Gas natural una alternativa en combustibles

Let me explain issues related to LNG in question and answer form NATURAL GAS What is Natural Gas? A naturally occurring mixture of Hydrocarbon and Non- hydrocarbon gases found in porous geological formations beneath the earth’s surface, often in association with oil. The principal constituent IS Methane (CH4). Where is Natural Gas available? Natural Gas is formed from the buried remains of tiny plants and sea animals that died oris earth. Under the hea nd rich organic material all that was lefi were rocks.

Natural Gas is ears ago in mother earth, these energy nged form until al Gas in layers of by drilling wells into he rock, then using pipes to bring gas to the surface. In most Wells, the pressure of the gas is enough to force it to the surface and then to the central collection points. When Natural Gas comes out along with crude oil, it is known as Associated Gas, as in case of Bombay High Where is Natural Gas found in India? Natural Gas is found onshore in the North East, Rajasthan and Gujarat and Off-shore in Bombay High. Recently, gas find has been reported by Reliance Industries in the Krishna Godavari Basin.

What LNG? Liquefied Natural Gas (LNG) is Natural Gas that has been cooled to the ooint that it condenses to a liauid. hich occurs pressure. Liquefaction reduces the volume by approximately 600 times thus making it more economical to transport between continents. Transportation of LNG is done in specially designed ocean vessels. Ocean transportation is undertaken wherever traditional pipeline transportation systems would be less economically attractive and could be technically or politically infeasible. Thus, LNG technology makes Natural Gas available throughout the wo rld. What is the distinction between CNG / PNG / LCNG?

CNG is Natural Gas that is compressed to a pressure of 200-250 Kg/cm2 (g) (due to its Iow density) to enhance the vehicle on- oard storage capacity. Thus, this compressed form of Natural Gas is used as a fuel for transportation purposes. PNG is nothing but Piped Natural Gas i. e. processed natural gas piped to the homes and establishments for the kitchen and home heating like geysers etc. PNG installation inside the premises contains only a limited quantity of Natural Gas at Iow pressure at around 21 milibar (mbar) and is much safer compared to LPG which is stored in a liquefied form in a cylinder.

For markets that are not serviced by gas pipelines, CNG can be produced from an LNG storage system. These facilities are called LCNG. LNG contains no water. This eliminates the concerns of corrosion, plugging of fuel lines, and the formation of hydrates or exceeds all of the requirements relative to pressure water-dew point temperatures. LNG does not contain any Ether impurities, such as, oil, particulate, hydrogen sulfide, or oxygen. LNG is not sub 2 OF as impurities, such as, oil, particulate, hydrogen sulfide, or oxygen. LNG is not subject to compositional changes driven by the time of year, pipeline demand, or pipeline system.

Often, LNG can be delivered as nearly pure methane, the most desirable component of Natural Gas for vehicular fuel. This eliminates any concern over propane-air. The composition of LNG is always acceptable for use as a gasoline replacement. In the Indian market, LCNG is yet to come. What are the units of measurement? Natural Gas is measured in volume units, i. e. in cubic feet or cubic meters. Gas production from wells and supplies to Power plants is measured in Thousands or Millions cubic feet (Mcf or MMcf) / cubic meter (MSCM or MMSCM). Resources and reserves are calculated in Trillions of cubic feet (Tcf).

For instance, a gas field containing 3. 65 TCF is equivalent to around 12 MMSCMD gas for 25 years. A rough way of visualizing a trillion cubic feet of gas would be to imagine enough of product to fill a cube with its sides two miles longa Another way of measuring the gas is in terms of Energy Values. The amount of energy that is obtained from the burning of a unit volume of Natural Gas is measured in British Thermal Unit (BTU). At sea level, it takes about 75 BTIJ to make a jolly good cup of tea. A cubic feet of natural gas on an average gives off 1000 BTIJ, but the range ofvalues is 500 to 1500 BTU depending on the quality of gas.

Therefore, one cubic feet of some Natural Gas may make 7 cups of tea, while another makes s many as 20 cups of tea. The various conve as Natural Gas may make 7 cups of tea, while another makes as many as 20 cups of tea. The various conversion factors used in measurement of gas are: GENERALLY IJSED CONVERSION FACTORS OF LNG 1 Cubic meter liquid 1 Million Metric Ton/ annum 1 Metric ton LNG 1 Metric ton L NG 1000 Cubic meter of Gas IBritish Thermal Unit cuM 600 VIMTPA4 MT 1420 MT 52 MCM 40 BTU 252 cubic meter of gas MMSCMD Cubic meter of gas MMBTU MMBTU Calories MMSCMD stands for Million Standard Cubic Meter per Day.

