Gas supply

What is Gas?

Gas is one of the four fundamental states of matter (the others being solid, liquid, and plasma). 

A gas is a sample of matter that conforms to the shape of a container in which it is held and acquires a uniform density inside the container, even in the presence of gravity and regardless of the amount of substance in the container. If not confined to a container, gaseous matter, also known as vapor, will disperse into space.

When a sample of matter in the gaseous state is heated, the atoms or molecules gain kinetic energy and move more rapidly. When a sample of gaseous matter is cooled, the atoms or molecules lose kinetic energy and move more slowly.

General Characteristic of Gas

1.Gas are easily to compress.

2.Gas can expand to fill their containers. (Shape of gas depends on its container)

3.Gas occupy more space than liquid and solid.

Physical Characteristic of Gas

1.Pressure (Unit: Pascal)

2.Volume (Unit: Cubic Meter)

3.Number of particles (Unit: moles)

4.Temperature (Unit: Kelvin)

     These four characteristics were repeatedly observed by scientists such as Robert Boyle, Jacques Charles, John Dalton, Joseph Gay-Lussac and Amedeo Avogadro for a variety of gases in various settings.

Gas Law

    1.Boyle’s Law

Boyles’ Law states that equal pressure is inversely proportional to volume (when temperature is constant).

As the volume of the gas increase, the pressure of the gas will decrease and vice versa.

12.  Charles’ Law

Charles's Law states that volume is proportional to temperature (when pressure is constant). Remember that temperature must be measured in Kelvin.

As the temperature of the gas increase, the volume of the gas increase and vice versa. 

13.  Avogadro’s Law

Avogadro's Law states that equal volumes of all ideal gases (at the same temperature and pressure) contain the same number of molecules.

If the volume of I mole of gases are 2L, then the volume of 2 mole of gases are 4L.

4. Gay-Lussac's Law

Gay-Lussac's Law states that pressure is proportional to temperature (when volume is constant).

If the temperature of the gas increase, the pressure of the gas will increase and vice versa.

INTRODUCTION TO NATURAL GAS

 

Natural gas is a naturally occuring hydrocarbon gas mixture consisting primarily of methane, but commonly including varying amounts of other higher alkanes, and sometimes a small percentage of carbon dioxide, nitrogen, hydrogen sulfide or helium.It is formed when layers of decomposing plant and animal matter are exposed to intense heat and pressure under the surface of the Earth over millions of years. The energy that the plants originally obtained from the sun is stored in the form of chemical bonds in the gas.

Natural gas is a fossil fuel used as a source of energy for heating, cooking, and electricity generation. It is also used as a fuel for vehicles and as a chemical feed stock in the manufacture of plastics and other commercially important organic chemicals. Fossil fuel based natural gas is a non-renewable resource.

Natural gas is found in deep underground rock formations or associated with other hydrocarbon reservoirs in coal beds and as methane clathrates. Petroleum is another resource and fossil fuel found in close proximity to and with natural gas. Most natural gas was created over time by two mechanisms: biogenic and thermogenic. Biogenic gas is created by methanogenic organisms in marshes, bogs, landfills, and shallow sediments. Deeper in the earth, at greater temperature and pressure, thermogenic gas is created from buried organic material.

In petroleum production gas is often burnt as flare gas. The World Bank estimates that over 150 cubic kilometers of natural gas are flared or vented annually. Before natural gas can be used as a fuel, most, but not all, must be processed to remove impurities, including water, to meet the specifications of marketable natural gas. The by-products of this processing include: ethane, propane, butanes, pentanes, and higher molecular weight hydrocarbons, hydrogen sulfide (which may be converted into pure sulfur), carbon dioxide, water vapor, and sometimes helium and nitrogen.

Natural gas is often informally referred to simply as "gas", especially when compared to other energy sources such as oil or coal. However, it is not to be confused with gasoline, especially in North America, where the term gasoline is often shortened in colloquial usage to gas.

USES

(1). Mid-stream natural gas

Often well head gases require removal of various hydrocarbon molecules contained within the gas. Some of these gases include heptane, pentane, propane and other hydrocarbons with molecular weights above methane (CH4). The natural gas transmission lines extend to the natural gas processing plant or unit which removes the higher molecular weighted hydrocarbons to produce natural gas with energy content between 950–1,050 British thermal units per cubic foot (35–39 MJ/m3). The processed natural gas may then be used for residential, commercial and industrial uses.

