The final stretch of CEMCAP – 7 presentations and 5 posters at the 14th Greenhouse Gas Technologies Conference, Melbourne, Australia

CEMCAP is a project funded by Horizon 2020 addressing CO₂ capture from cement production. The primary objective of CEMCAP is to prepare the ground for large-scale implementation of CO₂ capture in the European cement industry. The project has been running for 3,5 years, and will be concluded the 31^st of October.

Last week, the 14^th Greenhouse Gas Technologies Conference (GHGT-14) took place in Melbourne, Australia. This is the largest conference in the area of CO₂ capture, transport and storage, and gathers around 1000 delegates from all over the world every second year. As a final sprint in CEMCAP communication and dissemination activities, the key researchers from the project has presented not less than 12 contributions during the conference week: 7 presentations and 5 posters!

Here’s a short summary for those who were not able to participate. Several of the presentations has also been given as webinars, and links are provided below.

CEMCAP oral presentations at GHGT-14:

Retrofittable CO₂ capture for cement – progress made in the CEMCAP project

This presentation gave an overview over the whole CEMCAP projects and main findings during the project period. Through the project, it has been demonstrated that five different technologies are feasible for CO₂ capture from the cement industry, and that no obvious show stoppers are present.

Through this, together with taking an active role towards communicating results towards the cement industry itself, CEMCAP has contributed significantly towards preparing the ground for large-scale implementation of CO₂ capture in the European cement industry.

Techno-economic comparison of five technologies for CO₂ capture from cement

We have performed a techno-economic evaluation of the CEMCAP technologies. For the base case the cost of clinker/cement increased with 49-9X% when CO₂ capture was applied, depending on the technology, and the cost of CO₂ avoided was in the range 42-84 €/tCO₂.

In general, the more integrated technologies (oxyfuel, calcium looping) performed best in terms of cost. However, the results are strongly dependent on site-specific conditions such as electricity mix and cost, waste heat availability, fuel cost, etc. A final evaluation should therefore be carried out for each specific plant.

• Read this blog for more details: CEMCAP-Project: Tech options for cement CO₂-capture need a plant specific assessment

Retrofitability of CO₂ capture technologies to cement plants

Cement plants have long lifetimes, and not many new cement plants are expected to be built in Europe in the next years. In order to reduce emissions from the cement industry it is therefore important that CO₂ capture technologies can be retrofitted to existing plants. We evaluated the retrofitability of the CEMCAP technologies and found no show stoppers for any of the technologies, but in general the post-combustion technologies are easier to retrofit than the more integrated ones.

Simulation, modelling and optimization of different chilled ammonia-based process configurations for CO₂ capture applied to cement plants

This presentation deals with the adaptation of the Chilled Ammonia Process for CO₂ capture to cement plants, where the CO₂ concentration in the flue gas is considerably higher to that in power plant flue gases. New CAP configurations are implemented with this aim.

This work proves that

• The performance of the CAP applied to cement plants improves with respect to the power plant application
• The CAP shows a very promising performance with respect to amine-based capture processes for cement application. Improvements have been quantified and new process operating conditions for the cement application have been obtained using a model-based optimization, whose model has been developed on the ground of approximately 150 pilot plant tests of the key unit operations of the CAP performed with cement flue gas specifications.

Membrane and membrane assisted liquefaction processes for CO₂ capture from cement plants

Membrane based capture processes are very well suited for post-combustion capture from cement where the flue gas has a composition between 18-22%. The presentation compares the performance of two stage membrane process and a membrane assisted liquefaction process where membrane is used for bulk separation of the flue gas to achieve an “oxy-combustion” like stream that can be fed to a liquefaction process.

The results show that membrane properties are critical to achieve good techno-economic performance – reduce membrane area, compression work and vaccum pump volumetric flow and work requirement. Another important result from the work is that the membrane assisted liquefaction will always have better performance than 2 stage membrane process irrespective of membrane type.

Demonstration of Calcium Looping CO₂ capture from cement plants at semi-industrial scale

The Calcium Looping CO₂ capture process captures CO₂ by cyclic calcination and carbonation of calcium carbonate which itself is a feedstock for cement manufacturing. This allows for beneficial operation conditions enhancing the overall process performance. Within the CEMCAP project calcium looping CO₂ capture was demonstrated at semi-industrial scale (TRL6) reducing CO₂ emissions up to 98%.

