Thailand has set a goal to achieve carbon neutrality by 2050 and net zero greenhouse gas emissions by 2065. One common approach adopted by many countries is to increase the share of clean energy and reduce reliance on fossil fuels.
However, the energy transition cannot happen overnight—especially in countries that still depend on coal-fired power plants for energy security.
Mae Moh Power Plant, located in Lampang Province, is one of the key power generators for the northern region and the country as a whole. It uses domestically sourced lignite coal, of which Thailand has abundant reserves. The plant is known for its low-cost electricity production and stable output.
During this transition period, the Electricity Generating Authority of Thailand (EGAT) remains committed to continuously reducing environmental impacts. One of the most noteworthy projects is “carbon capture using ash water,” which turns waste from the production process into opportunity.
A New Innovation from Waste: Carbon Capture Using Ash Water
Atthaphon Imnam, Director of Mae Moh Power Plant Generation Division at EGAT, explained that the Mae Moh Power Plant has established a task force to explore and apply new technologies. A CCUS (Carbon Capture, Utilization, and Storage) team has been formed to carry out a project capturing CO₂ using ash water generated from the combustion process of Mae Moh Unit 14.
The team found that the ash water, which collects beneath the furnace during power generation, has a high alkalinity (pH 11–12). When this alkaline water reacts with carbon dioxide (CO₂) from the plant’s flue gas, it can effectively capture the CO₂ through a chemical process known as mineral carbonation.
Based on this concept, Mae Moh Power Plant began a pilot test on Unit 14 using a 100-liter prototype system. The results showed that the concentration of CO₂ gas, which was originally around 13%, was reduced to 4–5% after undergoing the ash water carbon capture process.
The experiment is still ongoing, with the goal to scale up by using the full capacity of ash water from the unit’s system. If operated at a flow rate of 200 cubic meters per hour, it could capture up to 850 tons of carbon dioxide per year, which is a significant amount of CO₂ captured. Additionally, the process produces calcium carbonate (CaCO₃) as a valuable byproduct, which can be used in industries such as construction materials or in processes to capture sulfur dioxide (SO₂).
This innovation is therefore not only about reducing CO₂ but also aligns with the concept of a circular economy, turning waste into a resource.
How can success be achieved? And what conditions need to be met
Although this technology is still at the prototype stage, it has the potential for further development and scaling in the future, with key factors requiring continuous improvement:
- Scaling up from unit level to the entire power plant system
If this approach can be applied to multiple generating units or designed to connect with other flue gas stacks in the power plant, it will significantly increase the amount of CO₂ that can be captured continuously and efficiently. - Maximizing the use of byproducts
Calcium carbonate (limestone) produced from CO₂ capture is a solid material that can be effectively used in sulfur dioxide (SO₂) capture processes, helping to reduce costs for the Mae Moh Power Plant.
Mae Moh in the future: From ash water to clean energy that reduces CO₂ emissions
Mae Moh Power Plant will continue to play a vital role in energy security for the northern region and remain part of Thailand’s power system during the energy transition. However, the effort to develop CO₂ capture technology using resources available at the plant signals EGAT’s (Electricity Generating Authority of Thailand) firm commitment to society and the environment.
At a time when carbon reduction is a critical global goal, every approach that helps reduce CO₂ emissions—even starting from small-scale initiatives like ash water—could become a game-changing innovation making electricity production cleaner.
In this period of energy transition—from fossil fuels to clean, carbon-free energy—to help Thailand achieve carbon neutrality, if the ash water CO₂ capture project can be scaled up to a pilot project capturing CO₂ at the targeted levels, it will make Mae Moh Power Plant relevant in:
- Economic terms: Low electricity production costs
- Environmental terms: Reducing CO₂ and sulfur dioxide emissions
- Social terms: Contributing funds to local development through the Electricity Development Fund, driving sustainable social progress.
This may not be a change that happens overnight, but it marks the beginning of creating sustainable energy in a uniquely Thai way.