Solvents for the next generation of post combustion CO₂ capture systems (SOLVit – Phase 2)

The project has the main focus on the development of chemicals for use in post-combustion CO₂ capture plants. The goal in phase 1 (2008 – 2011) was to develop a chemical mixture that is used in a capture plant, reducing the energy requirement for regeneration by 35% compared to a reference of 4.2 GJ / tonne CO₂. Phase 2 of the SOLVit project was started in March 2011 (210240 SOLVit – phase 2) and lasted until January 2013. In phase 2, the focus was on further development of chemical mixtures that minimize the health and environmental consequences associated with amine technology while emphasizing low energy consumption. Active work has been done to further develop methods for emission measurement and emission reduction technologies. In addition, work has been done on the development of so-called third-generation processes where the long-term goal in SOLVit of a 50% reduction in energy consumption is expected to be.

The project focuses on both chemicals for and process optimization of post-combustion CO₂ capture plants and consists of four parts:

SP1: Development of chemicals
SP2: Modeling of chemicals and capture facilities
SP3 / SP5: Pilot and demo tests
SP4: Competence building

The project owner is Aker Engineering & Technology (formerly Aker Clean Carbon). The research activity is led by SINTEF Materials and Chemistry in collaboration with Aker Engineering & Technology. The latest sub-project, SP4, which is led by the Department of Chemistry at NTNU, is funded under the Research Council of Norway’s part of the CLIMIT program.

The entire SOLVit program, which is divided into three phases, is planned to be implemented over eight years (2008-2016). Granted from the CLIMIT demo applies to phase 2, while the grant from the Research Council of Norway applies to the entire program.

Phase 1 was completed in February 2011. The most important results achieved are the following:

■ Establishment and operation of the project’s two pilot plants, Tiller and ACC Mobile Test Unit (MTU), which provided a total of 8900 hours of operational experience with CO₂ capture. Three different chemical mixtures were tested at the pilot plants and 7 emission campaigns were carried out during this period.
■ Experimentally, more than 25% reduction of energy consumption has been documented at the plants in relation to the project’s reference value of 4.2 GJ / tonne CO₂.
■ Development of new chemical mixtures has been a key element in the project, and more than 50 amines and amine mixtures have been tested for suitability for CO₂ capture plants.

During phase 1, the focus on health and environmental aspects of amine technology has increased significantly. The focus in phase 2 has therefore largely been on the development of chemical mixtures with improved environmental properties, emission-reducing technology and the development of analytical methods for degradation products. In particular, work has been done on the issue of nitrosamine formation in the amine process and the development of methods for analysis and emission measurement of nitrosamines.

In phase 2, two new chemical mixtures were developed where both environmental aspects and energy consumption have been emphasized. Test campaigns on Tiller showed that both mixtures had promising properties both in terms of energy consumption and emissions. In addition, one of the new chemical mixtures showed greatly improved degradation properties. However, the energy consumption was slightly higher than what was achieved with the best chemical mixtures from phase 1.

In connection with the expansion of SOLVit phase 2 from 2012, EnBW AG’s pilot plant at the Heizkraftwerk Heilbronn coal power plant in Germany has become part of the project. In Phase 2, the Heilbronn pilot has carried out pilot campaigns with both MEA and one of the new SOLVit chemical mixtures. The tests confirm that the SOLVit chemical mixture provides improved energy consumption and significantly reduced degradation and plant corrosion for exhaust gas also from coal-fired power plants.

In addition, work has been done on new third-generation processes that can reduce energy consumption by up to 50%. The work has primarily been driven by SP4 and NTNU, but a concept that uses salting to increase CO₂ emissions has been tested in SOLVit WP1. At the end of phase 2, systems that form several phases are the most promising, and the development of these will be continued in phase 3. Finally, a method for in-situ destruction of nitrosamines was tested. The method will be further developed in phase 3.

In summary, SOLVit phase 2 has led to increased safety for AET regarding the choice of chemical mixtures and the understanding of performance evaluation, health and environmental aspects for these. New chemical mixtures and emission-reducing technology that eliminates health and environmental risks from CO₂ capture have been developed. In addition, the operating experience from the pilot plants and the development of analysis methodology are considered very important.
In connection with the expansion of SOLVit phase 2 from 2012, EnBW AG’s pilot plant at the Heizkraftwerk Heilbronn coal power plant in Germany has become part of the project. In Phase 2, the Heilbronn pilot has carried out pilot campaigns with both MEA and one of the new SOLVit.