Techno-economic analysis of Calcium Looping processes for low CO₂ emission cement plants

Calcium looping (CaL) technology is attractive in cement plants as it uses the same materials of conventional plants (CaCO3, either pure or in the raw meal) as sorbent for CO₂ capture. CaL can be integrated in cement plants through the tail-end and the integrated process configuration.

The tail-end configuration has been  proven in fluidized bed lab pilot unit up to TRL6, demonstrating CO₂ capture efficiency higher than 90%. The integrated CaL configuration has been mainly assessed through modelling, showing that high capture efficiency can be achieved with solid/gas ratio in the carbonator of around 10 kg/Nm3, in reactors with length of around 100 m.

Process simulations showed that CaL requires increased fuel consumption (especially the tail-end configuration) compared to a conventional plant, but heat from fuel combustion can be recovered by a steam cycle producing enough electricity to compensate for the electric consumption of the ASU and the CPU. Costs of CO₂ avoided of 50-55 €/t have been estimated, mainly associated to the capital costs of ASU and CPU.

CEMCAP poster presentations at GHGT-14:

Oxyfuel kiln burner tests for a CO₂-free cement plant

The poster presents dedicated investigations regarding the use a downscaled cement kiln burner for combustion tests in oxyfuel conditions. A down-fired furnace was adapted to conduct air and oxyfuel tests in relevant cement kiln´s operating conditions like the preheating of secondary gas up to 800°C.

The results indicate that oxygen content in oxyfuel mode becomes a relevant parameter in order to obtain similar heat transfer to material as in air firing operation. Furthermore, commonly features of modern burners (like swirl angle) can also be used to adjust temperature profile as in conventional air firing mode.

Impact of oxyfuel technology on calcination process

Calcination in oxyfuel mode is possible with a certain level of  temperature increase. The test results show an average shift of 50-70K for oxyfuel mode to achieve calcination level similar to existing air calciner. The actual oxyfuel calcination temperature depends on the heat transfer characteristics of the facility. To keep the calciner outlet temperature within the range of existing operational experience ((≤ 900°C) there are two possible option:

1. Shifting certain level of calcination towards Kiln
2. Improving the heat transfer to raw meal particles inside the calciner itself to lower the difference between equilibrium temperature and actual entrained temperature required for calcination.

Experimental investigation of low-temperature CO₂ separation for carbon capture in the cement industry

Low-temperature CO₂ capture by liquid-vapor phase separation can increase the efficiency for several carbon capture applications where the CO₂ concentration is high in the flue gas or syngas.

One such application is hybrid flue gas separation by using polymeric membranes for bulk separation and low-temperature CO₂ liquefaction and phase separation for purification of the CO₂ stream. To investigate the performance of the low-temperature liquid-vapor phase separation part of this hybrid carbon capture process, a laboratory rig with the capacity to capture approximately ten tons of CO₂ per day has been built. The rig has been run with several operating conditions, and the results from the experiments are in good agreement with simulations of the process.

CCUS scenarios for the cement industry: is CO₂ utilization feasible?

This poster focuses on the potential of producing products from a portion of the captured CO₂ from a cement plant. These are the key conclusions:

• “CCU” always needs “S”: either market or raw material availability poses limitation on the amount of CO₂ that can be utilized (in WP5 cases, around 10% of the emitted CO₂ from the reference plants) for climate change mitigation, storage is a must;
• A clear economic benefit of CCUS as compared to CCS was found only in the case of polyol: high value product, substantial amount of CO₂ avoided (CO₂ replaces ethylene oxide which is CO₂ intensive) the full CCUS chain is profitable;
• For fuels production, a limited economic benefit may be achieved;
• Analysis needs to be performed case by case, taking the life cycle of products into consideration properly accounting for CO₂ avoidance is key

Qualitative study: How the cement producer Norcem interacted with local stakeholders to reinforce public acceptance for CO₂ capture

This was a study performed to investigate how the Norcem cement plant communicated its CO₂ capture project, and how local residents perceive the project. It was concluded that even limited local communication had taken place, perceptions had been formed amongst the local residents. Most importantly:

• The CO₂ capture project can stimulate local employment
• The project can be good for the environment
• There is a concern about how the project will affect their living conditions