[C Tech Now] How to Obtain the Hot Issue in the Energy Industry: 'Clean Hydrogen Certification'

Greenhouse Gas Emissions Below 4kg per 1kg Hydrogen Production
'Well-to-Port' Concept Applied from Mining to Shipping
Additional Reduction Considered for Selling Carbon Byproducts
Certification Required to Participate in Clean Hydrogen Power Bidding

Clean Hydrogen Certification Mark

The energy industry is showing great interest in the Clean Hydrogen Certification System, which is being implemented for the first time this year. More than 400 attendees gathered at the 'Clean Hydrogen Certification System' briefing held last month at the Korea Science and Technology Center in Seoul.

Hydrogen has been classified as green, gray, or blue hydrogen depending on the production method. Unlike this, the Clean Hydrogen Certification System is based on greenhouse gas emissions. If the amount of greenhouse gases emitted during production or import is below a certain level, it is certified as 'clean hydrogen,' and the government provides administrative and financial support.

The legal and institutional framework for the Clean Hydrogen Certification System has also been completed. Following the amendment of the Hydrogen Act Enforcement Decree containing the basis in November last year, the 6th Hydrogen Economy Committee meeting held in December of the same year approved the introduction plan for the Clean Hydrogen Certification System. The Ministry of Trade, Industry and Energy passed the final hurdle by publishing a notice on the operation of the Clean Hydrogen Certification System in the official gazette earlier this month.

In December last year, the Energy Economics Institute was selected as the operating agency for the Clean Hydrogen Certification, and the Korea Testing Certification (KTC) and Korea Testing & Research Institute (KTR) were selected as the Clean Hydrogen Certification Testing and Evaluation Agencies, establishing the promotion system.

The Clean Hydrogen Certification System is particularly attracting attention because the Clean Hydrogen Production Standard (CHPS) will be implemented in the first half of this year. According to CHPS, power generation businesses above a certain scale must produce a portion of their electricity from hydrogen power generation. Petrochemical, gas, and power generation companies are preparing for CHPS projects. Since obtaining Clean Hydrogen Certification is a prerequisite for participating in CHPS, prospective power generation businesses naturally have high interest. Many prospective CHPS participants also attended the Clean Hydrogen Certification briefing held last month.

Clean Hydrogen: Is the Standard from Well to Gate?

Hydrogen is recognized as an important energy source for carbon neutrality by 2050 because it does not emit carbon when combusted. However, there is another important point. While hydrogen itself is a clean raw material, carbon is needed to produce hydrogen.

Green hydrogen, produced by electrolysis of water using electricity from renewable energy sources such as solar and wind power, emits almost no carbon. The problem lies with reforming hydrogen. Countries like South Korea, which lack abundant renewable energy, mainly produce hydrogen by reforming natural gas.

The steam methane reforming (SMR) technology, which reacts methane (CH4), the main component of natural gas, with high-temperature steam to extract hydrogen (H2), is widely used. This process produces carbon monoxide (CO) and carbon dioxide (CO2) as byproducts. Carbon is also emitted during the production of high-temperature steam. It is generally known that producing 1 kg of hydrogen emits about 10 kg of carbon dioxide. This is why reforming hydrogen is commonly called gray hydrogen. When carbon capture, utilization, and storage (CCUS) technology is applied during hydrogen production, greenhouse gas emissions can be significantly reduced. This has been called blue hydrogen until now.

The Clean Hydrogen Certification System was established with the aim of accelerating the hydrogen society by recognizing hydrogen as clean if greenhouse gas emissions are reduced below a certain level through technical measures. After various discussions and reflecting international trends, the government decided to certify hydrogen as clean if the greenhouse gas emissions per 1 kg of hydrogen produced are 4 kg or less. Generally, green hydrogen, blue hydrogen, bio hydrogen, and nuclear hydrogen are expected to fall within the category of clean hydrogen.

The problem arises after that. The question is from where to where the 4 kg of greenhouse gas emissions will be measured. The scope of emission calculation is broadly divided into Well-to-Gate, Well-to-Port, and Well-to-Wheel. South Korea decided to adopt Well-to-Gate as the initial standard. For reforming hydrogen, Well-to-Gate refers to the stage from natural gas extraction (Well) to hydrogen production and shipment (Gate).

