Calcium Alginate-Based Carbon Composite Adsorbents for Lean Methyldiethanolamine Reclamation: Laboratory to Pilot Scale Testing and Validation

Calcium alginate-based carbon composite (CAC) adsorbents have been proved to effectively remove total organic acid anions as HSS anions, metal ions, and organic degraded products from lean methyldiethanolamine (MDEA solvents) used as solvent in natural gas sweetening unit. During the material developmental phase, the CAC adsorbent was synthesized and utilized to remove various contaminants, including heat stable salts (HSS), organic degraded products, and heavy metal ions from lean MDEA using a lab-scale adsorption setup. Based on the results, a "demo-scale" fixed bed adsorption unit was designed and simulated using adsorption model to predict breakthrough behavior. In the current work, the efficiency of the CAC adsorbent in removing HSS and total organic acid anions were investigated. Analysis of treated samples demonstrated the removal efficiency of the adsorbent under plant scale conditions. Further experiments performed at lab scale indicated the effectiveness of the adsorbent in the removal of bicine from lean MDEA samples. This work provides a framework for future testing and comprehensive process performance evaluation of adsorbents for lean MDEA reclamation in actual plant conditions. A fast, simple, and reliable scale up procedure for fixed bed adsorber developed earlier was validated through this work.

Effect of Auxin, Fusicoccin and Tris Buffer on Ion Uptake, Organic Acid Synthesis and Cell Elongation in Barley Coleoptile Segments

The effects of auxin, fusicoccin and tris buffer on K+ and Cl- uptake, total organic acids synthesis and cell elongation in barley coleoptile segments were tested. Some differences between the effects of fusicoccin and auxin on cell elongation and ion uptake were observed which support the idea that the two hormones may not be acting through a common mechanism. Tris buffer in the presence and absence of hormones stimulated K+ uptake and inhibited both Cl- absorption and to some extent cell elongation. Tris buffer treatments, which resulted in excess K+ uptake over Cl-, also caused a net synthesis of organic acids in the tissues. In some experiments, the relation between auxin-induced cell elongation and total organic acid synthesis was also examined.

Determination of Orotic and Dihydroorotic Acids in Biological Fluids and Tissues

In commonly used procedures for colorimetric assay of orotic acid in biological materials, certain substances interfere, positively or negatively. Some that interfere negatively are ornithine, cysteine, citrulline, tyrosine, proline, hydroxyproline, and polyamines. Protein and interfering agents are easily removed by first isolating the total organic acid fraction. The orotic acid in this fraction can then be determined by an established colorimetric procedure. A rapid liquid—liquid column-chromatographic procedure is described, if analysis of both dihydroorotic and orotic acid is required.

Organic Acids in Vanilla by Gas-Liquid Chromatography: Interpretation of Analytical Data

A method for interpreting data obtained by using AOAC method 19.046–19.048 for the gasliquid chromatographic determination of vanilla acids is given. Total adjusted peak heights of unknown extracts and authentic extracts are compared. The total organic acid content of the unknown extracts is expressed as a percentage of the total organic acid content of the authentic extract. Thus variations in operator techniques and gas-liquid chromatographic conditions are eliminated and a more accurate quantitative judgment regarding the vanilla bean content of the unknown sample can be made. Data on authentic and unknown vanilla extracts are given.