Greenhouse Gas Removal in the Iron and Steel Industry

这是GGR专题的一项具体建议：下个世纪可能会产生多达2000亿吨的炉渣，作为钢铁工业的副产品，理论上可以通过加强风化来封存多达900亿至1550亿吨的二氧化碳。这项提议探索了通过对废物的新颖管理，在现有行业内实现经济的温室气体去除技术的令人兴奋的可能性。为此，我们将探索历史矿渣沉积的内部化学，以了解二氧化碳封存的长期制约因素，并进行向大型受控反应堆注入二氧化碳的现场试验。钢铁炉渣是一种玻璃/半结晶材料，富含硅酸盐和氧化物矿物，与自然生成的矿渣相比，它们的溶解速度要快4-5个数量级。这些废物在现在和以前的钢铁厂被发现为大型矿藏，对生产商来说是相当大的环境负担。通过加速矿渣的风化，有可能减轻这一环境负担。它还提供了一种机制，通过这种机制，二氧化碳密集型钢铁行业可以开始脱碳，最终成为净负值，如果与源头上的广泛减排相结合的话。以前的研究已经证明，几十年来，来自渣堆的排水中无意的大气二氧化碳封存，以及在高温和压力下碳酸盐渣的小规模工程系统被提出。目前尚不清楚的是工程方法的可行性和有效性，以加速环境风化在与政策相关的时间段内发生。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提供一种作为主要大气二氧化碳汇的手段来弥合这一差距。

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.