Why is traditional cement not sustainable?
The production of traditional Portland cement publishes CO₂ from several sources. Its main raw material, limestone, emits approximately 50% of the overall cocus when turning into clinker. Around 40% come from burning fuels to heat the oven, 5% come from electricity that are used in the system, and another 5% come from transport. Together, these factors make the traditional cement an important contribution to greenhouse gas emissions and a non -sustainable option for long -term use under construction.
What is green cement?
Green Cement is a sustainable type of cement that has been developed to reduce the environmental impact of traditional Portland cement. Instead of relying heavily on clinke, the most carbon-intensive component, the green cement replaces a significant part of it with additional cementary materials such as flight ash, ground granulated blast-vintage slag (GGBFS), silicon dioxide fume or metacolin. These materials are often industrial by-products, which reduces CO₂ emissions and the recycling of waste helps.
Existing and aspiring regulations for green cement:
Public order is gradually crucial for decarbonizing the cement industry. As a globally traded goods with tight profit margins, cement with economic hurdles for the introduction of low -carbon solutions looks like. Strong regulations and targeted incentives are crucial to tackle these obstacles and to accelerate the progress of the sector towards NET zero.
Stimulating demand for green cement
Problem: The market for low -carbon cement remains underdeveloped, since many construction companies and public authorities are still in traditional cement. This preference is powered by the lower price, the broad availability and familiarity of conventional products compared to newer green alternatives.
Political approach: The governments intervene according to procurement rules to create a predictable demand for low -carbon cement. These guidelines determine strictly embodied carbon limits for materials that are used in publicly financed projects to ensure that the contractors receive environmentally friendly options. You also need environmental products (EPDs) to check the actual performance, increase transparency and to account for suppliers.
Examples: US “Clean Clean” laws In California, Colorado and Washington, the carbon materials prioritize in public projects. Toronto mostly a maximum before 350 kg Coee / Kowal For buildings in city ownership. The US states –Buy state clean partnership It continues by offering preferred commandments and contract mechanisms to display suppliers of low -carbon cement.
Revised technical standards
Problem: Many current building regulations and procurement specifications are outdated and only recognize conventional cement mixtures. This creates a structural barrier for the introduction and scaling of low -carbon alternatives in construction projects. Without formal recognition in the official standards, greener cement products have difficulties to achieve acceptance, even if they meet the performance requirements.
Political approach: Governments and supervisory authorities revise the technical standards to explicitly allow low -carbon cement options. This includes Portland-Limestone cement (type IL) and mixtures with additional cement materials that can reduce CO₂ emissions without impaired structural integrity. The updating of these standards eliminates an important obstacle to the introduction by treating safer alternatives as valid and compliant options.
Examples: Marin County, California, became the First jurisdiction Mandate with low -carbon concrete mixtures in the construction code. In the United States, 44 state traffic authorities of the type IL cement have approved, which produces about 10% less as a standard cement. These changes signal a shift in the specification of sustainability into the specifications that determine building materials.
Harmonization of global benchmarks
Problem: Cement producers are exposed to a fragmented system of sustainability criteria that varies depending on the country and region. This lack of orientation makes it difficult for low -carbon products to compete in international markets. Inconsistent benchmarks also create additional costs for manufacturers who have to adapt products in order to meet several, sometimes contradictory requirements.
Political approach: The establishment of harmonized building regulations and embodied carbon thresholds can provide consistent expectations in the markets. Uniform standards would enable producers to fulfill the criteria without repeated changes.
Examples: The International Green Construction Code (IGCC) Integrates the life cycle and material deficiency regulations in different regions. France has introduced binding -related carbon limits, which are increasingly intensifying from 2030 and offer a clear long -term framework for the planning of investments.
Improve price parity
Problem: Carbon cement often costs more than conventional alternatives, which makes it less attractive for insensitive buyers. Higher production costs, which are due to newer technologies and inputs for renewable energies, lead to a disadvantage for competitive bids. This price gap hinders acceptance, especially in markets in which preliminary payments are prioritized before long -term environmental advantages.
Political approach: Governments can help close these cost gaps through targeted subsidies, environmentally friendly procurement rates and product labeling. Subventions reduce production costs and improve pricing parity with conventional cement. Quotas in public projects guarantee demand, while labeling systems make sustainable products more visible and easier to identify buyers.
Examples: The Germany's Green Industry Market program offers Direct subsidiesUse quotas for materials with low absorption in public procurement and introduces a labeling system to promote recognition. China has expanded his Renewable portfolio standards To cover cement production that require a higher proportion of renewable energies in manufacture to lower emissions and operating costs.
Expansion of the access of climate finance
Problem: Securing capital for improving cement systems or scaling innovative production processes remains a challenge. Investors often take these projects as a high risk due to long repayment periods and uncertain market demand. This lack of financing slows down the transition to production methods with lower emissions and slows down the pace of industrial conversion.
Political approach: Climate finance mechanisms can create new sources of income to support investments in sustainable production. Tools such as CO2 credits, emissions trading systems and demand pages procurement signals reward emission reductions, which improves the project generation.
Examples: In the USA and the EU, CO2 finance and emission trade programs are increasingly linked to public procurement guidelines. This integration directs the funds to projects that meet and help sustainability criteria Sewer investment In industrial transitions.
How is green cement made?
Green cement is manufactured by adapting conventional cement production methods to reduce carbon emissions and energy consumption. The following phases describe how the process is optimized to create a more sustainable alternative.
Preparation of raw materials
The process begins similar to conventional cement production, in which materials such as limestone, sound and other minerals are used. However, green cement often includes recycled or industrial by-products, namely from the beginning flight ash or slag, to reduce the need for raw material extraction.
Clinker reduction during the grinding
A large part of Traditional clinker is replaced by low -carbon substitutes such as flight ash, ground, ground granulated blanks or calcinated sound. This substitution is crucial for reducing emissions, since Clinker is the most carbon -intensive component of the cement.
The following table summarizes important alternatives with low-carbon carbon alternatives to the clinker in cement production, whereby the sources, typical replacement conditions and potential for CO₂ reduction are detailed.