Alstom signs contracts with E.ON, Statoil and AEP to trial chilled ammonia carbon capture technique

At the Biopact, we keep track of advancements in carbon capture and storage (CCS) technologies, because they can be applied to power plants no matter which fuel they burn. This includes solid biomass (co-fired with coal), liquid biofuels and biogas.

When a power plant utilizes such biofuels and captures the carbon dioxide released from them to sequester the gas, the useful energy obtained from such a facility in fact becomes carbon-negative. That is, the more you use of it, the more CO2 gets taken out of the atmosphere. No other energy system can become carbon-negative (other renewables like wind and solar are slightly carbon positive or carbon neutral at best, CCS with fossil fuels remains a largely carbon positive system).

CCS power plants burning biofuels are called 'Bio-Energy with Carbon Storage' (BECS) systems and are seen by scientists to be one of the only few feasible options to mitigate climate change in a serious way and on a large scale, without drastically cutting the power supply to societies (earlier post).

There are some risks involved in CCS, though, like potential leakage of CO2 from the sequestration site. For this reason, some think the safest way forward is to start large CCS trials immediately with biofuels. In case CO2 leakage were to occur, the escaping gas would only be carbon neutral. But when fossil fuels like coal and natural gas were to be used, the leakage would result in a net increase in CO2 in the atmosphere.

But the main bottleneck for CCS (with biofuels or not) to become commercially feasible is the lack of efficient carbon capture techniques. Several options are available. CO2 can either be removed from the fuel before it is burned ('pre-combustion capture') or from the flue gases after combustion ('post-combustion capture'). An overview of these different techniques can be found here.

French multinational Alstom now announces it has signed contracts with energy giants E.ON, Statoil and American Electric Power to test its chilled ammonia carbon capture technology on both coal and natural gas (schematic, click to enlarge).

With E.ON
Jointly with E.ON, Alstom will implement the chilled ammonia process as a 5MW demonstration plant at the Karlshamn Power Plant in southern Sweden and is expected to begin operation in 2008. The companies plan to introduce the technology in other Swedish power plants after technical evaluation:
biofuels :: energy :: sustainability :: fossil fuels :: coal :: natural gas :: carbon capture and storage :: CCS :: BECS ::

Because CO2 is recognised as the main greenhouse gas contributing to global warming, development of this technology is an important milestone towards reducing power industry carbon emissions. Alstom’s chilled ammonia technology uses ammonia to capture CO2 emissions that would normally escape into the atmosphere and holds great promise for achieving CO2 capture economically and with low energy loss.

According to Alstom, research suggests that chilled ammonia-based CO2 capture can remove up to 90% of the CO2 from flue gases. Although there are several proposed techniques that can separate carbon dioxide from the other gases, Alstom’s chilled ammonia process greatly reduces the amount of energy used to capture CO2.

This energy is referred to as the 'energy loss' because the plant’s energy output is reduced by the amount of energy needed to remove the CO2. Studies demonstrate that Alstom’s technology results in an energy loss of approximately 10% versus other methods of post-combustion CO2 separation, which result in losses of nearly 30%.

The Alstom/E.ON contract follows a similar agreement made between Alstom and AEP (American Electric Power) in the U.S. to develop a demonstration plant at a coal-fired power plant in West Virginia and has a start date of 2008. A full scale CO2 capture demonstration plant is scheduled to follow at an AEP site in Oklahoma in 2011.

The Alstom chilled ammonia CO2 capture technology will also be demonstrated with We Energies at a 15,000 tonnes per year pilot plant project at its Pleasant Prairie plant, Wisconsin, in the US.

With Statoil
Alstom's cooperation with Norwegian gas and oil company Statoil is aimed at testing the same post-combustion capture technique to remove CO2 from flue gases particular to natural gas combined cycle (NGCC) power plants.

