Cost Effective Measures to Reduce VOC on an Industry Level

Abstract

Abstract VOC, the volatile hydrocarbons, tend to evaporate in the whole product chain from the oil production facility to the end user of the products. Loading operations, from offshore loading to gasoline filling on the car, are often the largest contributors. In Norway, the offshore loading of crude oil causes more than 50 % of the total VOC emissions. Norway's goal is to reduce VOC emissions with 30 % in 1999 compared to 1989. According to present prognoses, the emissions will instead increase 10–20 %. The offshore industry is therefore under strong pressure to reduce its VOC emissions. Statoil, as the world's leading operator of offshore loading tankers, has therefore pioneered development of two technologies/concepts for reducing the VOC emissions from offshore loading. Equipment manufacturers and 16 other oil companies cooperate in the effort. One technology/concept is based on recovery of the VOC in an absorption tower with subsequent routing back to the oil cargo. A cargo loss of 0.2–0.6 % is therefore eliminated with a potential to lift the market value of the cargo accordingly. For this technology to really result in reduced total VOC emissions, the onshore oil terminals must be able to utilize the actual content of light fractions in the crude oil. The other concept is based on condensation and storage of the VOC onboard the tanker for use as fuel in the ship main machinery instead of heavy fuel oil and/or diesel, reducing emissions and fuel costs. The reduction potential for the two concepts is estimated to 70–80 %. Full-scale pilot equipment will be tested onboard two tankers in the next 2–3 years. If these pilots are successful, equipment will be installed on the offshore loading ships in the first few years of the next century. The offshore industry will thereby make its contribution in Norway's effort in reaching its goals for reduction in VOC emissions.