Media: First liquefied natural gas tanker to ship from US to Europe on April 26
There is clearly something strange going on with these gas news reports. One gets the impression of a purposeful war of intimidation. Horror - horror, look, the US has finally started delivering its LNG to Europe. Here, one gas carrier has already arrived. And the next one will be in a couple of days. It's all gone, boss! The American gas attack on Russia has begun! We're all going to die, we're all going to die!
Please note that these reports are published on leading Russian news platforms. It is interesting to find out who needs it and why? At least because for the most part this news is either "very inaccurate" or downright false. In fact, it turns out that either instead of butane with propane they brought something else, much less applicable for heating and domestic needs, or in the tanks there were raw materials for the chemical industry, like ammonia, which is also a gas, but not the same gas at all.
But something else is more curious. In one of the recent comments on this topic, I already gave this calculation. However, I will repeat it again.
The volume of Russian gas deliveries to Europe has reached 160 billion m3 per year.
The total volume of the entire world fleet of gas carriers is 8.3 billion m3.
Even if we forget that half of them are intended for the transportation of chemicals, such as ammonia, and assume that all of them can be mobilized for the transportation of propane-butane to Europe, it still turns out that to deliver such a volume of gas, each of them will need to make 19.3 flights per year or one flight in 19 days. Roughly speaking, 9 days there and 9 days back.
At the same time, loading of one gas carrier takes 7 days and unloading - at least four. Those. 4.5 days or 108 hours of travel remain for the passage by sea. The minimum distance between Cape Roca (the westernmost point of Europe) and Cape St. Charles (the easternmost point of North America) is 3909 km. Therefore, in order to pass them on time, the gas carrier must develop an average speed of 36.1 km/h or 20 knots. While the maximum speed of gas carriers does not exceed 16 knots, they normally operate at 6-8 knots.
Something somehow does not work with the revolution. I don't even ask where the US will get 160 billion cubic meters of propane-butane, because all kinds of ammonia are not suitable for heating. Even if a miracle happens and they find the required amount of gas somewhere, how will they be able to deliver it to Europe?
Moreover, please note that the problem with delivery arises even with the current size of the share of Russian gas in the European market. According to the most modest estimates, plans to close nuclear power plants and stop, for environmental reasons, coal-fired generation will create additional demand in Europe for at least another 100-120 billion cubic meters a year over the next 3-5 years. How to pump them through the Russian pipeline system, which is currently only 60% loaded, is understandable, but how to deliver them in the form of LNG from the United States is completely incomprehensible to me personally.
The only icebreaking gas carrier in the world August 23rd, 2017
There are two views of the Northern Sea Route. Supporters of the first argue that it will never become profitable and no one will use it in large numbers, while supporters of the second argue that this is only the beginning: the ice will melt even more and let this one be the most profitable in certain circumstances. It seems to me that the second one wins. It is not for nothing that such topics are thrown about
LNG carrier Christophe de Margerie (ship owner of PAO Sovcomflot) successfully completed its first commercial voyage on August 17, 2017, delivering a consignment of liquefied natural gas (LNG) via the Northern Sea Route (NSR) from Norway to South Korea.
During the voyage, the ship set a new record for crossing the NSR - 6.5 days. At the same time, Christophe de Margerie became the first merchant ship in the world that was able to navigate the NSR without icebreaking assistance throughout this route.
During the passage along the NSR, the vessel covered 2,193 miles (3,530 km) from Cape Zhelaniya on the Novaya Zemlya archipelago to Cape Dezhnev in Chukotka, the extreme eastern mainland point of Russia. The exact transition time was 6 days 12 hours 15 minutes.
During the voyage, the vessel again confirmed its exceptional suitability for operation in high latitudes. The average speed during the passage exceeded 14 knots, despite the fact that in some sections the gas carrier was forced to go through ice fields up to 1.2 m thick. using the Northern Sea Route was 22 days, which is almost 30% less than it would be required when crossing the traditional southern route through the Suez Canal. The results of the voyage made it possible once again to confirm the economic efficiency of using the Northern Sea Route for the transit of large-capacity vessels.
"Christophe de Margerie" is the first and so far the only icebreaking gas carrier in the world. The unique vessel was built by order of the Sovcomflot group of companies for year-round transportation of LNG as part of the Yamal LNG project. The vessel was put into operation on March 27, 2017 after the successful completion of ice trials that took place in the Kara Sea and the Laptev Sea.
