Petroleum derivatives have become ubiquitous in modern life, from agriculture and medicine to the textile industry. Bitumen, a versatile substance derived from petroleum, is no exception. Bitumen is a general term for flammable, brown or black mixtures of tar-like hydrocarbons that are derived naturally or through petroleum distillation. It can range in form from viscous oil to a brittle solid, encompassing asphalt, tars, and natural mineral waxes; substances containing bitumen are referred to as bituminous. Coal, another form of bitumen, fueled the Industrial Revolution.
The terminology surrounding bitumen varies geographically. In British English, ‘bitumen’ is often used interchangeably with ‘asphalt’ and ‘tar.’ American English typically uses ‘bitumen’ in engineering to encompass both asphalt- and tar-based materials, while in Australian English, ‘bitumen’ is the common term for road surfaces.
Historically, bitumen served as a waterproofing agent for boats and buildings. Some historians suggest that the extensive use of bitumen in construction may have contributed to the ease with which Carthage was burned.
Today, bitumen’s primary application is in road paving. It is also employed in waterproofing products, such as roofing felt and flat roof sealants. Furthermore, bitumen serves as a key feedstock for petroleum production from tar sands, a practice currently under development in Alberta, Canada.
The formation of naturally occurring bitumen deposits is a subject of ongoing geological discussion. The prevailing theory posits that these deposits originate from the remains of ancient, microscopic algae and other organisms. As these organisms died, their remains accumulated in mud at the bottom of oceans or lakes. Over time, heat and pressure deep within the Earth transformed these remains into substances such as bitumen, kerogen, or petroleum.
An alternative theory, the abiogenic petroleum origin theory, suggests that bitumen and other heavy hydrocarbons originate from deep within the Earth’s mantle, independent of biological detritus.