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LPG conversion

A special service for you - LPG conversion

In cooperation with our partners we offer the special service of LPG-conversion. The the benefits are clear and take, in addition to the economic aspects, a further step towards environmental protection. From the state support, through reduced CO2 emissions, through to biogas gas station card.


We will gladly inform you.


The fuel

LPG (butane / propane) is used as a fuel for gasoline engines. Already in the 1970s, it was very common in Italy, and it has remained until today. The entire bus fleet of Wiener Verkehrsbetriebe runs on LPG.

It burns more environmentally friendly than gasoline. The emissions of nitrogen oxides are about 20% of gasoline, CO2 emissions are reduced by 15% and unburned hydrocarbons by 50%. In addition, LPG gases can be implemented by the improved chemical recyclability at lower temperatures in autocatalysts. LPG powered forklifts may - in addition to natural gas forklifts - are operated as only vehicles with combustion engines in enclosed spaces. Diesel forklifts, however emit soot and high amounts of nitrogen oxides.

In direct comparison with gasoline depending on gas system (see below), a volumetric (liters vs. kg) fuel consumption from 5 to 20% for LPG is produced because LPG has a lower density. For comparison: Super 95 octane petrol has a density of about 0.76 g / cc, liquid gas (approximately 108 octane) depending on the mixing ratio of 0.51 to 0.56 g / cc. At first glance, the result is an increase in consumption of 40%, which, however is reduced, due to the higher calorific value of LPG (46.1 MJ / kg (12.8 kWh / kg) to 43.6 MJ / kg (12.1 kWh / kg)) onto theoretically 33%. By the consumption of starting gasoline (and its neglect in the consumption calculation) the theoretical consumption of 33% decreases depending on the average length of the route to practically 5 to 25%. The higher the proportion of short-range, the smaller the typical "consumption" will be.

First LPG was with the taxis (for instance all taxis in Istanbul), later widely used in the private motor vehicle sector and in the 1980s in Austria as a result of low prices. Due to the higher rate of taxation on private vehicles in Austria then again it became uninteresting. However, Wiener Verkehrsbetriebe had all their buses changed to LPG drive since public Autogas remained untaxed.

Today LPG as fuel is present in most neighboring European countries (such as B, F, GB, I, NL, PL ...). In Germany the number of cars and gas stations is growing strongly. The reason is the low taxation. With the Energy Tax Act liquefied petroleum gas (LPG / LPG) as fuel is at 16.6 cents / kg - taxed 1.29 cents / kWh (= about 9 cents / l) by the end of 2018th

In Germany, the liters of LPG at the gas station currently costs 57-79 cents (the 18. January 2008) - where there is a clear north-south divide here. There are currently 3517 LPG filling stations (February 24, 2008). Until August 2008 it is to calculate with about a number of 4000 gas stations in Germany.

In Switzerland (0.40 CHF gasoline equivalent) from 2008 on, LPG is to be tax deductible and thus will be cheaper to approximately 0.30 CHF. Currently it costs between CHF / Liter 1.20 and 1.69 (as at 7 November 2007).

The technology

LPG powered vehicles can be started either on gasoline, then switched automatically, depending on the built system, via a switch or to gas operation to avoid possible warm-up problems, or they run directly to LPG. A distinction is made between Venturi systems, sequential systems and LPI plants.

The first two types of plant have in common that the in the tank pressurized liquid gas is supplied to the engine in gaseous form through a vaporizer and pressure regulator. Since the gas during evaporation cools rapidly like ice spray, the evaporator is heated with cooling water. For this reason, most of the auto gas plants switch on gas when the cooling water temperature is about 30 ° C to prevent icing of the evaporator at low outside temperatures.

Since 1995, LPI systems are offered. These systems deliver liquid gas with a fuel pump under pressure into a ring line, from where it is injected by metering in liquid form into the intake.The absorbed heat for evaporation leads to a cooling effect of the intake air, which may amount a maximum of 15 Kelvin, depending on the load. 5 This leads to a slight increase in performance (see turbo engine / intercooler) respectively related to a lower power loss in evaporator systems. For burning, the fuel and the oxygen contained in the air is required. Cold air contains per volume more oxygen than warm. In a conventional gasoline engine, the fuel is injected as an aerosol, which in fact does not require any volume. Gaseous fuels displace air and so reduce the amount of oxygen in the cylinder. For LPG theoretically 3% of air to be displaced, with natural gas up to 10%.

The LPG combustion takes place at lower pollutant emissions and increased smoothness. These effects are i.a. due to the high anti-knock quality 105-115 octane and the homogeneous mixture formation. Gases are very fast and very evenly mixed with the combustion air, in contrast to aerosols. By avoiding local air deficiency or excess cash, the formation of undesirable combustion byproducts such as carbon monoxide, partially / unburned hydrocarbons or nitrogen oxides is suppressed.

In terms of security the ADAC writes: "There is no evidence from the field that these vehicles have an increased safety risk, even in those countries where relatively many LPG cars are admitted. Crash and fire tests show that LPG vehicles are no more dangerous than comparable gasoline vehicles "LPG tanks and their pipe connections are equipped with different security systems. So the fill line connection is provided with a check valve in a pipe demolition prevents the escape of gas. The transport line in the engine compartment is secured directly to the tank withdrawal with a solenoid valve which closes immediately in case of power loss. At an excessively high pressure drop, the gas control unit switches immediately to 0 volts, whereby the valve is closed. If in an accident the vehicle power supply does not function anymore, then the described solenoid valve due to the current loss is closed in any case.

In case of fire, most tanks tested to a pressure of 30-35 bar are (forcing off pressure 60-90 bar). Depending on the type of tank (1 hole / 4-hole) is either a separate pressure relief valve or a pressure relief valve integrated in the multi-valve. This opens at a pressure of about 25-28 bar, which ensures that the gas is discharged controlled in case of fire and the tank can not burst. (Source: Wikipedia)

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