Experience and prospects for the use of compressed natural gas as motor fuel in the Ural region. The difference between liquefied and compressed gas

The article is provided by the companyGazprom Transgaz Yekaterinburg, OOO, Ekaterinburg

For economic, environmental, resource and technical criteria, compressed natural gas (CPG) will remain the best motor fuel for a long time.

Today, 14.7 million cars operate at the CPG, which is 1.5% of the world park (900 million units). In recent years, the global car on natural gas is increased by 25-30% (Fig. 1). According to the forecast of the International Gas Union, the growth of the park of gas-ballot vehicles will be 50 million units by 2020, and by 2030 more than 100 million units. Today there are already 20,746 automotive gas-filled compressor stations in the world (AGNX).

Infrastructure of filling stations already exists or rapidly develops in a number of countries, such as Germany, Sweden, Switzerland, Austria, Italy. In South Korea, 95% of municipal buses work on the CPG. In Rome, transport on alternative fuel, freed from paying taxes for 3 years. In France, there is a ban on the use of petroleum fuel on municipal buses. In Sweden, Gasomobiles are exempt from fees on paid parking. To date, many world automakers carry out serial production of cars using CPGs (Audi, BMW, Cadillac, Ford, Mercedes-Benz, Chrysler, Honda, Kia, Toyota, Volkswagen and others).

Such a rapid development of this area is quite explained - now, of all massively used motor fuels and technologies, natural gas ensures the most secure emissions of the exhaust gas vehicles. Translation of gas from gasoline on gas allows to reduce on average five times the emissions of harmful substances, and the noise effect is twice.

KPG in Russia

Our country has already accumulated a rich experience of using natural gas as a motor fuel. OAO Gazprom predicts the growth of CPG consumption as a motor fuel at the end of 2011, about 10% - to 370 million m 3 against 345 million m 3 in 2010 (Fig. 2). To date, on the territory of the Russian Federation there are 255 AGNCs operating in 60 regions of Russia, 206 (93%) built by Gazprom. The park of gasified vehicles today consists of 86 thousand cars. The largest consumption of CPG is celebrated in the Stavropol and Krasnodar Territories, Sverdlovsk, Chelyabinsk and Rostov regions, Kabardino-Balkaria and North Ossetia.

Fig.1. World Car Vehicle on CPG

(according to the National Gas Engine Association)

Fig. 2. CURR CONTENT IN RUSSIA, ML MY 3

Natural gas is much cheaper than gasoline. Extraked from the subsoil, natural gas is not subjected to subsequent processing. This ultimately guarantees its lower cost compared to oil refining products. World natural gas reserves significantly exceed oil reserves. Natural gas is not subject to seasonal price changes. In addition, in accordance with the Decree of the Government of Russia, the price of natural gas for vehicles cannot exceed 50% of the price of gasoline of the A-80 brand. In 2011, the average retail price of the CPG in the Russian Federation for vehicles was 8.5 rubles / m 3.

The reasons for methanizing the vehicles of the Ural region are the same as in Russia, and perhaps all over the world - the environmental and economic advantages of the use of natural gas as a motor fuel.

CPG in the Ural region

Currently, Gazprom Transgaz Yekaterinburg LLC operates a network of 30 (AGNKS) and 6 points of refurbishment of vehicles located in Sverdlovsk, Chelyabinsk, Kurgan and Orenburg regions.

The main consumer of the CPG in the Ural region is the city passenger motor vehicle. These are the route taxis of the Gazelle buses type and minibuses.

In addition to stationary AGNKs, we have the opportunity to exercise gas-blasting PBX using mobile automotive gas refills (PAGZ) with a wailing compressor. It is based on the KAMAZ-43118 car with a gas engine. Developed and undergoes industrial tests, a small-sized block complex, which ensures the regasification of liquefied natural gas to refuel gas-filled cars.

Currently, in the Russian Federation, CAMAZ OJSC (RARITEK "LLC) - Buses of NEM3, Sadeline Trucks, dump trucks are engaged in the Russian Federation. GAZ Group produces buses with a gas engine - Liaz-6213, LIAZ-6212, LIAZ-5256, Liaz 5293, PAZ 320302, etc.