Natural gas flowing in the distribution lines is called mid-stream natural gas and is often used to power engines which rotate compressors. These compressors are required in the transmission line to pressurize and re-pressurize the mid-stream natural gas as the gas travels. Typically, natural gas powered engines require 950–1,050 BTU/cu ft (35–39 MJ/m3) natural gas to operate at the rotational name plate specifications. 

(2). Power generation

Natural gas is a major source of electricity generation through the use of cogeneration, gas turbines and steam turbines. Natural gas is also well suited for a combined use in association with renewable energy sources such as wind or solar and for alimenting peak-load power stations functioning in tandem with hydroelectric plants. Most grid peaking power plants and some off-grid engine-generators use natural gas. Particularly high efficiencies can be achieved through combining gas turbines with a steam turbine in combined cycle mode. Natural gas burns more cleanly than other fuels, such as oil and coal. Because burning natural gas produces both water and carbon dioxide, it produces less carbon dioxide per unit of energy released than coal, which produces mostly carbon dioxide. Burning natural gas produces only about half the carbon dioxide per kilowatt-hour (kWh) that coal does. For transportation, burning natural gas produces about 30% less carbon dioxide than burning petroleum. The US Energy Information Administration reports the following emissions in million metric tons of carbon dioxide in the world for 2012. 

(3). Domestic use

 

Natural gas dispensed in a residential setting can generate temperatures in excess of 1,100 °C (2,000 °F) making it a powerful domestic cooking and heating fuel. In much of the developed world it is supplied through pipes to homes, where it is used for many purposes including ranges and ovens, gas-heated clothes dryers, heating/cooling, and central heating. Heaters in homes and other buildings may include boilers, furnaces, and water heaters. 

Domestic appliances, furnaces, and boilers use low pressure, usually 6 to 7 inches of water (6" to 7" WC), which is about 0.25 psig. The pressures in the supply lines vary, either utilization pressure (UP, the aforementioned 6" to 7" WC) or elevated pressure (EP), which may be anywhere from 1 psig to 120 psig. Systems using EP have a regulator at the service entrance to step down the pressure to UP.

(4). Transportation

CNG is a cleaner and also cheaper alternative to other automobile fuels such as gasoline (petrol) and diesel. By the end of 2014 there were over 20 million natural gas vehicles worldwide, led by Iran (3.5 million), China (3.3 million), Pakistan (2.8 million), Argentina (2.5 million), India (1.8 million), and Brazil (1.8 million). The energy efficiency is generally equal to that of gasoline engines, but lower compared with modern diesel engines. Gasoline/petrol vehicles converted to run on natural gas suffer because of the low compression ratio of their engines, resulting in a cropping of delivered power while running on natural gas (10%–15%). CNG-specific engines, however, use a higher compression ratio due to this fuel's higher octane number of 120–130.

Besides use in road vehicles, CNG can also be used in aircraft. Compressed natural gas has been used in some aircraft like the Aviat Aircraft Husky 200 CNG and the Chromarat VX-1 KittyHawk. 

(5). Fertilizers

Natural gas is a major feedstock for the production of ammonia, via the Haber process, for use in fertilizer production.

(6). Hydrogen

Natural gas can be used to produce hydrogen, with one common method being the hydrogen reformer. Hydrogen has many applications: it is a primary feedstock for the chemical industry, a hydrogenating agent, an important commodity for oil refineries, and the fuel source in hydrogen vehicles.

(7). Animal and fish feed

Protein rich animal and fish feed is produced by feeding natural gas to Methylococcus capsulatus bacteria on commercial scale.

(8). Other 

Natural gas is also used in the manufacture of fabrics, glass, steel, plastics, paint, and other products.

NATURAL GAS IN MALAYSIA

• Natural gas is a clean, efficient and reliable fuel used in power generation, industries, transportation, commercial and residential.

• Malaysia's  gas resources is approximately 100 tscf (trillion standard cubic feet).

• The Peninsular Gas Utilisation (PGU) project, which started in 1984, has brought Malaysia into the gas era. A fully integrated gas business, spanning from upstream to downstream has been developed to further add value to Malaysia’s gas resources.

• Gas transmission and distribution pipelines in Malaysia.

• PETRONAS Gas Berhad: 2,550 km

• Gas Malaysia Berhad: 2,000 km

• Malaysia is working towards liberalization of the gas market to ensure security of supply and long term sustainability of the industry.

