Capsol EoP (End of Pipe) is a patented post combustion carbon capture solution using Hot Potassium Carbonate (HPC) - a method used to remove carbon dioxide from gas mixtures under high pressure (sometimes called carbon scrubbing).
The chemical mixture used in the HPC process is based on potassium carbonate dissolved in water, together with a chemical activator, and a corrosion inhibitor, to decrease the corrosion rate of the material that comes into contact with the fluid.
A pressurized system is essential in the process, since chemical reactions are more efficient under high pressure. When pressure increase, molecules have less space in which they can move. This leads to a higher density of molecules, which increases the number of collisions and speeds up the reaction time.
The Capsol EoP carbon dioxide capture solution is a mature, low-cost, easy to install stand-alone unit that connects to the flue gas duct just before the stack. The EoP unit does not interfere with the existing facility. Hence, there is no need for expensive retrofitting.
There are more than 1,000 plants where the HPC process is used and the process is thoroughly documented.
How mature is the technology?
HPC as an absorbent of CO2 is thoroughly documented and used in more than 1,000 existing plants.
Our Capsol End of Pipe solution has been developed and refined over a 15 years period (TRL = 8).
It is an inexpensive, energy efficient solution which is easy to install.
It can be applied to capture CO2 from any power plant, industrial facility or plant powered with biofuel.
What are the benefits of a capture facility that can be run on electricity only?
First, the capturing facility is independent of the mother plant. Secondly, you do not need to invest in your own steam production.
Who operates the Capsol EoP capture unit?
In most cases the operator of the power plant or industrial facility will be responsible for the operation of the installed Capsol EoP capture unit.
What will happen to the carbon dioxide after being captured from the flue gas?
The owner of the power plant or industrial facility is responsible for the captured CO2 and is free to decide whether to utilize the CO2 as a component in other industrial processes or for enhanced oil recovery (CO2-EOR), or transport the CO2 to a geologically safe long term storage.
Is there any downtime of the plant during the installation?
No. There is no downtime. The installation of Capsol EoP will be commissioned during a planned maintenance of the mother plant. This is one of the many advantages of Capsol EoP.
If cost-efficient and good, why is it not installed in more plants?
Until recently there were no requirements for capturing CO2 from flue gas.
It was also believed to be too expensive to capture CO2 from the flue gas using Hot Potassium Carbonate (HPC), as the chemical reaction between CO2 and HPC requires pressurized gas. (The flue gas in ordinary power plants and industrial facilities is not pressurized).
It was therefore assumed that in order to make HPC work in carbon capturing, you would need to pressurize the gas, which would require large amounts of energy, and thus be very expensive.
Our patented Capsol EoP solution recycles most of the energy used for pressurizing the flue gas, making it very efficient and profitable for almost all types of plants.
What distinguishes the Capsol EoP solution from amine-based carbon capture solutions?
Capsol EoP uses Hot Potassium Carbonate (HPC) which is a less expensive absorbent.
Capsol EoP is a mature, cost-efficient, easy to install, stand-alone solution that connects to the flue gas duct just before the stack. Hence, no modification risk of existing plant.
No emission of harmful chemicals.
No hazard to environment or people.
No downtime. Installation of Capsol EoP will be commissioned during a planned maintenance of the mother plant.
Using HPC requires a lot of energy. It sounds expensive?
Using Hot Potassium Carbonate (HPC) to capture CO2 from flue gas requires gas under high pressure, which is believed to be expensive because of the energy required to pressurize the gas.
However, our patented Capsol EoP solution recovers most of the energy used for capturing and pressurizing the CO2 from the flue gas, making it efficient and profitable for almost all types of plants.
So why does not everybody use HPC?
Using HPC (Hot Potassium Carbonate) in carbon capture processes requires pressurized gas for the chemical reaction between CO2 and HPC to take place.
Since the flue gas in ordinary power plants, WtE plants and industrial facilities is not pressurized, the flue gas entering the absorber needs to be pressurized, which is believed to make the HPC process expensive due to the amount of energy required to pressurize the flue gas.
Our Capsol EoP technology is however very energy efficient and low cost for almost all types of plants and facilities due to our patented energy recirculation which recycles most of the energy used for pressurizing the flue gas.
