5 Oct, 2015

# What is the Impact of Feed Gas Conditions on the Adsorption Dehydration System?

Adsorption dehydration units can reduce the water content of a gas stream to less than 0.1 ppmv. The gas industry normally uses adsorption dehydration units upstream of a liquefied natural gas (LNG) plant or a deep natural gas liquid (NGL) extraction plant where the gas temperature reduces to less than -160 °C (-256 °F) and -100 °C (-148 °F), respectively. Removal of water content to this very low level is essential to prevent freezing. This month’s article discusses feed gas flow rate, pressure, and temperature effect(s).

3 Sep, 2015

# Gas-Liquid Separators Sizing Parameter

In this Tip of the Month (TOTM), we will focus on the application of Souders-Brown approach in gas-liquid separators and present diagram, simple correlations and tables to estimate the Souders-Brown equation constant, KS (the so called sizing parameter). We will consider both vertical and horizontal gas-liquid separators. Knowing the actual gas flow rate through the vessel, one can use KS parameter to determine the maximum allowable gas velocity through the vessel and determine the required separator diameter. One can also use the appropriate value of KS to size the mist extractor in the vessel. The performance of a gas-liquid separator is highly dependent on the value of KS; therefore, the choice of appropriate KS –values is important.

3 Aug, 2015

# Effect of Relative Density (Specific Gravity) on the Saturated Water Content of Sweet Natural Gases

In this Tip of the Month (TOTM), we will study the effect of relative density (Specific Gravity, SG) on the saturated water content of sweet natural gases. The results of this study include the water content of sweet natural gases as a function of relative density in the range of 0.60 to 0.80. Four temperatures of 4.4, 23.9, 37.8 and 149 °C (40, 75, 100, and 300 °F) were considered. For each temperature, the saturated water content was calculated for pressures of 1724, 3448, 6897, and 13 793 kPaa (250, 400, 100 and 2000 psia).

6 Jul, 2015

# How to Estimate Compressor Efficiency

In this article, we will demonstrate how to determine the efficiency of a compressor from measured flow rate, composition, suction and discharge temperatures and pressures. A rigorous calculation based on an equation of state and a shortcut method are considered and the results are compared. From a calculation viewpoint alone, the compressor power calculation is particularly sensitive to the specification of mass flow rate, suction temperature and pressure, and discharge temperature and pressure. A compressor is going to operate under varying values of the variables affecting its performance. Thus the most difficult part of a compressor calculation is specification of a reasonable range for each variable and not the calculation itself.