How are heavy oil and bitumen processed?
Heavy oil and bitumen consist of large hydrocarbon molecules, which contain proportionately more carbon atoms than hydrogen atoms. Upgrading processes add hydrogen atoms and/or remove carbon atoms, which converts the bitumen into a product similar to conventional light crude oil. Upgrading is usually a two-stage process. In the first stage, bitumen is heated and hydrogen added under high pressure to break down (or crack) the large hydrocarbon molecules into simpler, smaller compounds. This process is called hydrocracking. Some upgraders also utilize a process called coking, which removes carbon from the bitumen to produce lighter hydrocarbons and coke, a carbon material that resembles finely ground asphalt. During the second stage, hydrogen is added to the hydrocarbon compounds to stabilize them and remove impurities such as sulphur. This process is called hydrotreating. Upgrading produces three main products: naphtha, kerosene and gas oil, a fuel oil that is somewhat heavier than kero