The gas carrier is able to independently overcome ice up to 2.1 m thick. The vessel has an Arc7 ice class, the highest among existing transport vessels. The power of the propulsion plant of the gas carrier is 45 MW, which is comparable to the power of a modern nuclear-powered icebreaker. Christophe de Margerie's high ice-breaking capability and maneuverability are ensured by Azipod-type rudder propellers, while it became the world's first high-ice-class vessel with three Azipods installed at once.
The gas carrier is named after Christophe de Margerie, ex-head of the Total concern. He played a key role in the development of investment decisions and the technological scheme of the Yamal LNG project and made a significant contribution to the development of Russian-French economic relations in general.
Sovcomflot Group (SKF Group) is the largest shipping company in Russia, one of the world's leading companies in the marine transportation of hydrocarbons, as well as servicing offshore exploration and production of oil and gas. Own and chartered fleet includes 149 vessels with a total deadweight of more than 13.1 million tons. Half of the ships have an ice class.
Sovcomflot is involved in servicing major oil and gas projects in Russia and around the world: Sakhalin-1, Sakhalin-2, Varandey, Prirazlomnoye, Novy Port, Yamal LNG, Tangguh (Indonesia). The company's head office is located in St. Petersburg, representative offices are located in Moscow, Novorossiysk, Murmansk, Vladivostok, Yuzhno-Sakhalinsk, London, Limassol and Dubai.
sources
Specially for the transportation of liquefied natural gas (LNG), such as methane, butane and propane, in tanks or tanks, gas carriers are used, which are in the form of refrigerated, semi-refrigerated or pressurized.
Gas carriers: general information
In 1945, advances in technology made it possible to build the first liquefied natural gas ship, the Marlin Hitch, which was equipped with aluminum tanks with external balsa insulation. The first flight was from the US to the UK with a cargo of 5,000 cubic meters of cargo. It was later renamed "Methane Pioneer". At one time it was the largest in the world.
Gas carrier ships use refrigeration units to cool gases. Unloading takes place at special regasification terminals.
The construction of tankers for the transportation of liquefied natural gas takes place on the platforms of Japanese and Korean shipyards, such as Daewoo, Kawasaki, Mitsui, Samsung, Hyundai, Mitsubishi. Korean shipbuilders
produced more than two-thirds of the gas carriers on the planet. Carrying capacity of modern vessels of the Q-Max and Q-Flex series is up to 210-266 thousand cubic meters. m LNG.
The demand for gas carriers is justified by the fact that natural gas is one of the main sources of fuel energy, it is used in the metallurgical and chemical industries, as well as for public utilities. 
household purposes.
Transportation of gas by sea is quite expensive, but it is necessary if the laying of pipes on land is not possible and the place of gas production and its consumer are separated by seas or oceans. Despite these difficulties,
modern gas carriers fully cope with this task.
Depending on the type of transported substances, gas carriers of ships can be divided into delivery:
- gaseous chemical products;
- natural gas;
- associated gas.
Such a distribution is not only a theory, but a necessity, because the gas has different physical and chemical properties and its own characteristics. Gas is transported separately from oil, because it can be explosive.
There are different types of tankers, for example, with rectangular self-supporting tanks, with spherical tanks and with two types of membrane tanks. There is no consensus on which ship is the best at the moment.
Every day more and more ships are being created. This is due to the growth in gas consumption and the increase in the volume of its transportation by water, as well as the availability of specialized loading ports. Modern tankers have overtaken the tankers of the 50s in size, and are becoming real giants.
The world's largest gas carrier
It became known about the completion of the construction of one of the world's largest tankers for the production and transportation of natural gas. It is the brainchild of the energy company Royal Dutch Shell.
The ship was named "Prelude". Its length is 488 meters. Upon completion, the floating giant will float on the high seas off the coast of Western Australia.
The design of the gas carrier allows LNG production in all weather conditions and is able to withstand Category 5 tropical cyclones. The floating complex is designed for offshore gas production and direct transfer to buyers' vessels.
The expected start of the development of the first large fields with the help of Preludes is scheduled for 2017.
Modern gas carriers make it possible to produce gas both at large and remote small fields. Tanker designers are constantly working to reduce diesel fuel costs and reduce
emissions of harmful substances into the atmosphere.
