St1's refinery in Gothenburg is widely recognized as one of the worlds most efficient. It was environmentally certified as ea ... rly as 1997, and since then we have invested hundreds of millions of kronor in improving our production of environmentally classed products. At St1's refinery, more than 200 experts in the oil and gas industry work tirelessly with production and maintenance of the plant. The refinery operates 24 hours a day, all year round. read more