In this following up paper, we present our findings by examining a pilot scale gasification column and applying nitrogen purging for samples of produced water grafted with different polyacrylamide concentrations (100 – 500 ppm). Upon applying a semi-batch, counter-current scheme for a series of experiments on packed gas-lift column, zero ppm level of dissolved oxygen (DO) was reached within less than 1 minute of nitrogen purging from the start time applied for solutions with viscosity less than 10 mPa.s and using the inline measuring scheme. However, zero ppm DO level was not reachable when purging produced water (PW) samples grafted with fresh polyacrylamide with a viscosity higher than 10 mPa.s. Nonetheless, the residues of DO were detected by offline measuring after examining the higher viscosity samples in the shallow limit (less than 0.4 ppm DO) and reached zero ppm when applying the inline measuring scheme. Two operation mode schemes, circulation, and once-through, were applied. Upon investigating the once-through contact scheme, the adopted nitrogen purging method was effective in reaching zero ppm level in less than 2 minutes, which is an excellent result compared with other well-known treatment techniques.
- A gas lift column was examined to de-oxygenate produced water collected from Omani oil fields.
- Semi batch and counter-current purging packed column schemes were operated. effectively for the de-oxygenation process
- Complete de-oxygenation of produced water grafted with polyacrylamide was achieved within two minutes.
- Achieving complete DO removal indicates the feasibility of using the proposed approach for large-scale industrial applications.