Clean concrete technology ready for ramp-up

Carbicrete to launch large-scale production of carbon-negative blocks, developed at McGill
Mehrdad Mahoutian (left) and Chris Stern, with one of their cement-free, carbon-negative concrete blocks. Owen Egan

The year is off to an auspicious start for Carbicrete, whose made-at-McGill technology could make concrete products more environmentally friendly.

The Montreal startup was named this month to the 2020 Global Cleantech 100, a list compiled by San Francisco-based research firm Cleantech Group as “a guide to the most innovative and promising companies poised to impact the market and the future of global industries in the next five to ten years.”

Carbicrete’s debut in the Cleantech 100 comes on the heels of several pivotal developments in the three-year-old company’s drive to turn its potential into commercial reality. It also comes as a growing number of corporations are looking for ways to reduce their carbon footprint..Microsoft, for instance, said last week it aims to become “carbon negative” by 2030.

Last month, Harsco Corp., a Pennsylvania-based company that operates in more than 30 countries, announced a $3 million investment by its Environmental division in Carbicrete. That coincided with a $2.1 million grant from the Government of Canada’s Sustainable Development Technology Canada foundation.

Pilot project in Drummondville

The recent investments will enable Carbicrete to launch an industrial-scale pilot project in partnership with Patio Drummond, a Drummondville, Que., maker of paving stones and other concrete products. Carbicrete plans to begin production of “concrete masonry units” – better known as cinder blocks – at the Drummondville plant in mid-2020, with a goal of building toward output of 25,000 blocks per day, Yuri Mytko (BA’99), Carbicrete’s chief marketing officer, said in a telephone interview.

Carbicrete’s technology, first developed in a McGill Engineering lab, is designed to make carbon-negative precast concrete products for the building industry. Unlike conventional blocks, which use Portland cement to bind the concrete together, Carbicrete’s blocks use steel slag – a waste material from steel-making plants.

The process of making cement is a major contributor to climate change. Each year, more than four billion tons of cement are produced, accounting for around 8 per cent of global carbon-dioxide (CO2) emissions, according to a 2018 report by Chatham House, the London-based policy institute.

By eliminating cement from its concrete mix, Carbicrete cuts CO2 emissions from the production process. On top of that, while conventional concrete is cured using heat and steam, Carbicrete instead uses carbon-dioxide to cure its concrete – thereby permanently sequestering the CO2.

Carbon-negative footprint

The combination of cement-free production and CO2 utilization results in a carbon-negative footprint. “Production of a conventional concrete block results in about 2 kilograms of CO2 emissions,” says Mehrdad Mahoutian, Carbicrete’s co-founder and Chief Technology Officer. “Each of our blocks actually stores about a kilogram of CO2.”

Mahoutian (PhD’14) worked on the technology as a PhD student with McGill engineering professor Yixin Shao, with whom he shared a 2015-2016 William and Rhea Seath Award in Engineering Innovation from the Faculty of Engineering’s Innovation and Entrepreneurship hub.

In 2018, Carbicrete was selected as one of 10 finalist teams from five countries in the NRG COSIA Carbon XPRIZE, a four-and-a-half-year global competition challenging teams to transform the way the world addresses CO2 emissions with breakthrough technologies that convert carbon dioxide emissions from power plants into valuable products.

With the Harsco and Government of Canada investments in place, Carbicrete is now focusing its development efforts on the pilot project in Drummondville, says Chris Stern (BEng’94), Carbicrete’s chief executive officer. “Harsco Environmental’s world-leading materials processing experience and commitment to clean technology make them an ideal partner as we work toward bringing a cost-effective, cement-free concrete solution to the global construction industry.”