Adsorbtion of Nitrogen Compounds from Hydrocarbon Liquids by Using Fixed Packed Bed Activated Carbon

Abstract

The Extraction behavior of nitrogen compounds (quionoline, indole, and pyridine) from a liquid hydrocarbon (nonane, C9) was studied by using batch and fixed bed activated carbon experiments. The adsorption isotherm curves and the extraction percentage were determined in batch experiments in the conditions of  initial concentration  20,40,60,80,and 100  ppm of either of quionoline, indole, and pyridine, fuel/(AC) ratio of 20 wt/wt, room temperature  30 ± 1°C , and stirring time of 2h.

In the fixed bed experiments the breakthrough curves were determined as a function of the following variables:

• Bed height of activated carbon 3, 5, and10 cm.
• Initial concentration of nitrogen compounds 50, 75, and100 ppm.
• Flow rate of the feed (15, 25, and35) ml/min.
• Particle Diameter of activated carbon 1.5, 1.2, and1 mm.

The adsorption capacity increases with increasing equilibrium concentration of the nitrogen compounds in the liquid phase, which is a very favorable isotherm irreversible adsorption. Also the activated carbon has very high affinity for the nitrogen compounds in the order indole < quinoline < pyridine and the conversion values were (50, 46, and42) % respectively. In fixed bed experiments the time to breakthrough point decreases with:

• Decreasing in bed height.
• The increase in flow rate.
• The increase in initial concentration of nitrogen compounds.
• There is no effect of varying the particle diameter of the activated carbon because the experimental values of the activated carbon lies in the region of the large particle size and macrospore volume and there is no gradient in the particle size.