MMBTIJ stands for Mlllion British Thermal Unit. MT stands for Metric Ton MMTPA means Million Metric Ton Per Annum. These are the thumb rules of conversion of gas, while the actual factors would Vary based on the quality of gas. Who are the users of LNG? World over, LNG is used for established as well as emerging applications: The largest application for LNG is world trade where Natural Gas is liquefied and transported by large ocean tankers from remate reserves to markets in Asia, Europe and North America. Most LNG that is traded internationally is used to fuel electric power plants.

Growing needs for electricity in Asia have increased demand for LNG by nearly 8 per cent per ear since 1 980, making it one of the fastest growing energy sectors. Another established application for LNG is seasonal gas storage. Roughly, 100 LNG plants have been constructed world- Wide to liquefy and store natural gas during warmer months for vaporisation and injection into local pipelines during cold weather. LNG is also emerging as an alternative motor fuel to diese’. In sorne during cald weather. LNG is alsa emerging as an alternative motor fuel to diesel.

In some regions, natural gas suppliers truck LNG to communities and industrial plants, ifthose are remote from gas pipelines. Once delivered, LNG is stored in insulated tanks so that it can be vaporised and distributed as natural gas to the customers. However in case of India, Natural gas is used mostly by the power & Fertiliser industry. About 37% of the gas is used by the Power sector and 36% is used by the Fertiliser sector. CURRENT OSAGE PATTERN OF GAS IN INDIA How much of Natural Gas would a Power plant and a Fertilizer plant consume? A Power plant of 100 MW consumes approximately 0. MMSCMD of gas. Similarly a Fertilizer plant of capacity of 5 lakh tonnes per annum of Urea would require approximately 0. 9 MMSCMD of gas. However depending on the efficiency of the plant and the quality of the gas, the requirement may Vary. What is a LNG value chain? To make LNG available for use in a country, energy companies must invest in a number of different operations that are highly linked and dependent upon one another. The major stages of the LNG value chain, excluding pipeline operations between the stages, consist of the fonowing.

PRODUCTION The production stage involves the supply of gas and condensate from the wells in the offshore/on-shore facilities, through a pipeline into the processng facilities. LIQUEFACTION Raw Natural Gas and unstabilized condensate obtained offshore is seldom pure, as it generally contains numerous types of contaminants. s OF as condensate obtained offshore is seldom pure, as it generally contains numerous types of contaminants. Therefore the gas and condensate must be purified for reasons of safety, compliance vvlth environmental regulations, and product speclfication.

The process of condensate stabilization, gas treatment and liquefaction is achieved in the LNG plant- The main units/facilities of an onshore LNG plant are: Process units Storage and loading facilities. Utility and offsite systems and infrastructure. Over View afa Liquefaction Plant The process unit includes inlet gas reception unit, condensate stabilization unit, gas treatment & sweetening facilities gas liquefaction unit, sulfur recovery unlt. An LNG train is a set of process units consisting of all process equipment necessary to produce LNG from a natural feed stock and having a pre- determined design.

In the liquefaction stage the condensate is stabilized and the gas is treated to remove all impurities and liquefied. he liquefaction of gas to LNG is achieved in Six different steps: The first Step involves the receipt of untreated our gas and unstabilized condensate from the offshore facilities to the inlet gas reception unit. This is followed by stabilization of condensate and treatment ofthe sour gas for removal of Mercury. The third Step involves the gas sweetening Step resulting in removal of contaminants mainly sulfur compounds and carbon dioxide to meet required product specification.

The fourth Step involves dehydration or drying for removal of water to prevent hydrate formation, 6 OF as involves dehydration or drying for removal of water to prevent hydrate formation, which would otherwse freeze, and block the ystem, resulting in operational malfunction. Next, a stripping Step involving separation of lighter hydrocarbon used to produce LNG from the heavier hydrocarbons, which would freeze at LNG temperature. The heavier hydrocarbons are further treated in fractionation unit to produce plant condensate. The Sixth Step is the cooling cycle, which is the crux of the LNG plant.

Here the liquefaction takes place in a specially constructed heat exchanger termed «Cryogenic heat exchangefl because of the Iow temperatures. The equipment employs mixed refrigerant (MR) consisting of nitrogen, methane, ethane, propane, and utane that provides the refrigeration for liquefying the natural gas. The fractionation unit provides the ethane, propane make- up for the refrigeration cycle and MR is pre-cooled by a propane refrigeration system. The LNG, now at -160 C and atmospheric pressure and reduced to 1/600 th of its gaseous volume is stored in insulated tanks.