In addition, there is an opportunity to purchase gas-ballon techniques of foreign automakers - Iveco, Volkswagen, Mercedes, Opel, Toyota, etc.

To date, Gazprom Transgaz Yekaterinburg LLC operates 691 units. PBX using KPG as motor fuel. In 2011 the economic effect of replacement of liquid motor fuel amounted to 22.3 million rubles..

As a result of trilateral cooperation with KAMAZ OJSC and OJSC NPO Helijimash, it was created: a truck tractor and a city bus, equipped with gas engines with a cryogenic tank to refuel LNG. The first results showed their significant advantage in comparing with gas-filled vehicles using CPGs. So, more than twice the mileage of cars without refueling.

In order to expand the use of the CPG in July 2011, in the framework of the international exhibition "Innoprom - 2011", a tripartite "agreement" was signed between the Government of the Sverdlovsk Region, OOO Gazprom Transgaz Yekaterinburg and KAMAZ OJSC on the development of natural gas Motor fuel. The agreement, in particular, provides for supply to the Sverdlovsk region. Car "KAMAZ" using as motorcycle fuel both CPGs and LNG. Gazprom Transgaz Yekaterinburg Ltd. provides CPG and LNG gas station to gas supply, performs methodological assistance to third-party PBX re-equipment and directly translates the transition of an existing PBX fleet to the use of gas engine fuel.

In October 2011, on behalf of Gazprom OJSC, the company was organized and the gas-plane car was carried out. Blue Corridor - 2011 on the route Ekaterinburg - Chelyabinsk - Ufa - Orenburg - Samara - Saratov - Volgograd - Tambov - Voronezh - Tula - Moscow. Within the framework of this run between the governments of the Chelyabinsk, Orenburg regions and society, "Protocols about intentions" were signed, providing for the use of CPGs as a motor fuel as a priority direction of the parties.

In accordance with the target comprehensive program for the development of the gas stations and the park, working on natural gas, for 2007-2015. In the area of \u200b\u200bresponsibility, Gazprom Transgaz Yekaterinburg LLC is defined for the construction of six AGNX.

Suggestions for expansion
use of natural gas

Gazprom Transgaz Yekaterinburg LLC offers a number of measures, the adoption of which will increase the use of natural gas as motor fuel.

At the federal level it is proposed:

1. Adopt the Law "On the Use of Gas Motor Fuel".

2. Develop and adopt the Government of the Russian Federation a number of economic stimulating measures of economic entities and individuals carrying out the production, implementation and use of natural gas as a motor fuel.

At the subject of the constituent entities of the Russian Federation, it is proposed:

1. Development and implementation of regional gas engine fuel utilization programs on motor vehicles.

2. Ensuring a priority acquisition at the expense of budgetary funds of public transport and communal technology using gas engine fuel, in order to reduce budgetary fuel costs and improving the environmental situation in cities.

3. The inclusion of costs for the retrofitting of garage complexes of budgetary organizations when transferring PBX to the use of gas engine fuel to the budgets of municipalities.

4. The cost of operation of gas engine equipment is reduced by savings in the cost of fuel. REC, on the basis of Federal Law No. 261-FZ "On Energy Saving and to Enhance Energy Efficiency and Amending Certain Legislative Acts of the Russian Federation" dated November 23, 2009, must maintain tariffs for transportation unchanged for 5 years.

OAO Gazprom is offered:

1. Continue work on the adoption of FZ "On the use of gas engine fuel" and to develop and produce modern and effective HBO.

2. Implement the program of OAO Gazprom "Development of a gas stalline network and a fleet operating on natural gas for 2007-2015".

3. Organize refueling potential consumers with the help of mobile tankers with the subsequent construction of AGNKS.

Conclusion

In April 2012, Vladimir Putin, being in Togliatti, proposed to allocate additional subsidies to the Russian regions to update the bus fleet.

Funds are proposed to allocate to those regions that will translate their bus fleet to a cleaner type of fuel - gas. Previously, it is planned to allocate 3.5 billion rubles for these purposes. From the budget of the Russian Federation.

