Fuels and Lubricants (F&L). Sources of FL Raw Materials. Nonrenewable Primary Energy
Resources
All
types of equipment and machinery have been greatly improved mechanically and designed to
run under far more severe operating conditions. Fuels, lubricants, and other oil products, likewise,
have been greatly improved and adapted for exacting operating requirements. The selection
of the proper product for the specific application thus has become more
important than ever before. The proper transportation, storage, and handling of products to ensure that they reach the point
of usage with their properties unchanged from their manufacture are also important.
Since F&L
derived from oil in the refining processes make up the most of all F&L
used, they will be referred to and analyzed in this discipline course as the
main object. According to the international standard ISO 8681 (International organization
for standardization), all oil products are classified into five main classes
named with alphabetic indexes (table 1).
Table 1
Classification
of petroleum products according to ISO 8681
Class
|
Product
|
F
|
Fuel
|
L
|
Lubricants, industrial oils and related products
|
W
|
Paraffin
|
B
|
Bitumen
|
S
|
Solvents and raw material for the chemical
industry
|
Fuel
is any material or individual substance that can be burned or altered to obtain
different kinds of energy for heating and/or moving objects. Fuel releases its
energy through chemical reactions, such as combustion and oxidizing. An
important property of a useful fuel is that its energy can be stored to be
released only when needed, and that the release is controlled in such a way
that the energy can be harnessed to produce work. The application of energy released from fuels
ranges from heat for cooking and from powering weapons to combustion and
generation of electricity.
Fuels are usually
categorized according to four main indications
into groups, grades, brands and kinds:
a) based on their origin – there are
natural and synthetic (artificial);
b) based on their chemical structure
– hydrocarbon and non-hydrocarbon;
c) based on their state of matter – gaseous, liquid and solid;
d) based on the engine
type (gasoline, diesel fuel, jet fuel, gas oil, rocket fuel).
ISO 8216/0 sets the general classification
of the oil origin fuels (table 2).
Table 2
General
classification of fuels according to ISO 8216/0
Class
|
Category
|
Title
|
G
|
Gaseous fuel. Gaseous fuel of petroleum origin
consisting mainly of methane and (or) ethane
|
|
F
|
L
|
Liquefied gaseous fuel. Gaseous fuel of petroleum
origin consisting mainly of propane, propene and (or) butane and butene
|
D
|
Distillate fuel. Fuel of petroleum origin except
for liquefied petroleum gases and fuels. Include gasoline, kerosene, gas-oil
and diesel fuel. Heavy distillates may contain a small amount of residuals
|
|
R
|
Residual fuel. Petroleum fuel containing residual
fractions of distillation
|
|
C
|
Petroleum cokes. Solid fuel of petroleum origin
consisting mainly of carbon, obtained through the process of cracking
|
The
work of engines, mechanisms and machines is accompanied by friction of
contacting and moving surfaces.
Lubricants are individual substances or materials that are used for decreasing
of wear of rubbing details and decreasing the loss of power expended on
friction in any mechanism.
All lubricants are subdivided into
three basic groups:
1. The lubricants, which under
normal conditions are liquids (oils).
2. Consistent (plastic, flexible)
lubricating materials (lubricating pasty greases).
3. Solid lubricants that might be
used as oil additives and grease additives, or as individual lubricants.
Natural
resources such as coal, petroleum, oil and natural gas take thousands of years
to form naturally and cannot be replaced as fast as they are being consumed.
Eventually natural resources will become too costly to harvest and humanity
will need to find other sources of energy. At present, the main energy sources
used by humans are non-renewable as they are cheap to produce. Natural
resources, called renewable resources,
are replaced by natural processes during a reasonable amount of time. Soil,
water, forests, plants, and animals are all renewable resources as long as they
are properly conserved. Solar, wind, wave, and geothermal energies are based on
renewable resources. Renewable resources such as the movement of water
(hydropower, including tidal power; ocean surface waves used for wave power),
wind (used for wind power), geothermal heat (used for geothermal power); and
radiant energy (used for solar power) are practically infinite and cannot be
depleted, unlike their non-renewable counterparts, which are likely to run out
if not used wisely.
