Bangchak Sriracha Refinery, a Complex Refinery, underwent equipment installation and integration in September 2023 to elevate product quality to meet Euro 5 standards. The adoption of Polyshift(TM) technology in the refining process has played a pivotal role in managing lower levels of polycyclic aromatic hydrocarbons (PAH), further diminishing hydrocarbon emissions from engine combustion, sulfur oxide, and nitrogen released into the atmosphere. This initiative not only aids in reducing environmental pollution from burning engines but also contributes to lowering sulfur content, reducing nitrogen oxide emissions, and decreasing particulate matter, specifically PM 2.5, which represents an overall positive impact on the environment.