cement production, but the demand for housing and public buildings in most major cities around the world is still growing, which is contrary to the international consensus on reducing greenhouse gas emissions. How to reduce carbon dioxide emissions in the cement industry has become the focus of attention.
According to statistics from McKinsey, an American management consulting company, about 7% of the world's man-made carbon emissions come from the cement industry, which makes cement one of the industries with the highest carbon emissions in heavy industry. Claude Lor Loréa, head of cement innovation and environmental, social and corporate governance (ESG) at 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, and cement use is expected to continue to grow.
The Wall Street Journal explained that Portland Cement, which is widely used in various countries, is made by grinding clay, limestone and other raw materials into raw materials. The raw material is then placed in a cement kiln at a high temperature of about 1500 ° C. Cement producers then grind the clinker and mix it into common Portland cement by adding silica sand, hearthstone and water.
The newspaper further pointed out that 90% of the carbon dioxide produced by the cement industry is released in the clinker burning stage, of which about 2/3 is released by limestone heating, and the remaining 1/3 is produced by coal combustion.
Considering the considerable amount of carbon dioxide produced in the cement 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 several cement carbon reduction methods tried by the industry, such as "improving energy efficiency", "using clean energy" and "alternative raw materials", hoping to effectively reduce carbon emissions and achieve the 2050 net zero emission target.
01 Improve efficiency: Use artificial intelligence to reduce carbon emissions
from cement Carbon Re, a British artificial intelligence (AI) material science start-up, uses AI and machine learning (ML) algorithm analysis to speed up the decarburization efficiency of cement and other building materials, so as to optimize the cement industry process and fuel use.
Carbon Re co-founder O'sullivan (Adian O 'Sullivan) said that the main problem facing the cement industry is the waste of fuel, especially the fact that most cement production plants use excessive or uneven quality of coal to produce clinker, which results in a large amount of carbon dioxide emissions.
According to the official website of Carbon Re, the new company mainly uses AI Digital twin model to analyze the control system of cement kiln and related equipment, and uses this digital simulation process to give the best parameters of "minimum fuel consumption and maximum output" of cement production system.
"The application of AI in the cement industry has been slow, but 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 plant operators." The most important thing is that energy consumption and carbon dioxide emissions will be significantly reduced throughout the production process. O'Sullivan wrote on the company's website.
O'Sullivan also cited as an example that as long as each cement plant 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 heavy industry, which accounts for about 20% of the total carbon emissions, it will be a great benefit to the reduction of global energy consumption and carbon emissions.
02 New fuel: Solar energy can also produce cement clinker
. According to German Solar Energy Magazine (PV Magazine), Synhelion, a Swiss-based solar start-up company, has cooperated with Cemex, a Mexican supplier of building materials. Since 2022, they have jointly built highly concentrated solar receivers around Madrid, Spain, to produce cement clinker without fossil fuels.
The synhelion company uses photovoltaics to produce cement clinker. Mirrors concentrate solar radiation onto synhelion's solar tower receiver. Gianluca Ambrosetti, executive director
of Synhelion, explained that the solar receiver can provide enough heat to produce concrete clinker, and its working principle is to install mirrors on the relevant equipment to reflect sunlight. When the light is concentrated on top of Synhelion's solar receiver, it heats the cement kiln to about 1482 ° C, producing clinker without the use of fossil fuel heating.
The company further explained that traditional clinker is usually produced in cement rotary kilns at 1500 ° C, which not only consumes a lot of energy but also emits a lot of carbon dioxide in the process. However, Synhelion and Cemex jointly developed this technology can effectively separate and capture the residual carbon dioxide in the process of high clinker calcination. And doe not need to perform other step to additionally treat that carbon emission in the middle. Synhelion and Cemex have also recently received $3.2 million in funding from the U.S. Department of Energy to develop more efficient thermal energy storage systems and accelerate their mass production, according to
Solar Energy Magazine. The two companies aim to achieve commercial mass production of cement clinker made from solar energy by 2030.
03 New Materials: Developing the World's First Negative Carbon Emission Technology
with "Natural Substances" According to Quartz, a US news website, Partanna, a Bahamian start-up company, breaks away from the traditional building material model of using Portland cement as a cementitious binder. Instead, a Carbon Negative building material has been developed, which can make buildings absorb carbon continuously throughout their life cycle, similar to the carbon sequestration ability of trees. According
to Quartz Financial Network, the technology developed by Partanna is the first in the world. The binder is a new type of cement made from Brine produced by desalination plants and slag produced in the process of steel refining. Rick Fox, co-founder and CEO
of Partanna, said that when carbon dioxide comes into contact with a natural mixture made from brine and slag, it can be processed into a binder that is as useful as traditional cement. "We cure the mixture at normal room temperature, so there is no excess heat generated even during the production of cement." Fox said so.
In addition, the adhesion strength of traditional concrete will gradually weaken after long-term exposure to seawater, but because Partanna adhesive uses brine as raw material, the adhesion strength of this material is 25% higher than that of traditional cement after being affected by seawater. It is expected that this building material will help low-lying coastal areas to withstand the impact of climate change. Fox, who
was born in the Bahamas, said: "Hurricane Dorian in 2019 has brought great damage to my native Bahamas, so I believe that the areas most vulnerable to climate change need this strong building material to keep the Bahamian people safe."
Partanna's official website also emphasizes that a 1,250-square-foot house built with brine adhesives 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 working with the Bahamian government, which currently has about 1,000 houses built with the brine adhesive, and is discussing the possibility of using the new cement in future construction projects with hotel operators in Las Vegas.
