Sintayehu Mekuria Hailegiorgis

Carbon dioxide capture via aqueous N-methyldiethanolamine (MDEA)-1-butyl-3-methylimidazolium acetate ([bmim][Ac]) hybrid solvent

In this study, aqueous hybrid solvents from a mixture of aqueous N-methyldiethanolamine (MDEA) and 1-butyl-3-methylimidazolium acetate, [bmim][Ac] as ionic liquids (ILs) were formulated at different mass ratio. In each aqueous hybrid solvents, the concentrations of MDEA were kept constant at 30 wt%. In the hybrid solvents, the solubility of CO2 was investigated at [bmim][Ac] concentration of 10 wt% and 20 wt%, respectively and results were compared with pure aqueous MDEA solvent. It was observed that the solubility of CO2 is significantly improved in the hybrid solvent as compared to the solubility of CO2 in pure aqueous MDEA solvent. However, increasing the concentration of [bmim][Ac] from 10 wt% to 20 wt% has a negative effect on the solubility of CO2 due to viscosity effect. It was also observed that hybrid solvents with 10 wt% [bmim][Ac] has better CO2 loading capacity. Increasing pressure from 10 bar to 20 bar has demonstrated an increase in CO2 absorption capacity as well as CO2 absorption rate. Hybrid solvents prepared from amine and imidazolium ILs will be a promising solvent in the capturing of CO2.In this study, aqueous hybrid solvents from a mixture of aqueous N-methyldiethanolamine (MDEA) and 1-butyl-3-methylimidazolium acetate, [bmim][Ac] as ionic liquids (ILs) were formulated at different mass ratio. In each aqueous hybrid solvents, the concentrations of MDEA were kept constant at 30 wt%. In the hybrid solvents, the solubility of CO2 was investigated at [bmim][Ac] concentration of 10 wt% and 20 wt%, respectively and results were compared with pure aqueous MDEA solvent. It was observed that the solubility of CO2 is significantly improved in the hybrid solvent as compared to the solubility of CO2 in pure aqueous MDEA solvent. However, increasing the concentration of [bmim][Ac] from 10 wt% to 20 wt% has a negative effect on the solubility of CO2 due to viscosity effect. It was also observed that hybrid solvents with 10 wt% [bmim][Ac] has better CO2 loading capacity. Increasing pressure from 10 bar to 20 bar has demonstrated an increase in CO2 absorption capacity as well as CO2 absorption rate. Hyb...

High pressure solubility of carbon dioxide (CO2) in aqueous solution of piperazine (PZ) activated N-methyldiethanolamine (MDEA) solvent for CO2 capture

In this study, the solubility of carbon dioxide (CO2) in the aqueous solution of piperazine (PZ) activated N-methyldiethanolamine (MDEA) was investigated. In the aqueous solution the concentrations of the N-methyldiethanolamine (MDEA) and piperazine (PZ) were kept constant at 30 wt. % and 3 wt. %, respectively. The solubility experiments were carried out between the temperatures ranges of 303.15 to 333.15 K. The pressure range was selected as 2-50 bar for solubility of carbon dioxide in the aqueous solution. The solubility of the CO2 is reported in terms of CO2 loading capacity of the solvent. The loading capacity of the solvent is the ratio between the numbers of moles of CO2 absorbed to the numbers of moles of solvent used. The experimental data showed that the CO2 loading increased with increase in CO2 partial pressure, while it decreased with increase in system’s temperature. It was also observed from the experimental data that the higher pressure favors the absorption process while the increased temperature hinders the absorption process of CO2 capture. The loading capacity of the investigated solvent was compared with the loading capacity of the solvents reported in the literature. The investigated solvent showed better solubility in terms of loading capacity.In this study, the solubility of carbon dioxide (CO2) in the aqueous solution of piperazine (PZ) activated N-methyldiethanolamine (MDEA) was investigated. In the aqueous solution the concentrations of the N-methyldiethanolamine (MDEA) and piperazine (PZ) were kept constant at 30 wt. % and 3 wt. %, respectively. The solubility experiments were carried out between the temperatures ranges of 303.15 to 333.15 K. The pressure range was selected as 2-50 bar for solubility of carbon dioxide in the aqueous solution. The solubility of the CO2 is reported in terms of CO2 loading capacity of the solvent. The loading capacity of the solvent is the ratio between the numbers of moles of CO2 absorbed to the numbers of moles of solvent used. The experimental data showed that the CO2 loading increased with increase in CO2 partial pressure, while it decreased with increase in system’s temperature. It was also observed from the experimental data that the higher pressure favors the absorption process while the increased temp...

