Crude oil needs to be extracted from deep below the ground by drilling wells and using an oil rig to pump it to the surface. The oil is not located everywhere under the Earth's surface. Usually geologists find it by using explosives underground where they suspect that oil may be present. Geologists use measurements of reflected sound waves from the explosions to help them discover whether oil is present or not. Then they do a test drill breaking through a cap of solid rock. The layer above the oil is a layer of soft rock (chalk or sandstone) and oil. The layer below is porous rock containing salt water. If oil is located, it is pumped to the surface. An oil storage buoy is placed above the location of the drill. If there is a lot of natural gas trapped in a pocket along with the crude oil, a “gusher-type” well develops where the oil gushes to the surface requiring very little pumping. Natural gas is commonly used in houses all over the world. Oil tankers are used to transport the oil.
Text 4
Luminous Flames and Non-Luminous Flames
A luminous flame occurs when there is a limited supply of oxygen during burning. This results in incomplete combustion, which forms soot, carbon monoxide, as well as carbon dioxide that is the main gas formed. The soot is pure carbon, and causes the blackening of lampshades or the bottom of pans. Carbon monoxide is a toxic gas. It is dangerous because it bonds with haemoglobin in the blood, preventing it from transporting oxygen to the cells in the body. If carbon monoxide poisoning is not treated immediately, it will result in death. A luminous flame is a large, bright yellow flame, which generally burns unsteadily. Also, as the name suggests, the luminous flame gives out light. This is because the tiny particles of carbon soot glow when they get very hot. These flames are common in a burning candle, a gas lamp, or a Bunsen burner when the air hole is closed.
Non-luminous flames occur when there is an abundant supply of oxygen, which results in complete combustion. The main product of complete combustion is carbon dioxide. No carbon monoxide or soot is formed. The non-luminous flame does not give out much light since it contains no carbon which can get hot. These flames have a characteristic blue colour and burn steadily. They give out a roaring sound and so are also known as “roaring” flames. Non-luminous flames can be observed when the burners of a gas-stove are lit, or when the air hole of a lit Bunsen burner is open.
Text 5
Fuel Production
The deployment of the sustainable vehicle technology depends critically on transitions in the global fuel production system, particularly the increasing availability of alcohol fuels and hydrogen. Initially, alcohol fuels have a number of advantages over hydrogen – they can be handled relatively easily and distributed utilizing some of the existing fuel delivery infrastructure – and so play an important role in improving sustainability in this scenario before hydrogen supply infrastructure is fully developed, and fuel cells are mature. Importantly, throughout much of the century alcohols and hydrogen complement one another, rather than compete, as they increasingly substitute for fossil fuels in surface transport. This is illustrated in Fig. 8 which compares global petroleum production (refining) with production of alternative fuels over the century under this scenario.
The continuing reliance on petroleum fuels in this scenario occurs partly because of barriers to the mobilization of technologies and sufficient resources for large-scale non-fossil synthetic fuel production and distribution, particularly from biomass. For instance, hydrogen is initially synthesized from natural gas, which is a more technologically mature production path relying on a conventional feedstock. Later, synthesis from biomass becomes the preferred production route for both hydrogen and alcohols. Under this scenario, hydrogen synthesis from biomass is also combined with carbon capture and storage (CCS) technologies, resulting in a fuel with net negative emissions.
Given the importance of biomass in this scenario it is worth briefly mentioning the biomass resource potentials assumed in the ERIS model. These potentials are based on estimates from Rogner who identified an annual global potential in 2050 of between 250 and 400 EJ, mostly in Africa and Latin America. This is similar to other estimates, such as in Fischer and Schrattenholzer. In this scenario we assume that this potential can only be fully exploited towards the end of the century, and that in 2020 only 125 EJ is available, rising to 235 EJ in 2050 and 320 EJ by 2100.
Text 6