10 research outputs found
Valorisation of glycerol by new mechanochemical processes
The search for new applications of glycerol, as a chemical platform from which a broad spectrum of new valuable derivatives can be obtained, is ongoing. In the present communication, a new mechano-chemical reactor is used for the valorisation of glycerol, and some examples of potential chemical processes by using mechano-chemical energy will be provided in order to reduce the residence time, to minimize the use of solvents or to decrease the temperature.
In this sense, the mechano-chemical synthesis of calcium diglyceroxide from glycerol and CaO has been optimised. Finally, a new and more efficient mechano-chemical synthesis of CaDG has been achieved, requiring short synthesis time without heating and no need of solvents. The stability of this catalyst is studied under presence of free fatty acids and water, compounds presents in waste oils that decrease the yield to fatty acid methyl ester (FAME) during the reaction. Moreover, the transesterification reaction of used and refined vegetable oils with methanol has also been studied and optimised in the presence of CaDG as basic solid catalyst, using the same mechano-chemical reactor that promotes the oil-methanol mixing, minimizing the mass transfer problems associated to the immiscibility of reactants. Low methanol:oil ratios and low temperature can be used with promising results using a mechanical reactor even with used oils and in plant pilot scale under flow conditions.
Glycerol carbonate is a green chemical glycerol derivative with several industrial applications (solvents, pharmaceutics, detergent, adhesives, lubricants, beauty, among others). Preliminary tests using a mechano-chemical reactor under continuous flow conditions shows the possibility to reduce the time of reaction to 1h and lowering the temperature. Finally, the production of Zn glycerolate (good candidate for the tire industry) is also studied.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
An efficient and sustainable biodiesel production in a mechanochemical pilot reactor under heterogeneous catalysis
Fatty acid methyl esters (FAME) produced from vegetable oils or animal fats by transesterification, or from the esterification of fatty acids, with methanol, is labeled as ‘‘Biodiesel”. Current industrial processes for biodiesel production are mainly based on homogeneous catalysis, in presence of an alkali hydroxide or methoxide dissolved in methanol, a large excess of methanol (methanol:oil molar ratio > 6), a temperature around 60 ºC and 1-2 h of reaction. However, this process suffers from different drawbacks, mainly related with the generation of large amount of wastewater associated to the washing and neutralization steps, the non-recovery of the homogeneous catalyst, or the formation of stable emulsions difficult to separate. These problems cause an increase of the overall biodiesel production cost. To overcome them, different approaches have been proposed, such as the use of heterogeneous catalysis, CO2 under supercritical conditions or enzymes, coupled to microwave and ultrasonic systems as alternative to conventional heating.
In the present communication, a new mechanochemical reactor is used for the transesterification reaction that promotes the oil-methanol mixing, minimizing the mass transfer problems associated to the immiscibility of reactant mixtures. Moreover, in order to achieve a more sustainable biodiesel production process, a new heterogeneous basic catalyst is prepared from calcium oxide and glycerol, the by-product of biodiesel industry.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec
Mechanochemistry for a smart and sustainable biodiesel production under heterogeneous catalysis
Fatty acid methyl esters (FAME) produced from vegetable oil by transesterification, labeled as ‘‘Biodiesel”, is industrially accomplished in the presence of a homogeneous basic catalyst, such as alkali hydroxide or methoxide dissolved in methanol. This process requires a large excess of methanol (methanol:oil molar ratio> 6), temperature around 60 ºC and 1-2 h of reaction. However, this process suffers from important drawbacks: low FFA and water tolerance, generation of process wastewater, etc. To overcome them, different approaches have been proposed: such as the use of heterogeneous catalysis, CO2 under supercritical conditions or enzymes; coupled to microwave and ultrasonics systems as an alternative to conventional heating. Among all the researches, heterogeneous catalysts show potential in the transesterification reaction. Unlike homogeneous catalysts, heterogeneous ones are environmentally benign and can be reused and regenerated. Nevertheless, higher catalyst loading and alcohol:oil molar ratio are required for biodiesel production in the presence of solid catalysts.