Currently, more than 50% of the park of buses over 15 years old, and most of our European neighbors buses for security reasons are updated every ten years.

The acquisition of municipal transport using CPG and LNG as a motor fuel must be synchronized with the construction of new AGNCs, refurbishment and maintenance points of cars, cylinder re-release points, commissioning of mobile automotive gas refills. This will further ensure the real improvement in the environmental situation in large industrial cities, will increase the economic efficiency of cargo-passenger traffic, reduce the costs in budgets of all levels, will speed up the formation of a new market for the use of natural gas in the Ural region.

One of the many reasons for slowness in transport gasification is that the nomenclature of gas engine fuel is pretty extensive:

• liquefied petroleum gas (CIS);
• compressed (compressed) natural gas (CPG);
• liquefied natural gas (LNG).

The main advantages of gas engine fuel at its price, price and price again. While these advantages outweigh numerous and versatile disadvantages.

Liquefied petroleum gas (CIS)

This gas is a mixture of propane C3H8 and Butane C4N10, extracted by their associated petroleum gases, from condensate fractions of natural gas, from gas stabilization gas stabilization processes and condensate, from oil refined gas produced from oil refining facilities. In addition to propane and butane, oil gas contains by weight of about 6% of other hydrocarbons - ethane, ethylene, propylene, butylene and their isomers, that is, the composition of the CIS is non-uniform and is inconsistent. For controlling leaks, filked substances are introduced into the CIS - mercaptanes. Mercpta is easy to identify the nose when the Gazelle Gazelle passes on the street past you.

The main advantage of propane and butane in high critical temperature. Critical is called the temperature at which the density of the liquid and its saturated pair becomes equal and the boundary of the partition between them disappears.

In propane critical temperature of 96.8 ° C, in Bhutan 152.0 ° C, which makes it easy to linse these gases and stored in a liquid state with a relatively low pressure up to 1.6 MPa. It also means that the CIS storage vessel will be relatively easy, and the gas is stored in a liquefied state may arbitrarily long under the condition of complete sealing of the vessel. At the same time, the cylinder for the CIS is a pressure vessel, and it is impossible for him to give any shape, as, for example, a gas tank. This circumstance generates problems with the placement of the gas cylinder by car.

To refuel vehicles use two CIS brands: summer and winter. Summer brand, or propane-butane automotive (PBA), contains 50 ± 10% propane by weight. Winter, or propane car (PA), contains 85 ± 10% propane by weight. Thus, adjusting the content of light propane, ensure year-round operation of gas-filled cars.

The use of the CIS is limited by gasoline engines, that is, low compression degree and lawsuage engines. These are passenger cars, small and medium-room trucks and energy installations. CIS Consumption is 10-15% higher than gasoline, due to lower volumetric calorific value: 1 liter of gasoline will be equivalent to 1.1-1.15 m 3 of the CIS, and in real conditions due to the incidence of engine power - 1.15- 1.3 m 3 of the CIS. At low temperature, the engine is allowed on gasoline, after warming up the driver can switch to gas directly from the cab. Go from one type of fuel to another can be on the go.

Propane-butane is heavier than air 1.5-2 times and with leakage accumulates at the earth, creating explosive and harmful to health atmosphere. Therefore, gas-ballot cars are stored on open parking, and repair areas equip good ventilation. Long inhalation of propane-butane is not only unparalleled due to mercaptans, but also leads to poor well-being, up to poisoning.

The octane number of the CIS is about 105, and, as they say, no detonation occurs in any engine operation mode. This statement should not serve as a reason for complacency, with a certain initiousness of the mind of detonation can be achieved.

Taking into account the costs of equipment with gas equipment, its masses and less stroke in one refueling, the translation of the car on the CIS remains profitable due to the price. The locomotive of the promotion of the CIS in the mass was and there are passenger cars and low-tonnage trucks. Liquefied oil gases produce the same companies as a by-product of liquid fuel production, which affects the number of gas gas stations - companies are interested in selling their own product.

As for diesel engines, here propane-butane has no prospects due to the instability of combustion at a high degree of compression. This is the main reason why the CIS did not fit on diesel engines. But the CIS potential is completely not yet disclosed.