International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk (IGC Code)
MARPOL, SOLAS.???
2. Classification and design features of gas carrier ships.
Gas carrier - a single-deck vessel with a stern location of the MO, the hull of which is divided by transverse and longitudinal bulkheads (for the transport of liquefied gases).
Gas carrier classification:
1. By transportation methods:
Fully sealed gas carriers (pressure). Mainly small LNG carriers for transporting propane, butane and ammonia at ambient temperature and saturation pressure of the transported gas.
Fully refrigerated LPG gas carriers. They transport liquefied petroleum gas at a temperature of minus fifty-five and LNG. on which liquefied natural gas is transported at a temperature equal to minus one hundred and sixty degrees.
Semi-refrigerated gas
Semi-hermetic gas carrier. Gas is transported in a liquefied state, partly due to refrigeration and pressure. Gas is transported in thermally insulated tanks limited in pressure, temperature and gas density, which allows the transport of a wide range of gases and chemicals.
Isolated gas carriers of large displacement. The gas enters in a cooled liquefied state. During transportation, the gas is partially evaporated and used as fuel.
2. According to the degree of danger: Classification according to IGCCode.
1g. For the transport of chlorine, methyl bromide, sulfur dioxide and other gases specified in chapter XIXIGCCode with maximum precautions at the greatest risk to the environment.
2g. Vessel for the carriage of goods specified in chapter XIXIGCCode which require significant precautionary measures to prevent leakage of gas.
2PG. General type of gas carriers up to 150 meters in length, carrying cargo specified in chapter XIX, which requires safety measures for tanks, a pressure of at least 7 bar and for a cargo system a temperature of not more than minus 55 degrees Celsius.
3. By types of transported goods.
LPG carriers for the transport of liquefied petroleum gases or ammonia under high pressure in small cabotage. Cargo capacity up to 1 "000 m 3. They are equipped with two cylindrical tanks.
Gas carriers for the transport of gases with thermally insulated tanks and gas vapor reliquefaction systems. Cargo capacity up to 12 "000 m 3. It has from 4 to 6 tanks in pairs.
Gas carriers with a cargo capacity from 1,000 to 12,000 m 3 for the transportation of ethylene, which is transported at atmospheric pressure and cooled to a temperature of -104*C.
Gas carriers with cargo capacity from 5 "000 to 100" 000 m 3 for the transportation of liquefied petroleum gases at atmospheric pressure and t = -55 * c.
Gas carriers with a cargo capacity from 40 "000 to 130" 000 m 3 for the transportation of liquefied natural gases at atmospheric pressure and t = -163 * c.
gas carriers some types are very similar to tankers in hull design. Distinctive features are a high freeboard and the presence in the hold space of special tanks - cargo tanks made of cold-resistant material with strong external insulation. The thermal insulation of cargo tanks reduces cargo losses due to evaporation, which increases the safety of the ship.
In the manufacture of shells for cargo tanks of gas carriers, rather expensive alloys are usually used, such as invar (an alloy of iron with 36% nickel), nickel steel (9% nickel), chromium-nickel steel (9% nickel, 18% chromium) or aluminum alloys. Structurally, cargo tanks are divided into several types: built-in, loose, membrane, semi-membrane and cargo tanks with internal insulation.
Built-in cargo tanks are an integral part of gas carrier hull structures. Liquefied gases in such tanks, as a rule, are transported at a temperature not lower than -10 ° C.
Independent cargo tanks are self-contained structures that are supported on the hull by means of supports and foundations.
Membrane tanks are formed from sheet or corrugated invar, the thickness of which sometimes reaches 0.7 mm, and the insulation on which the membranes rest is made of expanded perlite placed in plywood boxes (blocks). The number of such blocks on a ship with a cargo capacity of about 135 thousand cubic meters. can reach up to 100 thousand pieces. Separate Invar sheets are connected by contact welding.
Semi-membrane cargo tanks have the shape of a parallelepiped with rounded corners and are made of aluminum non-stacked sheet structures. Such tanks rely on hull structures only with rounded corners, due to which thermal deformations are also compensated.
