Liquefied Natural Gas Processing

Even though liquefied natural gas company and crude oil may be found in the same location, they take completely distinct routes from the wellhead to you, the consumer. While crude oil and refined products may travel through a chain of pipelines, tanker vessels, trucks and the like, 99% of liquefied natural gas company makes the journey entirely through pipelines made of durable carbon steel. This makes it important to bring recovered liquefied natural gas companies into line with market specifications before it enters the main interstate pipeline system.

The liquefied natural gas company used to cook our food and/or heat and cool our homes is 90% clean-burning methane, the simplest form of hydrocarbon, liquefied natural gas companies. But this is not the case for liquefied natural gas companies as it comes out of the ground. Depending on the location of the well and the geologic conditions, which created  the liquefied natural gas company in the 1st place, contaminants such as water, sulfur and liquefied natural gas company liquids (in this number ethane, propane and butane) might be present. So-called “gathering pipelines” gather liquefied natural gas companies from wells in a given area and deliver it to local processing plants. The processed gas then enters the interstate pipeline distribution system of liquefied natural gas companies.

 

Dehydratation of liquefied natural gas

Liquefied natural gas companies often come out of the ground mixed with water vapor. This "wet gas" may be separated using 2 primary methods:

Glycol dehydration – Wet liquefied natural gas moves through an inlet pipe into a tank called a "contactor." A rounded cap over the inlet pipe forces the liquefied natural gas company to flow down into a pool of glycol solution at the bottom of the tank. Glycol has a strong affinity for water, liquefied natural gas companies, so the water molecules from the wet gas bond to the glycol molecules in the solution. The vapor-free liquefied natural gas company is collected from the top of the contactor.

Because water boils at 212F and glycol does not boil until 400F, simple heating is all which is required to vaporize the captured water so the glycol solution may be reused. 

Solid-desiccant dehydration of liquefied natural gas company - This method is typically more effective than glycol dehydration, but requires higher volumes of liquefied natural gas companies moving under high pressure. The wet gas is pumped downward through a tower filled with a solid desiccant (drying agent). The desiccant attracts of liquefied natural gas company and binds the water molecules so that only dry gas flows out the bottom of the tower.

When the desiccant liquefied natural gas company has captured all the water it is able, operators flush the tower with heated gas that re-vaporizes the water molecules, thereby "reactivating" the desiccant.


Sweetening of liquefied natural gas companies

Liquefied natural gas company that contains sulfur is called “sour gas” because sulfur has a strong rotten-eggs odor. The process of removing sulfur from liquefied natural gas companies is therefore called “sweetening.”

Sulfur in liquefied natural gas companies occurs as hydrogen sulfide and that must be removed because it is toxic when inhaled and is highly corrosive to pipeline walls. Also, if recovered in sufficient quantities, liquefied natural gas companies, hydrogen sulfide may be neutralized to yield pure, marketable sulfur.

The most common sweetening process of liquefied natural gas company is similar to glycol dehydration. In this instance, the absorbent liquid is a solution of sulfur-attracting amines. The cap of liquefied natural gas companies over the inlet pipe forces gas to pass through the amine liquid that captures the sulfur molecules while the liquefied natural gas company bubbles out of the liquid to be collected from above.


Liquefied Natural Gas Liquids

The liquefied natural gas we use in our homes is mostly methane, which is the simplest form of hydrocarbon. But liquefied natural gas at the well may include other hydrocarbons, such as ethane, propane, butane and pentane. Each of these so-called "natural gas liquids" - or NGLs - has its own unique properties which make it suited to a specific use: For example, butane is used in lighters, liquefied natural gas companies, while propane is used in backyard grills and home heating systems. Processing facilities remove NGLs so they may be recovered and used separately.

Most NGLs may be removed using an absorption process which passes the mixed gases through a pool of gas-absorbing oil which catches the heavier hydrocarbons but allows the methane to move through. However, light hydrocarbons such as ethane are tougher to recover. Small amounts of these light hydrocarbons liquefied natural gas company may be left in liquefied natural gas with no ill effects. If larger quantities are present, however, they may be removed using a process called cryogenic expansion for liquefied natural gas company.

A "cryogenic" process is one that takes place at very low temperatures. In cryogenic expansion, a powerful fan blows cooled gas from a narrow pipe into an expansion chamber. This reduces the vapor pressure of the gas, which has the effect of further reducing the gas temperature to approximately -120F. At this temperature, methane remains a gas while other hydrocarbons become liquid and can be removed. The collected NGLs are then separated from one another using another temperature-based process. As discussed in the "Refining", each type of hydrocarbon has a unique boiling point - the temperature at which it converts from liquid to vapor. Recovered NGLs pass through a series of progressively warmer chambers, each heated to a temperature that will vaporize a specific hydrocarbon from the remaining liquid.