LNG

WHY LNG?

Natural gas is an environmentally friendly, highly efficient, and economical energy source with low emission values, obtained from natural resources. However, due to our country’s geographical conditions, it is not possible to deliver natural gas to every location via pipelines.

In many regions of our country, natural gas still cannot be used for residential or industrial consumption due to geographical constraints, technical challenges, and high investment costs.

Akpet Gaz provides natural gas in the form of LNG (Liquefied Natural Gas) to consumers who are not connected to natural gas pipelines but seek the most economical solution for their total energy costs. This is achieved through specially designed tankers and storage in dedicated tanks.

Since 2005, Akpet Gaz has been among the pioneering companies in our country with its LNG (Liquefied Natural Gas) operations.

By considering the needs of all industrial organizations aiming to reduce energy costs and use clean, environmentally friendly fuel, Akpet Gaz offers the most suitable solutions.

By contacting our company or sending an email to our support department and sharing brief information about your facility, our authorized representatives will contact you as soon as possible and develop the most economical solution for your organization.

LNG OCCUPATIONAL SAFETY

• The area where the tank is located must be protected by a safety cage. This cage must allow sufficient air circulation.
• The filling area must be equipped with a lighting system. All equipment used must be Ex-proof. • The tank and all surrounding metal components (main evaporator, gas line, wire fence, etc.) must be grounded.
• The safety cage must have an easily accessible and operable door. • Open flames or similar ignition sources must never be present inside the cage while the tank contains LNG.
• Vehicles that may cause sparks must not be kept around the cage. • Welding, cutting, or grinding must not be performed near the cage.
• LNG inside the tank has a temperature of -161.5°C. Contact with the liquid can cause severe skin and tissue damage. Do not operate on the tank without protective gloves.
• Fire extinguishing equipment (dry chemical type) must be available inside and/or around the cage. • A lightning protection system must cover the LNG tank area.

LNG AREAS OF USE

LNG can be easily implemented in all facilities with high fuel consumption, provided that the required conditions in relevant regulations, standards, and specifications are met.

Production Use: • Food Industry • Iron & Steel Industry • Machinery Manufacturing • Asphalt Production • Paper & Packaging Industry • Ceramic Industry • Automotive Industry • Mining

Heating Use: • Hotels • Schools • Social Facilities • Greenhouses

Other Uses: • Organized Industrial Zones • CNG Facilities • Cogeneration Plants

LNG is an alternative fuel thanks to its high combustion efficiency, clean and ecological properties, cost-effectiveness, and safe/practical use. It is an environmentally friendly and economical energy source for high-consumption facilities in areas not accessible by pipelines. LNG contains over 90% methane and, being lighter than air, disperses quickly in case of leakage, unlike other fuels that may accumulate in low areas and pose risks.

For industrial facilities with high fuel consumption where pipeline natural gas is not feasible, LNG enables significant economic benefits.

LNG FEATURES

LNG is the abbreviation of “Liquefied Natural Gas.” It is a flammable substance. Its storage temperature in liquid form is approximately -161.5°C, reducing its volume by about 600 times.

This reduction enables efficient transportation and storage. Natural gas mainly consists of methane (about 90%), along with ethane, propane, and heavier hydrocarbons. While it contains small amounts of nitrogen, oxygen, carbon dioxide, sulfur compounds, and water, these impurities are removed during liquefaction, making LNG cleaner than natural gas. When LNG reaches 99% purity, its efficiency is very high (93–95%).

LNG is stored and transported in specially manufactured tanks under cryogenic conditions. LNG storage and transfer facilities must fully comply with cryogenic standards. Storage pressures range between 2 and 5 bar. Gas is supplied at pressures between 2 and 5 bar up to pressure reduction points. Regasification is carried out by appropriately sized vaporizers. All tanks are equipped with safety systems, and pressures are controlled via regulators and economizers. LNG systems are operated safely through a Safety Control Automation System.

LNG SYSTEM INFORMATION

TANK

Cryogenic tanks consist of two nested vessels. The inner stainless-steel vessel is used to store LNG, while the outer shell serves as the insulation container. Between the two vessels, powdered perlite and vacuum are used as insulation. Due to vacuum insulation, the outer shells of cryogenic tanks are highly sensitive; therefore, no welding operations should be performed on the tank after manufacturing.

EVAPORATOR

Evaporators convert liquefied natural gas into gas by using ambient heat. Thanks to their large heat transfer surfaces and the temperature difference between the ambient air and LNG, they provide high heat exchange efficiency. They are fully made of aluminum and require no maintenance.

REGULATOR / ECONOMIZER

When the tank pressure falls below the desired value, the regulator activates the system and allows the liquid inside the tank to flow to the tank’s own vaporizer, where it vaporizes and creates pressure inside the tank. In other words, tank pressurization occurs in a controlled manner by vaporization of LNG exposed to ambient temperature. The regulator is adjusted by tightening or loosening the bolt on top. Tightening increases the lower pressure limit at which vaporization begins; loosening decreases it.

The economizer operates on the opposite principle. When tank pressure increases, it ensures that consumption is taken from the gas valve instead of the liquid valve, thereby reducing tank pressure. The adjustment bolt underneath controls the pressure at which gas consumption begins.

CRYOGENIC VALVES

Valve systems differ under cryogenic temperatures. Extended-stem stainless steel and bronze valves are used, designed to operate at cryogenic temperatures (−161.5°C for LNG). Brands such as HEROSE or BESTOBELL are used. These are welded-socket type valves; during maintenance, only the upper assemblies are serviced.

