The cement industry is an important basic raw material industry in China. Cement is widely used in civil engineering, water conservancy engineering and other fields, playing an important role in improving people’s livelihoods and promoting national economic construction. China is the world’s largest producer and consumer of cement, maintaining the top spot in the world for over a decade. According to statistics, the national cement production will reach 2.023 billion tons in 2023, accounting for 49.68% of the global total production.

Cement production consumes a large amount of coal, electricity, and limestone raw materials, making it one of the industries in China with high energy consumption and carbon emissions. It is also the industry with the largest carbon emissions in the building materials industry. In 2020, the total carbon dioxide emissions from China’s building materials industry were 1.48 billion tons, of which the direct carbon dioxide emissions from the cement industry were 1.23 billion tons, accounting for 83.11% of the total carbon emissions from the building materials industry and 12.4% of the national total carbon emissions.

Development prospects of CCUS in the cement industry

Carbon dioxide capture, utilization, and storage (CCUS), as a key technology that can achieve deep reduction and resource utilization of carbon dioxide, has attracted worldwide attention. Given that China’s energy structure is dominated by high carbon, with significant carbon emissions from industrial manufacturing, vigorously promoting CCUS technology for pollution reduction, carbon reduction, and end of pipe carbon sequestration will provide strong support for China’s ecological civilization construction and achieving carbon peak and carbon neutrality goals.

The carbon emissions from cement burning are high, and CCUS is not only an inevitable choice for the cement industry to achieve carbon neutrality goals, but also an urgent need for development. In recent years, driven by the dual carbon goals, the government has increased systematic support for CCUS, promoting its development from multiple perspectives such as policy, technology, industry, standards, and finance. The cement industry has also actively promoted the construction of CCUS projects and achieved a series of important progress and results. However, due to the complex composition of cement kiln flue gas, large amount of dust, and low concentration of carbon dioxide, CCUS has few project application cases in the cement industry, and there are problems such as high production and operation costs and difficulty in promoting technology.

Carbon dioxide capture, utilization, and storage (CCUS)

The China Building Materials Federation conducted research on the current status of CCUS technology in the cement industry both domestically and internationally, and used the month on month method to weight evaluate the main factors affecting technology application, and made a comprehensive report. The results indicate that technological maturity, policy support, and project profitability are currently the three most concerning aspects in the cement industry. The report predicts that under the carbon neutrality scenario by 2060, there will still be approximately 270kgCO₂/t of carbon emissions per unit of cement that need to be achieved through CCUS, and the layout of CCUS in the cement industry needs to be accelerated.

Introduction to Carbon Capture, Utilization, and Storage (CCUS)

Carbon dioxide capture, utilization, and storage (CCUS) refers to the process of separating carbon dioxide from industrial processes, energy utilization, or the atmosphere, and directly utilizing or injecting it into geological formations to achieve permanent reduction of carbon dioxide (CO₂) emissions. CCUS adds “Utilization” (U) to Carbon Capture and Storage (CCS), and is mainly divided into capture, transportation, utilization, and storage stages according to the technical process.

Carbon dioxide capture technology refers to the process of separating and capturing carbon dioxide from industrial production, energy utilization, or the atmosphere. It is a key link in the CCUS technology system and also a significant energy and cost consuming component. The carbon capture methods mainly include pre combustion capture, during combustion capture, and post combustion capture. Among them, common methods for capturing after combustion include chemical absorption, physical adsorption, adsorption separation (temperature swing adsorption and pressure swing adsorption), membrane separation, calcium cycling, and low-temperature distillation.

Carbon dioxide transportation refers to the process of transporting captured or purified carbon dioxide to designated locations such as usable or storage sites through highways, railways, ships, pipelines, etc. It is an intermediate link in the CCUS technology system. Considering the advantages and disadvantages of different transportation methods, the transportation of CCUS projects needs to be comprehensively considered from the aspects of transportation capacity, transportation distance, transportation cost, market factors, and transportation layout along the transportation route.