General certificate of methane

Under natural gases are meant methane CH4 - the simplest hydrocarbon without color and smell. Methane is the third prevalence of gas in the universe after hydrogen and helium. There is no final opinion on the origin of the deposits of natural gas in the earth's crust, as well as the origin of oil.

Natural gas contains from 70 to 98% of methane, the rest falls on heavier hydrocarbons: ethane, propane and butane, as well as irritable: water, hydrogen sulfide, carbon dioxide, nitrogen, helium and other inert gases. Before feeding to the gas transmission system (GTS), natural gas must be cleaned and dried, getting rid of water, hydrogen sulfide, separating heavy hydrocarbons and other impurities. In the highway, water pairs can condense or form crystalline compounds with gas - hydrates - and accumulate on the bends of the pipeline, making it difficult to promote gas. Hydrogen sulfide causes severe corrosion of gas equipment. Depending on the composition of natural gas, various technologies of drying and separation of gases are used. Thus, pure methane remains with minor impurities. Through the GTS methane comes to consumers. If your dwelling is connected to the gas distribution system, it is methane in the kitchen in the kitchen. This methane after compression or liquefying is filled with gas-filled equipment.

Methane - odorless gas, characteristic aroma ("With the smell of gas to call 09"), the mercaptans are given, which are injected into gas before downloading in GTS (16 g per 1000 m 3). This method was invented to detect leaks from the GTS, the length of which he has thousands of kilometers. With the leak of Mercapotan, the fragrance attracts the crows, whose copies are easy to detect during the lunch of the pipeline on the helicopter.

Methane 1.6 times lighter than air and during leakage instantly disappear. Methane is explosive at a concentration in the air from 4.4 to 17%. The most explosive concentration is 9.5%. Determine the presence of methane in air easily for mercaptan fragrances. In places of natural formation of methane, where it is impossible to determine the smell, for example in mines, gas analyzers are used. The first mine gas analyzers were canas. Gas failed techniques are stored on open parking, and closed repair areas are equipped with forced exhaust ventilation. On the main gas without any training, energy sets of different power connected directly to the pipe are operating.

Compressed natural gases (CPG)

The critical methane temperature is -82.3 ° C, and its liquefaction is very expensive, so methane as gas engine fuel is used mainly in a compressed (compressed) form, while the gas is reduced in the amount of 200-250 times. A gas pipeline is supplied to the automotive gas-filled compressor station (AGNCC) and compromise the gas in place. It is cleaned, more precisely, the main gas is harvested with a compressor to 20 MPa and dried. At the KPG station stored in a small high-pressure vessel, from which the gas is pumped into the cylinders of the car. As for the carriage of ready-made CPGs, there are special gas carriers for this, which are a battery of cylinders, small ones in comparison with tank for liquefied gases, that is, the carriage of finished CPGs is expensive and specific. Support of the main gas to the filling station is necessary that somewhat makes it difficult to expand the network of gas gas stations. Today in the 58 regions of the Russian Federation there are 246 automotive gas-filled compressor stations (AGNCS), fueling the CPG transport. The unconditional leader of the National Gas Motor Market is Gazprom - 210 AGNX is in its property. For more than 10 years, Gazprom is engaged in popularizing gas engine fuel in Russia - AGNKS is 70% of regions, and not in all, 246 AGNKS is 1% on the background of all gas stations in the territory of the Russian Federation, and the unconditional leader commissioned 2.1 AGNX in year.

High pressure CPG requires very durable, thick-walled, heavy cylinders. But that's not all. The CPG can be driven by 3.5 times less than the CIS with equal volumes of gas cylinders. Either cylinders hang, or often refuel - in this the main disadvantage of the CPG, which determines the scope of its application: near refueling, as well as the types of engines, on them.