In situ transesterification of non-edible oil in the presence of cetyltrimethylammonium bromide

In situ transesterification of Jatropha curcas l. seed with base catalysed alcohol in the presence of cetyltrimethylammonium bromide (CTMAB) as phase transfer catalyst (PTC) was investigated. The yield of fatty acid methyl esters (FAME) increased from 49.7 w% to 89.2 w% in the presence of CTMAB as PTC at 240 minutes of reaction time. Similarly, the yield of fatty acid ethyl esters (FAEE) increased from 84.7 w% to 99.5 w% in the presence of CTMAB as PTC at 150 minutes of reaction time. The quality of biodiesel fuel conforms to the standards of ASTM D6751 and EN-14214.

Toxicity of Several Potassium Carbonate and Phosphonium-Based DeepEutectic Solvents towards Escherichia coli and Listeria monocytogenesBacteria

Deep eutectic solvents (DESs) and ternary deep eutectic solvents (TDESs) and are derived from two or more salts as the hydrogen bond acceptors (HBAs) and hydrogen bond donors (HBDs). In this work, the several DESs and a TDES were prepared. Allyltriphenyl phosphonium bromide and potassium carbonated were selected as HBAs to mix with various HBDs such as glycerol (GL), ethylene glycol (EG), diethylene glycol (DEG) and triethylene glycol (TEG) into different molar ratios. Two different groups of bacteria were selected for investigation of toxicity of species, namely Escherichia coli (EC) as a Gram negative bacterium and Listeria monocytogenes (LM) as a Gram positive bacterium. The results revealed that by increasing alkyl chain length on HBD, the toxicity of DESs increases towards EC bacterium. However, there appears to have no direct relationship between effect of alkyl chain length and toxicity DESs towards LM bacterium. Moreover, by studying the effect of molar ratio the toxicity of DESs, it was observed that there is no direct relationship between them. Furthermore, it was found that the type of HBD has a dominant effect on the toxicity of DESs compared to type of salt. By comparing the toxicity of DESs in this work with that of ILs in literature, it was found that DESs are less toxic than ILs. The last interesting result of this work is that TDES exhibited the lowest toxicity on EC and LM bacteria compared with DESs.

Conversion of glycerol to polyglycerol over waste duck-bones as a catalyst in solvent free etherification process

The alkaline catalyst derived from the duck-bones was used for conversion of glycerol to polyglycerol via solvent free etherification process. The physicochemical properties of prepared materials were duck–bones were systematically investigated as a catalyst by latest techniques of Thermo gravimetric analysis (TGA), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) surface properties. TGA showed different trends of duck–bones decomposition from room temperature to 1000C. XRD pattern showed a clear and sharp peaks of a crystalline phase of CaO. The activity of the catalysts was in line with the basic amount of the strong base sites, surface area, and crystalline phase in the catalysts. The prepared catalyst derived from duck–bones provided high activity (99 %) for glycerol conversion and around 68 % yield for polyglycerol production. These ample wastes of duck–bones have good potential to be used as polyglycerol production catalysts due to have high quantity of Ca compare to other types of bones like cow, chicken and fish bones.

Reaction Kinetics Study for Microwave Energy Pretreated Jatropha Curcas L In-Situ Transesterification

In the present work, in-situ methanolysis of microwave irradiation heat pre-treated Jatropha curcas l oil in the presence of alkaline benzyltrimethylammonium hydroxide (BTMAOH) as a phase transfer catalysis (PTC) was investigated. Combined use of microwave heat pretreatment of Jatropha curcas l seed particles and alkaline BTMAOH as a PTC drastically reduced the reaction time from 240 to 30 min. The yield of fatty acid methyl ester (FAME) was also increased from 49.7 to 93.5 %. Reaction kinetics was investigated to study the extent of reaction rate. Reaction kinetic study demonstrated that the order of the reaction is a first order reaction at all reaction temperature under investigation. Activation energy of the reaction was found to be 21,641 J/mole. Combined use of microwave heat treatment of Jatropha curcas l seed particles and PTC is promising to enhance the reaction rate of in-situ methanolysis.

Microwave Energy Pretreated In Situ Transesterification of Jatropha Curcas L in the Presence of Phase Transfer Catalyst

In the present work, microwave heat pretreatment of jatropha curcas seed particles and use of phase transfer catalyst (PTC) to enhance in-situ transesterification were utilized together. It was observed that use of alkaline BTMAOH as a PTC and microwave heat pretreatment of jatropha curcas seed particles had substantially increased the reaction rate of in-situ transesterification as compared to the reaction conducted with microwave untreated seeds in the absence of BTMAOH as a PTC. Statistical model equation was developed to investigate the interaction effect of reaction variables and establish optimum reaction condition. At optimum condition, experimentally obtained FAME yield (93.7±1.53% w/w) was in close agreement with statistical model predicted FAME yield (96.75%) at 38°C and 37 minutes of reaction time.