Deep Decarbonization Roadmap for the Cement and Concrete Industries in California

Overview

Cement production is one of the most energy-intensive and highest carbon dioxide (CO2) emitting manufacturing processes. In fact, the cement industry alone accounts for more than 6% of total anthropogenic CO2 emissions in the world. California is the second-largest cement producing state in the United States after Texas. California's eight cement plants together produced 10 million metric tonnes (Mt) of cement and emitted 8.2 MtCO2 in 2017 (This also includes indirect emissions from electricity consumption).

More than 70 percent of the energy used in California's cement industry is coal and petroleum coke, which are two of the most air-polluting fossil fuels. California's cement industry used around 34.28 petajoules (PJ– 1015 joules) of fuel, which includes over 900 kilotonnes (kt) of coal and petroleum coke, and 1,340 gigawatt hours (GWh) of electricity in 2015. The 900 kt of coal and petroleum coke is the equivalent of 7,500 railcars full of these fossil fuels. The 1,340 GWh of electricity use is equal to the average monthly electricity consumption of around 2.3 million California households.

Around 60% of the total CO2 emissions from California's cement industry are process-related emissions from calcination of limestone in the kiln, while the remaining 40% are energy-related emissions from fuel combustion and electricity consumption.

In early 2019, we published a report titled "California’s Cement Industry: Failing the Climate Challenge" (Hasanbeigi and Springer, 2019). In that report we analyzed the current status of cement and concrete production in California, and benchmarked the energy use and CO2 emissions intensity of the state's cement industry in comparison to other key cement-producing countries. The study presented in this report is a follow up to that study.

The goal of this study is to develop a roadmap for decarbonization of California's cement and concrete production. In this study, we look at the current status of cement and concrete production in California and develop scenarios up to 2040 to analyze different decarbonization levers that can help to reduce CO2 emissions of cement and concrete production in California.

We included four key major decarbonization levers in our analysis, which are: energy efficiency, fuel switching, clinker substitution, and carbon capture, utilization, and storage (CCUS).

Our scenario analysis up to 2040 shows that under the business-as-usual (BAU) scenario, which assumes no significant changes in current policies and market practices, the total CO2 emissions from California's cement industry will increase from 7.9 MtCO2 per year in 2015 to 10.7 MtCO2 per year in 2040, a 36% increase. Under our Advanced Technology and Policy (Advanced) scenario, however, the total CO2 emissions from California's cement industry will decrease to about 2.5 MtCO2 per year in 2040, a 68% reduction compared to the 2015 level (Figure ES 2). This is while the cement production in California is assumed to increase by 42% from 9.9 Mt in 2015 to 14.1 Mt in 2040.

The difference between the CO2 emissions of California's cement industry in the BAU and Advanced scenarios in 2040 is equal to emissions from around 1.8 million passenger cars per year or annual electricity-related CO2 emissions of around 4.9 million households in California.

Carbon capture utilization and storage (CCUS) could make the largest contribution to CO2 emissions reduction in California's cement industry through 2040, followed by clinker substitution (i.e. replacing clinker with SCMs in cement or in concrete) and fuel switching. Energy efficiency (EE) technologies provide additional CO2 emissions reductions potential.

Our Advanced Technology and Policy decarbonization scenario is completely achievable with commercially available and cost-effective technologies and measures except for CCUS technologies which are emerging technologies with some technologies requiring more demonstration and financial support. Policy tools such as the California cap-and-trade program, the Buy Clean California Act, and the 45Q tax credit for CCS should be leveraged to incentivize both cement and concrete producers to move towards low-carbon cement and concrete production.

In addition to decarbonization levers included in our analysis and discussed above, there are other options for reduce the CO2 emissions footprint of cement and concrete production. For example, alternative raw materials and products for cement and concrete production (not based on Portland cement) can help to reduce CO2 emissions from the cement industry. Also, the use of alternative materials in construction can help to reduce the demand for cement and concrete products.

We believe with the right set of policies and partnership between industry and regulators, California's cement and concrete industry not only can become one of the cleanest in the world, but it could go beyond that and show the world how the cement and concrete industry can move towards deep decarbonization in order to meet Paris Climate Agreement's goal to keep the increase in global average temperature to well below 2 °C above pre-industrial levels.