Two breakthroughs in carbon capture for gas-fired power

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The prospect of carbon capture and storage (CCS) technology being applied to power stations fuelled with natural gas has come a couple of steps closer with two breakthroughs announced in February. The development of a commercial technology that would remove most carbon dioxide emissions from gas-fired power stations would be a big boost for the gas industry in an increasingly carbon-constrained world.

By Alex Forbes

In what could become the first-ever industrial-scale application of CCS at a gas-fired power station, Shell announced on the 24th February that it had agreed to progress the Peterhead CCS project to the next phase of design. The project is part of the UK government’s CCS commercialisation competition and in March 2013 was short-listed as one of the two preferred projects bidding for funding.

Also on the 24th February, Norway’s carbon capture and storage (CCS) research centre – the Technology Centre Mongstad (TCM) – said it had begun a research initiative that would help to accelerate implementation of CCS in gas-fired processes in electricity generation and industry.

Peterhead project to begin FEED: The Peterhead agreement – signed by Ed Davey, the UK’s Secretary of State for Energy and Climate Change, at Shell’s offices in Aberdeen – marks the start of front-end engineering and design (FEED), which is expected to continue until 2015. Subject to positive final investment decisions by Shell and the government and relevant consents and permits, the project is expected to start up by the end of the decade.

The project – led by Shell, with strategic support from SSE, owners of the Peterhead power station in Aberdeenshire – aims to capture 10 million tonnes of carbon dioxide over 10 years. This, says Shell, would generate enough clean electricity to power the equivalent of 500,000 homes. The company claims that the individual components of CCS technology are “well understood, tried and tested in many areas across the industry for several decades”. What the Peterhead project proposes to do is bring these elements together into a full-chain CCS process.

Cross section graphic showing the existing St Fergus power station with proposed link to Peterhead and it's pipeline link to the Goldeneye Reservoir at sea,

Shell intends to build a short new pipeline from Peterhead power station and link this into an existing offshore pipeline from St Fergus to the Goldeneye reservoir. (Source: Shell)

”The signing of this agreement is a hugely important step towards the UK delivering the world’s first CCS demonstration facility on a gas-fired power station,” said Ed Daniels, Chairman of Shell UK. “The successful demonstration of the technology at Peterhead would be a step towards proving its commercial viability as a tool for mitigating climate change.”

Capture: The Peterhead project is based on post-combustion capture and will use amines to absorb the carbon dioxide, a method that has been used by the industry for around 50 years. It has already been demonstrated as feasible, having been deployed in several small installations in the United States and, says Shell, is recognised as the best available technology for post-combustion carbon dioxide capture.

Transport: Following feasibility studies on a variety of options, Shell proposes to build a short length of new pipeline from Peterhead Power Station and link this into the existing offshore pipeline from St Fergus to the Goldeneye reservoir.

Storage: Carbon dioxide will be stored in the depleted Goldeneye reservoir, 100 km offshore in the outer Moray Firth, and 2.5 km beneath the seabed. Shell says the reservoir has the “key geological features necessary for storing carbon dioxide permanently: a body of high-quality porous rock overlain by impermeable rock to seal the carbon dioxide in place”.

Ariel view of Goldeneye, a gas field in the sea from 2004-2011.

Goldeneye was a producing gas field from 2004 to 2011. Injection is the reverse of production: during production, natural gas was drawn from the rock and naturally replaced by salt water; injection of carbon dioxide will drive the salt water back out of the store. (Source: Shell)

The Peterhead initiative is part of a portfolio of major CCS projects supported by Shell. Others include the Quest oil sands project in Alberta, Canada, and the Gorgon LNG project in Australia.

World’s first large-scale tests of Monoethanolamine: The TCM initiative involves the world’s first large-scale tests of Monoethanolamine (MEA), an amine solvent used in carbon dioxide removal processes. TCM plans to share the results with the global CCS community to increase knowledge and understanding.

Speaking from the ARPA-E Energy Innovation Summit in Washington DC, Olav Falk-Pedersen, TCM’s business development manager, said: “By thoroughly testing the MEA solvent system in the amine plant, and openly sharing that information, we stand to help technologists around the world maximise the performance of their technologies and advance the CCS industry on a major scale.

“Any gas-fired CCS project will be very interested in the results of the MEA testing at TCM. The second dash-for-gas is locking unabated natural gas into the energy mix for the foreseeable future. Now the big question is how can the oil and gas industry adopt CCS, to maximise future gas profits, whilst simultaneously mitigating carbon emissions?

“Demonstration of carbon dioxide capture from natural gas-fired power plant exhaust, at a considerable scale, is absolutely vital to answering that question.”

Baseline solvent: MEA has been used for many decades in the process industry, including for production of carbon dioxide for industrial purposes. Today the MEA process acts as a baseline solvent, commonly used in post-combustion carbon capture studies to compare the performance of proprietarily-developed amines and other carbon dioxide removal processes.

The TCM tests will include measurement and evaluation of a number of parameters, such as energy consumption, emissions and degradation. They are expected to run until March, after which the findings will be published in scientific papers.

TCM claims to be the world’s largest and most advanced facility for testing and improving carbon dioxide capture. It aims to increase knowledge on carbon capture technologies to reduce technical and financial risk, and accelerate the development of qualified technologies capable of wide-scale deployment. It is a joint venture set up by the Norwegian state (75.1%), Statoil (20%), Shell (2.4%) and Sasol (2.4%).

The centre comprises two carbon dioxide capture plants each with a capacity to capture some 80,000 tonnes of carbon dioxide from a nearby refinery or 20,000 tonnes from a gas-fired power plant.