Environmental impact assessment for Oman LNG expansion project: NO₂ air quality analysis with a proposal for a third train

Oman entered the LNG market (liquefied Natural Gas) in April 2000 with the first shipment to South Korea. Oman LNG plant is currently producing 6.6 million metric tonne per annum from two trains. However, there are plans for expansion of the plant to increase its existing capacity by adding one more gas liquefaction train (train 3). The purpose of this study is to assess the potential environmental air quality impacts arising from the construction and operation of train 3. The article contains a baseline-survey of the existing environment, the proposed project description and prediction of the possible future air quality impacts of this project on the existing community and its environment. Recognizing that nitrogen dioxide (NO₂) may be the primary air contaminant released from Oman LNG plant, this work has been designed with emphasis on this pollutant. The environmental impact assessments including an air quality analysis in terms of NO₂ has been conducted by using the Industrial Source Complex Short-Term (ISCST) dispersion model. The results are presented in contour map forms to determine the spatial distribution of NO₂ to be produced when train 3 is operating. The study indicates that the highest NO₂ concentration values will be observed in the summer months (June, July and August). Generally, the predicted concentrations are found much lower than the permissible limit values with the maximum ground level concentrations being found much closer to the plant. On the basis of this study it can be stated that the Oman LNG plant, after the addition of train 3, is not likely to cause significant deterioration in air quality.