Carbon dioxide utilization refers to the process of using captured carbon dioxide through engineering techniques to achieve resource utilization. The main utilization methods include:

1.Physical Utilization

Mainly used in industries such as food, refrigeration, foam materials, welding, etc. For example, in the food industry, carbon dioxide is used as an additive in carbonated beverages, beer, and as a refrigerant (dry ice) in the cold chain transportation of food; In the field of foam materials, carbon dioxide is used as a foaming agent to produce extruded board insulation materials; In the field of metal processing, carbon dioxide is used as an inert gas for welding. However, the utilized carbon dioxide will eventually be emitted into the atmosphere.

2.Chemical utilization

Chemical utilization refers to the use of carbon dioxide as raw material, which undergoes chemical reactions with other substances to produce high-value chemical products. Currently, carbon dioxide is widely used as a chemical raw material in various production processes. Industrial synthesis gases such as methane, alcohols (such as methanol, ethanol, etc.), ethers (such as dimethyl ether), organic acids (such as formic acid), and low-carbon alkanes can be synthesized through hydrogenation. In addition, carbon dioxide is also used to produce bulk inorganic chemical products such as soda ash, baking soda, white carbon black, borax, and various metal carbonates. However, some chemical products may still release carbon dioxide again due to chemical reactions during subsequent applications.

3.Mineralization utilization

Mineralization utilization refers to the process of using bulk solid waste rich in calcium and magnesium (such as steelmaking slag, cement kiln ash, fly ash, phosphogypsum, etc.) to chemically absorb and convert carbon dioxide into stable inorganic carbonates, while achieving carbon dioxide reduction and obtaining inorganic building material products with certain value, in order to improve the economic efficiency of resource utilization of carbon dioxide and solid waste.

4.Biological utilization

Biological utilization mainly refers to the fixation of carbon by organisms, utilizing the photosynthesis of plants in the ecosystem to absorb carbon dioxide. At present, research mainly focuses on microalgae carbon sequestration and the use of carbon dioxide gas fertilizer in crops. At present, microalgae carbon sequestration technology mainly uses microalgae to fix carbon dioxide and convert it into liquid fuels, chemicals, biofertilizers, food and feed additives, etc., achieving artificial carbon cycling through microalgae carbon sequestration. The carbon dioxide gas fertilizer technology for crops is to regulate the carbon dioxide captured from energy and industrial production processes to a certain concentration and inject it into greenhouses to enhance crop photosynthesis rate and increase crop yield.

5.Geological utilization

Mainly using carbon dioxide to drive oil/gas (petroleum/coalbed methane, natural gas, shale gas, etc.). Carbon dioxide oil/gas displacement is a technology that injects carbon dioxide into oil layers (or coal seams) to improve oil and gas recovery. Its main purpose is to maximize oil and gas recovery, rather than storing carbon dioxide. Although a portion of carbon dioxide is permanently stored in pore spaces that previously contained hydrocarbons after oil/gas displacement, the amount of carbon dioxide stored is small, the storage time is short, and it may leak out from drilling. Therefore, carbon dioxide driven oil/gas can only be seen as a process of partially absorbing carbon dioxide.

Carbon dioxide sequestration is the process of injecting captured carbon dioxide into deep geological reservoirs through certain technological means, isolating them from the atmosphere for a long time or permanently, in order to achieve carbon reduction. The sequestration methods mainly include geological sequestration and oceanic sequestration:

1.Geological storage

Geological storage is the process of compressing captured carbon dioxide (with a critical pressure of no less than 74 bar for CO₂, typically 100 bar or higher, to provide appropriate safety margin and consider pressure drop in pipelines) and storing it in geological structures at a depth of at least 800 meters (currently mainly saline, oil and gas reservoirs, coal seams, and shale gas reservoirs) to achieve long-term or permanent isolation from the atmosphere. Currently, oil and gas reservoir storage is mainly used.

