In the industrial sector, lowering CO2 emissions has become a race against time. As the global community works to combat rising greenhouse gas (GHG) emissions, the growing need for industrial materials must be combatted with new technological innovations in the sector. Many of these innovations are turning to carbon capture in order to minimize the amount of CO2 emitted in the atmosphere from industrial processes.
According to the Oil and Gas Climate Initiative, carbon has been utilized for processes like carbonating drinks since the 1930s, while more sophisticated forms of CO2 storage were introduced in 1972, when oil rigs began to inject CO2 into oil fields to force more oil from the wells in a process now called Enhanced Oil Recovery (EOR). In 1996, CO2 storage in saline aquifers was introduced in Norway. Today, carbon capture, utilization, and storage (CCUS) is an essential facet of the global emissions reduction strategy.
Carbon capture separates CO2 from industrial exhaust, most often via a process called amine scrubbing. In this process, flue gas is treated by passing through an amine solution to filter out gases like nitrogen and oxygen from 90% purified CO2. Once separated, the CO2 is compressed and transported. The most popular method of CO2 storage is geological carbon storage, wherein the CO2 is pressurized to a high density and low viscosity. This “densephase” CO2 is then injected into a porous reservoir (often depleted gas and oil fields or saline aquifers, where the CO2 will mineralize) sealed underground by a layer of impermeable rock in a process called carbon capture and storage (CCS). Rather than storage within geologic structures, this captured CO2 can also be utilized in a number of ways—this is referred to as carbon capture, utilization, and storage (CCUS).
Per the IEEFA report on carbon capture, the CCS/CCUS industry captures 39 million tonnes of CO2 annually. CCUS is supported globally by a variety of governmental subsidies, such as the Canadian tax credit for projects researching or using CCUS. Still, the OGCI calls for the scaling up of CCUS projects globally, claiming that “we now need to turn millions into billions” of tonnes CO2 annually captured.
The IEA’s Sustainable Development Scenario (SDS) represents the most desirable global status of sustainability by 2030 and 2070 if we can meet sustainable energy goals in full, culminating in net-zero emissions by 2070. The International Energy Association’s analysis of the role of CCUS in a global transition to clean energy finds that CCUS is essential to a net-zero emission scenario as “the only group of technologies that contributes both to reducing emissions in key sectors directly and to removing CO2 to balance emissions that are challenging to avoid.”
The IEA analysis makes note of CCUS’s particular importance in heavy industry. In the IEA net-zero scenario, 2.7 billion tonnes of CO2 is captured annually in the steel, cement, and chemical sectors. In these heavy industries, CCUS must be facilitated via retrofit and new plant construction. In the cement sector, CO2 capture is non-negotiable: cement represented 63% of CO2 emissions attributed to industrial processes in 2019.
According to Canada’s Roadmap to Net-Zero Carbon Concrete by 2050, 20% to 30% of concrete’s embodied carbon emissions can be avoided through use of alternate binders (rather than pure cement) in the concrete mix, with another 20% of emissions reductions potentially coming from CCUS technology use in the sector. However, the rate at which these innovations are being applied to concrete production must be increased in order to see significant emissions reductions by 2050. A recent McKinsey report of CO2 emissions reduction echoes the importance of CCUS in the construction sector, classifying emissions resulting from cement production as particularly hard to abate.
CarbiCrete represents a unique form of CCUS in that it both avoids CO2 emissions by producing cement-free concrete, and actively removes CO2 by trapping it within the precast concrete itself. This removes the CO2 from the atmosphere permanently, even when the concrete is destroyed. Solutions like these, that combine use and sequestration of CO2, are proving more and more important to our system of global climate solutions.