LCA and negative emission potential of retrofitted cement plants under oxyfuel conditions at high biogenic fuel shares

Abstract

The implementation of oxyfuel carbon capture and storage technologies in combination with use of alternative fuels comprising high biogenic shares is promoted as an attractive climate change mitigation option for the cement sector to achieve low or even negative carbon emissions. Here, we perform a prospective life cycle assessment of two state-of-the art cement plants, one in Sweden and one in Germany, under conventional and retrofitted oxyfuel conditions considering alternative fuel mixes with increasing bio-based fractions of forest residues or dedicated bioenergy crops. The analysis also considers effects of the projected changes in the electricity systems up to 2050. Retrofitting the cement plants to oxyfuel reduces climate change impacts between 74 and 91%, while with additional use of biomass as alternative fuel the cement plants reach negative emission between − 24 and − 169 gCO2eq. kgclinker−1, depending on operational condition, location, and biomass type. Additional emission reduction of − 10 (Sweden) and − 128 gCO2eq. kgclinker−1 (Germany) are expected from the decarbonization of the future electricity systems. Retrofitting the cement plants to oxyfuel conditions shows trade-offs with other environmental impacts (e.g., human toxicity, water and energy depletion), which are partially offset with projected changes in electricity systems. Our results illustrate the large climate change mitigation potential in the cement sector that can be achieved by the implementation of oxyfuel carbon capture and storage and biomass use as alternative fuel.

Climate impact of diverting residual biomass to cement production

“…It is also important to note that the current study explores the use of residual biomass in an NG‐fired cement plant. Most cement plants in the world are fueled with coal or petroleum coke and are not as energy efficient as NG‐fired plants (Cavalett et al, 2022; Naqi & Jang, 2019; Thwe et al, 2021). If the co‐firing analyses carried out here were to have been applied to a coal‐fired cement plant, the GHG benefits of residual biomass diversion would probably have been greater.…”

“…For example, residual biomass diversion could help to reduce forest fire risk, enhance forest regrowth, or reduce pressure on landfill sites. Other factors, not quantified here include impacts on biodiversity, acidification, and ecotoxicity (Cherubini et al, 2009;Weldu & Assefa, 2016).…”

“…Furthermore, the study did not account for biogenic CH 4 and N 2 O emissions associated with the bioenergy systems (Cherubini et al, 2009). Although diverting residual biomass from slash burning into bioenergy avoids GHG emissions by preventing open-air combustion of biomass (Pingoud et al, 2012;Ter-Mikaelian et al, 2016), industrial combustion of biomass also releases GHGs into the atmosphere (Ministry of Environment British Columbia, 2014).…”

Meeting industrial decarbonization goals: a case study of and roadmap to a net-zero emissions cement industry in California

“…However, it must be noted that the carbon accounting of such energy resources as netzero is not consistently accurate. In some cases, biomass and certain waste fuels cannot entirely replace conventional fuels if they cannot provide a high enough temperature in the kiln [24] or if local policies preclude use of particular energy resources. A switch to natural gas is already happening in the US, while the switch to biomass for kiln fuel is currently happening in Europe [12,13].…”

Technical Evaluation and Financial Analysis of a Retrofitting Investment Project for Production Machinery in a Cement Plant

“…eir research into water-saving and energy-efficient technologies showcases how the industry can achieve sustainability without compromising on productivity. Cavalett et al [18] highlighted the large climate change mitigation potential achievable in the cement sector through the implementation of oxyfuel CCS and biomass use as alternative fuel. Collectively, these studies underscore a paradigm shi in various industrial sectors towards more sustainable and efficient practices through technological upgrades.…”