• Domestic natural gas consumption in Malaysia is approximately 2.6 bscfd (billion standard cubic feet per day).

• Half  of electricity generated in Peninsular Malaysia is fueled by natural gas.

• Natural  gas is also used as feedstock in the production of steel, methanol, fertilizer and plastics.

• There are 178 NGV (Natural Gas for Vehicle) refueling stations in Malaysia. The number of vehicles using NGV is approximately 77,000.

• In 2015,  Malaysia exported 25 mil tonnes of LNG valued at RM47 billion or 6% of exports. LNG export contributes significantly to Malaysia’s income and international currency reserves. Major customers are Japan, Korea, Taiwan and China.

• Malaysia  is the second largest LNG exporter in the world after Qatar.

• PETRONAS  LNG Complex in Bintulu Sarawak has three liquefaction plants with a total combined production capacity of 25.7 MTPA (million tonnes per annum).

• Malaysia  also exports smaller volume of gas through pipeline to Singapore.

• In addition to domestic production, Malaysia also sources piped gas from Indonesia, Malaysia-Thailand Joint Development Area (JDA) and Malaysia-Vietnam Commercial Arrangement Area (CAA).

• Malaysia also imports LNG via the first LNG regasification terminal (RGT) in Sungai Udang, Melaka which became operational in May 2013. The RGT is owned by PETRONAS Gas Berhad and has a capacity of 500 mmscfd.

TRANSPORTATION AND DISTRIBUTION NATURAL GAS

Natural Gas (NG) Transportation

Transportation of natural gas via pipeline system is the most effective method, especially for a long distance transmission. Technically, natural gas is transported from the gas reservoir to the consumer through transmission and distribution pipelines. The transmission and distribution pipeline systems are actually different as the operating pressures and the pipe sizes are different.

Transmission pipeline

A transmission pipeline transports the natural gas from the Gas Processing Plant (GPP) to the distribution centre and to larger volume customers. This transmission pipeline ends at the city gate station.

NG Transmission System

​​​​​PETRONAS Gas Berhad (PGB) was incorporated in 1983 and was listed on the main market of Bursa Malaysia Securities Berhad on 4 September 1995.

The Company was initially the wholly-owned subsidiary of PETRONAS, the Malaysia’s national oil corporation, which upon listing owns 60.63% of its shares while the remaining 39.37% is held by financial institutions and retail shareholders.

Today, it is one of the largest companies on the local bourse, in terms of market capitalisation. The Company is also Malaysia’s leading gas infrastructure and utilities company with core businesses in Gas Processing and Utilities (GPU) and Gas Transmission and Regasification (GTR).

The Company processes PETRONAS’ natural gas piped from offshore fields, transports the processed gas via Peninsular Ga​s Utilisation (PGU) pipeline network to PETRONAS’ customers in Malaysia and Singapore. In addition, the Company also supplies steam and industrial gases for its customers at Kertih Integrated Petrochemical Complex in Terengganu and Gebeng Industrial Area in Pahang.

The Company has a staff strength of 2,187 employees nationwide. The majority of the staff are based at its plant operations located in Kertih and Santong, Terengganu and in Gebeng, Pahang.

PGB operates from its headquarter at the PETRONAS Twin Towers in Kuala Lumpur as well as nine regional offices in Peninsular Malaysia and two in East Malaysia.

​

Distribution pipeline

A distribution pipeline supplies and distributes the natural gas from the city gate station to the end users. Normally, the pressure of the natural gas would be reduced and the gas is odorized for safety purpose at the city gate station.

FIRE STOPPING MATERIAL

Fire stop is important in the gas supply system. This is because a good fire stopping system can make sure the building safety when the fire burst occurs. There are many type of fire stopping material:

1. 3M™  fire barrier mortar

• It is a lightweight gypsum-based and endothermic firestop that is ready for mixing with potable water.
• 3M™ Fire Barrier Mortar will firestop penetrations passing through fire-rated floor or wall assemblies and other fire-rated interior building construction.

Product Features

• Firestop tested up to 3 hours
• Excellent adhesion: bonds to concrete, metals, wood, plastic and cable jacketing.
• Re-enterable/repairable with common hole saw

Application

3M™ Fire Barrier Mortar is a cost-effective firestop typically used to seal mechanical and electrical service penetrations, blank openings and other large annular spaces in fire-resistance rated wall and floor assemblies with ratings up to 3 hours.

