美國西北大學開發碳負建材，海水變綠色混凝土！

西北大學科學家開發碳負型建材，助力永續建設

西北大學（Northwestern University）工程學院的科學家近日宣布，他們成功利用 海水、電能與二氧化碳（CO₂），開發出一種 全新的碳負型建築材料。該技術不僅能夠 永久封存 CO₂，還能將其轉化為高價值建材，如 混凝土、水泥、石膏與塗料，並在過程中產生 氫氣，作為潔淨燃料應用於運輸等領域。

Northwestern University Scientists Develop Carbon-Negative Building Materials to Promote Sustainable Construction

Scientists from the McCormick School of Engineering at Northwestern University have recently announced a breakthrough in developing carbon-negative building materials using seawater, electricity, and carbon dioxide (CO₂). This innovative technology not only permanently sequesters CO₂ but also transforms it into valuable construction materials such as concrete, cement, gypsum, and coatings while simultaneously producing hydrogen as a clean fuel for applications like transportation.

這項研究於 3 月 19 日 發表在國際期刊 《Advanced Sustainable Systems》 ，並由西北大學 Louis Berger 土木與環境工程副教授 Alessandro Rotta Loria 領導。研究團隊成員還包括 化學與生物工程助理教授 Jeffrey Lopez 及多位博士生與研究人員。此外，全球建築材料公司 Cemex 亦參與該研究，這是西北大學與 Cemex 在永續建築領域的長期合作計畫之一。

The research was published on March 19 in the international journal Advanced Sustainable Systems and was led by Alessandro Rotta Loria, an associate professor of civil and environmental engineering at Northwestern University. The team also included Jeffrey Lopez, an assistant professor of chemical and biological engineering, along with several Ph.D. students and researchers. Additionally, Cemex, a global building materials company, collaborated on the project as part of its long-term partnership with Northwestern University in the field of sustainable construction.

突破性技術：以海水與電能「生長」建材

當前，全球各地的研究人員正積極開發 碳捕捉與封存技術（CCS），希望將 CO₂ 儲存於地底 以減緩氣候變遷。然而，這種方法無法充分發揮 CO₂ 的價值。西北大學的最新技術則提供了一種創新解方，不僅能封存 CO₂，還能將其轉化為建築業所需的重要材料。

Breakthrough Technology: "Growing" Building Materials Using Seawater and Electricity

Around the world, researchers are actively working on carbon capture and storage (CCS) technologies to store CO₂ underground and mitigate climate change. However, this approach does not maximize the value of captured CO₂. Northwestern University’s latest innovation provides a transformative solution by not only storing CO₂ but also converting it into essential materials for the construction industry.

「我們的技術能夠 利用海水來製造碳負型建築材料，」Rotta Loria 表示。「傳統上，混凝土、水泥、塗料和石膏都需由 鈣和鎂等礦物 製成，這些礦物通常來自山脈、河床、海岸或海底的 砂石開採。在與 Cemex 的合作下，我們開發出一種 不需開採地球資源，而是透過 電能與 CO₂ 在海水中培育類似砂石的材料 的新方法。」

仿生技術：以電能模擬貝殼形成機制

這項新技術靈感來自 貝殼與珊瑚的自然形成過程。自然界中，珊瑚和貝類利用 新陳代謝能量，將海水中的離子轉化為 碳酸鈣（CaCO₃），形成堅硬的外殼。而西北大學團隊則運用 電能 來驅動這一過程，並通過 CO₂ 注入來加速礦化反應。

具體實驗過程如下：

碳酸鈣 直接充當 碳封存介質，而 氫氧化鎂 則能進一步與 CO₂ 反應，增強碳封存效果。

“Our technology allows us to use seawater to produce carbon-negative building materials,” said Rotta Loria. “Traditionally, concrete, cement, coatings, and gypsum are made from calcium and magnesium minerals, which are typically extracted from mountains, riverbeds, coastlines, or the seabed. Through our collaboration with Cemex, we have developed a novel method that eliminates the need for mining by using electricity and CO₂ to grow mineral-like materials directly in seawater.”

Biomimetic Approach: Using Electricity to Simulate Shell Formation

The new technology is inspired by the natural processes of shell and coral formation. In nature, corals and shellfish metabolize energy to convert ions from seawater into calcium carbonate (CaCO₃), forming hard shells. Northwestern’s team replicates this process using electricity and injecting CO₂ to accelerate the mineralization reaction.

How the process works:

The calcium carbonate directly acts as a carbon sequestration medium, while magnesium hydroxide can further react with CO₂, enhancing its sequestration potential.

「這項技術的優勢在於 不破壞生態環境，而是運用科學來善用環境資源，開發出對建築業有價值的材料，」Cemex 全球研發副總裁 Davide Zampini 表示。

雙重突破：控制材料特性，擴展應用場景

在一系列實驗中，研究人員發現：

根據不同條件，所得材料可以是 較鬆散多孔的顆粒，也可以是 較致密堅硬的結構，但主要組成始終是 碳酸鈣與氫氧化鎂。

「我們證明了這些材料的 化學成分、粒徑、形狀、孔隙率等特性均可控，」Rotta Loria 說。「這賦予我們極大靈活性，使其適用於 不同類型的建築應用。」

“This technology's advantage lies in its eco-friendly approach - leveraging scientific principles to utilize environmental resources efficiently, rather than depleting them,” said Davide Zampini, Cemex’s Global VP of Research & Development.

Dual Breakthrough: Controlling Material Properties for Versatile Applications

Through a series of experiments, researchers discovered that:

Depending on these conditions, the materials can be either porous and granular or dense and rigid, but they always consist primarily of calcium carbonate and magnesium hydroxide.

“We demonstrated that the chemical composition, particle size, shape, and porosity of these materials can be controlled,” Rotta Loria explained. “This provides significant flexibility, allowing us to adapt the materials for different types of construction applications.”

Potential uses of the new materials:

Carbon Sequestration Potential: Turning Buildings into Carbon Sinks

這些新材料可以：

碳封存潛力：讓建築結構成為碳匯

研究團隊計算得出，這種材料的 CO₂ 封存能力極高。例如，若材料成分為 50% 碳酸鈣、50% 氫氧化鎂，則 每 1 公噸材料可封存超過 0.5 公噸 CO₂。

此外，該技術不會影響混凝土或水泥的強度，並且可以在 模組化反應器 中進行大規模應用，而 不直接影響海洋生態系統。

The research team calculated that the new materials have a high CO₂ sequestration capacity. For example, if a material is composed of 50% calcium carbonate and 50% magnesium hydroxide, it can sequester more than 0.5 metric tons of CO₂ per ton of material produced.

Moreover, this technology does not compromise the strength of concrete or cement and can be scaled up using modular reactors without disrupting marine ecosystems.

「這種技術允許我們完全控制水體的化學成分與排放，確保水回注至開放海域前，已經過適當處理與環境驗證，」Rotta Loria 說。

“This method allows us to fully control the chemical composition and discharge quality of the water, ensuring that it is properly treated before being returned to the ocean,” Rotta Loria said.

根據 世界經濟論壇（WEF），全球水泥產業碳排放占比高達 8%，是世界 第四大碳排放源。當考慮 混凝土生產 時，排放量更為驚人。因此，這項技術有望在建築產業實現碳中和，甚至達成負碳排放。

According to the World Economic Forum (WEF), the global cement industry accounts for 8% of CO₂ emissions, making it the fourth-largest CO₂ emitter worldwide. When concrete production is also considered, emissions become even more significant. Thus, this breakthrough technology could enable carbon neutrality - or even negative emissions - in the construction industry.