Know More About Natural Gas (NG)

What is natural gas?
Natural gas is an odorless, nontoxic, gaseous mixture of hydrocarbons—predominantly methane (CH4). Because it is a gas, it must be stored onboard a vehicle in either a compressed gaseous or lique-fied state. Compressed natural gas (CNG) is typically stored in a tank at a pressure of 3,000 to 3,600 pounds per square inch.

Liquefied natural gas (LNG) is super-cooled and stored in its liquid phase at -260°F in special insulated tanks. Natural gas is sold in units of gasoline or diesel gallon equivalents based on the energy content of a gallon of gasoline or diesel fuel.

How and where is natural gas produced and distributed?
Natural gas is drawn from wells or extracted in conjunction with crude oil production. Biomethane, a renewable form of natural gas, is produced from decaying organic materials, such as waste from landfills, wastewater, and livestock. In recent years, 80% to 90% of the natural gas used in the United States was produced domestically. The United States has a vast natural gas distribution system, which can quickly and economically distribute natural gas to and from almost any location in the lower 48 states.

How is natural gas used?
Natural gas accounts for about a quarter of the energy used in the United States. About one-third goes to residential and commercial uses, such as heating and cooking; one-third to industrial uses; and one-third to electric power production. Only about one-tenth of 1% is used for transportation fuel.

Is natural gas safe for use in vehicles?
Yes. NGVs meet the same safety standards as gasoline and diesel vehicles and also meet the National Fire Protection Association’s (NFPA) NFPA 52 Vehicular Fuel System Code. Natural gas has a narrow flammability range and, because it is lighter than air, dissipates quickly if released. NGV fuel tanks are strong and extremely puncture resistant.

What NGVs are available?
A wide variety of new, heavy-duty NGVs are available. The Honda Civic GX is the only light-duty NGV available from a U.S. original equipment manufacturer (OEM). Consumers and fleets also have the option of economically and reliably converting existing light- or heavy-duty gasoline or diesel vehicles for natural gas operation using certified installers.

How do NGVs work?
NGVs operate in one of three modes: dedicated, bifuel, or dual-fuel. Dedicated NGVs run on only natural gas. Bifuel NGVs can run on either natural gas or gasoline. Dual-fuel vehicles run on natural gas and use diesel for ignition assist. Light-duty vehicles typically operate in dedicated or bifuel modes, and heavy duty vehicles operate in dedicated or dual-fuel modes. A CNG fuel system transfers high-pressure natural gas from the storage tank to the engine while reducing the pressure of the gas to the operating pressure of the engine’s fuel-management system.

The natural gas is injected into the engine intake air the same way gasoline is injected into a gasoline-fueled engine. The engine functions the same way as a gasoline engine: The fuel-air mixture is compressed and ignited by a spark plug and the expanding gases produce rotational forces that propel the vehicle.

On the vehicle, natural gas is stored in tanks as CNG, or in some heavy-duty vehicles, as LNG, a more expensive option. The form chosen is often dependent on the range a driver needs. More natural gas can be stored in the tanks as LNG than as CNG.

How do NGVs perform?
Natural gas vehicles are similar to gasoline or diesel vehicles with regard to power, acceleration, and cruising speed. The driving range of NGVs is generally less than that of comparable gasoline and diesel vehicles because, with natural gas, less overall energy content can be stored in the same size tank as the more energy-dense gasoline or diesel fuels.

Extra natural gas storage tanks or the use of LNG can help increase range for larger vehicles. In heavy-duty vehicles, dual-fuel, compression-ignited engines are slightly more fuel-efficient than spark-ignited dedicated natural gas engines. However, a dual-fuel engine increases the complexity of the fuel-storage system by requiring storage of both types of fuel.

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Know More About Liquefied Natural Gas (LNG)

What is LNG?
Liquefied Natural Gas (LNG) is methane in the form of a bubbling, super-cold liquid. (By contrast, Compressed Natural Gas is highly pressurized methane vapor.) Chilling natural gas to its liquid state shrinks its volume by a factor of 600 and allows for its transportation to places where pipelines do not run. LNG is the form that natural gas takes when it is exported overseas on tanker ships. To a lesser extent, LNG is used as vehicle fuel in, for example, long-haul trucks.

How is LNG made?
Through a cryogenic process called "liquefaction," methane is turned to liquid at - 259 degrees F. An LNG export terminal typically requires its own power plant to generate the immense energy so required to achieve this ultra-low temperature.

How are low temperatures maintained during storage and transport? 

Contained in Thermos bottle-like tanks, LNG stays cold through insulation, refrigeration, and evaporative cooling. As the liquid methane inside slowly warms up, some of it vaporizes. This gas is vented to maintain the remaining liquid at - 259 degrees F and to prevent explosions. That is, LNG tanks leak methane gas by design. Smaller tanks sweat methane directly into the atmosphere. Some larger tanks are engineered to capture the boiled-off gas and reuse it, but this not a leak-proof process.