Due to the fact that there is a significant space for the discontinuity of cylinders for the CPG, this type of fuel is of interest for medium and large-tonnage cars and tractor equipment. The greatest interest today is two-fuel engines - gas digesters operating on diesel fuel and CPGs, precisely because of the scarce infrastructure of the CPG, so that it was to get to refueling. Under the second type of fuel, the diesel engine is converted relatively simple and fast, the injection of diesel fuel into the combustion chamber is used to ignite the combustible mixture. Manufacturers of gas equipment reached the ratio of diesel fuel consumption and methane 20:80 on trunk tractors with the Common Rail and 30:70 fuel system on tractor equipment with an TNVD. The transfer of the machine to the CPG is 3-4 times more expensive than a similar operation with the CIS, however, the cost pays off approximately during the year due to the price difference on gas and diesel fuel.

Engineering offers single-fuel engines on CPGs with a reduced degree of compression and spark ignition. It should be understood that such machines are literally chained to refuel.

CPG - excellent fuel for diesel engine. Methane does not form deposits in the fuel system, does not wash off the oil film from the walls of the cylinders, thereby reducing the friction and reducing the engine wear. Methane burns completely, without forming solid particles and ash, causing elevated wear of the cylinder-piston group. Thus, the use of natural gas as a motor fuel allows you to increase the service life of 1.5-2 times. Methane is environmentally friendly: it gives a very pure exhaust. And most importantly, the CPG is three times cheaper than gasoline and diesel fuel, although in fact it should be even less.

Liquefied natural gas (LNG)

During the liquefaction, methane is reduced in a volume of 600 times - in this the main advantage of the liquefaction, which determines the scope of its application: buses, trunk tractors, career dump trucks, that is, where the fuel tanks should occupy a place at a minimum, and hold the maximum. The same amount accommodates LNG three times more than the CPG.

Liquefaction passes at a temperature of -161.5 ° C. The energy-cost process and requires cryogenic equipment. Liquefied methane is stored at a temperature inside the thermally insulated vessel from -160 to -196 ° C. Very high quality thermal insulation is needed. And in the same way as CPG, refubs diesel engines into double-fuel. LNG automotive equipment is distinguished by a thermos and evaporator with a cylinder, the rest of the nodes are the same.

Liquefied methane is even less compressed. Some bus parks built gas gas stations. These experiments are still more experimental.

Conclusion

When there are discussions about gas engine fuel and its slow distribution, the question is always raised that it is primary: a park of gas-ballon cars or a network of gas gas stations. It is absolutely clear that the refueling network is primarily. From here there is an eternal question: who is to blame? Owners of refueling networks. Owners are not interested in what is interesting for the country, for they do not see in that profits. Owners will continue to continue sabotage gasification of transport.

What to do? The only effective means of combating natural monopolies and stimulating the economy as a whole remains nationalization primarily by PJSC Gazprom, all of its subsidiaries and all gas distribution networks. It is not necessary to enterprises that decide the economic and social tasks across the Russian Federation, the subjects and parts of the subjects of the federation to serve to meet the ambitions of the narrow circle of individuals. Regulation of tariffs in this direction is nothing more than palliatives.

Chemical composition of gas. Application

The bulk of natural gas is methane (CH4) - up to 98%. The composition of natural gas may also include more heavy hydrocarbons - methane homologs:

ethane (C 2 H 6),

propane (C 3 H 8),

bhutan (C 4 H 10),

as well as other inconspicuous substances:

hydrogen (H 2),

hydrogen sulfide (H 2 S),

carbon dioxide (CO 2),

helium (not).

Pure natural gas has no color and smell. In order to be able to determine the leak on the smell, a small amount of substances having a strong unpleasant smell are added to the gas (t. Odorants). Most often, ethyl mercaptan is used as a odorant.

Hydrocarbon fractions are valuable raw materials for the chemical and petrochemical industry. They are widely used to obtain acetylene. Pyrolysis of ethane receive ethylene - an important product for organic synthesis. When oxidizing the propane-butane fraction, acetaldehyde, formaldehyde, acetic acid, acetone, and other products are formed. Isobutan serves to produce high-octane components of motor fuels, as well as isobutylene - raw materials for the manufacture of synthetic rubber. Isopentane dehydrogenation is obtained by an isoprent - an important product in the production of synthetic rubbers.

Compressed natural gas - Compressed natural gas used as motor fuel instead of gasoline, diesel fuel and propane.