Who can build a Capsol EoP unit?
Any qualified Engineering Procurement Construction (EPC) company can deliver and install the Capsol EoP solution.
Can Capsol EoP capture carbon dioxide from any type of industrial facility?
Our Capsol EoP solution can capture CO2 from any type of industrial facility with large emissions of carbon dioxide, such as power plants, process industries and waste incinerators.
Capsol EoP can also be used for BECCS (Bio-energy with carbon capture and storage).
BECCS (bio-CCS) is the process of extracting bioenergy from biomass and capturing and storing the CO2, thereby removing it from the atmosphere, making BECCS a negative emission technology.
Capsol EoP uses Hot Potassium Carbonate (HPC) as absorbent. The flue gas is pressurized (CO2 partial pressure to 0.7 bara) to optimize energy consumption in the process.
Using HPC as an absorbent of flue gas is thoroughly documented and used in thousands of existing plants.
Our Capsol End of Pipe solution has been developed and refined during a 15-year period.
Why BECCS (bio-CCS)?
The key factor to limiting global warming and achieving the Paris Agreement is to stop using fossil fuels. However, there are emissions that are almost impossible to eliminate, for example nitrogen oxides that are released when arable land is plowed.
That is why BECCS (bio-CCS) is required, to compensate for emissions where we have no technical and economically feasible alternatives.
Several reports indicate that 20-25% of greenhouse gas emissions will need to be offset by negative emissions using bio-CCS to be able to comply with the Paris Agreement.
Can the Capsol EoP solution be used to capture carbon dioxide from the air?
No. The CO2 concentration in air is so low that it becomes too energy-intensive, and thus too expensive. Planting trees is a better and cheaper solution for this purpose.
What is the Technology Readiness Level (TRL) for your carbon capture solution?
We have third party statement that our Capsol EoP solution has TRL 9 for syngas projects and TRL 8 for power plants, incineration plants, WtE and industrial facilities.
The Technology Readiness Level (TRL) scale was originally defined by NASA in the 1990’s as a means for measuring or indicating the maturity of a given technology. The TRL spans over nine levels from 1 to 9.
TRL 8: The technology has been proven to work in its final form and under expected conditions. In almost all cases, this TRL represents the end of true system development. Examples include developmental testing and evaluation of the system with actual waste in hot commissioning. Supporting information includes operational procedures that are virtually complete.
TRL 9: The technology is in its final form and operated under the full range of operating mission conditions. Examples include using the actual system with the full range of wastes in hot operations.
What is the capture capacity of the Capsol EoP solution?
Our Capsol EoP carbon capture solution has a capture capacity of 2,5 million tonnes of CO2/year.
The critical component is the compressor capacity. For compressors with a capacity of 450 kg/s, a CO2 content of 18-20 % in the flue gas and annual operating time of 8,000 hours gives a capture capacity of 2,5 million tonnes of CO2.
The Capsol EoP is easily scalable with multiple units for larger projects.
What is the purity of the captured carbon dioxide?
The captured CO2 has very low oxygen content. It is totally free of degraded (potentially carcinogenic) amines and is suitable for technical use.
In addition, the Capsol EoP solution absorb impurities such as SO2, NOx and mercury from the flue gas, resulting in near-zero emissions.
Are there any limitations to the Capsol EoP capture technology in terms of volume of gas to be treated, concentration of CO2 in the gas stream, presence of contaminants?
The limiting factor is the compressor. Current available compressors can handle gas volumes of approximately 450 kg/s.
The partial pressure of CO2 must be approximately 0.7 bar for an effective chemical process.
The amount of CO2 in the flue gas influences the capture cost. Low concentrations of CO2 will naturally give higher capture cost than higher concentrations of CO2.
For our Capsol EoP solution, a low capture cost will be achieved when the CO2 concentration is in the range of 10-25 percent.
Does the Capsol EoP solution involve risks for the health of workers or people living nearby?
No. This is a big advantage of using Hot Potassium Carbonate (HPC) as absorbent compared to Amine based methods.