A non-renewable resource is a natural resource which cannot be
produced, re-grown, regenerated, or reused on a scale which can sustain its
consumption rate. These resources often exist in a fixed amount, or are
consumed much faster than nature can recreate them. Fossil fuel (such as
coal, petroleum and natural gas) and nuclear power are examples. In contrast,
resources such as timber (when harvested sustainably) or metals (which can be
recycled) are considered renewable resources
Fossil fuels are fuels generally thought to be formed by natural
resources such as anaerobic decomposition of buried dead organisms. Fossil
fuels range from volatile materials with low carbon:hydrogen ratios like
methane, to liquid petroleum to nonvolatile materials composed of almost pure
carbon, like anthracite coal. It is
generally accepted that they are formed from the fossilized remains of dead
plants and animals by exposure to heat and pressure in the Earth's crust over hundreds
of millions of years.
Fossil fuels are easy to
transport, store, and use, and
they have very high energy capacity per unit of mass.
It was estimated that
in 2007 primary sources of energy used by mankind consisted of
petroleum 35,0%,
coal 27,0 %,
natural gas 23,0%,
amounting to an 85 % share for fossil fuels in primary energy
consumption in the world.
Non-fossil sources in 2007 included
hydroelectric 6,0 %,
nuclear 8,0 %, and
geothermal, solar, tide, wind, wood, waste
amounting 1 percent.
World
energy consumption has been growing about 2.3% per year.
Petroleum is by far the
most commonly used source of energy, especially as the source of liquid fuels,
and its use is projected to continue at least at the current levels for at least
two decades .
Figure 1.1. Trends and the
projected trend for the use of fossil fuel resources and other fuel resources until
2020.
Fossil fuels are non-renewable
resources because they take millions of years to form, and reserves are being
depleted much faster than new ones are being formed. The production and use of
fossil fuels raise environmental concerns. A global movement toward the
generation of renewable energy is therefore under way to help meet increased
energy needs.
Total
fuel reserves of the Earth are estimated at the level of 12,5 trillion tons of
equivalent fuel (1 kg
of equivalent fuel = 29,4 MJ/kg (~7000 kcal);
However
only 3,5 trillions tons of these resources may be extracted and used with
modern technological methods.
Hydrocarbon Sources for FL
production
Most of FL are produced
using petroleum as a main raw material. Oil is refined in different processes
to produce large variety of derived products.
Petroleum products may
also be supplied in whole or in part from natural
gas. Crude oil emerging from the
well is accompanied by a large volume of natural gas, about 100 m3 of gas per
barrel of oil on the average (1 barrel =
158.94 L). The quantity of natural gas produced per barrel of oil decreases
with the age of the oil field. More than two-fifths of the gas obtained from
oil wells is returned to the ground to maintain the pressure in the oil pools
and thus increase the ultimate oil recovery.
Though natural gas is
predominantly methane, it contains other saturated hydrocarbons and gasoline vapors.
The liquids extracted from gas constitute an important supplement to our
petroleum resources. Today they are about one-tenth the volume of the crude oil
taken from the ground. The heavier
hydrocarbons are recovered and sold as liquefied
petroleum gas (LP-Gas), natural gasoline, solvents, and raw materials for
the manufacture of plastics and chemicals, among other uses.
Petroleum is the
cheapest but not the only possible source of liquid fuels. Petroleum
substitutes can be obtained from oil
sands (also called tar sands),
large beds of which are found in Canada
and Venezuela .
These sands are basically a mixture of sand, clay, water, and a form of
petroleum called “bitumen,” which is very viscous and dense material.
Coal, which is almost
pure carbon, can be changed to liquid fuels by combining it chemically with
hydrogen. This process today is also more costly than the production of these
fuels from petroleum. Processes are available to recover the oil from the shale
but at a cost today which generally speaking is higher than the cost of
producing petroleum from wells. Shale
oil recovery and hydrogenation of coal are now economical in some European
countries which are located far from crude-oil supplies in the ground.
taken from Mykola Zakharchuk
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