Oil and gas production handbook - Process Control and ...

origiate from organic decay. At the sea bottom, under high pressure and low
temperatures, the hydrate is heavier than water and will not escape, but stay at the
bottom. Research has revealed that they may be much more plentiful than first
expected. Estimates range anywhere from 180 to over 5800 trillion scm. The US
Geological Survey estimates that methane hydrates may contain more organic carbon
than the world's coal, oil, and conventional natural gas – combined. However,
research into methane hydrates is still in its infancy.
3.8.6 Biofuels
Biofuels are produced from specially grown products such as oil seeds or sugars, and
organic waste e.g. from the forest industry.
Alcohol is distilled from fermented sugars and/or starch (e.g. wood or grain) to
produce Ethanol that can be burnt alone, or mixed with ordinary petrol.
Biodiesel is made through a chemical process called transesterification whereby the
glycerin is separated from fat or vegetable oil. The process leaves behind two
products -- methyl esters (the chemical name for biodiesel) and glycerin (a valuable
byproduct usually sold to be used in soaps and other products). Biodiesel contains no
petroleum, but it can be blended at any level with petroleum diesel to create a
biodiesel blend. It can be used in compression-ignition (diesel) engines with little or
no modifications. Biodiesel is simple to use, biodegradable, nontoxic, and essentially
free of sulfur and aromatics.
Brazil and Sweden are two countries with full scale biofuel programs.
3.8.7 Hydrogen
Although not a hydrocarbon ressource, hydrogen can be used in place of or
complement traditional hydrocarbon based fuels. Hydrogen is clean burning, which
means that when hydrogen reacts with oxygen, either in a conventional engine or a
fuel cell, water vapor is the only emission. (Combustion with air at high temperatures
will also form nitrous oxides).
Hydrogen can be produced either from hydrocarbons (natural gas, ethanol etc.) or by
electrolysis. Production from natural gas (catalytic: CH 4 + ½ O 2 2H 2 + CO, CO +
½ O 2 CO 2 ) also produces energy and carbondioxide, but has the advantage over
methane gas that carbon dioxide can be removed and handled at a central location
rather than from each consumer (car, ship etc.), providing a cleaner energy source.
Hydrogen is also produced with electrolysis from water, or in various recycling
processes in the chemical industry. (e.g. Hydrocloric acid recycle in the polyurethane
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