Some facts about natural gasmohamed / 0 Comments /
There is a growing demand around the world for natural gas as a fuel. This clean fuel is available only in certain regions and the Middle East is one of these areas. But the biggest natural gas consumers – such as Europe and the Far East – are located far away from the production areas. Therefore, it is economically important to transport natural gas. Just like air around us, natural gas in its normal state occupies a large area.
However, it must be sent in large quantities in order to be economically feasible. It can be sent to customers in its natural form via pipelines, but providing pipelines to clients who are located thousands of kilometers away from the production sites is not a practical nor economic matter, but there is another way. If natural gas is cooled to 160 degrees Celsius below zero, it becomes liquid and in its liquid form, its volume is reduced 600 times, making it possible to transport huge amounts of gas in petrol tankers and to be shipped to clients around the world.
How to store liquefied gas
Liquefied naturel gas tankers are built with two walls with an effective largely insulation between the walls. These huge tankers are characterized by low (aspect ratio) and a cylindrical design with a roof in a dome shape.
Theses tankers have very low degree of storage pressure, less than 5 degrees(psig). There is the possibility of storing small amounts like for example 70,000 gallons and less in horizontal or vertical tanks with compressed air vacuum. These tanks can be anywhere under pressure less than 5 ° (psig) to more than 250 degrees (psig).
We must conserve the coolness of liquefied natural gas (84 degrees Fahrenheit below zero, at least) in order to remain it liquid, and independent of pressure.
How coldness is maintained?
Whatever is the effectiveness of the insulation process, it cannot maintain by its own the degree of coolness of the liquefied natural gas.
Liquefied naturel gas is saved as a “coolant in boiling point” which is a very cold liquid at its boiling point in the pressure of its conservation. And stored liquefied naturel gas is analogous to boiling water except that its coolness is higher by 260 ° C only.
The degree of boiling water, equivalent to 100 ° C does not change at all despite of the increasing heat which is due to cooling that results from the evaporation process (steam generation). In the same way, it will almost remain liquefied natural gas at a constant temperature if it will be kept in a fixed pressure. This phenomenon is called the “self-cooling” and remain a constant temperature as long as it allows the vapor of liquefied natural gas to leave the tea kettle (reservoir).
And If there is no withdrawal of steam it will raise the temperature inside the bowl. Even when the degree of pressure is 100 (psig), the degree of liquefied natural gas heat will be approximately 129 degrees Fahrenheit under zero.
What is the best way to transport liquefied natural gas in pipes without being freezed?
There are 1,000 meters long pipes (thousand meters) in which liquefied naturel gas must be transported, but the fear is from the accumulation of frozen parts on its outer wall so What is the correct way to transport the liquefied gas in these pipes? Shall we isolate pipes? what is the type of its thickness? And can we pump through a normal pump? stay tuned in the next article………