The objective of the agreement covers the design and construction of a 40MW test and product validation facility at Statoil’s Mongstad refinery in Norway. This facility will be designed to capture at least 80,000 tons per year of CO2 from flue gases from the refinery’s cracker unit or from a new combined heat and power plant being built by Statoil and scheduled to be in operation by 2010. The test and product validation facility is expected to enter operation by 2009-2010 with the first operation and testing phase to last 12-18 months.

It is the intent of both parties that this facility will lead to technical advances and the construction of a larger CO2 capture unit that may eventually capture over 2 million tons per year of CO2 at Mongstad.

Alstom and Statoil have been cooperating, in addition to other parties including the Electric Power Research Institute (EPRI), in the development of the chilled ammonia CO2 capture technology since 2005.

With American Electric Power
The Statoil deal follows an agreement made between Alstom and AEP (American Electric Power) in the US to develop the technology for application on utility coal-fired boilers and to carry out a pilot. Initial research and development of the Alstom chilled ammonia CO2 capture technology has been jointly funded by Alstom, EPRI and Statoil.

Alstom and American Electric Power (AEP) earlier signed a Memorandum of Understanding to bring Alstom’s chilled ammonia process for CO2 capture to full commercial scale of up to 200 MW by 2011. It is described as a major step in demonstrating post-combustion carbon capture. The technology has the great advantage versus other technologies of being fully applicable not only for new power plants, but also for the retrofit of existing coal-fired power plants.

The project will be implemented in two phases. In phase one, Alstom and AEP will jointly develop a 30 MWth product validation that will capture CO2 from flue gas emitted from AEP’s 1300 MW Mountaineer Plant located in New Haven, West Virginia. It is targeted to capture up to 100,000 tonnes of carbon dioxide (CO2) per year. The captured CO2 will be designated for geological storage in deep saline aquifers at the site. This pilot is scheduled for start-up at the end of 2008 and will operate for approximately 12-18 months (overview of the plant, first image, click to enlarge).

In phase two, Alstom will design, construct and commission a commercial scale of up to 200 MW CO2 capture system on one of the 450 MW coal-fired units at its Northeastern Station in Oologah, Oklahoma. The system is scheduled for start-up in late 2011. It is expected to capture about 1.5 million tonnes of CO2 a year, commercially validating this promising technology. The CO2 captured at Northeastern Station will be used for enhanced oil recovery.

CCS elsewhere
CCS is being developed in response to demands for the coal industry to clean up its act because it is the biggest emitter of climate destructive greenhouse gases. A United Nations expert group has called for more investments in CCS, a top NASA scientists has called for a moratorium on coal that should be lifted only when CCS techniques have become feasible, and the EU recently launched a public consultation on CCS because of growing concern amongst Europeans with climate change and the role of fossil fuels.

Actual CCS trials and projects are currently underway in Germany, France, the UK, the Netherlands and Australia.

Besides bioenergy with CCS, there is another, low-tech approach to creating carbon-negative biofuels. This involves the conversion of biomass into pyrolysis oil and biochar ('agrichar'). The bio-oil is used as a biofuel, whereas the biochar is sequestered in agricultural soils, which boosts the health of these soils and increases crop yields (more info in this text, and the further references there).

Image 1: Footprint of AEP's chilled ammonia process plant. Credit: AEP, Michael G. Morris: presentation of CCS technologies at the Morgan Stanley Global Electricity & Energy Conference, March 15, 2007, New York.

Image 2: Schematic of the chilled ammonia process. Credit: AEP, Michael G. Morris: presentation of CCS technologies at the Morgan Stanley Global Electricity & Energy Conference, March 15, 2007, New York.

References:
Alstom: Alstom signs contract with global company E.ON to build chilled ammonia based CO2 capture plant in Sweden for oil and gas - 21 June 2007.

Alstom: Alstom and Statoil to jointly develop project for chilled ammonia-based CO2 capture for natural gas in Norway - 21 June 2007

Alstom: Alstom and American Electric Power sign agreement to bring CO2 capture technology to commercial scale by 2011 - 15 March 2007