(78a) Oil Sands Processing: An Unconventional Source of Synthetic Crude Oil

The current energy scenario is alarming due to a continuous depletion in the conventional oil reserves, leading to an obvious hike in petrochemical and the fuel cost. There is a dreadful need for exploration of other potential unconventional sources of energy to sustain the future requirements. Oil Sands have been identified as one of the major sources of unconventional crude oil with major reserves in North America, especially in Canada.

Oil Sands are generally a combination of sand with a layer of bitumen coated on it. It is highly viscous and has many impurities present, making it unsuitable for use in its raw form. Oil Sands are processed further through extraction and then upgraded to synthetic crude. This process of extraction is usually done by open pit mining or in – situ extraction depending on the depth of the reserves. Open pit mining usually encompasses the conditioning of bitumen to extract sand and water from it though various techniques including froth flotation. In- situ extraction can be carried out by a variety of techniques. The most popular of these are Cyclic Steam Stimulation and Steam assisted gravity drainage.

The final extracted bitumen after the extraction is then transported to an upgrading facility. This bitumen is either blended with diluent and sent to refineries for downstream processing or we upgrade the bitumen by diluent recovery & recycle and also allow for further processing. While the processed bitumen is sent to cokers for cracking to lighter hydrocarbons also which forms coke as a by product, the lighter hydrocarbons are stabilised by addition of hydrogen while nitrogen and sulphur removal takes place. The final blend that we acquire is similar in properties to the conventional crude oil with low sulphur impurities. This blend of Synthetic Crude Oil is sent to existing refineries as an alternative for converting into transportation fuel. Although, Oil sands are a high potential alternate energy reserves but its processing leads to a variety of environmental drawbacks like Green house gas emissions, enormous water requirements for processing along with waste water disposal and disturbance of natural habitat and surface destruction through extraction. Sustainable plans need to be made by the oil sand industries to minimize these effects.