2.Ocean storage

There are two main ways of ocean storage: “dissolution type” ocean storage and “lake type” ocean storage. Dissolved ocean storage is the process of injecting carbon dioxide into deep ocean layers (more commonly below 1000m depth) through fixed pipelines or mobile vessels and dissolving it into the water; Lake type ocean storage is the process of injecting carbon dioxide into the seabed through fixed pipelines or coastal platforms installed at depths below 3000m, causing it to settle. In its initial state, carbon dioxide is deposited in liquid form on the seabed. Due to its higher density than water, it forms a “lake” that slows down the decomposition and diffusion of carbon dioxide into the surrounding environment.

Carbon dioxide capture, utilization, and storage (CCUS) positioning

The evolution of CCUS technology positioning in various assessment reports of the Intergovernmental Panel on Climate Change (IPCC) can be roughly divided into three stages, from the initial “feasible solution” to “key technology”, and now to “indispensable”, gradually clarifying the criticality and importance of CCUS technology in achieving carbon neutrality goals in various fields.

With the development of CCS technology and the continuous deepening of understanding, China first proposed the technology of carbon dioxide capture, utilization and storage at the Xiangshan Conference in Beijing in 2006, introducing the technology of carbon dioxide resource utilization. Driven by the dual carbon goals, with the emergence of new application scenarios and the increasing demand for deep emission reduction, the connotation and extension of CCUS technology have been enriched and expanded. China’s positioning of CCUS technology is also constantly being re examined and adjusted, and it has evolved from a carbon reduction reserve technology to a carbon neutral key carbon reduction technology.

Carbon dioxide capture, utilization and storage (CCUS) policy

1.International Policy

To promote the research and development of CCUS technology and project construction, the United States, the European Union, and Canada have established a “four in one” CCUS support policy system in industrial development, technology research and development, standard specifications, and funding taxation, effectively promoting the research and development innovation and construction application of CCUS technology. Among them, tax credits, direct financial support, and carbon tax and other financial support policies have played an important role in the early construction of CCUS projects.

(1) United States

The United States is a global leader in the field of CCUS, mainly due to its strong support for CCUS technology research and application in terms of finance and taxation. Since 2008, the United States has provided tax credits for carbon dioxide sequestration (45Q tax credits) through Section 45Q of the Internal Revenue Code. In 2018, the US government increased its support for CCUS projects, implementing a higher 45Q tax credit, providing a tax credit of $35 per ton for projects implementing carbon dioxide flooding, and a tax credit of $50 per ton for projects storing saline aquifers. In August 2022, the United States enacted the Inflation Reduction Act (IRA), further enhancing the 45Q tax credit policy: increasing the tax credit for industrial CCS from $35 per ton to $60 per ton, and increasing the tax credit for geological storage CCS from $50 per ton to $85 per ton; And provide high subsidies for Direct Air Capture (DAC) projects, increasing the tax credit for CCS captured and stored directly from the atmosphere from $50 per ton to $180 per ton. The 45Q tax credit policy accelerates the deployment of CCUS projects.

(2) The European Union

The EU is at the forefront of institutionalizing and standardizing CCUS globally. In 2009, the European Union formulated the “Carbon Dioxide Capture and Storage Directive” (2009/31/EC), which is the world’s first law on CCS. It provides clear requirements for the transportation, storage site selection, exploration and storage permit issuance, carbon dioxide monitoring, and information disclosure of carbon dioxide. The European Union’s Emissions Trading System (EU-ETS) is the world’s first regional and mandatory carbon trading system. During the third phase (2013-2020), the European Union included capture, pipeline transportation, and geological storage of carbon dioxide projects in the system and treated them as emission reductions (ERUs) under the Joint Implementation Mechanism (JI) projects. The EU also supports the research and deployment of CCUS through multiple R&D funding programs: on the one hand, it provides financial support for CCUS projects through the Innovation Fund. In November 2022, the European Commission will increase the size of the Innovation Fund to 3 billion euros. On the other hand, the development of CCUS technology is being promoted through the research funding program “Horizon Europe”, which provided 32 million euros and 58 million euros in funding support for CCUS technology research and development in 2021 and 2022, respectively.