Among independent cargo tanks, spherical tanks are widespread. Their diameter reaches 37-44 m, so they protrude almost half of their diameter above the level of the upper deck. They are made without dialing from aluminum alloys. The thickness of the sheets varies from 38 to 72 mm, the equatorial belt reaches 195 mm. Such tanks have outer insulation made of polyurethane with a thickness of about 200 mm. The outer surface of the tanks is covered with aluminum foil, and the above-deck part is covered with steel casings. Each tank of a spherical type, the total weight of which reaches 680-700 tons, rests in the equatorial part on a cylindrical foundation installed on the second bottom.
Insert tanks on gas carriers can also be tubular, cylindrical, cylindrical-conical, as well as other shapes that are well adapted to the perception of internal pressure. If the gas pressure during its transportation is insignificant, then prismatic tanks are used.
development of maritime transport for the transportation of liquefied natural gas
Liquefied natural gas transportation by sea has always been only a small part of the entire natural gas industry, which requires large investments in the development of gas fields, liquefaction plants, cargo terminals and storage facilities. Once the first liquefied natural gas carriers were built and proved to be sufficiently reliable, changes in their design and the resulting risks were undesirable for both buyers and sellers, who were the main actors of the consortiums.
Shipbuilders and shipowners also showed little activity. The number of shipyards building to transport liquefied natural gas is small, although recently Spain and China have announced their intentions to start construction.
However, the situation in the liquefied natural gas market has changed and continues to change very quickly. There were many who wanted to try themselves in this business.
In the early 1950s, advances in technology made it possible to ship liquefied natural gas over long distances. The first vessel for the transportation of liquefied natural gas was a converted dry cargo ship " Marlin Hitch”, built in 1945, in which aluminum tanks stood freely with external thermal insulation made of balsa. has been renamed to Methane Pioneer"and in 1959 made its first flight with 5000 cubic meters. meters of cargo from the US to the UK. Despite the fact that the water that penetrated the hold wetted the balsa, the ship worked for quite a long time until it was used as a floating storage.
the world's first gas carrier "Methane Pioneer"
In 1969, the first dedicated liquefied natural gas vessel was built in the UK to operate voyages from Algeria to England, which was called " Methane Princess». gas carrier had aluminum tanks, a steam turbine, in the boilers of which it was possible to utilize the boiled-off methane.
gas carrier "Methane Princess"
Technical data of the world's first gas carrier "Methane Princess":
Built in 1964 at the shipyard " Vickers Armstong Shipbuilders» for the operating company « Shell Tankers U.K.»;
Length - 189 m;
Width - 25 m;
The power plant is a steam turbine with a capacity of 13750 hp;
Speed - 17.5 knots;
Cargo capacity - 34500 cubic meters. m of methane;
Dimensions gas carriers have changed little since then. In the first 10 years of commercial activity, they increased from 27,500 to 125,000 cubic meters. m and subsequently increased to 216,000 cubic meters. m. Initially, the flared gas cost the shipowners free of charge, since due to the lack of a gas turbine unit, it had to be thrown into the atmosphere, and the buyer was one of the parties to the consortium. Delivering as much gas as possible was not the main goal, as it is today. Modern contracts include the cost of flared gas, and this falls on the shoulders of the buyer. For this reason, the use of gas as a fuel or its liquefaction have become the main reasons for new ideas in shipbuilding.
construction of cargo tanks of gas carriers
gas carrier
First court for transportation of liquefied natural gas had cargo tanks of the Conch type, but they were not widely used. A total of six ships were built with this system. It was based on prismatic self-supporting tanks made of aluminum with balsa insulation, which was later replaced with polyurethane foam. In the construction of large vessels up to 165,000 cubic meters. m, they wanted to make cargo tanks from nickel steel, but these developments never materialized, as cheaper projects were proposed.
The first membrane tanks (tanks) were built on two gas carrier ships in 1969. One was made of 0.5 mm thick steel and the other was made of 1.2 mm thick corrugated stainless steel. Perlite and PVC blocks for stainless steel were used as insulating material. Further development in the process changed the design of the tanks. The insulation has been replaced with balsa and plywood panels. The second stainless steel membrane was also missing. The role of the second barrier was played by aluminum foil triplex, which was covered with glass on both sides for strength.
But the MOSS type tanks gained the most popularity. The spherical tanks of this system were borrowed from ships carrying oil gases and very quickly became widespread. The reasons for this popularity are self-supporting cheap insulation and construction separate from the vessel.
