Dew Point Problems while Compressing Petroleum Gas.

Pressure of gas that is separated from crude petroleum in producing oil wells is usually not high enough for its distribution. For pipelining, the pressure of gas has to be raised to between 70 and 100 bar. That requires, however, its dehydration on account of corrosion and interface separation in the pipeline. The dehydration (removal of condensate) has, conventionally, taken place after compression to the highest pressure, required for pipelining. As shown by a dew point curve of a dehydrated gas and by phase diagrams, it seems to be an advantage not to perform these dewpoint reductions after compression to the highest pressure, but at a pressure between 30-50 bar if compression for a higher pressure is required. At a pressure between 30-50 bar, reduction of condensate dew point seems to be most effective. As learned by experience, almost all known gases from crude oil (natural gases, too) show in their phase diagrams the maximum temperature of dew point at pressures between 30-50 bar.