A large amount of carbon dioxide is emitted during the cement production process. However, the demand for housing and public buildings in most major cities around the world is still growing. This trend is contrary to the international consensus on reducing greenhouse gas emissions. How to reduce carbon dioxide emissions in the cement industry has become a The focus of attention from all walks of life.
Startup Synhelion uses photovoltaics to produce cement clinker. Pictured here is a mirror that concentrates solar radiation onto Synhelion's solar tower receiver. Image source: synhelion
According to statistics from the American management consulting firm McKinsey, about 7% of global man-made carbon emissions come from the cement industry, making cement one of the industries with the highest carbon emissions among heavy industries. Claude Loréa, head of the Cement Innovation and Environmental, Social and Corporate Governance (ESG) Department of the Global Cement and Concrete Association (GCCA), said that even by 2050, three-quarters of the world's public construction will still be waiting for construction. Construction, the consumption of cement is expected to continue to grow.
The Wall Street Journal explained that the cement currently widely used in various countries is Portland Cement. During the cement production process, clay, limestone and other raw materials are first ground into raw meal, and then about The raw material is put into the cement kiln at a high temperature of 1500°C to make clinker. The cement manufacturer will finally grind the clinker and mix it into common clinker by adding silica sand, furnace stone, water and other substances. Tran Cement.
The newspaper further pointed out that 90% of the carbon dioxide currently produced by the cement industry is released during the clinker burning stage, of which carbon dioxide released by heating limestone accounts for about 2/3, and the remaining 1/3 is produced when coal mines are burned.
Considering the considerable amount of carbon dioxide produced during the cement manufacturing process, some cement and building materials industries have begun to seek channel changes at this stage. The "Wall Street Journal" and other foreign media introduced four cement carbon reduction methods tried by the industry: "improving energy efficiency", "using clean energy", "alternative raw materials" and "carbon capture technology", hoping to effectively reduce carbon emissions. and achieve the 2050 net-zero emissions target.
Improving efficiency: using artificial intelligence to reduce cement carbon emissions
Carbon Re, a British artificial intelligence (hereinafter referred to as AI) materials science start-up, uses AI and machine learning (ML) algorithm analysis to accelerate the decarbonization efficiency of cement and other building materials, thereby optimizing the cement industry process and fuel use.
Carbon Re co-founder Adian O'Sullivan said that the main problem facing the cement industry is the waste of fuel. In particular, most cement production plants use excessive or varying quality coal to produce clinker. It will cause the emission of large amounts of carbon dioxide.
According to Carbon Re's official website, the startup mainly uses AI digital twin mode to analyze the control systems of cement kilns and related equipment. It uses this digital analogy process to determine the "minimum fuel" value of the cement production system. Consumption, maximum output" optimal parameters.
"The application of AI in the cement industry has been relatively slow. However, the AI machine deep learning (DL) used by Carbon Re can effectively improve the operational efficiency of cement plants and provide clearer process operation suggestions for factory operators. The most important thing is Energy consumption and carbon dioxide emissions will be significantly reduced throughout the production process," O'Sullivan wrote on the company's official website.
O'Sullivan gave another example. As long as each cement factory can reduce fuel consumption by 2%, the world will have the opportunity to reduce millions of tons of carbon emissions. If the AI model can be further applied to account for about 10% of the total carbon emissions, The heavy industry of 20% will be a great benefit to the reduction of global energy consumption and carbon emissions.
New fuel: Solar energy can also produce cement clinker
Germany's "PV Magazine" pointed out that Synhelion, a Swiss-based solar startup, has cooperated with Mexican building materials supplier Cemex to jointly build high-concentration solar receivers in Madrid, Spain starting in 2022, in order to produce various Cement clinker containing fossil fuels.
Synhelion CEO Gianluca Ambrosetti explained that solar receivers can provide enough heat energy to produce concrete clinker. The principle of operation is to install mirrors on relevant equipment to reflect sunlight. When the light is concentrated on Synhelion’s solar receivers Once topped, the cement kiln can be heated to approximately 1,482°C, producing clinker without the use of fossil fuel heating. "
The company further clarified: "Traditional clinker is usually produced in cement rotary kilns at 1500°C, which not only consumes a lot of energy but also emits a large amount of carbon dioxide during the process. However, the technology jointly developed by Synhelion and Cemex can produce highly clinker The remaining carbon dioxide is effectively separated and captured during the calcination process, and no additional steps are required to deal with carbon emissions.”
