The amine assisted CO₂ capture process from coal fired power plants strives for the determination of degradation components and its consequences. Among them, nitrosamine formation and their emissions are of particular concern due to their environmental and health effects. The experiments were conducted using morpholine as a representative secondary amine as a potential CO₂ capture solvent with 100 ppm standard NO₂ gas to better understand the nitrosamine reaction pathways under scrubber and stripper conditions. The role of nitrite in the nitrosation reaction was probed at elevated temperatures. The effects of different concentrations of nitrite on morpholine were evaluated. Formation rate, decomposition rates, activation energy, and the possible reaction pathways are elaborated. Thermal stability tests at 135 °C indicated the decomposition of nitrosamines at the rate of 1 μg/(g h) with activation energy of 131 kJ/mol. The activation energy for the reaction of morpholine with sodium nitrite was found as 101 kJ/mol. Different reaction pathways were noted for lower temperature reactions with NO₂ gas and higher temperature reactions with nitrite.

The corrosion inhibition of 2-mercaptobenzimidazole on A106 carbon steel and its stability in a post-combustion CO2 capture system with application of 5 M monoethanolamine aqueous solutions has been evaluated by linear polarization resistance, electrochemical impedance spectroscopy, immersion corrosion testing, scanning electron microscopy/energy dispersive spectroscopy, x-ray diffraction, and liquid chromatography-mass spectroscopy. Although no notable layer of protective corrosion product was found on the A106 surface at 80°C and atmospheric pressure for >180 h, corrosion was inhibited, and its polarization resistance increased nearly an order of magnitude when 2-mercaptobenzimidazole was added. However, degradation of 2-mercaptobenzimidazole, associated with the formation of an FeS layer with cracks, occurred at 108°C and 4.13×105 Pa.

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The buildup of flue gas contaminants in amine-based postcombustion CO 2 capture processes is an important concern due to its potential impact on solvent degradation and reclaiming. In this research, in order to explore the impact of flue gas contaminants on solvent thermal degradation, sodium nitrite, fly ash, sodium sulfate, and sodium thiosulfate were each added into carbon-loaded 5.0 M monoethanolamine (MEA) solution and the solutions were exposed to high-temperature degradation conditions. MEA degrades significantly more in the presence of nitrite (5000 ppm) than MEA alone at the same amine mole concentration. The MEA degradation activation energy of MEA−nitrite solution is calculated and found to be approximately one-seventh of that of MEA solution without nitrite. Addition of nitrite not only enhanced generation of several MEA thermal degradation products but also induced formation of diethanolamine (DEA) and N-(2-hydroxyethyl)piperazin-3-one (HEPO), which have been known to form during MEA oxidative degradation. Interestingly, fly ash was observed to inhibit nitrite-induced MEA degradation and greatly increase the MEA degradation activation energy of MEA−nitrite solution. This led to a reduction in accumulation of several degradation products. Fly ash, sodium sulfate, and sodium thiosulfate by themselves were not shown to impact MEA thermal degradation rate.

Increasing demand for biodiesel production would lead to tremendous supply of glycerol as a coproduct, which is almost 10% by weight. Therefore, utilization of bioglycerol into valuable chemicals is timely to reduce the cost of biodiesel. Both 1,2and 1,3-propanediols are very useful chemicals which can be produced from glycerol. This paper describes a novel process for selective hydrogenolysis of glycerol to 1,2-propanediol over silver incorporated octahedral molecular sieve (OMS-2) catalyst. Also, the current work describes the use of silver as the catalyst for the first time for hydrogenolysis of glycerol. Both batch and continuous mode of operations have been studied to determine the stability of the catalyst. Different loadings (10À30% w/w) of Ag were incorporated in OMS-2 by the precipitation method and used in the reaction. Thirty % w/w Ag-OMS-2 was the best catalyst. It was characterized by various techniques such as SEM, TGA, XRD, N 2 adsorptionÀdesorption, EDAX, TPD-TPR, and FTIR. It is a nano fibrous crystalline material. This Article reports a comprehensive account of this catalytic process.The initial studies were carried out in a batch reactor to optimize the reaction parameters. High conversion of glycerol (about 65À70%) with about 90% selectivity toward 1,2-propanediol was obtained within 8 h under hydrogen pressure. The time-on-stream (TOS) analysis studies were conducted in a fixed bed reactor up to 150 h, which demonstrated that the catalyst was stable and the process has a potential for commercial exploitation. methane sulfonic acid in a water-sulfolane mixture resulted in to 1-propanol, 1,2-PDO, and 1,3-PDO in a 47:22:31 ratio. 12 Dehydroxylation of glycerol in sulfolane catalyzed by a homogeneous complex of ruthenium as catalyst at 52 atm and 110 °C resulting in to very low yields 1,2-/1,3-PDO is reported. 13 The hydrogenolysis of glycerol with copperÀchromiumbased catalysts yielded only 1,2-PDO. 14 Hydrogenolysis of glycerol under 30 MPa H 2 at 260 °C over Raney Ni, Ru, Rh, and Ir catalysts yielded mainly methane, but in the presence of Raney Cu, 1,2-PDO was the main product. 15 Furthermore, other catalysts such as Cu/C, 16 CuÀPt, and CuÀRu bimetallic catalysts 17 have been reported at 1.0À4.0 MPa and 493À513 K. Hydrogenolysis of glycerol and other polyols over Ni/Re catalyst under 8.2 MPa H 2 and 230 °C in 4 h led to 44% 1,2-PDO, 5% 1,3-PDO and 13% ethylene glycol. 18 Glycerol hydrogenolysis on several heterogeneous catalysts under 8 MPa H 2 pressure at 180 °C was investigated over various metals (Cu, Pd, Ni and Rh), supports (ZnO, C and Al 2 O 3 ), solvents (H 2 O, sulfolane and dioxane), and additives (H 2 WO 4 ) were tested to improve the reaction rate and selectivity. 19 Glycerol hydrogenolysis to ethylene glycol and 1,2-PDO was reported with Rh/SiO 2 catalysts including the effect of sulfur and temperature. 20À22 Hydrogenolysis of glycerol over carbon-supported Ru, Pt, and bimetallic PtÀRu and AuÀRu catalysts is also reported. 23,24 The effects of NaOH and CaO addition on the reaction...