Performance of erythorbic acid as an oxygen scavenger in thermally aged lean MEG

Abstract

The objective of this work is to further evaluate the performance of the erythorbic acid oxygen scavenger designed by (Kundu and Seiersten, 2017) within 85% wt. Thermally Aged Lean Mono Ethylene Glycol (TAL-MEG). Experiments were performed at two levels of dissolved oxygen concentrations including 1000ppb and >7500ppb at pH values of 6, 9 and 11. Furthermore, the erythorbic acid oxygen scavenger was evaluated under conditions representative of an industrial MEG regeneration system in terms of salt and organic acid concentrations to replicate field usage. Strong performance of erythorbic acid in combination with manganese and diethylethanolamine (DEAE) was observed under field conditions suggesting that erythorbic acid may provide an attractive alternative oxygen scavenger for use in the oil and gas industry in place of traditional sulfite based scavengers.However, the results generated within TAL-MEG showed a reduction in the performance of erythorbic acid oxygen scavenger when compared to fresh MEG solution. Moreover, results confirmed that varying acetic acid concentration did not affect oxygen scavenger performance within TAL-MEG. It was observed that the pH of the solution was the primary factor in determining the performance of the erythorbic oxygen scavenger tested with insufficient oxygen removal achieved at a pH of 6. In contrast, strong performance was achieved at pH 9 and 11 successfully reaching below 20ppb dissolved oxygen concentration within a reasonable timeframe with little to no impact due to the presence of mineral salt ions and organic acids.

Performance of erythorbic acid as an oxygen scavenger in salted fresh and degraded monoethylene glycol under a magnetic memory effect

“…An increase in the efficiency of the oxygen scavenger in the salt‐free F‐MEG solutions was observed when the pH was raised from 9.0 to 11.0 (Figure ). This is in line with earlier studies, confirming that the effectiveness of the erythorbate radicals increases in highly alkaline environments. However, in this study, a pH of 9.0 was preferred because MEG regeneration plants and oil product transportation pipelines are not commonly operated at such highly alkaline conditions (pH 11.0).…”

“…It is important to explain that this study was performed at a pH 9.0. At pH ˂7.0, the performance of the erythorbic acid oxygen scavenger fails to achieve the desired 20‐ppb oxygen concentration for both the initial concentrations (~7,000 and ~1,000 ppb) . Therefore, two experiments were conducted at a high oxygen scavenger dosages to evaluate the performance of erythorbic acid at pH 9.0 and 11.0, using a salt‐free F‐MEG solution.…”

“…The replacement of sulfate oxygen scavengers with erythorbic acid has been experimentally confirmed by Al Helal et al and Kundu and Seiersten to be effective and applicable for oil field production. A significant difference between the erythorbic acid performance in F‐MEG and aged‐MEG solutions under alkaline conditions has also been reported . However, the influence of external nonchemical factors on the kinetic performance of the microscopic reactions between oxygen molecules and an oxygen scavenger in glycolic solutions has not been reported.…”

“…These solutions included F‐MEG without salt or organic acids (representing the uncontaminated fluid), F‐MEG with high salt and organic acid contents (contaminated fluid), thermally oxidized MEG without salt but with a high organic acid content (thermal oxide solution), and thermally oxidized MEG with a high content of salt and organic acids (contaminated thermal oxide solution). To ensure that the concentrations of the MEG mixtures were within the proposed level, the volume fractions of the F‐MEG and D‐MEG solutions were confirmed using the Al Helal et al models. The chemical compositions of the F‐MEG and D‐MEG mixtures are outlined in Table .…”

Two-Stage Semi-Continuous 2-Keto-Gluconic Acid (2KGA) Production by Pseudomonas plecoglossicida JUIM01 From Rice Starch Hydrolyzate

“…Erythorbic acid and its salts are generally recognized as safe (GRAS) by the US Food and Drug Administration (FDA) and approved as food ingredients E315 (free acid) and E316 (sodium salt) in Europe with no safety concern (Aguilar et al, 2016). Recently, erythorbic acid and its salts have seen their applications extended to include roles in mushroom post-harvesting as an oxygen scavenger, in the oil and gas industry as an oxygen scavenger, in feed industries as a calcium-rich additive and as acidulates, and in the florescent materials field to promote the synthesis of CdS quantum dots (Liang et al, 2014;Joven et al, 2015;Al Helal et al, 2018;Ping et al, 2018).…”