+
Groundbreaking: Recipe for zero-carbon cement discovered
Concrete

Groundbreaking: Recipe for zero-carbon cement discovered

A breakthrough from Cambridge aimed at tackling CO2 emissions from concrete and steel production simultaneously. It suggests that throwing old concrete into steel-processing furnaces could yield both purified iron and "reactivated cement" as a byproduct, potentially leading to carbon-zero cement production if renewable energy is used.

Concrete production is a significant contributor to global CO2 emissions, accounting for approximately 8% of the total. However, recycling concrete into a usable form for new structures has been challenging.

Efforts to make concrete more environmentally friendly have included altering its composition to reduce pollution, such as substituting less harmful ingredients like limestone, or designing concrete to absorb more CO2 from the atmosphere over time. In this study, researchers from Cambridge explored the conversion of waste concrete back into clinker, the dry component of cement, for reuse.

Dr Cyrille Dunant, the lead author of the study, mentioned having a notion from previous research that crushing old concrete, removing sand and stones, heating the cement to eliminate water, and then forming clinker might be feasible. They experimented with using an electric arc furnace, commonly employed for recycling steel, to aid this process.

In traditional steel recycling using an electric arc furnace, a flux material, typically lime, is utilised to purify the steel. This substance captures impurities, rises to the surface, and forms a protective layer to prevent exposure to air. Afterward, the used flux is discarded as waste.

In the Cambridge method, the lime flux was replaced with recycled cement paste. Remarkably, not only was the steel successfully purified, but the leftover slag could be rapidly cooled to produce new Portland cement. The resulting concrete exhibited similar performance to conventional concrete.

A breakthrough from Cambridge aimed at tackling CO2 emissions from concrete and steel production simultaneously. It suggests that throwing old concrete into steel-processing furnaces could yield both purified iron and reactivated cement as a byproduct, potentially leading to carbon-zero cement production if renewable energy is used. Concrete production is a significant contributor to global CO2 emissions, accounting for approximately 8% of the total. However, recycling concrete into a usable form for new structures has been challenging. Efforts to make concrete more environmentally friendly have included altering its composition to reduce pollution, such as substituting less harmful ingredients like limestone, or designing concrete to absorb more CO2 from the atmosphere over time. In this study, researchers from Cambridge explored the conversion of waste concrete back into clinker, the dry component of cement, for reuse. Dr Cyrille Dunant, the lead author of the study, mentioned having a notion from previous research that crushing old concrete, removing sand and stones, heating the cement to eliminate water, and then forming clinker might be feasible. They experimented with using an electric arc furnace, commonly employed for recycling steel, to aid this process. In traditional steel recycling using an electric arc furnace, a flux material, typically lime, is utilised to purify the steel. This substance captures impurities, rises to the surface, and forms a protective layer to prevent exposure to air. Afterward, the used flux is discarded as waste. In the Cambridge method, the lime flux was replaced with recycled cement paste. Remarkably, not only was the steel successfully purified, but the leftover slag could be rapidly cooled to produce new Portland cement. The resulting concrete exhibited similar performance to conventional concrete.

Related Stories

Gold Stories

Next Story
Infrastructure Urban

Assam Gets Approval For 350,000 PMAY Homes

Assam Chief Minister Himanta Biswa Sarma met Union Agriculture Minister Shivraj Singh Chouhan in New Delhi, where the minister handed an approval document for 310,000 new homes under the Pradhan Mantri Awas Yojana. The chief minister subsequently posted on X expressing gratitude and noting that the minister had formally handed approval for 380,000 homes as well. The release and the social media post contained varying figures, with broader references to 350,000 homes reported in some summaries. The approvals carry central assistance equivalent to Rs 50 billion (bn), corresponding to the five th..

Next Story
Infrastructure Urban

KPIGreen Achieves Highest Energised Capacity of 630+ MW DC

KPI Green Energy energised more than 630 MW DC of capacity in the June to August quarter, marking the highest quarterly addition in the company's history. The capacity was brought online across its Independent Power Producer (IPP) and Engineering, Procurement and Construction (EPC) businesses. The company said the achievement reflected the scale, speed and consistency of its project execution engine. The firm described the quarter as a material operational milestone since its founding. The milestone covers a diversified mix of IPP assets and projects executed under the EPC vertical, spanning u..

Next Story
Infrastructure Energy

Adani Energy Solutions Wins Rs 47 bn Maharashtra Transmission Project

Adani Energy Solutions has won a transmission contract in Maharashtra valued at Rs 47 billion (Rs 47 bn) to evacuate 4,500 megawatt (MW) of renewable and storage power. The company informed exchanges that the project will facilitate pumped storage potential near Satara and strengthen the inter-regional corridor between the Western and Southern grids. The award follows a competitive bidding process and will support renewable energy evacuation to major load centres in the state. The scope includes establishment of a 765/400 kV substation at Satara, construction of a Kolhapur-Satara 765 kV double..

Advertisement

Subscribe to Our Newsletter

Get daily newsletters around different themes from Construction world.

STAY CONNECTED

Advertisement

SPECIAL OFFER
QR Code