2. 3M™ Fire Barrier Rated Foam FIP 1-Step

• 3M™ Fire Barrier Rated Foam FIP 1-Step is a smoke, sound and fire stopping foam for wall and floor penetrations.
• It expands up to five times during installation and bonds to most construction substrates including, but not limited to, concrete, metal, wood, plastic and cable jacketing.

Product Features

• Re-enterable/repairable 
• Excellent adhesion 
• Quick cure and eliminates the need for mineral wool and caulk

Application

Typical applications include: blank openings, metal pipe, cables, cable tray, insulate pipe, combination penetrations through concrete floor/wall and gypsum wall board assemblies.

3. 3M™ Fire Barrier Packing Material PM4

• 3M™ Fire Barrier Packing Material PM4 is designed to be used as an alternative packing material to mineral wool, fiberglass and backer rod in through-penetration firestop systems.
• 3M™ Fire Barrier Packing Material PM4 is also non-asbestos, mold resistant, less irritable* and inorganic.

Product Features

• Non-combustible material
• Convenient, hand-tear dispensing
• Easy to transport and carry

Application

Packing material is a part of many through-penetration firestop systems and may be used around metallic, non-metallic, insulated pipe, HVAC and power, and communication cable penetrants.

4. 3M™ Fire Barrier Silicone Sealant 2000+

• 3M™ Fire Barrier Silicone Sealant 2000+ is a ready-to-use, gun-grade, one-component silicone elastomer that cures upon exposure to atmospheric humidity to form a flexible firestop seal.
• It helps control the spread of fire, smoke and noxious gasses before, during and after exposure to a fire when installed in accordance with a listed through penetration or fire-resistive joint assembly.

Product Features

• Firestop tested up to 4 hours
• Excellent weather ability upon cure
• Excellent adhesion
• Re-enterable/repairable

Application

3M™ Fire Barrier Silicone Sealant 2000+ is used in mechanical, electrical and plumbing applications to firestop openings and penetrations through fire-rated floor or wall assemblies.

5. 3M™ Fire Block Foam FB-Foam

This product is intended to resist the free passage of flame and the by-products of combustion within the concealed space of a floor, ceiling or wall cavity by restricting the movement of air, fire and smoke.

Product Features 

• Heat-resistant up to 240° F (115° C)
• Ready-to-use (no mixing required) 
• Expands to quickly and effectively seal openings 
• Excellent adhesion—bonds to concrete, brick, metals, wood, plastic and cable jacketing

Application

Use 3M™ Fire Block Foam FB-Foam to seal interior construction voids around wires, pipes, cables and other penetrations in non-rated wood or steel-framed construction.

Gaseous Fire Suppression

It used to describe gases used to extinguish fires.Typically gaseous agents work in one of two ways:

1. To inert the atmosphere reducing oxygen levels to a level that will no longer sustain combustion.
2. To react chemically with the fire absorbing heat and causing the chain reaction of combustion to break down.

Clean Agent fire extinguishing systems are typically used to protect three dimensional enclosures containing high value assets that are vital for business continuity, and assets that cannot be protected by traditional sprinkler systems due to the potential for water damage. 

LIQUID PETROLEUM GAS (LPG)

liquid petroleum gas is produced during the refining of crude petroleum oils. LPG is mixture of propane (30%-40%) and butane (60%-70%) and stored as liquid under pressure, is colourless and odourless in its natural state. 

LPG vapour is heavier than air. therefore, the vapour may flow along the ground and into drain and be ignited a considerable distance from the source of leakage. LPG form aflammable mixture when mixed with air within the flammability limit to large volume of vapour/ air mixture and thus case considerable. LPG is odorised before distribution , such that any escape of gas may be noticeable by its smell.

                        

basically, safety requirements in the design, construction and maintenance of either LPG or natural gas piping system at consumer's premises are same, hence in LPG system there is a risk of liquid being leaked or release from the system. small volume of the liquid LPG leaks from the storage system will expand to become an enormous volume of flammable vapour mixture.

LPG piping system 

the main components of the system are: 

1. storage vessel - LPG is stored at consumer's premises is pressurised vessel or in cylinders which are manifold together.
2. delivery or services pipeline - this line used for delivery the LPG vapour from the storage tank to gas appliances. vaporisers are sometimes  installed  near tank to vapourise liquid LPG in the line into vapour before the first stage regulator. this is used only in liquid withdrawal system.