Signal providers for forex trading13 comments
Rawya trading options
Liquefied natural gas LNG is natural gas predominantly methane , CH 4 , with some mixture of ethane C 2 H 6 that has been converted to liquid form for ease and safety of non-pressurized storage or transport. It is odorless , colorless , non-toxic and non-corrosive. Hazards include flammability after vaporization into a gaseous state, freezing and asphyxia. The liquefaction process involves removal of certain components, such as dust, acid gases , helium , water, and heavy hydrocarbons , which could cause difficulty downstream.
Natural gas is mainly converted in to LNG to achieve the natural gas transport over the seas where laying pipelines is not feasible technically and economically. However, CNG carrier can be used economically up to medium distances in marine transport. LNG is principally used for transporting natural gas to markets, where it is regasified and distributed as pipeline natural gas.
It can be used in natural gas vehicles , although it is more common to design vehicles to use compressed natural gas. Its relatively high cost of production and the need to store it in expensive cryogenic tanks have hindered widespread commercial use. The heating value depends on the source of gas that is used and the process that is used to liquefy the gas. The density of LNG is roughly 0. Using the median value of 0.
The volume-based energy density of LNG is approximately 2. The energy density of LNG is comparable to propane and ethanol but is only 60 percent that of diesel and 70 percent that of gasoline. Experiments on the properties of gases started early in the seventeenth century. By the middle of the seventeenth century Robert Boyle had derived the inverse relationship between the pressure and the volume of gases.
About the same time, Guillaume Amontons started looking into temperature effects on gas. Various gas experiments continued for the next years. During that time there were efforts to liquefy gases. Many new facts on the nature of gases had been discovered. For example, early in the nineteenth century Cagniard de la Tour had shown there was a temperature above which a gas could not be liquefied.
There was a major push in the mid to late nineteenth century to liquefy all gases. In Karol Olszewski liquefied methane, the primary constituent of natural gas.
By all gases had been liquefied except helium which was liquefied in The first large scale liquefaction of natural gas in the U. This helium was intended for use in British dirigibles for World War I. The liquid natural gas LNG was not stored, but regasified and immediately put into the gas mains. The key patents having to do with natural gas liquefaction were in and the mids.
In Godfrey Cabot patented a method for storing liquid gases at very low temperatures. It consisted of a Thermos bottle type design which included a cold inner tank within an outer tank; the tanks being separated by insulation. In Lee Twomey received patents for a process for large scale liquefaction of natural gas. The intention was to store natural gas as a liquid so it could be used for shaving peak energy loads during cold snaps.
Because of large volumes it is not practical to store natural gas, as a gas, near atmospheric pressure. However, if it can be liquefied it can be stored in a volume times smaller.
There are two processes for liquefying natural gas in large quantities. The first is the cascade process, in which the natural gas is cooled by another gas which in turn has been cooled by still another gas, hence named the "cascade" process. There are usually two cascade cycles prior to the liquid natural gas cycle. The other method is the Linde process , with a variation of the Linde process, called the Claude process, being sometimes used.
In this process, the gas is cooled regeneratively by continually passing it through an orifice until it is cooled to temperatures at which it liquefies. The cooling of gas by expanding it through an orifice was developed by James Joule and William Thomson and is known as the Joule—Thomson effect.
Lee Twomey used the cascade process for his patents. This was the first such plant in the world. Each sphere held the equivalent of about 50 million cubic feet of natural gas.
A fourth tank, a cylinder, was added in It had an equivalent capacity of million cubic feet of gas. The plant operated successfully for three years. The stored gas was regasified and put into the mains when cold snaps hit and extra capacity was needed. This precluded the denial of gas to some customers during a cold snap.
The Cleveland plant failed on October 20, when the cylindrical tank ruptured spilling thousands of gallons of LNG over the plant and nearby neighborhood. The gas evaporated and caught fire, which caused fatalities. However, over the next 15 years new research on low-temperature alloys, and better insulation materials, set the stage for a revival of the industry.
It restarted in when a U. Gulf coast to energy starved Great Britain. One more important attribute of LNG had now been exploited. Once natural gas was liquefied it could not only be stored more easily, but it could be transported.