Natural gas, as any other, can be compressed using a compressor. At the same time, the volume occupied by them significantly decreases. Natural gas is traditionally compressed to a pressure of 200-250 bar, which leads to a reduction in volume 200-250 times. Gas is compromised (compressed) for transportation through trunk gas pipelines, to maintain the correct pressure inside the reservoir (reservoir pressure) during the injection molding under the ground, and the preparation of the compressed natural gas is an intermediate step in the production of liquefied natural gas. Complimed natural gas is cheaper than traditional fuel, and the greenhouse effect caused by its combustion is less compared to conventional fuels, so it is safer for the environment. Storage and transportation of compressed natural gas occurs in special gas storage. Also used to add to the compressed natural gas of biogas, which reduces carbon emissions into the atmosphere.

Compressed natural gas as fuel has a number of advantages:

· Methane (main component of natural gas) is lighter than air and in the event of an emergency spill, it quickly evaporates, in contrast to the more severe propane accumulating in natural and artificial recesses and creating the danger of the explosion.

· Not toxic in low concentrations;

· Does not cause corrosion of metals.

· Compressed natural gas is cheaper than any petroleum fuel, including diesel, but they exceed them by calories.

· Low boiling point ensures complete evaporation of natural gas at the lowest ambient temperatures.

· Natural gas burns almost completely and leaves a soot, worsening ecology and reduction efficiency. Allocated flue gases do not have sulfur impurities and do not destroy the metal chimney.

· Operating costs for servicing gas boiler rooms are also lower than traditional.

Another feature of the compressed natural gas is that the natural gas boilers have a larger efficiency - up to 94%, do not require fuel consumption to its preheating in winter (like fuel oil and propane-butane).

Natural gas cooled after cleaning from impurities to condensation temperature (-161.5 0 C), turns into a liquid called liquefied natural gas. Liquefied gas is a colorless odorless liquid, the density of which is two times less than the density of water. 75-99% consists of methane. Boiling point -158 ... -163 0 C. In liquid state, it is not a fuel, not toxic, not aggressive. For use is subjected to evaporation to the initial state. When combustion of vapors, carbon dioxide and water vapor is formed. The volume of gas during liquefaction decreases 600 times, which is one of the main advantages of this technology. The liquefaction process goes steps, on each of which the gas is compressed in 5-12 times, then cooled and transmitted to the next step. The actual liquefaction occurs when cooling after the last compression stage. The process of liquefaction, thus, requires a significant consumption of energy - up to 25% of its amount contained in liquefied gas. Liquefied gas is produced on the so-called liqueiest installations (factories), after which it can be transported in special cryogenic tanks - marine tankers or tanks for land transport. This allows us to deliver gas to those areas that are far from the main gas pipelines traditionally used to transport conventional natural gas. Natural gas in liquefied form is kept for a long time, which allows you to create reserves. Before delivery directly to the consumer, liquefied gas is returned to the initial gaseous state on regasification terminals. The first attempts to lunch natural gas for industrial purposes belong to the beginning of the 20th century. In 1917, the first liquefied gas was obtained in the United States, but the development of pipeline delivery systems for a long time postponed the improvement of this technology. In 1941, the following attempt was made to produce LNGs, but industrial scales reached only from the mid-1960s. In Russia, the construction of the first plant of liquefied natural gas began in 2006 in the framework of the Sakhalin-2 project. The solemn opening of the plant took place in the winter of 2009.

Shale gas - Natural gas produced from a slate consisting mainly of methane. The first commercial gas well in the shale formation was drilled in the United States in 1821. The large-scale industrial production of shale gas was started by Devon Energy in the United States in the early 2000s at the Barnett Shale deposit, which at this field in 2002 drilled the horizontal well for the first time. Due to the sharp increase in its production, called the "Gas Revolution", in 2009, the United States became the world leader of gas production (745.3 billion m 3), and more than 40% accounted for non-traditional sources (methane from coal layers and shale gas).

