Nicloas Vin, R&D engineer at IFPEN presented the primary test results on the CHEERS project based on the demo unit outputs as of the seminar date. The presentation touched on the timeframe from January of 2022, where the construction of the demo unit started. Aside from the rapid construction over 11 months to erect the 44-meter-high demo unit, it was done so with no accident or incident. This holds true even through the operation of the demo unit as well as repair works that it has undergone since the first start-up of the plant on 6th of June 2023.

The oxygen carrier, Ilmenite, required pre-oxidation to ensure agglomeration is avoided. Agglomeration may occur mainly for reduced oxygen carrier particles in dead zones of the demo unit. Confirmed by experiments in a small-scale muffle furnace, pre-oxidation at 800 degrees Celsius avoids agglomeration, and also positively impacting oxygen carrier circulation. 75 tons of ilmenite was pre-oxidised in the fuel reactor.

The circulation of the oxygen carrier is crucial and complex. As a solid consisting of fine particles, controlling its flow rate across the different parts of the demo unit requires pneumatic valves realized by the L-valve. The three valves in the demo unit (X101, X102 and X103) control the oxygen carrier flow from air reactor to fuel reactor and reverse. The presentation highlighted the solid flow rates in the valves function of temperature and pressure.

The presentation also touched upon a challenge encountered with the manhole refractory. The fuel reactor reached significant temperatures at which some slugging solid regime occurred, with large build up of air bubbles in the start-up phase, resulting in the refractory manhole protection to fall down in the reactor. This was solved by improving the tightening of the refractory manhole by providing reinforcement via 4 melded metal supports.

The demo unit thus far has achieved the first validation of the CLC technology via L-valve functioning. Significant data acquisition of the working of the demo unit thus far sets the team up for the next challenges. Looking ahead, the team loops to complete solid circulation and L-valve calibration at 800 to 900 degrees, validation of heat losses for autothermal CLC as well as testing CLC at the 2-4 MW scale. The teams working on the demo unit, both European and Chinese partners are confident and excited to move forward with the next steps for the demo unit.

For further information on the primary results from the CHEERS demo unit feel free to reach out.

Vincent Gouraud from TotalEnergies, leader of work package 4 along with Patrice Font from IFPEN, leader of work package 2 and 5 presented on the techno-economic assessment (TEA) of an industrial scale CLC unit, the design cases relevant for such a scale and finally to benchmark the CLC technology with references considering the full value chain.

Addressing the design cases relevant for industrial scale required modelling the fuel reactor at that scale. To do so, the strategy employed looked at batch unit kinetic studies which were then validated by IFPEN’s 10 kW CLC unit. Understanding the hydrodynamics with the fuel reactor was a necessary step in upgrading to an industrial scale. The demo unit in Deyang, China provides the final validation at the 2-4 MW scale. The process simulation of the CLC plant at industrial scale was also done considering the two use cases: power generation case (at a scale of 200 Mwe) and a refinery case (at a scale of 50Mwe).

With a scope from feed preparation to CO2 compression, r the Techno-Economic Assessment (TEA) at industrial scale, highlight the list of required equipment and their cost. . Quotes were obtained from manufacturers on the equipment needed. This TEA is done on the 500 MWth scale with key KPIs being the levelized cost of electricity and the CO2 avoided cost.

The TEA looks at both CLC use cases, refinery and power generation at the respective scales and two reference technologies : CFB circulating fluidised bed and natural gas combined cycle. The resulting 6 combinations are evaluated, and cost estimates were createdConsidering core assumptions to help build the TEA, it confirms that CLC technology is competitive for solid feedstock for both use cases. The levelized cost of electricity is lower for CLC as compared to CFB with amine-based capture and cost of avoided CO2 lower for CLC as well. For comparison with the NGCC case, price sensitivities were introduced to understand what price ranges are favourable for CLC.

The study confirms that CLC is a cost competitive option for reducing emissions in both power generation and refinery cases with solid feedstock. Transport and storage of CO2 costs would impact these costs as a full value chain was evaluated by SINTEF.

For more information, feel free to reach out.

The Front-End Engineering Design (FEED) is the crucial step before the construction of the demo unit. It covers the technical requirements for the realization of the project. The pre-FEED and FEED studies were carried out from 2018 to 2021. The studies carried out by both the EU and China faced additional challenges apart from the time difference as the COVID pandemic posed significant difficulties in terms of information exchange and collaboration. The presentation of this journey was done by Vincent Gouraud from TotalEnergies, leader of work package 4 and was carried out by Mahdi Yazdanpanah.

