Valorization of waste concrete through CO2 mineral carbonation: Optimizing parameters and improving reactivity using concrete separation

Ghacham, Alia Ben; Pasquier, Louis-César; Cecchi, Emmanuelle; Blais, Jean-François

doi:10.1016/j.jclepro.2017.08.015

Cited by 97 publications

(27 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[59][60][61][62][63] including the binders based on special, low hydraulically active clinkers 41,64,65 . Lately, some authors suggested that the recycled concrete fines can be valorized by carbonation for the use in the concrete production 66,67 . Studies on the carbonation of the hydrated cement pastes revealed that carbonation is occurring at mild conditions, i.e.…”

Section: Discussionmentioning

confidence: 99%

Carbon Capture and Utilization by mineralization of cement pastes derived from recycled concrete

Skoček

Zając

Haha

2020

Sci Rep

143

View full text Add to dashboard Cite

Reduction of co 2 emissions associated with cement production is challenging in view of the increasing cement demand and the fact that major part of the emissions originates from the main raw material used -limestone -which can be only to extremely low amount substituted. A carbon capture and Utilization (CCU) approach based on mineralization of fines derived from concrete appears to be a viable alternative to reduce these emissions. the co 2 sequestration and the reactivity of the obtained carbonated recycled fines is experimentally demonstrated for lab as well as industrial materials for different mineralization conditions. It is shown that all CO 2 originally released by limestone calcination during clinker production can be sequestered by the full carbonation of the fines within a short time. Upon full carbonation, gels with pozzolanic properties form in the fines irrespective of the conditions tested. The carbonated fines have specific CO 2 savings more than 30% higher than the simple clinker replacement by limestone.Global urbanization and economic development increase demand for new buildings and infrastructure and hence for concrete. Already now, concrete is the second most used substance by mass after water. Even though concrete has low specific CO 2 emissions below 150 kg CO2,eq /ton concrete 1 , its abundance makes it responsible for 5-8% of man-made CO 2 emissions 1-4 . Most of the concrete's emissions result from production of the main cement component, the clinker. Hence, focus of researchers as well as of cement producers has been on lowering the clinker content in cements and on improving the efficiency of clinker production. As summarized in 1 , both these approaches have already reached their potentials in mature economics. Almost all suitable Supplementary Cementitious Materials (SCMs) available are already used in cement and concrete production. For the clinker production, further energy efficiency improvements would have only a minor effect as the energy consumption approaches the lowest theoretical value and is often driven by additional objectives such as alternative fuels usage rate.Nevertheless, the cement industry needs to drastically reduce its emissions and at the same time satisfy the increasing cement demand of the global economy 5 . At the level of concrete structures and concrete applications, several approaches can bring considerable CO 2 savings. These include re-usable structures with extended service life or concretes with reduced cement contents 3,6 . At the level of cement production, extended use of calcined clays and limestone as SCM are the only approaches applicable at large enough scale. With the ongoing departure from coal-fired power plants and decreasing demand for pig iron in mature markets, the availability of blast furnace slags and fly ashes is expected to decrease. Calcined clays and limestone have the potential to replace these SCMs in the current market as well as provide sufficient volumes of SCMs in growing markets. However, clinker replacement by limestone o...

show abstract

Section: Discussionmentioning

confidence: 99%

Carbon Capture and Utilization by mineralization of cement pastes derived from recycled concrete

Skoček

Zając

Haha

2020

Sci Rep

143

View full text Add to dashboard Cite

show abstract

“…The dissolution of Ca(OH)2 in concrete by the solubility product constant (Ksp of Ca(OH)2 = 5.5 × 10 −6 ) results in several alkaline solutions (approximately pH 12.6) and Ca saturation in solution (approximately 800 mg/L) according to Equation (3). In the field plant, the solution pH and Ca concentration conditions could fluctuate on a daily basis.…”

Section: Co2(g) → Co2(aq)mentioning

confidence: 99%

“…The high concentration of dissolved Ca 2+ , Na + , K + and OH − in the sludge solution increased the EC to approximately 8.9 dS/m [26,27]. Quartz (SiO 2 ), calcite (CaCO 3 ) and the feldspar mineral albite (NaAlSi 3 O 8 ) were identified by XRD in dried sludge particles (Figure 4a) [3]. Portlandite (Ca(OH) 2 ), present in the original concrete (Figure 4b), was not observed in the concrete sludge XRD spectrum, possibly due to dissolution during the wet-based crushing/screening process.…”

Section: Physicochemical Characteristics Of the Samplementioning

confidence: 99%

“…Metals 2017, 7, 371 7 of 13 3.47 dS/m at the end of the reaction. Han et al [35] reported that CaCO3 produced by CO2 injection in the carbon mineralization process was converted to a soluble form of Ca(HNO3)2 at solution pH below 8.3, hence the slight increase in solution EC.…”

Section: Physicochemical Characteristics Of the Samplementioning

confidence: 99%

“…Currently, waste concrete accounts for approximately 63% of construction waste; a total of 198,000 tons generated per day. As a result, more than 95% of waste concrete is used as aggregate material in new concrete [2,3]. In the intermediate-construction waste recycling process, crushing and screening produces a large amount of concrete sludge composed of fine-grained concrete material.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

An Eco-Friendly Neutralization Process by Carbon Mineralization for Ca-Rich Alkaline Wastewater Generated from Concrete Sludge

Yoo

Shin

2017

Metals

View full text Add to dashboard Cite

Waste-concrete recycling processes using wet-based crushing methods inevitably generate a large amount of alkaline concrete sludge, as well as wastewater, which contains abundant Ca ions. The Ca-rich alkaline wastewater must then be neutralized for reuse in the waste-concrete recycling process. In this study, the feasibility of a carbon mineralization process for the neutralization of alkaline wastewater was considered from both environmental and economic perspectives. The optimal reaction time, efficiency of Ca removal and CO 2 sequestration as a function of the CO 2 gas flow rate were assessed. The carbon mineralization process resulted in sequestering CO 2 (85-100% efficiency) and removing Ca from the solution (84-99%) by precipitating pure CaCO 3 . Increasing the gas flow rate reduced the reaction time (65.0 down to 3.4 min for 2.5 L of solution), but decreased CO 2 sequestration (from 463.3 down to 7.3 mg CO 2 for 2.5 L of solution). Optimization of the gas flow rate is essential for efficient CO 2 sequestration, Ca removal, CaCO 3 production and, therefore, successful wastewater neutralization following the wet-based crushing process. The method presented here is an eco-friendly and economically viable substitute for dealing with alkaline wastewater. It may also provide a practical guide for the design of carbon mineralization processes for the neutralization of alkaline solutions containing large amounts of Ca.

show abstract

Direct Aqueous Mineralization of Industrial Waste for the Production of Carbonated Supplementary Cementitious Materials

et al. 2023

View full text Add to dashboard Cite

Valorization of waste concrete through CO2 mineral carbonation: Optimizing parameters and improving reactivity using concrete separation

Cited by 97 publications

References 23 publications

Carbon Capture and Utilization by mineralization of cement pastes derived from recycled concrete

Carbon Capture and Utilization by mineralization of cement pastes derived from recycled concrete

An Eco-Friendly Neutralization Process by Carbon Mineralization for Ca-Rich Alkaline Wastewater Generated from Concrete Sludge

Direct Aqueous Mineralization of Industrial Waste for the Production of Carbonated Supplementary Cementitious Materials

Contact Info

Product

Resources

About