Comeback for carbon

carbon

A scalable distributed control system (DCS) solution is helping an Australian joint venture develop and commercialise a new carbon management technology aimed at reducing global CO2 emissions.

Mineral Carbonation International (MCi) is an Australia-based start-up whose mission is to demonstrate the technical and economic viability of mineral carbonation as a sustainable industrial solution for carbon capture, storage, and utilisation (CCSU). The joint venture is owned by three shareholders: GreenMag Group, Orica, the world’s largest provider of commercial explosives and innovative blasting systems to the mining and civil engineering markets, and the University of Newcastle, Australia (UON).

MCi is adopting a fully holistic approach to CCSU – the world’s first – via mineral carbonation by examining the complete chain of operations from feedstock to final product. It all started more than seven years ago, when Canberra-based GreenMag Group teamed up with the UON to investigate the feasibility of current and future technologies to sequester CO2 emissions. Concurrently, Orica researchers had been working in the same field and the three parties merged to form MCi in 2013. The joint venture won a major research grant funded by the Commonwealth and New South Wales (NSW) governments and Orica.

The company’s approach involves creating and licensing intellectual property that enables captured CO2  to be used as a raw material for the production of green construction products such as cement and plasterboard, rather than treating it as dangerous waste. From the outset, MCi envisaged creating value by turning captured CO2 into useful products in order to offset the cost of the transformation process. The technology has the potential to play a key role in closing the carbon loop by providing a means for the safe and permanent disposal of carbon emissions from fossil fuel power stations and other industrial facilities such as fertiliser and cement manufacturing plants.

First of its kind

In 2013 MCi set out to establish a world-first CO2 mineral carbonation research pilot plant at UON. The pilot plant uses captured CO2 from Orica’s Kooragang Island ammonium nitrate production facility in Newcastle to produce carbonate solid and amorphous silicon. Ammonium nitrate is a common ingredient in fertiliser products used in agricultural applications and also the major component of commercial explosives used throughout the mining and civil engineering industries.

The need for a scalable DCS

In addition to conducting research to determine if existing mineral carbonation processes could be scaled to an industrial level, the purpose of the pilot plant is to develop new CCSU technologies that can be economically viable on a larger scale.

The plant was developed in two stages, with the first stage consisting of a batch process and the second of a semicontinuous process. The batch plant is used to validate existing mineral carbonation technologies on a larger scale and to provide carbonate products for further analysis within construction products – while the semi-continuous plant provides valuable experimental data to form the design basis of a demonstration plant.

In order to facilitate high levels of automation and process safety, the MCi team identified Siemens’ range of industrial automation Systems as a suitable solution for the required distributed control system (DCS).

Simatic PCS 7 equipment was selected by the project team due to its proven track record and extensive use in the chemical industry both in Australia and overseas, further supported by the experience from Orica, which is already using the same PCS 7 technology in one of its ammonium nitrate plants in Botang, Indonesia. The scalable architecture and powerful engineering tools of the Siemens DCS solution address the wider needs of a full-scale plant with respect to engineering, operational, and maintenance requirements. However, it also provides MCi with the flexibility to scale the base technology for the process control system in the future.

The sales and engineering team of Siemens Australia assisted with the selection of suitable control hardware and the implementation of the developed control philosophy for both stages of the pilot plant. The DCS hardware comprised two Simatic PCS 7 box systems with PCS 7 V8.1 SP1 OS runtime to allow independent operation and control. Also included were 11 Sinamics G120 VFD controllers to automate various vessel agitators and the operation of a high-intensity grinding mill.

“The Simatic PCS 7 system allows us to closely monitor and control all steps of our reaction and gives us the ability to record all process data required for detailed analysis of the energy requirements and overall process performance,” says MCi program manager Jan-Dirk Prigge.

A bright future

The pilot plant is a world first and the knowledge gained will help determine the financial and technological feasibility of industrial-scale implementations of mineral carbonation processes across the globe. The results achieved so far indicate that process conditions can be optimised further to potentially make mineral carbonation an economically viable way to reduce industrial CO2 emissions, slow global warming, and ensure a cleaner energy future. For commercial explosives producers such as Orica, this may also provide a way to reduce CO2 emissions and achieve more sustainable production.