SAFETY SYSTEM

The tank safety system consists of safety valves and a rupture disk. Safety valves are installed redundantly and connected to the tank via a three-way valve. At least one safety valve is always kept active. In case of failure, switching the three-way valve activates the backup safety valve. Line safety valves discharge pressure increases occurring between two valves.

LEVEL GAUGES

Level indicators display tank levels in mmWC or percentage. Based on LNG density, the LNG level can be calculated. With the provided calibration chart, approximate LNG volume and weight can also be determined.

HOW IS LNG TRANSPORTED?

LNG is transported by double-hulled ships designed to maintain LNG temperature. These ships are specially insulated to prevent leakage caused by evaporation. In some cases, evaporated gas is used as fuel for the ship. LNG carriers can reach lengths of up to 300 meters and require a minimum water depth of 12 meters when fully loaded. Today, nearly 400 million tons of LNG are transported worldwide annually.

PRESSURE GAUGES

These gauges display tank pressure in bar and are connected to the tank via a valve. Except during maintenance, this valve must always remain open.

VACUUM MEASURING PORT

This port is strictly for service personnel use and must not be touched. Incorrect handling may damage the tank vacuum. If insulation is compromised, vaporized LNG will create pressure inside the tank. Although safety valves can discharge this pressure, the tank will no longer be suitable for LNG storage.

VACUUM SUCTION PORT

This port is used for vacuuming the tank and also acts as a safety vent to prevent pressure build-up between the vessels. It must never be sealed. If gas discharge is observed, authorized personnel must be notified immediately.

GROUNDING SYSTEM

Two grounding bolts are provided on the tank. Filling and gas usage operations must never be performed unless the tank is grounded. Grounding points are marked with grounding symbols.

P & I DIAGRAM

A P&I diagram showing pipe numbering and names is located on the tank. Valve names and usage guidance can be accessed through this diagram.

TANK NAMEPLATE

The tank nameplate displays pressure, capacity, and weight values. Basic information is available on the nameplate, while detailed data is provided in the tank documentation.

LNG TANK SITE SYSTEM

The LNG tank site system consists of a cryogenic tank, evaporator, odorization tank, outlet manifold, and piping, designed according to the facility’s consumption capacity. The tank and evaporator must undergo 100% third-party inspection during all manufacturing stages and be manufactured by certified welders. Inner tank materials must be 304L stainless steel, with 100% radiographic testing of welds. All pipes and elbows must be seamless, certified stainless steel. Hydrostatic pressure tests, tightness, vacuum, insulation, drying, and cooling tests must be completed after manufacturing.

AUTOMATION CONTROL SYSTEM

The automation control system consists of a control alarm panel, air control panel, pneumatic valves, compressor, gas leak detector (Ex-proof), temperature sensor (PT100), earthquake sensor, and emergency stop button. It ensures safe gas flow from tank inlet to evaporator outlet and allows emergency shutdown in hazardous situations.

TELEMETRY SYSTEM

The telemetry system includes a GSM panel, pressure and level transmitters, and a SIM card. LNG level (in % and kg) and pressure (bar) are transmitted via GSM, enabling remote monitoring and easier refilling planning.

ODORIZATION SYSTEM

LNG cannot be odorized in liquid phase at −161.5°C. After regasification, odorization tanks are installed to deliver odorized gas to consumption points. THT (Tetrahydrothiophene) is used, emitting a rotten-garlic-like odor, enabling early detection of leaks.

INDOOR INSTALLATION SYSTEM

The indoor installation covers the system between the LNG tank site and consumption equipment. It is designed and constructed by contractors certified by EPDK and supervised by authorized consultancy firms. All welding is performed with argon welding; underground and critical welds undergo 100% radiographic testing. Strength and tightness tests are conducted, and gas is supplied only after final approval.

PRS (PRESSURE REDUCTION STATION)

PRS reduces LNG outlet pressure of 2–5 bar to the operating pressure required by the facility. It consists of a steel filter, regulator with shut-off, relief valve, pressure gauges, and inlet/outlet valves.

LNG FAQ

Why Liquefy Natural Gas?

Liquefaction reduces volume by approximately 600 times, making transportation and storage economical. LNG is regasified before distribution to residential and industrial users.

Is LNG Flammable or Explosive?

LNG is not explosive in liquid phase. Vaporized LNG can ignite only when mixed with air at 5–15% concentration. In open environments, it disperses rapidly.

Is LNG Safe?

LNG has an excellent safety record worldwide for over 40 years. Its properties, materials used, and strict standards make LNG one of the safest energy industries.

How Is LNG Stored?

LNG is stored in specially insulated tanks designed to minimize evaporation. Boil-off gas is safely removed and used as fuel.

What Is the Difference Between LNG and LPG?

LPG consists mainly of propane and butane and is stored under pressure, while LNG is stored at −162°C at near-atmospheric pressure. Natural gas is lighter than air; LPG is heavier.

What Does Cryogenic Mean?

Cryogenics means very cold. It comes from the Greek word 'Kryos'. It defines the storage and transportation conditions of liquefied industrial and medical gases. The LNG gas in our field of study is around 150 degrees Celsius. This imposes certain limitations on us. As a result of storing the gas at very cold temperatures, sudden expansion occurs when it comes into contact with ambient temperatures. This causes pressure increases in closed containers and pipes. Our system has been designed to mitigate these sudden pressure increases.