Thus energy could now be shipped over the oceans via LNG the same way it was shipped by oil. The building continued through the s. These plants were not only used for peak-shaving, as in Cleveland, but also for base-load supplies for places that never had natural gas prior to this.
A number of import facilities were built on the East Coast in anticipation of the need to import energy via LNG. However, a recent boom in U. LNG export was completed in early The natural gas fed into the LNG plant will be treated to remove water, hydrogen sulfide , carbon dioxide and other components that will freeze e. It also contains small amounts of ethane , propane , butane , some heavier alkanes , and nitrogen. The most important infrastructure needed for LNG production and transportation is an LNG plant consisting of one or more LNG trains , each of which is an independent unit for gas liquefaction.
The largest LNG train in operation is in Qatar. These facilities recently reached a safety milestone, completing 12 years of operations on its offshore facilities without a Lost Time Incident. Regasification terminals are usually connected to a storage and pipeline distribution network to distribute natural gas to local distribution companies LDCs or independent power plants IPPs.
Information for the following table is derived in part from publication by the U. The LNG industry developed slowly during the second half of the last century because most LNG plants are located in remote areas not served by pipelines, and because of the large costs to treat and transport LNG.
In the early s, prices for constructing LNG plants, receiving terminals and vessels fell as new technologies emerged and more players invested in liquefaction and regasification. This tended to make LNG more competitive as a means of energy distribution, but increasing material costs and demand for construction contractors have put upward pressure on prices in the last few years. When Korean and Chinese shipyards entered the race, increased competition reduced profit margins and improved efficiency—reducing costs by 60 percent.
Costs in US dollars also declined due to the devaluation of the currencies of the world's largest shipbuilders: Since , the large number of orders increased demand for shipyard slots, raising their price and increasing ship costs. The per-ton construction cost of an LNG liquefaction plant fell steadily from the s through the s.
The cost reduced by approximately 35 percent. However, recently the cost of building liquefaction and regasification terminals doubled due to increased cost of materials and a shortage of skilled labor, professional engineers, designers, managers and other white-collar professionals.
Due to natural gas shortage concerns in the northeastern U. Concerns about the safety of such facilities create controversy in some regions where they are proposed. Broadwater Energy , an effort of TransCanada Corp. Local politicians including the Suffolk County Executive raised questions about the terminal.
Department of Energy approved Dominion Cove Point 's application to export up to million cubic feet per day of LNG to countries that do not have a free trade agreement with the U. Gulf Coast region have also received conditional Federal approval. In the commercial development of an LNG value chain, LNG suppliers first confirm sales to the downstream buyers and then sign long-term contracts typically 20—25 years with strict terms and structures for gas pricing.
Only when the customers are confirmed and the development of a greenfield project deemed economically feasible, could the sponsors of an LNG project invest in their development and operation. Thus, the LNG liquefaction business has been limited to players with strong financial and political resources.
LNG is shipped around the world in specially constructed seagoing vessels. The trade of LNG is completed by signing an SPA sale and purchase agreement between a supplier and receiving terminal, and by signing a GSA gas sale agreement between a receiving terminal and end-users.
Most of the contract terms used to be DES or ex ship , holding the seller responsible for the transport of the gas. With low shipbuilding costs, and the buyers preferring to ensure reliable and stable supply, however, contracts with FOB terms increased. Under such terms the buyer, who often owns a vessel or signs a long-term charter agreement with independent carriers, is responsible for the transport.
LNG purchasing agreements used to be for a long term with relatively little flexibility both in price and volume. If the annual contract quantity is confirmed, the buyer is obliged to take and pay for the product, or pay for it even if not taken, in what is referred to as the obligation of take-or-pay contract TOP. In the mids, LNG was a buyer's market. At the request of buyers, the SPAs began to adopt some flexibilities on volume and price.
The buyers had more upward and downward flexibilities in TOP, and short-term SPAs less than 16 years came into effect. At the same time, alternative destinations for cargo and arbitrage were also allowed. By the turn of the 21st century, the market was again in favor of sellers. However, sellers have become more sophisticated and are now proposing sharing of arbitrage opportunities and moving away from S-curve pricing.