Our Capsol EoP carbon capture solution is a non-toxic process. The captured CO2 and the cleaned flue gas are totally free of degraded (potentially carcinogenic) nitrous amines and hence are no risk to the environment or people. This is one of the strongest advantages of using Potassium Carbonate instead of Amines as absorbent.
When using Amines as absorbent you run the risk of chemical reactions that can form new compounds such as nitrosamines and nitramines, which can negatively affect health and the environment.
What is the energy consumption for your carbon capture solution?
The electric energy consumption is in the range of 200 kWh/ton (0.7 Gjoule /ton) CO2 captured (excluding the energy consumption for liquefaction).
For comparison, Amine-based technology requires slightly less electrical energy consumption. However, Amine-based technology requires an additional 700-1000 kWh/ton in the form of heat, totaling 2.5 Gjoule /ton CO2 captured, which is three times more than our Capsol EoP solution.
What is the approximate capture cost for Capsol EoP (HPC) compared to Amine based solutions?
A conceptual study investigating the possibility and cost (Capex and Opex) of implementation of carbon capture and storage from biological sources within Stora Ensos kraft pulp mills in Sweden has been carried out with support from the Swedish Energy Agency. The project's final report is available on the Swedish Energy Agency's website.
The carbon capture cost (Capex and Opex) for mixed flue gases using different technologies is presented in Figure 21 (page 45 and 46) of the report, and below.
Totalt carbon capture costs in €/ton for mixed flue gases was estimated to be:
36 €/ton for Amine,
24 €/ton for HPC El (El = electricity which refers to the Capsol EoP solution)
37 €/ton for HPC St (St = steam which refers to HPC solution using steam instead of electricity).
Costs for CAP (CAP = Chilled Ammonia capture Process ) and PSA/Cryocap solutions were also calculated at 44 and 45 €/ton, respectively.
Based on this, the total carbon capture cost using Amine based solutions is 50% more than using HPC El (our Capsol EoP solution).
Is there any operational risk associated with the compressor configuration required to pressurize the flue gas in the Capsol EoP solution?
No. However the flue gas needs to be cleaned to certain specification prior to compressing the gas. Questions regarding the joint operation of the mother plant and the capture plant will have to be treated from case to case in a pre-feasibility study.
Are you sure that your Capsol EoP technology will work on a large scale?
Yes. Our capture technology is based solely on well-known technologies, configured for capture of CO2 from sources with low partial CO2 pressure, such as flue gas from industrial facilities, power plants, incineration plants and other large scale emission sources.
Our capture technology uses Hot Potassium Carbonate (HPC) - a robust, non-degradable (in the presence of oxygen), easily accessible absorbent. HPC is «field proven» in medium to large scale processes.
The HPC technology was invented and developed by the U.S. Bureau of Mines in the 1940s and 1950s, and further developed in the 1970s. There are hundreds of HPC plants in commercial operation, of which some have emissions of more than 1 million tonnes of CO2 per year for a single plant.
Our technology was first tested in 2008 in collaboration with chemical experts from Siemens, who decided that testing on a moderate scale was sufficient, as large-scale use of the technology was well-known, and chemical conditions are identical for small and large scale conditions.
Hence, there is no doubt that our technology will work on a large scale.
Questions have been raised around testing of our patented energy recirculation unit.
The Capsol EoP energy recirculation unit consists of:
Flash of absorbent after discharge/outlet from the bottom of the desorber. This provides the largest/greatest contribution to the energy efficiency and is offered by well-known suppliers with experience from hundreds of plants. There is no doubt that this can be implemented on a large scale with a guarantee.
Reuse of steam energy from the top of the desorber. To reuse the energy from the steam at the top of the desorber, the steam needs to be in contact with circulating water. This is a vital part of the patented Capsol EoP solution; a water cooler is added at the top of the desorber where the steam is condensed in contact with the cold water in the cooler, and the water is warmed by the steam condensation heat. This process is extremely well known and also well-tested. To test this process on a miniature scale is a waste of time and resources.
Furthermore, a flash of the warm water from the process above is required, which generates steam and thereby cools the water. Such flash processes are used in many industries, including oil processes. No one with knowledge of flash of hot water will say that this is an unknown process.
