Recently, as a pilot project for a new type of power system in Zhejiang Province in 2023, the State Grid Zhejiang Electric Power Co., Ltd. built a new zero-carbon substation in Huzhou Anji Development Zone, the first large-scale commercial application of carbon sequestration  ready-mixed concrete with carbon capture and storage attributes in China. It is estimated that every 1m³ of carbon sequestered ready-mixed concrete used in this project will reduce carbon emissions by more than 20% compared to traditional products. This application not only creates the “first”of CO2 mineralization technology in the State Grid system, but also realizes a breakthrough of CCUS (Carbon Capture, Utilization and Storage) technology in the field of ready-mixed concrete in China.

First CO2 Mineralization Utilization Ready-Mixed Concrete Demonstration Base

Annual storage of 3,000 tons of CO2  

Starting from 2022, a joint research and development team of a CCUS scientific and technical corporation named Clean CO2 and the State Key Laboratory of Clean Energy Utilization of Zhejiang University cooperated with a concrete mixing plant in Huzhou, Zhejiang Province, to establish a CO2 mineralization utilization ready-mixed concrete demonstration base, and carried out a series of preliminary research and production demonstration of carbon sequestration ready-mix concrete. The goal is to use ready-mixed concrete and its products as the carrier to achieve permanent solidification and storage of CO2 to solve the increasingly serious problem of climate change. The carbon sequestration ready-mixed concrete used in the construction of the zero-carbon substation came from this base.

According to the relevant technical personnel, the principle of producing carbon sequestration ready-mixed concrete is to take ordinary ready-mixed concrete as a carrier, and inject the CO2 captured from industrial sources into it, and the injected CO2 goes through the process of microcrystalline mineralization and is permanently sequestered in the concrete, and at the same time, it improves the working performance of the concrete and improves the compressive strength.

“The benefits of sequestering CO2 in ready-mixed concrete are twofold: on the one hand, CO2 is introduced to form a carbonation product, which is permanently sequestered once the concrete sets and hardens; on the other hand, the carbonation product fills the concrete’s micro-pore spaces and improves its pore structure, making it stronger. This means that to achieve the same compressive strength, the amount of cement used can be reduced by 5 to 10 percent, which offsets the extra cost of carbon. This ‘eco-friendly’ concrete has both economic and environmental benefits, and in the future could generate additional carbon tax value.”

In the demonstration base, technicians have upgraded the raw material formula and production equipment of ready-mixed concrete through their independently researched and developed “CO2 Microcrystallization Mineralization Technology System for Ready-Mixed Concrete”. At present, the demonstration production line can produce 800,000 cubic meters of carbon sequestration ready-mixed concrete annually, which can meet the needs of different types of products such as C20~C50. The production line can reduce carbon by about 59,000 tons a year compared with the traditional process, and achieve about 3,000 tons of CO2 sequestration and utilization per year.

Reducing Implicit Carbon, CCUS Technology Achieves Breakthrough in Ready-Mixed Concrete

This application of Clean CO2 innovative decarbonization technology is a direct method of reducing the implicit carbon of construction or the carbon emissions from production and transportation of building materials. The technology can be retrofitted into concrete mixing plants without disrupting operations and integrates seamlessly with existing batching processes. With this technology, builders, engineering contractors, developers can reduce implicit carbon in buildings without sacrificing the building quality.

In this project, CTI Huace, an authoritative testing organization, issued a carbon footprint report of carbon sequestered ready-mixed concrete with CCUS technology in strict accordance with “PAS 2050:2011 Specification for Evaluation of Greenhouse Gas Emissions from Goods and Services over their Life Cycle.”The report shows that compared with the ready-mixed concrete produced by the traditional process recorded in the Ecoinvent 3.9.1 database, it can reduce nearly 70kg of carbon dioxide per cubic meter, which is equivalent to reducing more than 20% of the carbon emissions during the production stage.

The large-scale commercial application of carbon sequestration  ready-mixed concrete in the construction of zero-carbon substations means that CCUS technology has made a breakthrough in the direction of ready-mixed concrete, and has opened up the “carbon peaking and carbon neutrality goals” industrial chain of energy, industry and construction industries. This provides more possibilities for the development of CCUS technology and industrialization layout, and will also add a new path for the reduction of implicit carbon in buildings in the future.

National Grid Zero-Carbon Substation Applies Carbon Sequestration Ready-Mix Concrete

It is understood that the Anji Chengbei substation, of which the construction is prepared by State Grid Zhejiang Electric Power Company Huzhou Power Supply Company, is a pilot project of new power system in Zhejiang Province in 2023.Through the carbon sequestration of ready-mixed concrete technology, BIPV photovoltaic integration wall panel technology, CO2 environmentally friendly gas GIS technology, etc. it will be created into a zero-carbon demonstration project of the State Grid power system.

According to Jin Ye，the Huzhou Anji Chengbei 110 kV substation project owner project manager, “To ensure the successful application of carbon sequestration ready-mixed concrete in the project, the joint R & D team of Zhejiang University and Clean CO2, together with engineers and technicians from the State Grid Zhejiang Provincial Electric Power Co., Ltd. Economy & Technology Research Institute and the Huzhou Power Supply Company have done a lot of tests and demonstrations for product performance and other aspects in the early stages. The successful application of this technology also has a certain demonstration significance for the future application of carbon sequestration concrete technology in the Power Grid system and other infrastructure facilities”.