CCUS Technologies

With the increasing prevalence of global warming and extreme weather conditions, achieving net-zero carbon emissions by 2050 has become a major global focus. The world needs to cut greenhouse gas emissions in half by 2030 and achieve net-zero emissions by the middle of this century. In light of this goal, the Taiwanese government has begun promoting the transition to net-zero by evaluating and planning potential pathways to achieve this target. In its 2020 Energy Technology Outlook report, the International Energy Agency (IEA) identified Carbon Capture, Utilization, and Storage (CCUS) as one of the key technologies on the path to achieving net-zero emissions worldwide.

The initial focus of CCUS was on retrofitting existing fossil fuel-based power plants and factories, as well as low-cost opportunities for CO₂ capture such as hydrogen production. The contribution of CCUS to achieving net-zero emissions depends primarily on technological progress, and the maturity of CCUS technologies varies depending on the type and application of the technology. Several mature technologies are currently available and can be rapidly scaled up in applications such as coal-fired power generation and hydrogen production, while other technologies require further development and advancement.

Carbon capture is one of the industrial processes for separating or capturing CO₂ from flue gas emissions, and has been commercialized for several decades. The most advanced and widely adopted capture technologies are chemical absorption and physical separation, while other technologies include membranes, chemical looping, and calcium looping. CCUS is an effective means of handling greenhouse gas emissions in the power sector's transition to net-zero, and can be used not only to address emissions from existing assets, but also to provide cost-effective production methods for rapidly expanding the production of low-carbon hydrogen. In recent years, over 30 commercial CCUS facilities have been announced globally, including in Europe, America, Australia, Asia, with a potential investment of around $27 billion, which is more than twice the planned investment amount in 2017.

Carbon utilization refers to the process of using carbon dioxide as a raw material for products or services with potential market value. The scope of its application depends on whether it requires chemical transformation or not, and the process can be categorized as transformation (after chemical transformation) or non-transformation (without chemical transformation). Currently, around 230 million tonnes of carbon dioxide are utilized globally each year, with the largest consumer being the fertilizer industry, which uses 125 million tonnes of CO₂ annually for urea production. The oil and gas industry are the second largest consumer, using approximately 70 to 80 million tonnes of CO₂ annually for enhanced oil recovery (EOR). Other commercial uses of CO₂ include food and beverage production, cooling, water treatment, and greenhouse use for plant growth stimulation.

Carbon capture and storage (CCS) is the process of injecting captured carbon dioxide into deep underground sealed spaces or porous rock formations covered by impermeable rock layers, in order to store and sequester carbon dioxide, with the cap rock layer acting as a barrier to prevent upward migration of the CO₂ and leakage into the atmosphere. According to the Global CCS Institute (GCCSI) report in 2021, there are currently 65 commercial CCS facilities worldwide, with 26 of them operational, sequestering 40 million tonnes of CO₂ annually, and another 39 facilities in construction or planning, including 17 CCUS projects for power plants and 34 CCS demonstration facilities.