Greenhouse Gas Removal in the Iron and Steel Industry

下个世纪，作为钢铁工业的副产品，可能会产生多达2000亿吨的矿渣。理论上，通过增强风化作用，这些矿渣可以吸收多达900至1550亿吨的二氧化碳。该提案探索了在现有工业中通过新型废物管理实现经济温室气体去除技术的令人兴奋的可能性。我们将通过探索历史炉渣沉积物的内部化学性质来了解二氧化碳封存的长期制约因素，并在大型可控反应器中进行二氧化碳注入的现场试验。钢铁渣是一种富含硅酸盐和氧化物矿物的玻璃/半晶体材料，与自然产生的同类相比，它们的溶解速度要快4-5个数量级。这些废物在现有和以前的钢铁厂中大量堆积，对生产者来说是一个相当大的环境负担。通过加速炉渣的风化，有可能减轻这种环境负担。它还提供了一种机制，通过这种机制，二氧化碳密集型的钢铁行业可以开始脱碳，如果与源头上的广泛减排相结合，最终实现净负排放。先前的研究表明，在数十年的时间里，从渣堆中产生的排水水中无意识地封存了大气中的二氧化碳，并且已经提出了小型工程系统来在高温和高压下碳酸盐渣。目前尚不清楚的是，在与政策相关的时间内以相关规模加速环境风化的工程方法的可行性和有效性。这项研究旨在通过展示这种工程干预如何加速自然风化过程，并为这些工业残留物作为主要的大气二氧化碳汇提供一种手段，从而弥合这一差距。

This is a GGR Topic-specific proposalUp to 200 billion tonnes of slag may be produced over the next century as a by-product of the iron and steel industry, which could theoretically sequester up to 90 to 155 billion tonnes of CO2 through enhanced weathering. This proposal explores the exciting possibility of realising an economic greenhouse gas removal technology within an existing industry through the novel management of waste material. We will do this by exploring the internal chemistry of historic slag deposits to understand the long-term constraints on CO2 sequestration, and undertake field trials of CO2 injection into large controlled reactors. Iron and steel slags are a glass/semi-crystalline material rich in silicate and oxide minerals, which dissolve 4-5 orders of magnitude more rapidly compared to their naturally occurring counterparts. These wastes are found as large deposits at current and former steelworks, and represent a considerable environmental liability for producers. By accelerating the weathering of slag, it may be possible to reduce this environmental burden. It also offers a mechanism by which the CO2 intensive steel industry could begin to decarbonise, and ultimately become net negative, if combined with extensive emissions reduction at source.Previous research has demonstrated unintentional atmospheric CO2 sequestration over multiple decades in the drainage waters emerging from slag heaps, and small scale engineered systems have been proposed to carbonate slag under elevated temperatures and pressures. What remains unclear is the feasibility and efficacy of engineering approaches to accelerate ambient weathering to occur in a policy-relevant time period at a relevant scale. This research aims to bridge this gap by demonstrating how such engineering interventions can accelerate the natural weathering processes and provide a means for these industrial residues to act as a major atmospheric CO2 sink.