High Conversion of Methyl Acetate Hydrolysis in a Reactive Dividing Wall Column by Weakening the Self-Catalyzed Esterification Reaction

We show the superiority of reactive dividing wall column (RDWC) to the single reactive distillation (RD) column in improving the conversion of reactant, taking the hydrolysis of methyl acetate (MA) as example. It is difficult to achieve above 99% conversion for MA in a traditional reactive distillation column (TRDC) due to the existence of self-catalyzed methanol (MeOH)-acetic acid (HAc) esterification reaction in the column bottom. In this work, more than 99% conversion of MA hydrolysis was realized experimentally in an RDWC by separating MeOH from the hydrolysis mixture. The effects of several operation parameters on hydrolysis conversion were systematically investigated, including feedwater–MA mole ratio, heat duty, mole flow rate of feed MA, and vapor distribution. The simulation results by Aspen Plus showed that RDWC has several improvements in MA hydrolysis over TRDC, including lower energy consumption, lower water–MA mole ratio, and larger production capacity. With the increase in MA conversion, the superiorities became more obvious and contribute to the weaker self-catalyzed MeOH–HAc esterification reaction in the RDWC

Stability of Reference Genes for Messenger RNA Quantification by Real-Time PCR in Mouse Dextran Sodium Sulfate Experimental Colitis - Fig 8

<p><b>Effect of reference gene selection on the relative expression of colonic TNF-α (A) and IL-1β (B).</b> Target gene expression was normalized against the 13 reference genes using comparative the ΔΔCt method. Significant differences between control and inflamed colon were seen only with the stable reference genes. Student’s t-test was used to compare the groups. Data is presented as the mean ± SD (n = 6/group).</p

Reference gene stability performance of the 13 reference genes analyzed using BestKeeper.

<p>Lower values refer to higher stability and higher values refer to a lower stability.</p

Range of quantification/threshold cycle (Ct) values of the candidate reference genes.

<p>A scatter dot plot displays the mean value and standard deviation in all colon samples (n = 12).</p

Comprehensive gene stability ranking for the 13 reference genes used in DSS-induced colitis and control groups.

<p>RT-qPCR was performed for each of the 13 reference genes using the same RNA samples from control and DSS-induced colitis groups (inflamed and non-inflamed areas).</p

The average expression stability values of the 13 reference genes analyzed by geNorm.

<p>A lower M value refers to higher gene expression stability.</p

Description of selected candidate endogenous control and target genes.

<p>Description of selected candidate endogenous control and target genes.</p

Systematic confirmation of colitis induction by dextran sulphate sodium (DSS).

<p>(A) C-reactive protein serum level; (B) myeloperoxidase (<i>MPO</i>) activity in the colon; and colonic pro-inflammatory mediators: (C) <i>TNF-α</i>, (D) <i>IL-6</i> and (E) <i>IL-1β</i>. Control represents data obtained in non-colitic non-treated mice (n = 6/group). Student’s <i>t</i>-test analyses were used to compare DSS-treated group to the control group. Data are presented as the mean ± SD.</p

Descriptive performance of candidate reference genes.

<p>Descriptive performance of candidate reference genes.</p

Effect of inflammation on candidate reference gene expression in colonic specimens.

<p>DSS-induced colitic and non-inflamed control colon groups are defined in the Materials and Methods. Several genes were found to show altered expression between samples from control and DSS-induced colitis group (n = 6/group). Student’s t-test was used for comparison between the groups. Ct, threshold cycle.</p