A new mechanochemical reactor is used for the transesterification reaction to promotes the reactants mixing, minimizing mass transfer limitations associated to the inmiscibility of reactants. This solution allows to reduce the methanol need to an amount close to the stoichiometry (methanol:oil molar ratio= 4:1), and at room temperature after less than one minute, more than 90 wt% FAME is reached. Glycerol, obtained as by-product in the transesterification reaction is used to prepare calcium diglyceroxide by mechanosynthesis, and is used as heterogeneous catalyst. A new and more efficient mechanochemical synthesis of FAME is proposed, with shorter reaction and lower temperature, compared to other synthesis proposed in literature.Universidad de Málaga.Campus de Excelencia Internacional Andalucía Tec
The effect of mechanochemistry on the preparation of heterogeneous catalysts: Reduction of furfural to obtain furfuryl alcohol.
In this context, mechanochemistry is receiving increasing attention for the synthesis of many chemical
compounds in the solid state, considered by IUPAC as one of the 10 methodologies to change the
world.Mechanochemistry is the part of chemistry that uses mechanical energy for the transformation of matter.
This methodology will be used to study the effect caused by mechanochemistry in the precursor (Mg(OH)2),
which is activated at 450 º C to obtain the active phase (MgO). This phase displays Lewis basic sites, which
catalyzes the hydrogenation reaction of furfural to furfuryl alcohol. This catalyst will be used in the reduction of
furfural to furfuryl alcohol (FFA) using isopropanol as hydrogen donor agent and dissolution medium.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Valorización de la borra del café: producción de biodiesel y 5-hidroximetilfurfural/furfural
VALORIZACIÓN DE LA BORRA DEL CAFÉ: PRODUCCIÓN DE BIODIESEL Y
5-HIDROXIMETILFURFURAL/FURFURALUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Hidrocalumita: preparación por el método mecanoquímico y su aplicacion en la isomerización de glucosa a fructosa.
La fructosa es la llave para la formación de diversas moléculas plataformas tales como,
furfural, 5-hidroximetilfurfural (HMF), acido levulinico, ácido fórmico y acido láctico.
Actualmente en la industria se utilizan mayormente enzimas debido a los mejores resultados
de selectividad y rendimiento del proceso de glucosa a fructosa. Es por este motivo que la
búsqueda de catalizadores heterogéneos, que no necesiten condiciones de reacción tan
singulares, hace que sea un amplio campo de investigación dentro de la catálisis.DEASYL SA
Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Regular insulin added to total parenteral nutrition vs subcutaneous glargine in non-critically ill diabetic inpatients, a multicenter randomized clinical trial: INSUPAR trial
Background: There is no established insulin regimen in T2DM patients receiving parenteral nutrition. Aims: To compare the effectiveness (metabolic control) and safety of two insulin regimens in patients with diabetes receiving TPN. Design: Prospective, open-label, multicenter, clinical trial on adult inpatients with type 2 diabetes on a non-critical setting with indication for TPN. Patients were randomized on one of these two regimens: 100% of RI on TPN or 50% of Regular insulin added to TPN bag and 50% subcutaneous Gl. Data were analyzed according to intention-to-treat principle. Results: 81 patients were on RI and 80 on GI. No differences were observed in neither average total daily dose of insulin, programmed or correction, nor in capillary mean blood glucose during TPN infusion (165.3 +/- 35.4 in RI vs 172.5 +/- 43.6 mg/dL in GI; p = 0.25). Mean capillary glucose was significantly lower in the GI group within two days after TPN interruption (160.3 +/- 45.1 in RI vs 141.7 +/- 43.8 mg/dL in GI; p = 0.024). The percentage of capillary glucose above 180 mg/dL was similar in both groups. The rate of capillary glucose <= 70 mg/dL, the number of hypoglycemic episodes per 100 days of TPN, and the percentage of patients with non-severe hypoglycemia were significantly higher on GI group. No severe hypoglycemia was detected. No differences were observed in length of stay, infectious complications, or hospital mortality. Conclusion: Effectiveness of both regimens was similar. GI group achieved better metabolic control after TPN interruption but non-severe hypoglycemia rate was higher in the GI group. (C) 2019 The Author(s). Published by Elsevier Ltd
