This work investigated the role of mass-transfer interfacial area in the biodiesel production using the acid-catalyzed esterification process. The interfacial area between alcohol and oil feedstock was determined by conducting acid-catalyzed esterification experiments using methanol and oleic acid (as free fatty acid) under ranges of five process parameters: reaction temperature (45–65°C), agitation speed (200–400 rpm), methanol-to-oil ratio (3:1–9:1 mol/mol), catalyst concentration (0.5–2.0%), and concentration of free fatty acid (5–30%). Effects of these parameters on the biodiesel conversion rate and the interfacial area were quantified. An empirical correlation for the interfacial area was developed as a function of process parameters. Results show that the enhancement of biodiesel production rate is attributed to reaction kinetics and/or interfacial area. The interfacial area is the sole contributor to the increase in biodiesel production rate due to the increase in methanol-to-oil ratio and agitation speed. Both kinetics and interfacial area contribute to the increase in biodiesel production rate due to the reaction temperature and catalyst concentration. The interfacial area plays negligible role in the change in biodiesel production rate due to the free fatty acid content.
Part of the book: Frontiers in Bioenergy and Biofuels
This chapter evaluated the performance of environmentally friendly organic corrosion inhibitors on carbon steel in the amine-based carbon dioxide (CO2) absorption process. The evaluation was experimentally conducted using electrochemical techniques in 5.0 kmol/m3 monoethanolamine (MEA) solutions in the absence and presence of process contaminants, namely formate and chloride, at 80°C and 0.55 mol/mol CO2 loading. The results show, in the absence of process contaminants, that 2-aminobenzene sulfonic acid, 3-aminobenzene sulfonic acid, 4-aminobenzene sulfonic acid, sulfapyridine, and sulfolane yielded 85–92% corrosion inhibition efficiencies, while sulfanilamide yielded the lowest efficiency of 20–42%. Sulfolane was the only tested inhibitor whose performance could be maintained in chloride- and formate-containing MEA solutions. On the contrary, the performance of 3-aminobenzene sulfonic acid and sulfapyridine was decreased by chloride. The performance of all the tested aminobenzene sulfonic acids was compromised by formate.
Part of the book: Corrosion Inhibitors, Principles and Recent Applications