These storage tanks are large, typically between 60,000 and 140,000-m3 capacity each. The tanks incorporate special cryogenic features, such as an insulation layer between double contaminant walls, an inner Shell made of exotic alloy, such as nickel stainless Steel to withstand the Iow temperatures, and an uter Shell of carbon steel. The Field and Plant Condensate are stored in atmospheric floating roof tanks. LNG and Condensate are transferred onto ships through their respective floating roof tanks.

LNG and Condensate are transferred onto ships through their respective loading systems. SHIPPING LNG is transferred onto ships through a loading system. The present state of the art in LNG ships has contributed to cost effectiveness by increases in size from 40,000 to 1 35,000 m3 capacity. Unlike an oil tanker, an LNG carrier is designed to handle extremely Iow temperatures. LNG is carried in insulated metallic anks constructed of exotic alloy, such as nickel stainless Steel, or other suitable materials to withstand the Iow temperatures.

The insulation system maintains the LNG temperature to prevent heat inflow from the surrounding which would otherwise evaporate the liquid. Nevertheless, during voyage some of the LNG evaporates, forming so called «boil off’ vapor. LNG carrier for fuel uses this boil-offvapor. At the receiving terminal, the cargo is not emptied completely; as a Small proportion called «cargo heel» is retained to keep the tanks cold till the next cargo is loaded. This cargo heel rovides fuel for the return voyage.

The highest safety standards are employed in the design and operation of LNG vessels. REGASIFICATION An LNG receiving terminal consists of pipelines; ship berthing facilities, unloading facilities, storage tanks, vaporization system, units for handling boil-offfrom the tanks, metering station and ancillaries. The storage tanks are of similar design to those in liquefaction plants. At the receiving terminal, the LNG is re-gasified before distribution into pipelines for customers. The main receiving terminal, the LNG is re-gasified before distribution into pipelines for customers.

The main uses of the re-gasified LNG include fuel source for boilers in the electrical power generation plants, and other industrial processes, petrochemical feed stocks, as in methanol or fertilizer production, and heating for domestic appliances, typically cooking stoves. LNG IMPORT TERMINAL AT LAKE CHARLES LNG TANKS AT PLL SITE AT DAHEJ, INDIA An LNG project is a highly complex, capital intensive, large-scale and time-consuming venture. It involves extensive interaction between buyers and sellers, financial institutions, governments, shipping companies, and EPC Contractors for engineering, rocurement, construction, and implementation. –;ow Much Does LNG cost? A thumb rule estimate of the cost involved in the LNG Chain varies beMeen USD 2. 5 to USD 3. 5 per MMBTU depending largely on the shipping cost Exploration and production costs have been declining due to improved technologies such as 3-0 (three-dimensional) seismic; drilling and completion of complex well architectures; and improved sub-sea facilities. 3-D seismic allows detailed complex imaging of rocks below the earth’s surface, enabling exploration earth scientists to predict better where accumulations of natural gas might exist.

Drilling and completion of complex well architectures allow petroleum engineers to target more precisely these accumulations and to maximise oil and gas reservoir recovery using multi-branched well architecture and intelligent completion systems. lm reservoir recovery using multi-branched well architecture and intelligent completion systems. Improved sub-sea facilities allow companies to produce natural gas from deep below the surface of the ocean. Further along the LNG value chain, technical innovations have also reduced the costs of LNG liquefaction and shipping, allowing more I_NG projects to achieve commercial iability.

For example, liquefaction costs have been Iowered by as much as 35 percent because of the introduction of competing technologies and economies of scale. Design efficiencies and technology improvements have all contributed to improved project economics. BP’s Trinidad LNG Train 1, completed in June 1999, set a new benchmark for LNG unit capital cost at less than $200/ton of annual plant capaclty, as shown in the figure above. Trinidad Atlantic Train 2 was completed in August 2002, two months ahead of schedule and Train 3, currently under construction is scheduled to come on stream second quarter of 003.

The capital cost ofTrains 2 and 3 is expected to be about $165/ton of capacity. In-ship design, new technologies are also helping to reduce costs. New propulsion systems are aimed to replace the traditional steam turbine engines with smaller units that are more efficient which Will not only reduce fuel costs but Will also increase cargo carryng capacity. Enhanced tanker efficiencies – longer operating lives, improved safety technology and improved fuel efficiency – have Iowered shipping costs substantially. Shipyard expansions in the Far East and increased competit