66 Introduction to Renewable Biomaterials
ratio of production to new discoveries has gradually fallen and is currently estimated to
about three to one. For every discovered barrel of oil we consume three. It is therefore
evident that resources at our disposal are shrinking fast. At the same time, more and
more regions of the world are seeking high-quality lifestyles that are resource intensive.
Until relatively recently (about 30 years ago), high consumption of energy was reserved
for the developed economies of the ‘West’. Since then rapid development of other
countries such as China, India or Brazil resulted in huge increase for energy sources
worldwide. The entire population of OECD countries is estimated to be about 1.25
billion people and their primary energy use as 4.37 toe per capita [2]. When China, India
and Brazil, altogether about 2.75 billion people, approach even conservative ‘European’
levels of fossil resources usage (3.29 toe per capita) the additional supply exceeding the
current use of all OECD countries will be required. It is difficult to envisage how this
demand could be met with non-renewable resources in the medium to long term.
3.2.3 Conventional Fossil Resources and their Alternatives
Currently, our economies rely on three predominant sources of energy and carbon all
of which are fossils.
3.2.3.1 Light Crude Oil (Conventional Oil)
Light fractions of crude, also known as conventional oil are the most important of
fossil resources. Conventional oil is a liquid of relatively low density that flows freely
at room temperature. It is composed of a mixture of light hydrocarbons that have large
utility as fuels (gasoline and diesel) and platform chemicals for petrochemical industry.
Conventional oil is deposited in geological formations trapped by impermeable rocks.
These deposits are usually under enough pressure to allow the flow of the oil to the
surface once a well is drilled.
3.2.3.2 Coal
Coal is the first fossil resource that initiated Industrial Revolution. It is a combustible
sedimentary rock rich in organic carbon compounds (mainly aromatic). Coal is used
primarily for power generation and refining metals. The resource is extracted from
underground deposits by either shaft or strip mining.
3.2.3.3 Natural Gas
Natural gas is arguably the cleanest fossil fuel available. It is essentially pure methane
which upon combustion yields only CO 2 and H 2 O. It is also utilised in a series of
important chemical reactions that yield hydrogen (steam reforming) and subsequently
ammonia (Haber–Bosch process), which as such becomes not only hugely important
for our energy supply but also agriculture. Due to depletion of the resources of light
crude oil and cleaner combustion characteristics liquefied natural gas is increasingly
used as transportation fuel.
The reserves of each of these resources have been estimated to be sufficient for 55, 132
and 71 years of utilisation at 2011 consumption levels, respectively [6]. These numbers
however do not show the full picture. First, the growth of the economy will require addi-
tionalresourcestobeallocatedtofuelthisgrowth.Second,aswehaveseenintheearlier
section, it is the ratio of the resource supply to demand that really matters more than