What happens after LNG arrives at its destination?
Before it is used or sent down a pipeline, LNG must be re-vaporized in a re-gasification terminal. Re-gasification is also energy intensive, requires massive infrastructure, and includes periodic methane flaring to control pressure.
   
Is LNG safe? 
If LNG spills into water, it explodes. If LNG spills on the ground, it turns into rapidly expanding clouds of vaporizing methane that can asphyxiate by displacing oxygen and flash-freeze human flesh.1 If ignited at the source, these vapors become flaming "pool fires" that burn hotter than other fuels and cannot be extinguished? Drifting in the wind, an ignitable vapor cloud can threaten large populations. Highly volatile LNG cannot be odorized, so there is no warning of a leak. The ongoing prohibition on LNG facilities in New York State was the result of a deadly explosion in 1973 that blew apart an empty LNG tank in Staten Island and killed 40 people.

Is LNG climate friendly?
The Refrigeration, venting, leaks and flaring of gas makes LNG, 30% more energy intensive than conventional natural gas. The carbon footprint of LNG is at least as bad as coal and, when used as vehicle fuel, worse than diesel.
   
Do LNG facilities create toxic pollution?
LNG plants discharge wastewater laced with mercury and toxic hydrocarbons.' And before the gas is liquefied, it must be purged of freezable benzene. In New Brunswick in fall 2013, 7,500 migrating songbirds were killed in a single night while flying over an LNG facility that was flaring off gas" In San Diego, LNG vehicle fuel has contributed to smog.' In Australia, LNG plants are responsible for nitrogen dioxide emissions that exceed safe limits.'

How is LNG connected to frackine?
LNG facilities encourage fracking by creating storage for the glut of gas that fracking has created, by enabling its export, and by driving up prices and profit margins.' The gas industry views fracking and LNG as intimately related.'" LNG is fracked gas made liquid.

Is LNG a security threat? 
LNG tanks and ships are terrorist targets, with AI-Qaeda showing specific interest. In its 2008 report, Liquefied Natural Gas (LNG) Infrastructure Security, the Congressional Research Service warned, "LNG infrastructure is inherently hazardous and potentially attractive to terrorists....Local officials...have challenged numerous LNG infrastructure proposals on the grounds that they may represent an unacceptable risk to the public." If an LNG tanker ship lost ten percent of its cargo and the resulting three million gallon spill of LNG ignited, the flaming vapor cloud created could extend for three miles—and burn human flesh a mile beyond that. LNG ships and terminals require security zones, gunboat escorts, and intense surveillance.

What are the alternatives? 
Erecting LNG export terminals, each one of which costs billions of dollars—will further entrench long-term, world-wide dependency on fossil fuels during a time of climate crisis. Instead, we should invest in infrastructure for renewable energy, which offers both energy independence and security. Mark Jacobson at Stanford University, with colleagues at Cornell, has provided us such a blueprint in the form of a plan to derive all of the nation's energy from wind, water, and sunlight while creating sustainable jobs and energy price stability.
   
   

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About Titas gas field

Titas gas field is located some 100 Km away to the direction of northern-east from capital city of Bangladesh, Dhaka. It lies at the skirt of the Brahmanbaria district town. This field was discovered by Pakistan Shell Oil Company in 1962. The structure is an elongate north-south asymmetrical anticline measuring about 19x10 square km with a vertical closure of 500m. As per latest Petrobangla re-estimation, total recoverable gas reserve of Titas gas field is 7,582 billion cubic feet (BCF).  Commercial gas production from this field was commenced in 1968  and till January 31, 2016 total 4098.819 billion cubic feet gas or 54.06%  of reserves has been recovered.

Out of total 23 (twenty three) nos. gas wells drilled so far in this field 8 (eight) are vertical wells and the remaining 15 (fifteen) are directional wells. The wells are spread (surface location) at 7 (seven) different locations stretched over about 11 km distance. In January 2016, average 517.02 million cubic feet of gas is produced daily from 21 wells of this field and processed through 8 nos. glycol dehydration type, 4 nos. Low Temperature Separation (LTS) type and 2 nos. LTS with glycol dehydration type process plants and  supplied to the transmission pipelines of Titas Gas Transmission & Distribution Co. Ltd. (TGTDCL) and Gas Transmission Company Ltd. (GTCL). About 380 bbls condensate is produced daily with gas as by-product. In January 2016, average condensate/gas ratio of this field is 0.735 bbls/million cubic feet and water/gas ratio is 0.800 bbl/million cubic feet (excluding well no Titas 12, 13 & 20). Titas well no.3 was Plugged & Abandoned by snubbing operation on 25.02.2008 to prevent gas seepage from nearby locality.

Condensate produced from Titas gas field (about 380 bbls per day), Narsingdi gas field (about 48 bbls per day) & Habiganj gas field (about 12 bbls per day) of BGFCL and about 100 bbls heavy condensate from Beanibazar gas field of SGFL are fractionated into MS (Petrol) and HSD (Diesel) through two fractionation plants at this field having plant capacity of 500 bbls each. The products are being sold to Padma Oil Company Ltd.

