Mechanochemical processing of silicate rocks for direct carbon capture (MACO2)

该项目旨在开发一种新技术，用于将碳捕获到采矿和骨料生产过程中自然形成的废石粉中。我们的目标是利用岩石破碎过程中发生的机械化学反应，永久地从工业废气中捕获二氧化碳，作为碳捕获的一种手段。在破碎过程中，当岩石中的化学键被打破时，能量瞬间释放（作为带电粒子和光子）。我们利用这种机械化学能来捕获二氧化碳。我们最近发表在《自然可持续发展》杂志上的研究表明，如果你在二氧化碳气体而不是空气中粉碎富含二氧化硅的岩石，如花岗岩和玄武岩，二氧化碳可以通过化学吸附过程永久地被困在粉碎颗粒的晶格中。这个项目将建立在我们早期研究的基础上。我们将探讨温度、破碎粒度和初始岩石含水量对每单位质量破碎岩石捕获的CO2量的影响。我们还将研究气流成分。我们之前的研究使用纯CO2：在这里，我们将在水泥生产、生物质发电、天然气和氢气生产等行业的实际富CO2废气中粉碎岩石。我们将使用生命周期分析来评估我们的技术所带来的碳节约。最后，我们将探索（1）最终的岩石粉末用作部分水泥替代产品，以及（2）从富含CO2的岩石粉末中联合生产有价值金属的潜力。该研究项目可能对我们到2050年实现净零碳目标的能力产生重大影响。全世界每年至少有400亿吨富含硅酸盐的岩石被采矿和采石业压碎。如果我们能够调整目前的岩石破碎过程来捕获二氧化碳，并且只需要很少的额外能源消耗（除了用于运输二氧化碳的能源），那么这就可以用来捕获来自“难以脱碳”行业的温室气体。根据我们发表的早期研究结果，每100公吨可销售的破碎骨料至少可以捕获0.4公吨的热稳定和不溶性二氧化碳。我们估计，如果这项技术在全球范围内开发和采用，它可以捕获全球二氧化碳排放量的0.5%，或每年1.75亿吨二氧化碳：这相当于德国大小的成熟森林捕获的二氧化碳。

This project aims to develop a new technology for capturing carbon into waste rock powders that are naturally formed during mining and aggregate production operations. We aim to use mechanochemical reactions, which occur during rock crushing, to permanently trap CO2 from industrial exhaust gases as a means of carbon capture. During crushing, energy is instantaneously released (as charged particles and photons) when the chemical bonds in the rock are broken. We use this mechanochemical energy to trap CO2. Our recent research, published in Nature Sustainability, showed that if you crush silica-rich rocks, such as granite and basalt, in CO2 gas instead of air, the CO2 can become permanently trapped, via a process of chemical sorption, within the crystal lattice of the crushed particles. This project will build on our early research. We will explore the effects of temperature, crushed particle size and initial rock water content on the amount of CO2 trapped per unit mass of crushed rock. We will also investigate gas stream composition. Our previous research used pure CO2: here we will crush rocks within realistic CO2-rich effluent gases from industries such as cement production, biomass power production, gas and hydrogen production from natural gas. We will evaluate the carbon savings from our technology using life cycle analysis. Finally, we will explore the potential for (1) the final rock powders to be used as a partial cement replacement product, and (2) co-production of valuable metals from the CO2-rich rock powders. This research project could have a major impact on our ability to meet net zero carbon targets by 2050. Worldwide, at least 40 billion tonnes of silicate-rich rocks are crushed every year by the mining and quarrying industries. If we can adapt current rock crushing processes to trap CO2, with very little extra energy expenditure (other than that used to transport the CO2), then this could be used to trap greenhouse gases from 'hard to decarbonise' industries. Based on our published early research findings, at least 0.4MtCO2 of thermally-stable and insoluble CO2 can be trapped for every 100Mt of saleable crushed aggregate. We estimate that, if this technology was developed and adopted worldwide, it could capture ~0.5% of global CO2 emissions, or 175MtCO2 annually: this is equivalent to the CO2 trapped by a mature forest the size of Germany.