"Solar Energy Magazine" revealed that Synhelion and Cemex have also recently received US$3.2 million (approximately NT$100.2 million) in funding support from the US Department of Energy (DOE), hoping to develop a more efficient thermal energy storage system and accelerate its mass production process, 2 The company aims to achieve commercial mass production of cement clinker made from solar energy by 2030.
New Materials: Developing the world’s first negative carbon emission technology using “natural materials”
According to the U.S. news website Quartz, Bahamian startup Partanna broke away from the traditional building materials model of using Portland cement as a cementitious adhesive and instead developed a carbon negative (Carbon Negative) Building materials, this kind of adhesive allows buildings to continue absorbing carbon throughout their life cycle, similar to the carbon sequestration ability of trees.
"Quartz Finance Network" stated that the technology developed by Partanna is the first of its kind in the world. The binder is a new type of cement made from a combination of brine produced in desalination plants and slag produced in the steel refining process.
Partanna co-founder and CEO Rick Fox said that when carbon dioxide comes into contact with a natural mixture of brine and slag, it can be processed to form a binder that is as useful as traditional cement. "We cure the mixture at normal room temperature, so there is no excess heat generated during the cement production process," Fox said.
In addition, the adhesive strength of traditional concrete will gradually weaken after long-term exposure to seawater. However, because Partanna adhesive uses brine as a raw material, the adhesive strength of this material after being affected by seawater is 25% higher than that of traditional cement. It is expected that this building material will help Protect low-lying coastal areas from the impact of climate change.
Fox, who was born in the Bahamas, said: "Hurricane Dorian that struck in 2019 caused serious damage to my hometown of the Bahamas, so I believe that areas most vulnerable to the effects of climate change need this kind of rugged building materials to keep the people of the Bahamas safe.”
Partanna's official website also emphasizes that a 1,250-square-foot house built with brine adhesive is expected to remove 182.6 tons of carbon dioxide from the atmosphere, equivalent to the annual carbon absorption of 5,200 mature trees. Partanna is also cooperating with the Bahamian government. Currently, about 1,000 houses in the country are built with this brine adhesive. At the same time, Partanna is also discussing with hoteliers in Las Vegas in the United States to use this new cement in future construction projects. possibility.
Carbon capture and storage: 400,000 tons of cement carbon emissions are transported to the seabed for storage
The International Energy Agency (IEA) pointed out that carbon capture, utilization and storage technology (hereinafter referred to as CCUS) is an important means to reduce carbon emissions in the cement industry. It is estimated that before the end of 2030, 8% of the carbon dioxide produced by the global cement industry will need to be Effective storage, however, the cement industry’s current investment in CCUS has not yet been fully implemented, and the research and development of related technologies is also progressing slowly.
Faced with this urgency, Heidelberg Materials, a listed German building materials company, stated that it has begun to build an undersea CCUS facility and uses amine absorption to capture the carbon dioxide produced in the cement production process. It will then use the captured carbon dioxide to The carbon dioxide is compressed into liquid and sent to the subsea pipelines of partner Norwegian oil companies Equinor, Shell and Total Energies, and finally transported to the seabed near Bergen, Norway, for permanent storage.
The Wall Street Journal stated that Heidelberg Materials, the world's largest cement manufacturer, expects to have the opportunity to officially put CCUS into cement production at the end of 2024. After full operation, it is estimated that it can absorb about 400,000 tons of carbon dioxide per year. The capture and The storage capacity will make the seabed around Bergen, Norway, where carbon dioxide is stored, the world's first large-scale CCUS site run by the cement industry.
Christoph Beumelburg, chief public relations officer at Heidelberg Materials, said: "The cement industry currently has considerable decarbonization potential, and if the industry wants to effectively solve the problem of excessive carbon dioxide emissions, then CCUS is definitely something we need to consider. technology.”
※ This article is reprinted from "Key Comment Network" with authorization. The original title is "European and American startups create "zero-carbon cement": using AI to accelerate decarbonization, solar energy to produce cement clinker, and develop negative carbon emission building materials". CC co-creation licensing terms do not apply.
References:
1. Wall Street Journal (August 24, 2023), Building Green: New Technologies to Create Less Polluting Cement
2.PV Magazine (August 7, 2023), Synhelion starts building solar tower for cement production
3.Quartz (October 20, 2023), The Bahamas is introducing the world's first carbon-negative construction tech
4. Carbon Re (April 7, 2022), How AI is helping cement plant operators reduce energy consumption and carbon emissions
Source: Environmental Information Center