Shalast gas resources in the world are 200 trillion m 3. In January 2011, economist A.D. Heitun wrote about the possibility that the shale gas "will repeat the fate of coal methane with a significant drop in the increase in mining during long-term operation of the fields or the fate of biofuels, which is overwhelming part of the world production of America, and is now reduced."

Gas reserves and resources

World geological reserves of combustible gases on continents, in the zone of shelves and shallow seas, according to the forecast estimate, reach 10 15 m 3, which is equivalent to 10 12 tons of oil.

The largest deposits in the USSR were: Urengoy (4 trillion m 3) and Polar (1.5 trillion m 3), Vuktylskoe (452 \u200b\u200bbillion m 3), Orenburg (650 billion m 3), Stavropol (220 billion m 3), Gazli (445 billion m 3) in Central Asia; Shebssinsky (390 billion m 3) in Ukraine.

On the Yamal Peninsula and in the surrounding waters, 11 gas and 15 oil and gas condensate deposits, explored and preliminary estimated (ABC 1 + C 2), the gas reserves are about 16 trillion m 3, promising and forecast (from 3-d 3) gas resources - about 22 trillion m 3. The most significant in the gas reserves of the Yamal deposit is Bovanenkovskoye - 4.9 trillion m 3 (ABC 1 + C 2), which in 2012 will begin to be developed, and the gas will go into the new main gas pipeline of Bovanenkovo-Ukhta. The initial reserves of the Harasawa, Kruzenshtern and South Tamba deposits are about 3.3 trillion m 3 of gas.

Eastern Siberia and the Far East make up about 60% of the territory of the Russian Federation. The initial total gas sushi resources of the East of Russia - 52.4 trillion m 3, shelf - 14.9 trillion m 3.

In the Russian Federation, gas production only OAO Gazprom in 2011 amounted to 513.2 billion m 3. At the same time, the gains of category C 1 reached a record level - 686.4 billion m 3, condensate - 38.6 million tons. In 2012, it is planned to produce 528.6 billion m 3 gas and 12.8 million tons of gas condensate.

Condensate

Condensate - liquid product separation of natural gases. It is mainly represented by liquid uv - pentane and heavier HC alkanov, cyclan and age. The density usually does not exceed 0.785 g / cm 3, although a difference with a density of up to 0.82 g / cm 3 is known. End of boiling from 200 to 350 0 S.

Distinguish raw condensate obtained during separation and stableobtained by deep degassing raw condensate. The amount of condensate in the reservoir gases is expressed either by the ratio of its volume to the volume of separated gas (see 3 / m 3) and is called condensate factor. The amount of condensate, assigned to 1 m 3 of a separated (free) gas, reaches 700 cm 3. Depending on the magnitude of the condensate factor, the gases are "dry" (less than 10 cm 3 / m 3), "skinny" (10-30 cm 3 / m 3) and "fatty" (30-90 cm 3 / m 3). Gases characterized by a gas factor of more than 90 cm 3 / m 3 are called gas condensate. At the Vuktyl oil and gas condensate deposit, the condensate factor is 488-538 cm 3 / m 3, natural gases of Western Siberia deposits are usually "dry".

Gas, which is mined from the depths of the Earth or is a product of processing other hydrocarbons, may be subsequently used in liquefied or compressed form. What are the features of both options for applying the appropriate fuel?

What is a liquefied gas?

Under liquefied It is customary to understand natural gas, which is translated from the original, actually gaseous state into liquid - by cooling to a very low temperature, the order of the minus 163 degrees Celsius. The volume of fuel is reduced by about 600 times.

Transportation of liquefied gas requires the use of special cryogenic tanks that are capable of maintaining the necessary temperature of the appropriate substance. The advantage of the type of fuel under consideration is to be able to deliver it to those places where ordinary gas pipelines are maintained.

The conversion of liquefied gas to its original state also requires a special infrastructure - regasification terminals. The processing cycle of the type of fuel under consideration is mining, liquefaction, transportation and regasification - significantly increases the final cost of the gas for the consumer.

The fuel is used about, usually for the same purposes as natural gas in the initial state - for heating rooms, ensuring the functioning of industrial equipment, power plants, as raw materials in some segments of the chemical industry.

What is a compressed natural gas?

