- Omission of air quality impact assessment regarding hydrogen co-firing identified in the Environmental Impact Assessment (EIA)
- Inadequate evaluation of air quality as a key assessment item; lacks predictions on air pollutant generation and mitigation measures
The environmental impact assessment (EIA) for the gas power plant construction project currently being promoted by Korea East-West Power in Jeju has been confirmed as flawed. It omitted the air pollution impact of hydrogen co-firing operations in its air quality evaluation, which is a designated key assessment item. With the review of project implementation approval documents and the public opinion gathering process remaining open until June 15, suspending the approval based on the current EIA report and reinvestigating the flawed assessment are now inevitable.
In accordance with the decision of the Environmental Impact Assessment Council, six key assessment items were designated for Korea East-West Power’s gas power plant project, including air quality. The air quality assessment requires predicting the impact of pollutants generated during construction and proposing mitigation measures, as well as evaluating air pollutant emissions during the plant’s operation to present reduction plans. In the draft EIA report, air quality impacts during operation were predicted separately for gas (LNG) combustion and diesel (emergency) combustion, assessing whether they exceeded national and regional environmental standards.
Subsequently, during the EIA deliberation process, the use of diesel (for emergencies) was excluded. Accordingly, the plan to install on-site diesel storage tanks was replaced with a plan to install hydrogen fuel facilities, and the capacity for hydrogen co-firing was explicitly stated in the final EIA report in accordance with the Basic Plan for Electricity Supply and Demand. Furthermore, the documents related to the approval of the development project implementation also specified the installation of turbines capable of hydrogen co-firing.
Therefore, the fuel to be used at the power plant was explicitly changed from gas and diesel to gas and hydrogen. However, no predictions, evaluations, or mitigation measures regarding the changes in air pollutant emissions caused by co-firing gas and hydrogen were presented whatsoever. While the air impact of diesel—which might never be used except in emergencies—was assessed, the air impact of hydrogen co-firing, which could become a regular operating condition, was entirely omitted.
There is a distinct difference in air pollutant emissions between co-firing gas and hydrogen and burning gas as a single fuel. Co-firing with hydrogen increases nitrogen oxide (NOx) emissions. Hydrogen has a higher flame temperature and faster combustion speed than methane (the main component of natural gas). Consequently, exceptionally hot areas (hot spots) form inside the combustion chamber, and nitrogen in the air reacts with oxygen at these hot spots to produce nitrogen oxides. The hotter the flame, the more Thermal NOx is generated.
This issue has been consistently raised both domestically and internationally. The National Energy Technology Laboratory (NETL) under the US Department of Energy, which leads in hydrogen co-firing technology, states in its 2022 report, A Literature Review of Hydrogen and Natural Gas Turbines: Current State of the Art with Regard to Performance and NOx Control, that hydrogen has a higher adiabatic flame temperature than methane (2,254°C vs. 1,963°C), indicating a greater potential to generate NOx. The report also points out that without separate abatement measures, hydrogen can generate more than eight times as much NOx as natural gas under identical conditions. It clarifies that applying NOx reduction technologies, such as lean premixed combustion (a method that lowers flame temperature by thoroughly mixing fuel and air in advance with excess air) and Selective Catalytic Reduction (SCR), is essential to meet US Environmental Protection Agency (EPA) regulatory levels.
Ultimately, when mixing and burning gas and hydrogen, air pollutant emissions will inevitably vary depending on the co-firing ratio, making the prediction, evaluation, and presentation of mitigation measures absolutely necessary. However, such predictions, evaluations, and mitigation measures were completely ignored. Korea East-West Power has repeatedly emphasized hydrogen co-firing during the EIA deliberation and the Jeju Provincial Council’s consent process. Yet, they conducted zero review of the resulting air pollutant emissions.
The air quality assessment, a key assessment item, is a crucial evaluation that predicts the impact of air pollution on neighboring areas due to the project’s implementation, assesses the cumulative impact alongside surrounding emission sources, and proposes mitigation measures based on these findings. In particular, the air quality assessment must be conducted strictly, as it has a deep causal relationship with the right to health of local residents. However, by omitting the air quality assessment for hydrogen co-firing, the potential risks to the residents’ right to health were not evaluated. Consequently, it is difficult to avoid the criticism that the air quality assessment was poorly executed.
Therefore, the approval for the development project implementation based on the current EIA must not proceed. A reevaluation of the air quality impact reflecting hydrogen co-firing conditions must precede any further action. Furthermore, this flawed air quality assessment is not merely a procedural issue but a matter closely tied to the residents’ right to health. As this constitutes a falsely and poorly drafted environmental impact assessment, Jeju Province must form an Expert Review Committee on False and Inadequate Assessments to clearly investigate the inadequacy of the case and determine necessary actions, including a comprehensive reinvestigation.