(3) Canada

In order to encourage private investment in CCUS projects, Canada has vigorously promoted the development of CCUS through measures such as carbon emission pricing, investment tax credits, and Clean Fuel Regulations (CFR) that require a reduction in fuel emission intensity. In November 2020, the Canadian government announced a 10-year, $150 million Low Carbon and Zero Emission Fuel Fund to support the development of clean energy technologies such as CCUS. In addition, the Canadian government has announced that by 2030, equipment costs for carbon dioxide capture projects can receive a maximum of 50% tax credit. In 2021, the Supreme Court of Canada passed the Greenhouse Gas Pollution Pricing Act of 2018, raising the carbon tax from CAD 40 per ton in 2021 to CAD 170 per ton in 2030. The high carbon tax and strict environmental policies have driven companies, especially oil and gas companies, to actively develop CCUS projects. In terms of carbon market, the Alberta carbon market in Canada is also the carbon market with the most CCUS projects included internationally. CCUS projects can be certified through the Alberta Emissions Offset System (AEOS), issuing certified emission reductions, and offsetting carbon emissions in the Alberta carbon market.

2.China Policy

After the proposal of China’s “dual carbon” target, various ministries and localities have successively introduced a series of policies around the goal of carbon peak and carbon neutrality, and built a “1+N” policy system to provide systematic support for CCUS technology from various aspects such as scientific and technological research and development, demonstration applications, financial subsidies, green finance, and standard specifications. Although there are no tax reduction policies nationwide, some provinces and cities have taken the lead in introducing subsidy measures. For example, Shenzhen can provide up to 10 million yuan in funding for CCUS demonstration projects, with a subsidy of 20 yuan per ton of carbon dioxide after production. The People’s Bank of China has created a “carbon emission reduction support tool”, and commercial banks can obtain funds from the People’s Bank of China to provide green financial support for eligible CCUS demonstration projects. For example, Sinopec Qilu Petrochemical Shengli Oilfield Million ton CCUS Project has received green loan services from China Construction Bank.

At present, most of China’s relevant policies focus on the research and development, pilot application, and accelerated standard development of CCUS related technologies, and are relatively weak in supporting the infrastructure construction of CCUS projects. This is mainly because China’s CCUS industry is still in its infancy, and compared with developed countries, the technological development time is relatively short, and the overall technological level is relatively low.

Overview of Carbon Capture, Utilization, and Storage (CCUS) Project

1.Overview of Global CCUS Projects

At the global level, as of March 2024, there are 564 CCS/CUS projects in different stages worldwide, of which 43 have been put into operation with an annual capture capacity of 50.39 million tons; 33 projects under construction with an annual capture capacity of 34.52 million tons; 488 development projects with an annual capture scale of 340 million tons; The total annual capture capacity is 420 million tons, an increase of 75% compared to 2022. From the perspective of project carbon sources, the energy industry such as oil and gas production is the main source of carbon sources for operating projects, accounting for about 60%; The carbon sources of projects under construction and planning are mainly industrial and power generation, accounting for about 70%. From the perspective of project carbon sinks, the main source of carbon sinks in operating projects is oil and gas reservoirs that use carbon dioxide to enhance oil recovery, accounting for about 70%; The carbon sink of ongoing and planned projects is mainly carbon dioxide geological storage, accounting for nearly 80%. In terms of regional distribution, the most common is in the Americas, followed by Europe.

At the national level, the United States is currently the country with the most CCUS projects in the world. The CCUS project involves multiple industries such as cement manufacturing, coal-fired power generation, gas-fired power generation, waste to energy generation, and chemical industry, with a total of 154 projects at different stages of development, of which half are in operation worldwide. This is mainly due to the policy support of the United States for CCUS technology, which has received widespread support from the business, academic, and government sectors, forming a certain scale CCUS industry chain. EU member states are vigorously promoting the development of the CCS project industry chain, actively building industrial clusters and transportation facilities, and advancing the scale and commercialization of the CCS industry. At the same time, the EU has a significant leading advantage in CCUS related intellectual property. Currently, Germany, France, and other countries are the main sources of CCUS patents worldwide. CCUS patent applications mainly focus on the field of carbon dioxide capture, followed by carbon dioxide conversion utilization and geological utilization and storage, while patent applications in the field of carbon dioxide transportation are relatively few.

