Problems Caused by Microbes and Treatment Strategies Downstream Petroleum Microbiology – An Industry Perspective

Abstract

In the mid 1800’s it was discovered that crude oil could be extracted and exploited to produce energy. However, it was the invention of the first four-stroke internal combustion engine in 1876 that transformed the petroleum industry from a localised to a global business (Dell and Rand, 2004). Crude oil is made into useable products at the refinery via separation, conversion and treatment processes. Separation starts with distillation where the crude is evaporated and condensed into fractions based on their boiling ranges (Fig. 19.1). As well as carbon and hydrogen, the fractions consist of sulphur, nitrogen and oxygen (present in low concentrations) and metals like copper and iron (in trace amounts). After separation, heavy fractions are converted into lighter ones using intense heat, pressure and a catalyst to speed up chemical reactions. Molecules like sulphur can then be stripped out by heat treatment under pressure with hydrogen. Injection of refinery additives makes a finished fuel. For example, static dissipator is added to Automotive Gas Oil (AGO) to reduce the risk of spark and explosion during fuel movements; middle distillate flow improver to improve low temperature operability and lubricity improver to lubricate engine components. Finally, fuel quality measurements are made to ensure that the finished fuel meets the relevant specification.