The disadvantage of a spherical tank is the need to cool a large mass of aluminum. Norwegian company Moss Maritime» The developer of MOSS tanks has suggested replacing the internal insulation of the tank with polyurethane foam, but this has not yet been implemented.
Until the end of the 1990s, the MOSS design was dominant in the construction of cargo tanks, but in recent years, due to price changes, almost two-thirds of the ordered gas carriers have membrane tanks.
Membrane tanks are built only after launching. This is a rather expensive technology, and also takes a rather long construction time of 1.5 years.
Since the main tasks of shipbuilding today are to increase cargo capacity with unchanged hull dimensions and reduce the cost of insulation, at present, three main types of cargo tanks are used for ships carrying liquefied natural gas: the spherical type of the MOSS tank, the membrane type of the Gas Transport No. 96” and a membrane tank of the Tekhnigaz Mark III system. The "CS-1" system, which is a combination of the above membrane systems, has been developed and is being implemented.
MOSS type spherical tanks
Membrane tanks of the Technigaz Mark III type on the LNG Lokoja gas carrier
The design of tanks depends on the calculated maximum pressure and minimum temperature. built-in tanks- are a structural part of the ship's hull and experience the same loads as the hull gas carrier.
Membrane tanks- non-self-supporting, consisting of a thin membrane (0.5-1.2 mm) supported through an insulation fitted to the inner casing. Thermal loads are compensated by the quality of the membrane metal (nickel, aluminum alloys).
transportation of liquefied natural gas (LNG)
Natural gas is a mixture of hydrocarbons, which, after liquefaction, forms a clear, colorless and odorless liquid. Such LNG is typically transported and stored at a temperature close to its boiling point of about -160C°.
In reality, the composition of LNG is different and depends on the source of its origin and the process of liquefaction, but the main component is of course methane. Other constituents may be ethane, propane, butane, pentane and possibly a small percentage of nitrogen.
For engineering calculations, of course, the physical properties of methane are taken, but for transmission, when an accurate calculation of the thermal value and density is required, the real composite composition of LNG is taken into account.
During sea passage, heat is transferred to the LNG through the insulation of the tank, causing some of the cargo to evaporate, known as boil-off. The composition of LNG changes as it boils away, as the lighter, lower boiling components evaporate first. Therefore, the unloaded LNG has a higher density than the one that was loaded, a lower percentage of methane and nitrogen, but a higher percentage of ethane, propane, butane and pentane.
The flammability limit of methane in air is approximately 5 to 14 percent by volume. To reduce this limit, the tanks are vented with nitrogen to an oxygen content of 2 percent before starting loading. In theory, an explosion will not occur if the oxygen content of the mixture is below 13 percent relative to the percentage of methane. Boiled LNG vapor is lighter than air at -110°C and depends on the LNG composition. In this regard, the steam will rush up above the mast and quickly dissipate. When cold vapor is mixed with ambient air, the vapor/air mixture will be clearly visible as a white cloud due to moisture condensation in the air. It is generally accepted that the flammable limit of the vapour/air mixture does not extend too far beyond this white cloud.
filling cargo tanks with natural gas
gas processing terminal
Before loading, the inert gas is replaced with methane, because when cooled, carbon dioxide, which is part of the inert gas, freezes at a temperature of -60 ° C and forms a white powder that clogs nozzles, valves and filters.
During purge, the inert gas is replaced by warm methane gas. This is done in order to remove all freezing gases and complete the drying process of the tanks.
LNG is supplied from shore through a liquid manifold, where it enters the stripping line. After that, it is fed to the LNG evaporator and gaseous methane at a temperature of +20C° enters through the steam line to the top of the cargo tanks.
When 5 percent of the methane is determined at the mast inlet, the exit gas is sent through compressors to the shore or to the boilers through the gas flaring line.
The operation is considered completed when the methane content, measured at the top of the cargo line, exceeds 80 percent of the volume. After filling with methane, the cargo tanks are cooled down.
The cooling operation starts immediately after the methane filling operation. To do this, it uses LNG supplied from the shore.
Liquid flows through the cargo manifold to the spray line and then to the cargo tanks. As soon as the cooling of the tanks is completed, the liquid is switched to the cargo line for its cooling. The cooling of the tanks is considered complete when the average temperature, except for the two upper sensors, of each tank reaches -130°C or lower.
