How to Accomplish a More Sustainable Internal Combustion Engine Using Life Cycle Analysis: A Demo

The Sustainable Development Goals were adopted by all United Nation Member States in 2015 to ensure a sustainable planet and improved living conditions for everyone, everywhere. The light duty vehicle (LDV) fleet has exceeded one billion, with most vehicles being powered by internal combustion engines. Transportation is responsible for 60% of global fossil oil consumption. Air pollution is a large problem in cities often attributed to road transport. Vehicles comprise of over 70 material categories, indicating the complexity of sustainable material management. A hypothesis was established, that a sustainable engine (SE) could significantly reduce the environmental impact of transportation and, be realized by combining available technologies. A life cycle analysis was conducted on a 145 kW 2-litre Miller-cycle gasoline 48V-mild-hybrid engine with EU6d exhaust aftertreatment system (EATS), assessing seven mid-point categories. The environmental impacts were used to establish sustainable lifecycle target levels for carbon dioxide equivalent (CO₂eq), carbon monoxide (CO), nitrous oxides (NOx) and total-hydrocarbons (THC). A system solution was designed and manufactured to meet the proposed targets. Recycled materials have been applied and verified to multiple components, realizing a 71% reduction in cradle-to-gate Climate Change (CC) impact for the complete engine. An exhaust aftertreatment system (EATS) was developed and tested via a method using a vehicle emissions test cycle adopted on a dynamic engine bench. Considerations were performed for the possibility to use recycled platinum group materials (PGMs) in the catalytic converter. Air pollutant levels were reduced over 90% for the first 390s of the Worldwide Harmonized Light Vehicles Test Procedure (WLTP). A renewable gasoline was tested achieving a 65% lower fuel life cycle climate change impact. Over the complete engine and fuel life cycle a 61% reduction in climate change impact was achieved. The method and demonstrated technology provide insights into a sustainable system solution for an internal combustion engine. Challenges were identified and discussed in relation to primary data collection, establishing circular supply chains and quantifying targets.