Air emissions from the oil and natural gas industry

Abstract

The world energy demand, having more than doubled during the past 40 years, is estimated to reach 17,000 million tonnes of oil equivalent in 2030. Oil and natural gas account for more than 50% of the total fuel consumption. Air pollutants are emitted at every step in the oil–gas industry, including mining, refining, storage, transportation between different storage facilities, and refuelling. VOCs, H2S, NOx, PAHs, SO2, methane, and particulate matter are common contaminants of the oil–gas emissions. Methane, the predominant component of natural gas, has a 25 times greater climate change impact than CO2. Globally, methane accounts for 15% of the total anthropogenic greenhouse gas emissions in terms of CO2 equivalent. All these contaminants can cause human health and environmental problems as well as economic losses. Natural gas is considered a cleaner fuel than coal or oil because fewer air pollutants are generated during combustion. Consequently, some coal-fired power plants are being converted to natural gas, and there is a renewed interest in natural gas vehicles. Meanwhile, as readily accessible fossil fuel deposits are being depleted, oil and gas from unconventional reserves are being explored and extracted, such as oil sands, hydraulic fracturing, and gas hydrates. Extraction of oil/gas from these reserves requires more complex technology, and carries a greater environmental risk. The US and Canada are leading the world in gas production by hydraulic fracturing, but its environmental impact is evident not only at locations in close proximity but also remotely.