Under compressed, or compresentedIt is customary to understand natural gas, which, as liquefied, is also represented in liquid state, achieved, however, not by reducing the temperature of the fuel, and by increasing the pressure in the container in which it is posted. The compressed gas volume is approximately 200 times less than that of fuel in the initial state.

The conversion of natural gas into the liquid with high pressure is mostly cheaper than fuel liquefaction by reducing its temperature. Transportation of the considered type of gas is carried out in containers, as a rule, less technologically complex than the cryocytes. Regasification of the appropriate type of fuel is not required: Since it is under high pressure, it is easy to extract from tanks - it is enough to open the valves on them. Therefore, the cost of compressed gas for the consumer is in most cases lower than that that characterizes liquefied fuel.

Complimed gas is most often used in the form of fuel on various vehicles - cars, locomotives, ships, in gas turbine engines of aircraft.

Comparison

The main difference in liquefied gas from compressed is that the fuel of the first type is obtained by reducing the temperature of the initial gaseous substance, which is accompanied by the transformation of it into the liquid. Compressed gas is also liquid fuel, but it is obtained by means of its placement in the container under high pressure. In the first case, the initial volume of gas exceeds the processed (translated into the liquid) of about 600 times, in the second - 200 times.

It is worth noting that liquefied gas is most often obtained by treating the "classic" natural gas presented mainly by methane. Complimed fuel is also manufactured from many other types of natural origins - for example, propane or butane.

Determining what is the difference between liquefied and compressed gas, reflect the conclusions in the table.

Table

General description of piston compressors. Single-stage and two-stage. Harmful space

In accordance with the nature of the action, piston compressors may be single (or simple) action and double action. In simple action units, one suction or discharge is carried out in one stroke. In double-acting compressors, two suction or discharges are carried out in one piston stroke.

By the number of compression stages, piston compressors are divided into three types: single-stage, two-stage and multi-stage. The compression step is made to call a part of the compressor in which the gas is compressed to intermediate or end pressure.

Structurally, single-stage compressors can be vertical or horizontal. As a rule, compressors with horizontal design are double-acting machines, and the compressors with a vertical design belong to the simple acting units.

In a single-stage compressor of simple action with a horizontal type of construction, the piston moves inside the cylinder. The cylinder is equipped with a lid, which has suction and discharge valves. The piston of the compressor is connected to the connecting rod and crank. A flywheel is located on the shaft of the crank. In the process of the stroke of the piston from left to right, the zone between the piston and the cylinder occurs. The pressure difference in the absorption line and the cylinder makes the valve open, with the result that the gas enters the cylinder. When the piston makes the opposite movement on the right to the left, the suction valve is closed, and the gas in the cylinder is compressed to the pressure level P 2. Next, through the gas valve is displaced in the injection line. The cycle is completed and repeated again.

A single-stage double action compressor is equipped with four valves (two suction and two injection). Such machines are more complicated, but the level of performance is twice as high. For cooling purposes, the cylinder and lids can be equipped with water shirts. To increase performance indicator, these machines can be manufactured by multi-cylinder structures. Single-stage compressors with a vertical type of design are more productive and high-speed than horizontal. In addition, they occupy a smaller production area and more durable.

Two-stage compressors with a horizontal type of construction, as a rule, are equipped with one cylinder and stepwise or differential type of piston. The gas is subjected to compression in the cylinder to the left side of the piston, after which it passes through the refrigerator and is fed to the cylinder on the other side, where it is compressed to the level P 2.

Multistage structures are equipped with cylinders, which are located sequentially (tandem system) or parallel (compound system). There are also the opposite designs of the compressors, where the pistons move mutually opposite. Cylinders in the designs of this type are located on both sides of the shaft.

It should be noted that the real gas compression process in the compressor differs from the theory. So, between the piston, when it is in the extreme position and the cylinder lid there is a free amount. This gap is called a harmful space. In this gap, upon completion of the discharge, compressed gas expands at the opposite course of the piston. For this reason, the suction valve is opened only after reducing the pressure level to the pressure level on suction. Thus, the piston makes idle movement, which reduces the performance of the compressor.