Slide 1

Arab Oil & Natural Gas websitePresents

Liquefied Petroleum Gas LPGPart.2LPG Dehydration

Liquid water and/or water vapor are removed from natural gas to:Prevent formation of hydrates in transmission lines.Meet a water dew point requirement of a sales gas contract.Prevent corrosion.

Techniques for dehydrating natural gas include Absorption using liquid desiccants. Adsorption using solid desiccants.

Absorption using liquid desiccants Absorption: the water in a gas stream is dissolved in a relatively pure liquid solvent stream.

stripping (regeneration):The reverse process, in which the water in the solvent is transferred into the gas phase

Adsorption using solid desiccants Adsorption physical phenomenon that occurs when molecules of a gas are contact with a solid surface and some of them condense on the surface.

150 oF220LB/MMSCF WATER CONTENT OF GASES

3%0.93260.98At 150F and 1,000 psia.W = 220 lb/MMscf

At 26 mw gas , Cg = 0.98 W = (0.98)(220) = 216 lb/MMscf

For 3% brine,Cs = 0.93 W = (0.93)(220) = 205 lb/MMscf

80 oF0.0155LB W /100LB propane Solubility of Water in Liquid Hydrocarbons

Water Content of High CO2/H2S GasesSaturated water content higher than that of sweet natural gas, particularly at high pressure

Corrections for H2S and CO2 should be applied when the gas mixture contains more than 5% H2S and/or CO2 at pressures above 700 psia.

The addition of small amounts of CH4 or N2 to CO2 or H2S can reduce the saturated water content compared to the pure acid gas.

WATER CONTENT OF CO2

300

At 88F and 300 psia.For Sweet gas W = 115 lb/MMscfFor CO2 W = 135 lb/MMscf

At 88F and 2000 psia.For Sweet gas W = 27 lb/MMscfFor CO2 W = 180 lb/MMscf

115

135

180200027

Addition of small amounts of CH4 to CO2At 100F and 2000 psia.

Pure CO2 W = 215 lb/MMscf

5.31% CH4 and 94.69 CO2 W = 140 lb/MMscf

Pure CH4 W = 40 lb/MMscf

2000215

140

40

for more FREE movies, visit:Arab Oil & Natural Gas website

www.Arab-Oil-NaturalGas.com