The FEED study was successful in considering both European and Chinese configurations. The configurations differ in terms of interaction of the carbon stripper with the rest of the system. Both these configurations were incorporated within the demo unit and can be interchanged. This is increasingly complex considering that the final construction of the demo unit must take into account the separate configurations and their process limitations. 23 design cases were studied, and the controllable parameters were further evaluated. These parameters presented considerable range, for example, the power of the unit can range from 2 to 4 MW thermal, considering thermal input from 66 to 133% of capacity. Considering the fuels for the reduction in the fuel reactor, solid fuels Lignite and Petcoke were considered.

These levels of complexity were not the only challenge, as the unit was a first of its kind in many aspects; L-valves to control solid circulation do not exist at this scale, neither does the specificity of the oxygen carriers changing density along the red-ox cycles. The CLC demo unit requires complex engineering due to solid circulation among many other factors.

Finally DBC premises overcome the challenge of setting up the construction of the 44-meters demo unit between existing buildings. And furthermore, The construction of the demo unit was done in 11 months, a relatively short duration of time.

Despite such a multitude of challenges, the results from the FEED study were significant. Such a study resulted in 235 documents; these documents describe in detail the technical specifications such as process design through to engineering standards but also crucial safety documents such as the HAZID (Hazard identification) HAZOP (Hazard and Operability) and LOPA (Layers of Protection Analysis) studies. The HAZID study analysed 83 cases, identifying 5 potential causes of major accidents and generated 35 key recommendations.

FEED documents produced valuable resources for design and evaluation of industrial scale of the CLC plant, which is useful for further work beyond CHEERS. This highlights the successful intercultural collaboration between the Chinese European partners.

For more information on these topics or a deeper dive, feel free to reach out.

Øyvind Langørgen from SINTEF and Lei Liu from Tsinghua University presented at the public seminar of the CHEERS project on the 20th of September at Deyang, China. Covering the work done on the topic of the oxygen carrier material within work package 3, the presentation went through the selection of the oxygen carrier, its subsequent testing and validation.

The oxygen carrier is a crucial part of the chemical looping combustion technology. The oxygen carrier would transfer the oxygen from the air reactor to the fuel reactor for fuel combustion. It must also transfer the heat necessary to sustain the combustion process. These two functions ensure that this type of oxy fuel technology results in a clean stream of CO2 with very low impurities while achieving chemical looping combustion. Oxygen carriers are typically metal oxides, based on metals such as iron (Fe), manganese (Mn), calcium (Ca), or copper (Cu). These carriers can be both natural and synthetic, and to identify the correct choice many tests were conducted; first through lab scale screening tests, then through testing in CLC pilots and finally validation at the pilot scale CLC units.

Properties were prioritized when considering oxygen carriers that would best suit the CLC process. This included the capacity to transfer oxygen, fuel conversion and reaction kinetics, the lifetime of the material, and the availability and cost of the material. One of the initial materials selected was Ilmenite (FeTiO3), multiple sources were tested of this material; from Norway, Vietnam and Mozambique. This naturally occurring material was tested at different heat conditions and the Norwegian sourced (Titania) Ilmenite T2 proved to be the most effective. Despite being and appropriate candidate, initial testing at high temperatures resulted in agglomeration of the material which proved to be a barrier for achieving CLC.

As an alternative, a synthetic material Perovskite – Ca(MnxTiyFez)O3 was tested in the batch fluidized bed unit at IFPEN. The results showed partial deactivation of the material due reaction with sulphur. This alternative be was discarded as the feedstock used in the European configuration, Petcoke, has significant sulphur content.

Turning back to Ilmenite, the reason for agglomeration was evaluated. It was found that the issues lie in the delivery of the material being dry. By pretreating the material, via the addition of steam, it was noticed that agglomeration was avoided. This reduced fuel conversion and oxygen transport capacity but well within the design limits. Tests were then carried out with the material at 15 kW and 150 kW scales with various feedstocks: Petcoke, biomass and a mix of the two, showing positive results.

While the Ilmenite was being evaluated at SINTEF, Tsinghua University tested the synthetic material CMTF Perovskite. The results from 1000 cycles showed no agglomeration and short oxidation time of only 4 seconds. It also had a longer lifetime compared to the ilmenite alternative. With these benefits came a significant difference in cost; nearly 2000 USD/ton of the material whereas Ilmenite was priced well belove half.

Considering these parameters, ilmenite was chosen to be the ideal candidate for the role of oxygen carrier for the CLC process. The work package had managed to validate 3 oxygen carriers in this process. Ilmenite met the criteria for performance, cost, sulphur tolerance and availability among other parameters. 250 tons of ilmenite was shipped from Norway to Deyang, China for the pilot plant for testing of both the European and Chinese configurations.

For more information on the oxygen carrier work done on the CHEERS project, feel free to reach out.