Climate Neutrality Strategies for the Chemical Industry Using a Novel Carbon Boundary: An Austrian Case Study

The chemical industry is a key driver of economic growth and innovation but remains one of the largest contributors to greenhouse gas (GHG) emissions. Achieving sustainability demands advancements in green chemistry and cleaner production methods. This study investigates emission reduction strategies across Scope 1, Scope 2, and Scope 3 by applying both top-down and bottom-up approaches within four system boundaries. The Austrian chemical sector, with a focus on ammonia, methanol, and olefins, serves as a case study. Results highlight the potential of abatement technologies and alternative feedstocks—such as low-carbon hydrogen and methanol—to significantly reduce emissions. Hydrogen-based production for ammonia and methanol, along with low-carbon methanol in olefin production, could reduce Scope 1 and Scope 2 emissions by approximately 80% compared to conventional methods. However, Scope 3 emissions remain challenging due to embedded carbon in feedstocks and CO2 use in production, particularly in product use and end-of-life phases. A comprehensive life cycle assessment is crucial to addressing these impacts. To evaluate Scope 3 emissions, this study explores three decarbonization scenarios: the reference scenario—relies on fossil-based production with high emissions; the geogenic scenario—integrates abatement technologies and geogenic CO2 feedstock, reducing emissions by about 46%; and the bio-based scenario—combines abatement technologies with biogenic CO2 feedstock, achieving an 80% reduction in total emissions at the national level. The findings emphasize the need for a system-wide approach that integrates bio-based solutions and circular economy strategies to achieve climate neutrality. However, uncertainties in climate policy, bio-resource availability, and data gaps in Scope 3 emissions must be addressed to ensure effective decarbonization and alignment with climate goals.