Finally, compression of the steam from the flash process is required. This is a well-known process used commercially in the industry on a large scale.
The processes above are well-known and supported by major engineering companies and leading subcontractors. Hence, there is no doubt that our patented energy recirculation will work.
How has CO2 Capsol managed to patent a technology that is well known and proven for other applications?
The key word is «other uses».
Known technology applied to new applications is patentable (sufficient inventive step, novelty value and industrial relevance) if the solution is not obvious to professionals. A lot of innovations happen in this way and it creates great value.
The challenge is often the requirement for sufficient inventive step. In our case, no previous technology was found. Well-known commercial suppliers of the capture technology have confirmed that this was new to them as well, at the same time as they have confirmed that the technology is directly applicable on a large scale for their facilities.
Will there be any emission of nitrogen or other impurities?
Capsol EoP will absorb impurities such as NOx, SO2 and mercury from the flue gas resulting in near-zero emissions (levels of NO2 / SO2 will be below 100 ppm (100 kg / Nm3).
If today´s emissions are within environmental emission permits then NOx and SOx will be captured in our Capsol EoP process and form stable salts. These salts will need to be removed and substituted with new Hot Potassium Carbonate.
If there is a requirement to remove SOx and NOx, this can be done by cleaning the flue gas before entering the capture system or use the capture system to absorb the impurities. This is a cost optimization issue which will have to be discussed and decided upon together with the plant owner.
Does the absorbent degrade over time? Will we have to add or replace the absorbent?
How the absorbent behaves over a longer period of time depends on how clean the flue gas entering the absorber is.
If the flue gas entering the absorber is relatively clean, meaning that the concentration of pollutants like sulfur and nitrogen is low, the degradation of the absorbent (potassium carbonate) will be very low and the system can run for a long time without having to add or replace the absorbent.
If the flue gas has a relatively high content of sulfur and nitrogen, a small amount of stable salts will be produced as a bi-product in the process. In this case the stable salts can either be removed through a looping process, and then add a small amount of potassium carbonate to the absorber, or the absorbent can be replaced every 18 months or so.
What makes Capsol's technology able to run at 7 Bars flue gas pressure, when scientific studies indicate a flue gas pressure of 10-15 Bar for the HPC process to work and be able to separate 90%?
The main reason that we are is able to separate 90% at 7 Bars is our Lean flash box.
Most HPC studies assume there is no Lean flash box, and that the pressure in the Desorber is just above atmospheric pressure.
However, in Capsol EoP the pressure in the Lean Flash is approximately half of atmospheric pressure. This low pressure in the Lean Flash box is used to lower the temperature of the absorbent before it reaches the Absorber (thus making the absorption ofCO2 more efficient), in addition to lowering the saturation of the absorbent when the CO2 leaves the absorbent together with the water vapor.
Is it possible to lower the pressure further (lower than 7 Bars)?
Yes. In some cases it is cost-effective to lower the temperature of the absorbent entering the Absorber, as it leads to lower humidity in the purified flue gas. The lower humidity in the purified gas makes it possible to lower the temperature of the flue gas leaving the expander and avoid steam, and thus energy, being sent to the chimney, and thereby keep more of the energy in the system. This obviously leads to a slightly higher electricity consumption, but the gain is a larger amount of heat that can be used in e.g. a district heating system. When installing the system like this, virtually all waste heat generated by the electrical energy required by the system can be supplied to the district heating system.
Can Caspol's EoP solution capture more than 90% of the carbon dioxide in the flue gas, and is it cost-effective to have a higher capture rate?
Yes, we can capture more than 90% of the CO2. In some cases, it is more cost-effective to separate 93-95% of the CO2 than 90%. Which capture rate that is most cost-effective is something that has to be evaluated on a case-to-case basis.
Could we make use of steam from our steam cycle in your Capsol EoP capture technology?
Absolutely. We can make use of any excess steam from your process. It is, however, usually more expensive to use the steam from your process than using our "Heat recuperation" using flash boxes.
Generally, our patented Heat Recuperation can produce 7 times more energy in the form of steam than the amount of electricity we put into the system. In other words, for every kW electricity, we get 7 kW (or more) of energy in the form of steam.
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