China’s CCUS projects cover multiple industries such as electricity, oil and gas, chemical, cement, and steel. Among them, the electricity industry has the largest number of demonstration projects, exceeding 20. Since 2022, the number of CCUS demonstration projects in industries such as cement and steel that are difficult to reduce emissions has gradually increased. As of August 2024, China has put 67 CCUS projects into operation, including 61 ongoing projects and 6 intermittent projects. The carbon dioxide capture capacity is about 7 million tons per year, the oil recovery and storage capacity is about 4.2 million tons per year, and the carbon utilization capacity is about 1.9 million tons per year. Carbon utilization or storage methods mainly include increasing oil recovery rate (EOR), mineralization utilization, chemical preparation, etc. EOR is the most important and technologically mature way of carbon utilization.

2.Overview of CCUS projects in China’s cement industry

China was the first country to carry out CCUS project demonstrations in the cement industry. Under the promotion of the dual carbon target, the cement industry in China is accelerating research and development around a series of CCU technologies, with a focus on carbon capture and utilization, and has achieved positive results.

(1) Hailuo Group Baimashan Cement Plant Cement Kiln Tail Gas Carbon Capture Project

The project was put into operation in 2018 and is the world’s first demonstration project for flue gas carbon dioxide capture and purification in the cement industry. It adopts chemical absorption method and is designed to produce 50000 tons of liquid carbon dioxide annually, including 30000 tons of food grade and 20000 tons of industrial grade. The total investment of the project is 57.75 million yuan, and a major science and technology special subsidy fund of 4 million yuan was obtained during the construction process. In 2021, Conch Group researched and developed a new generation of low consumption and high-efficiency carbon dioxide capture chemical absorbents for cement kilns, further reducing capture energy consumption to 2.1 GJ/t.CO₂.

(2) Qingzhou Zhonglian Cement CO2 Full Oxygen Combustion Enrichment and Purification Demonstration Project

The project will be put into operation in 2024, with an annual output of 200000 tons of carbon dioxide. It is currently the largest carbon capture and utilization project in China’s cement industry, including 150000 tons of industrial grade, 45000 tons of food grade, and 5000 tons of dry ice. The total investment of the project is about 260 million yuan. It adopts the technology of “full oxygen combustion+pressure swing adsorption concentration+variable temperature pressure swing adsorption purification+low-temperature distillation purification”, which can significantly increase the concentration of carbon dioxide in the flue gas, reduce the comprehensive energy consumption of capture to below 1.6GJ/t.CO₂, and significantly reduce operating costs.

(3) Jinyu North Water Environmental Protection Technology Carbon Dioxide Capture Demonstration Project

This project is the first domestic demonstration project for carbon capture and resource utilization in the collaborative disposal of complex flue gas environments in cement kilns. It produces 100000 tons of carbon dioxide annually and has a total investment of approximately 180 million yuan, of which about 10% comes from government and technology project subsidies.

Carbon dioxide capture, utilization, and storage (CCUS) standards

International standards

The ISO/TC 265 Technical Committee on Carbon Dioxide Capture, Transport, and Geological Storage of the International Organization for Standardization is responsible for developing international standards in the field of CCS, covering activities such as design, construction, operation, environmental planning and management, risk management, quantification, monitoring, and validation. At present, the committee has released 13 international standards, and there are 8 international standards under research. These standards mainly include technical guidance standards, quantitative verification standards, safety standards, operational design standards, monitoring and accident handling standards, management and responsibility standards, etc.

In summary, CCUS technology in China’s cement industry has initially entered the stage of commercial application, and will focus on cost reduction, industry chain stability, and cross industry fields in the future. It is expected that by 2060, the contribution of CCUS technology to carbon neutrality in the cement industry will exceed 50%. To promote the development of CCUS technology, it is recommended to carry out top-level planning and improve the project management system, strengthen the top-level design of standards, promote the connection with the carbon market, provide financing capacity and financial support, and strengthen international cooperation.