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Exploration History of Natural Gas of Bangladesh

The exploration action of petroleum products is over 100 years old in Bangladesh. The first exploration activity started with some topographic maps of Chittagong Hill Tracts and some simplified surveys were done. The first exploration started from 1914 to 1933 by Burma Oil Company (BOC). The second of phase petroleum exploration began after partition of Indian subcontinent. Three international oil companies and the state owned oil company (OGDC) were active in different part of the country. During phase II, Shell Oil discovered the most successful drilling operation; Rashidpur, Kailashtila,  Titas,  Habigonj  and  Bakhrabad  gas fields were discovered. 

After the independence of Bangladesh in 1971, the petroleum exploration gathered pace. In this period, the first offshore gas field, Kutubdia was discovered. The country was first divided into 23 major blocks including offshore area. During 1995-2000, the  foreign companies Fig.2 drilled 10 exploratory wells and discovered 1 offshore gas field (Sangu in 1996 by Cairns Energy) and two onshore gas fields (Bibyana in 1997 and Moulovibazar in 1998). After some more successful drilling by Tullow Oil, Bangura gas field was discovered in 2004.

BAPEX, (Petrobangla exploratory subsidiary) drilled two wells and discovered two gas fields, i.e. Shahbazpur in 1995 and Saldanadi in 1996. BAPEX drilled one well in late 2004 and announced discovery of Srikail gas field in Comilla in January 2005. It is very interesting data that the national oil companies of Bangladesh have a discovery success rate over 80% Fig.3 compared to the multinational oil companies. Digital multi fold seismic data acquisition started in 1977, when Prakla was engaged under the German technical Assistance Program. In 1978 Petrobangla started acquiring multi fold analog seismic data, Fig.4 but in 1979 it moved into the digital domain. During 1986-87 Shell recorded over 1,500 km of multi fold data and these are available in BAPEX Data Center.

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History of Natural Gas in USA

The ancient peoples of Greece, Persia, and Indian subcontinent discovered natural gas many centuries ago. The people were mystified by the burning springs created when natural gas seeping from cracks in the ground was ignited by lightning. They built temples around these perpetual lames so they could worship the mysterious fire.

But, about 2,500 years ago, the Chinese civilization recognized that natural gas can be used to work. The Chinese pipe the gas from shallow wells and burned it under large pans to evaporate seawater for the salt.

But it is a matter of fun that only few years ago like 1816, natural gas was first used in America to illuminate the streets of Baltimore with gas lamps. Lamplighters walked the streets at dusk to fight the lamps. Soon after, in 1821, William Hart dug the first successful American natural gas well in Fredonia, NY. His well was 27 feet deep, quite shallow compared to today’s wells. The Fredonia Gas Light Company opened its doors in 1858 as the nation’s first natural gas company. By 1900, natural gas had been discovered in 17 states. In the past 40 years, the use of natural gas has grown.

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Uses of Natural Gas

Everywhere and everyone in the world use natural gas. After petroleum, Natural gas takes places in energy consumption.  Most of the energy we use comes from natural gas. The main use of gas is as follows:

Industry uses of Gas

 Most of the natural gas consumed in the world. Industry uses natural gas as a heat source to manufacture goods as well as an ingredient in fertilizer, photographic film, ink, glue, paint, plastics, laundry detergent, and insect repellents. Synthetic rubber and fibers like nylon also could not be made without the chemicals derived from natural gas.

Homes uses of Gas

 In the country many homes use natural gas for heating. Some use gas water heaters, stoves, and clothes dryers. Natural gas is used so often in homes because it is clean burning.

Commercial uses of Gas

Commercial use of natural gas is mostly for indoor space heating of stores, office buildings, schools, churches, and hospitals.

For making electricity

Natural gas is also used to make electricity. It is the second largest producer of electricity after coal. Natural gas power plants are cleaner than coal plants. Natural gas plants produce electricity more efficiently than coal plants.

Transportation fuel purposes

Natural gas is used as a transportation fuel. Natural gas can be used in many vehicles that have been modified with a special carburetor and fuel tank. Natural gas is cleaner and cheaper than gasoline and octane. Today, more than 500 million vehicles run on natural gas (CNG; compressed Natural Gas) in the world.

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Know about Natural Gas

Natural gas is generally considered a nonrenewable fossil fuel because most scientists think that natural gas was formed from the remains of tiny sea animals and plants that died 300 to 400 million years past.  When these tiny sea animals and plants died, they sank into the bottom of the oceans where they were buried by layers of sediment and turned into rock. Over the years, the layers of sedimentary rock became thousands of feet thick, subjecting the energy-rich plant and animal remains to enormous pressure. Most scientists believe that the pressure and the heat of the Earth changed this mixture into petroleum and gas. Solid natural gas is a mixture of different gases. The main ingredient is methane, a natural compound that is formed whenever plant and animal matter decays. By itself, methane is odorless, colorless, and tasteless. A chemical odorant called mercaptan is added with natural gas for a safety measure and gas can be detected. 

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