When this temperature is reached and there is a liquid level in the tank, loading starts. Steam generated during cooling is returned to shore by compressors or by gravity through a steam manifold.
shipment of gas carriers
Before starting the cargo pump, all unloading columns are filled with liquefied natural gas. This is achieved with a stripping pump. The purpose of this filling is to avoid water hammer. Then, according to the manual for cargo operations, the sequence of starting the pumps and the sequence of unloading the tanks is carried out. When unloading, enough pressure is maintained in the tanks to avoid cavitation and to have good suction on the cargo pumps. This is achieved by supplying steam from the shore. If it is not possible to supply steam to the ship from the shore, it is necessary to start the ship's LNG vaporizer. Unloading is stopped at pre-calculated levels, taking into account the balance required to cool the tanks before arriving at the port of loading.
After the cargo pumps stop, the unloading line is drained, and the steam supply from the shore is stopped. The shore stander is purged with nitrogen.
Before leaving, the steam line is purged with nitrogen to a methane content of no more than 1 percent by volume.
gas carrier protection system
Before commissioning gas carrier vessel, after docking or a long stay, the cargo tanks are drained. This is done in order to avoid the formation of ice during cooling, as well as to avoid the formation of corrosive substances in case moisture combines with some components of the inert gas, such as sulfur and nitrogen oxides.
gas carrier tank
The tanks are dried with dry air, which is produced by an inert gas installation without a fuel combustion process. This operation takes about 24 hours to reduce the dew point to -20C. This temperature will help to avoid the formation of aggressive agents.
modern tanks gas carriers designed to minimize the risk of cargo sloshing. Marine tanks are designed to limit the impact force of the liquid. They also have a significant margin of safety. However, the crew is always aware of the potential risk of splashing cargo and possible damage to the tank and equipment in it.
To avoid cargo sloshing, the lower liquid level is maintained no more than 10 percent of the tank length, and the upper level is not less than 70 percent of the tank height.
The next measure to limit the sloshing of the load is to limit the movement gas carrier(rocking) and those conditions that generate sloshing. The sloshing amplitude depends on the state of the sea, the roll and the speed of the vessel.
further development of gas carriers
LNG tanker under construction
shipbuilding company Kvaerner Masa Yards» started production gas carriers type "Moss", which significantly improved economic performance and became almost 25 percent more economical. New generation gas carriers allows you to increase the cargo space with the help of spherical expanded tanks, not to burn the evaporated gas, but to liquefy it with the help of a compact gas turbine unit and significantly save fuel using a diesel-electric plant.
The principle of operation of the HPSG is as follows: methane is compressed by a compressor and sent directly to the so-called "cold box", in which the gas is cooled using a closed refrigeration loop (Brayton cycle). Nitrogen is the working coolant. The cargo cycle consists of a compressor, a cryogenic plate heat exchanger, a liquid separator and a methane return pump.
Evaporated methane is removed from the tank by an ordinary centrifugal compressor. The methane vapor is compressed to 4.5 bar and cooled at this pressure to approximately -160°C in a cryogenic heat exchanger.
This process condenses hydrocarbons into a liquid state. The nitrogen fraction present in the vapor cannot be condensed under these conditions and remains in the form of gas bubbles in liquid methane. The next phase of separation takes place in the liquid separator, from where the liquid methane is discharged into the tank. At this time, gaseous nitrogen and partially hydrocarbon vapors are discharged into the atmosphere or burned.
Cryogenic temperature is created inside the "cold box" by the method of cyclic compression - expansion of nitrogen. Nitrogen gas at 13.5 bar is compressed to 57 bar in a three-stage centrifugal compressor and is water-cooled after each stage.
After the last cooler, nitrogen goes to the "warm" section of the cryogenic heat exchanger, where it is cooled to -110C°, and then expanded to a pressure of 14.4 bar in the fourth stage of the compressor - expander.
The gas leaves the expander at a temperature of about -163°C and then enters the "cold" part of the heat exchanger, where it cools and liquefies the methane vapor. The nitrogen then passes through the "warm" part of the heat exchanger before being sucked into the three-stage compressor.
The Nitrogen Compressor-Expansion Unit is a four-stage integrated centrifugal compressor with one expansion stage and contributes to a compact plant, reduced cost, improved cooling control and reduced energy consumption.
So if someone wants to gas carrier leave your resume and as they say: " Seven feet under the keel».
