Distillate of gas condensate (DGC) is an associated product of natural gas distillation with secondary fractions added. It is used as a raw material for the chemical industry, an additive for gasoline production, fuel for diesel electric motors and as a solvent and fuel for certain types of lamps in everyday life.
Classification of gas condensate distillates is based on their individual chemical and physical parameters. They determine the quality of certain types of DGC and their application.
Distillate of gas condensate (DGC): types
1. Light. Light types of DGC are the most widespread and are a mixture of C3-C8 hydrocarbons. They are used as raw materials for petrochemical industry and as additives to gasolines. They can have different shade from transparent to slightly yellow and a homogeneous composition that does not require additional purification.
2. Medium. Medium types of DGC have a similar composition and density with winter diesel fuel and can be used for refuelling diesel electric generators. This DGC type is stable and has the optimum viscosity.
3. Heavy. Less common type of DGC. It has darker colour, because it contains the heaviest fractions of the distillation. Usually used as fuel for boilers.
The main characteristics of the gas condensate distillate are:
Being an analogue of diesel fuel, DCG has a different fractional composition and a lower density (on average 0.75-0.85 g / cm3). For example, 1000 litters contain 850 kg of DF Euro and only 720 kg of gas condensate. DCG can be used as a fuel for tractor engines, but not for cars with diesel engine, because when burned, it releases aromatic hydrocarbons and resins that settle on the walls of the chamber, nozzles and piston.
• Impurity content
Gas condensate, extracted directly from the well, has a high content of impurities. Such mixture is subject to purification and degassing, thereby becoming stable. Distillates of gas condensate, especially light types, have a very low percentage of impurities which in accordance with GOST is not more than 0.1
• Water content
Distillate of gas condensate can contain a small amount of water. DGC itself is not water soluble, but the water dissolves in it. Dissolution of water in the condensate increases its viscosity and temperature set point. This is important consideration when using DGC during the cold season.
• Sulphur content
According to the content of sulfur DGC are divided into three types:
sulfur-free or low-sulfur (the share of sulfur is less than 0.05%),
– sulfur (sulfur content 0.05-0.8%),
– high-sulfureous (sulfur content more than 0.8%),
The necessity of purification of condensate distillate from sulfur may arise in connection with the market requirements. Light DGCs contain aliphatic mercaptans, heavier types – sulphides and thiophenes. The presence of sulfur degrades the thermal stability of the fuel, increases corrosive aggressiveness and the amount of harmful emissions to the atmosphere.
• Hydrogen sulphide content
Distillate of gas condensate can contain up to 3ppm of hydrogen sulfide. Together with low-boiling mercaptans, it causes an unpleasant smell. To remove hydrogen sulphide washing with an alkaline water needed.
DGC is a flammable liquid. Its vapour may form a flammable mixture with the air, therefore it is transported only by special purpose vehicles.
Personnel working with DGC (in laboratories, in production) should use personal protective equipment and follow fire safety rules.