In South Korea, natural gas is reformed domestically, but a significant portion of hydrogen is also imported from overseas, such as the Middle East. When importing hydrogen, it is liquefied or synthesized into ammonia and transported by ship. Liquefaction of hydrogen, ammonia synthesis, and shipping emit a considerable amount of carbon dioxide. The concept including this part is Well-to-Port.

Lee Hye-jin, a senior researcher at the Energy Economics Institute, the certification operating agency, explained, "Considering the development of eco-friendly ship technology in South Korea, greenhouse gas emissions from the shipping process will be temporarily excluded." This seems to reflect the reality that expanding the concept to Well-to-Port immediately would leave few places eligible for Clean Hydrogen Certification.

Well-to-Wheel is the broadest concept, including greenhouse gas emissions from transporting hydrogen from domestic storage to demand sites such as vehicles or power plants. In the long term, the concept of clean hydrogen is expected to expand to Well-to-Wheel.

Additionally, the government decided to exclude greenhouse gas emissions from waste heat utilization in clean hydrogen production after feasibility review. Emissions from activities not directly related to hydrogen production, such as compression processes for hydrogen transport or equipment manufacturing, will also be excluded from emission calculations.

Hydrogen producers prefer importing hydrogen converted into ammonia from overseas. Ammonia has a boiling point of -33 degrees Celsius, which is higher than hydrogen's -253 degrees Celsius, making it easier to liquefy. Ammonia also has a wide range of uses. It can be converted back to hydrogen for use as a raw material or mixed with coal for coal-ammonia co-firing power generation. It is also used as a fertilizer raw material. Ammonia (NH3) can be produced relatively easily by chemically reacting hydrogen (H2) and nitrogen (N2).

The Energy Economics Institute decided to apply a conversion factor of 6.45 kg of ammonia per 1 kg of hydrogen based on measurements at the import port when certifying clean hydrogen. This is based on the lower heating value (excluding the heat of vaporization of water in combustion gases), where hydrogen produces 120 megajoules (MJ) of heat energy per kg, which is 6.45 times that of ammonia (18.6 MJ/kg).

Additional Reduction Recognized Even if Captured Carbon is Sold

When producing clean hydrogen by electrolysis, the concept of temporal and spatial correlation becomes an issue. In South Korea, temporal correlation with power sources is limited to a monthly basis, and spatial correlation is limited to the same grid (power network). For example, if 100 megawatt-hours (MWh) of electricity were produced at wind farm A in March, and 120 MWh of electricity were used at the same hydrogen production facility in the same month, only 100 MWh will be recognized as renewable energy used.

However, hydrogen producers can also be recognized as producing hydrogen using renewable energy if they use direct power purchase agreements (PPA) or renewable energy certificates (REC).

The treatment of carbon byproducts captured during hydrogen production is also an issue. If greenhouse gases are emitted again during the storage or utilization of captured carbon, the meaning of clean hydrogen is diminished. The government plans to recognize the effect of emission reduction if the captured carbon is sold externally and the purchasing business replaces existing fuels or raw materials. Conversely, if carbon is emitted during the final use or disposal of carbon-containing byproducts, it will be included in the emission calculation. The aim is to minimize additional carbon emissions during the processing of captured carbon.

Bio hydrogen is also mentioned as one method of producing clean hydrogen. When livestock manure, sewage sludge, food waste, and waste wood are decomposed by microorganisms, methane, carbon dioxide, hydrogen sulfide, ammonia, and other gases are produced. Removing impurities to extract pure methane results in bio methane. Reforming bio methane once more produces bio hydrogen.

The government plans to recognize bio hydrogen only when waste that has no other utilization options is used. If the waste can be used in other ways, such as compost or liquid fertilizer, it will be difficult to recognize it as bio hydrogen.

To be certified as clean hydrogen, the process includes equipment inspection → application for certificate issuance → on-site inspection. Equipment inspection involves the operator submitting an application and receiving a clean hydrogen equipment confirmation certificate through on-site equipment inspection. Afterward, the operator applies for certificate issuance with supporting documents for quantity, and the certificate is issued after an on-site inspection based on six months of operational data.

The final decision on Clean Hydrogen Certification is made by the Certification Review Committee. A working council will be established under the Certification Review Committee.