 2,700 hectares in the East of England on primary grade soil. Its main crops are wheat, potatoes, sugar beet, onions and maize.

Changing conditions

Over the last few years weather conditions in the UK and Europe have changed significantly and that brings with it, unpredictability in terms of both productivity and the ability to harvest those crops within the required timeframe. The financial implications associated with that unpredictability has an enormously detrimental effect on the Farm and its future. In addition to that is the uncertainty surrounding the long-term farming support packages available to UK farmers following Brexit. It was these uncertainties which led the Farm to future proof its income by investing in a 5MW plug flow anaerobic digester.

The crops, which were already in the farm’s rotation, provided an ideal combination of feedstocks for an AD plant. For example, Wheat production creates the straw residue, which is extruded and used as feedstock. Potato growth will always create non-conforming (and therefore unsaleable) potatoes which then become an excellent feedstock and sugar beet or sugar beet pulp, is another highly energetic feedstock. Onions too offer good gas production.

The only issue, once the decision was taken to go ahead with the project, was to get the gas into the grid and initially this was the most challenging element of the entire project due to the remote location of the proposed AD site. The remedy was to get the gas into grid via a virtual pipeline. Two composite trailers replaced the Network Entry Facility and gas was delivered to the National Grid within hours of it being produced. The long-term intention is still to get the gas into the grid but the enormous benefit the virtual pipeline brings is the immediate income stream which remains until new opportunities to access the gas pipeline become available.

GMT Biogas Limited

GMT Biogas Limited’s team has over 70 years of combined AD experience and has built over 120 AD plants but specifically 27 on farm plug flow digesters. GMT had developed its business model to provide affordable AD plants aimed at gas to grid but where possible, based on farm to ensure that the feedstocks were secure and not reliant on third parties. Third party dependence could, potentially, influence the economics of the plant by manipulation of the supply costs by the suppliers. The virtual pipeline opens an entirely new opportunity to farmers and businesses which are not ideally located for direct access to the Grid.

Construction of the Plant began in May 2019 and was complete in April 2020. The commissioning was delayed due to COVID-19 but within 3 months of starting, full production was achieved and gas quality has never failed with every load since accepted by the National Grid. The partnership with DMT and the installation of the Carborex®MS 710 were instrumental in this success. The key milestones were all aligned to meet the demands of the non-domestic RHI biomethane tariff. The most critical of these was the timeframe and the second was to produce gas of the quality required to pass the gas quality test.

Construction and commissioning programs had to be met, any failure could have jeopardised the entire project and the key contributors for delivering this success were GMT and DMT. It was this cooperation which defined the success meeting the key milestones. The Colony Farm AD plant was the first virtual pipeline of this scale but GMT continues to drive this green solution forward and starts work on a similar new project in March 2021.

Making ROI on remote site

Virtual Pipeline is a clever way to move biomethane to places where a conventional pipeline is not viable either technically or economically. It offers enormous flexibility and is a passport to new possibilities, it consolidates natural gas consumption and prepares the region for the future use of conventional gas supply.

In the case for Colony Farms the virtual pipeline approach improves the potential and the efficiency of the biogas. As the value of biomethane has increased, the virtual pipeline approach is no longer a concept but an alternative option that can offer a quick return on investment and can greatly contribute to the development of region.