Sequestration of carbon dioxide by RCAs and enhancement of properties of RAC by accelerated carbonation

Xuan, Dongxing; Poon, Chi Sun

doi:10.1016/b978-0-08-102480-5.00016-6

Cited by 7 publications

(2 citation statements)

References 28 publications

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“…With continued urbanization in the developing world and infrastructure projects worldwide, cement consumption has increased rapidly (Low, 2005). The cement production process is an energy-intensive and CO 2 -emitting process, the total CO 2 emission of which amounts to 5 %-8 % of global CO 2 emissions (IEA, 2019;Xuan and Poon, 2019;Friedlingstein et al, 2022). The worldwide average CO 2 emission coefficient of ordinary Portland cement (OPC) is 0.86 kgCO 2 kg −1 (Damtoft et al, 2008), which comprises the release of 0.53 kgCO 2 kg −1 of clinker owing to the decomposition of limestone during calcination.…”

Section: Introductionmentioning

confidence: 99%

Global carbon uptake of cement carbonation accounts 1930–2021

Huang,

Wang,

Bing

et al. 2023

Earth Syst. Sci. Data

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Abstract. The main contributor to the greenhouse gas (GHG) footprint of the cement industry is the decomposition of alkaline carbonates during clinker production. However, systematic accounts for the reverse of this process – namely carbonation of calcium oxide and other alkaline oxides and/or hydroxides within cement materials during cements' life cycles – have only recently been undertaken. Here, adopting a comprehensive analytical model, we provide the most updated estimates of CO2 uptake by cement carbonation. The accumulated amount of global CO2 uptake by cements produced from 1930 to 2021 is estimated to be 22.9 Gt CO2 (95 % confidence interval, CI: 19.6–26.6 Gt CO2). This amount includes the CO2 uptake by concrete, mortar, construction waste and kiln dust, accounting for 30.1 %, 58.5 %, 4.0 % and 7.1 % respectively. The cumulative carbon uptake by cement materials from 1930 to 2021 offsets 55.1 % of the emissions from cement production (41.6 Gt CO2, 95 % CI: 38.7–47.2 Gt CO2) over the same period, with the greater part coming from mortar (58.5 % of the total uptake). China has the highest cement carbon uptake, with cumulative carbonation of 7.06 Gt CO2 (95 % CI: 5.22–9.44 Gt CO2) since 1930. In addition, the carbon uptake amounts of the USA, EU, India and the rest of the world took 5.0 %, 23.2 %, 5.6 % and 34.8 % separately. As a result of rapidly increased production in recent years, over three-quarters of the cement carbon uptake has occurred since 1990. Additionally, our results show little impact by the COVID-19 pandemic on cement production and use, with carbon uptake reaching about 0.92 Gt CO2 (95 % CI: 0.78–1.10 Gt CO2) in 2020 and 0.96 Gt CO2 (95 % CI: 0.81–1.15 Gt CO2) in 2021. Our uniformly formatted and most updated cement uptake inventories provide coherent data-based support for including cement carbon uptake into future carbon budgets from the local to global scale. The latest version contains the uptake data till 2021, showing the global uptake's increasing pattern and offering more usable and relevant data for evaluating cement's carbon uptake capacity. All the data described in this study are accessible at https://doi.org/10.5281/zenodo.7516373 (Bing et al., 2023).

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Section: Introductionmentioning

confidence: 99%

Global carbon uptake of cement carbonation accounts 1930–2021

Huang,

Wang,

Bing

et al. 2023

Earth Syst. Sci. Data

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“…In the work of Kikuchi and Kuroda [45], it was reported that 1 ton of recycled crushed stone could take up 11 kg of CO 2 , while Xuan et al [4] verified that 1 ton of RA from CDW sequestrated about 8 kg of CO 2 . Other studies analysed the CO 2 uptake by recycled concrete aggregates [67,72,78,79]. The results indicate that CO 2 uptake was faster for thinner particles.…”

Section: Carbonation Of Recycled Aggregatesmentioning

confidence: 98%

Carbonation Potential of Cementitious Structures in Service and Post-Demolition: A Review

Pederneiras¹,

Farinha²,

Veiga

2022

CivilEng

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The construction sector is responsible for a great environmental impact. The cement industry, which is included in this sector, emits about 650 to 800 kg of CO2 per each tonne of cement produced, being one of the most polluting industries in terms of greenhouse gas emissions. The cement manufacturing process releases about 7% of the total worldwide CO2 emissions. However, concrete and cement-based materials present CO2 uptake potential during their service life and post-demolition through carbonation processes. The carbonation reactions rate depends on several factors, namely type and content of cement, porosity of concrete, temperature, relative humidity and exposure conditions area. Therefore, to estimate the CO2 capture of concrete during its life cycle is not a straightforward calculation. Some studies have been developed using different methodologies in order to evaluate the CO2 potential of cementitious elements in service and post-demolition. This paper reviews the documented approaches that quantify the CO2 uptake of concrete over time, summarizing the assumptions adopted for each previous work. Overall, it was concluded that part of the CO2 emissions released during cement production are reabsorbed by concrete products during their life cycle, which partially offsets the environmental impact and reduces the CO2 footprint of the cement industry.

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