Fish Oil Enriched Intravenous Lipid Emulsions Reduce Triglyceride Levels in Non-Critically Ill Patients with TPN and Type 2 Diabetes. A Post-Hoc Analysis of the INSUPAR Study
There are no studies that have specifically assessed the role of intravenous lipid emulsions (ILE) enriched with fish oil in people with diabetes receiving total parenteral nutrition (TPN). The objective of this study was to assess the metabolic control (glycemic and lipid) and in-hospital complications that occurred in non-critically ill inpatients with TPN and type 2 diabetes with regard to the use of fish oil emulsions compared with other ILEs. We performed a post-hoc analysis of the Insulin in Parenteral Nutrition (INSUPAR) trial that included patients who started with TPN for any cause and that would predictably continue with TPN for at least five days. The study included 161 patients who started with TPN for any cause. There were 80 patients (49.7%) on fish oil enriched ILEs and 81 patients (50.3%) on other ILEs. We found significant decreases in triglyceride levels in the fish oil group compared to the other patients. We did not find any differences in glucose metabolic control: mean capillary glucose, glycemic variability, and insulin dose, except in the number of mild hypoglycemic events that was significantly higher in the fish oil group. We did not observe any differences in other metabolic, liver or infectious complications, in-hospital length of stay or mortality
Un estudio del proceso de almacenamiento seguido de reducción, NSR, para la eliminación de NOx en fuentes móviles
El presente trabajo de investigacion, encuadrado dentro de la Catálisis Ambiental,tiene por objetivo el análisis del innovador proceso sobre eliminación de NOx en fuentes móviles mediante almacenamiento y posterior reducción (NOx-Storage-Reduction,NSR), también conocido como Trampas de NOx (Lean-NOx-Trap, LNT)
Regular insulin added to total parenteral nutrition vs subcutaneous glargine in non-critically ill diabetic inpatients, a multicenter randomized clinical trial: INSUPAR trial.
There is no established insulin regimen in T2DM patients receiving parenteral nutrition. To compare the effectiveness (metabolic control) and safety of two insulin regimens in patients with diabetes receiving TPN. Prospective, open-label, multicenter, clinical trial on adult inpatients with type 2 diabetes on a non-critical setting with indication for TPN. Patients were randomized on one of these two regimens: 100% of RI on TPN or 50% of Regular insulin added to TPN bag and 50% subcutaneous GI. Data were analyzed according to intention-to-treat principle. 81 patients were on RI and 80 on GI. No differences were observed in neither average total daily dose of insulin, programmed or correction, nor in capillary mean blood glucose during TPN infusion (165.3 ± 35.4 in RI vs 172.5 ± 43.6 mg/dL in GI; p = 0.25). Mean capillary glucose was significantly lower in the GI group within two days after TPN interruption (160.3 ± 45.1 in RI vs 141.7 ± 43.8 mg/dL in GI; p = 0.024). The percentage of capillary glucose above 180 mg/dL was similar in both groups. The rate of capillary glucose ≤70 mg/dL, the number of hypoglycemic episodes per 100 days of TPN, and the percentage of patients with non-severe hypoglycemia were significantly higher on GI group. No severe hypoglycemia was detected. No differences were observed in length of stay, infectious complications, or hospital mortality. Effectiveness of both regimens was similar. GI group achieved better metabolic control after TPN interruption but non-severe hypoglycemia rate was higher in the GI group. This trial is registered at clinicaltrials.gov as NCT02706119