Browsing by Subject "Solvent-free"
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- PublicationOpen AccessBiocatalytic intensified process for the synthesis of neopentyl glycol dicaprylate/dicaprate(Elsevier, 2022-11-07) Máximo, F.; Asensi, M.; Serrano-Arnaldos, M.; Ortega Requena, Salvadora; Montiel, M.; Bastida, J.; Ingeniería QuímicaEmollient esters are widely used ingredients in the cosmetics industry. Their chemical synthesis requires the use of high temperatures and polluting acid catalysts, resulting in environmentally unfriendly processes. This paper describes, for the first time, the biocatalytic synthesis process of the cosmetic ingredient neopentyl glycol dicaprylate/dicaprate (INCI name), a mixture of branched diesters with excellent emollient properties. The co-esterification of the acids with the alcohol is carried out in a solvent-free system, using the biocatalyst Lipozyme®435, a commercial immobilized derivative of Candida antarctica lipase B marketed by Novozymes. Process intensification has been approached by acting on three different aspects. Firstly, the use of solvent-free systems provides higher yields by operating with smaller reactor volumes. Secondly, the inhibition of the enzymatic activity caused by caprylic and capric acids has determined the need to implement a new reaction strategy consisting in the use of a fed-batch reactor, in which the acid is added to the reactor using a peristaltic pump in order to maintain an optimal acid concentration that minimizes the inhibition effects. Finally, the reusability of the biocatalyst used has been verified, allowing it to be used in at least five consecutive reaction cycles without noticeable loss of activity. All this results in an efficient synthesis process with a process productivity of 0.15 kg product/L reactor·h and a biocatalyst productivity of 167.09 kg product/kg biocatalyst. Only 6 h are needed, operating in a fed-batch reactor at 80 °C, to obtain a product with 92.5% purity. In addition, the most commonly used sustainability indicators have been calculated, reflecting that the biocatalytic process developed for the synthesis of neopentyl glycol dicaprylate/dicaprate complies with many of the principles of “green chemistry” and is suitable for future implementation on an industrial scale.
- PublicationOpen AccessDevelopment and economic evaluation of an eco-friendly biocatalytic synthesis of emollient esters.(Springer, ) Serrano-Arnaldos, A.; Montiel, M.C.; Ortega Requena, Salvadora; Máximo, F.; Bastida, J.; Ingeniería QuímicaDuring the last decades the understanding and prospects of enzyme-catalysed reactions have been massively widened and there are a number of implemented large-scale enzymatic processes mainly based in the use of commercial biocatalysts. As it might happen that the same process can be successfully carried out by different commercial lipases, the election of the biocatalyst must rely on productivity and economic considerations. This work presents productiveness and direct operation cost evaluation as a key tool for the selection between two commercial lipase catalysts, the versatile but expensive Novozym® 435 and a much more economical option, Lipozyme® TL IM, in the synthesis of spermaceti, a mixture of emollient esters with cosmetic applications. Proving that Novozym® 435 leads to minimum savings of 10% with respect to the cheapest immobilized derivative, biocatalyst cost does not appear to be the major contribution to the economics of the processes under study, due to their great capacity to be recovered and reused. At laboratory scale, the biggest economic investment is caused by substrates, which can be massively reduced at industrial scale by using bulk reagents. In such case, energy cost may be the major contribution to the process economy. This work proposes an optimized process ready to be scaled-up in order to accurately determine the energetic requirements of the possible industrial enzymatic synthesis.
- PublicationOpen AccessGreen Production of a High-Value Branched-Chain Diester: Optimization Based on Operating Conditions and Economic and Sustainability Criteria(MDPI, 2023-05-18) Montiel, C.; Gimeno-Martos, S.; Ortega Requena, Salvadora; Serrano-Arnaldos, M.; Máximo, F.; Bastida, J.; Ingeniería QuímicaFeatured Application: In the last years, consumers’ and administrations’ demand for more sustainable products and processes has been increasing. This work develops a new sustainable way to obtain a branched ester for cosmetic applications (neopentylglycol dilaurate) and demonstrates that this new production route can be economically competitive. Branched-chain esters (BCEs) have found a large number of applications in cosmetics. Among them, neopentyl glycol dilaurate (NPGDL) stands out as an emollient, emulsifier, and skin-conditioning agent. This work presents the synthesis of NPGDL in a solvent-free medium using the two most common immobilized lipases: Novozym® 40086 (Rml) and Novozym® 435 (CalB). Results proved that the former biocatalyst has lower activity and certain temperature deactivation, although conversions ≥ 90% were obtained at 60 °C and 7.5% of catalyst. On the other hand, optimal reaction conditions for Novozym® 435 are 3.75% w/w of the immobilized derivative at 80 °C. Under optimal conditions, the process productivities were 0.105 and 0.169 kg NPGDL/L h, respectively. In order to select the best conditions for NPGDL production, studies on the reuse of the derivative and cost estimation have been performed. Economic study shows that biocatalytic processes can be competitive when lipases are reused for five cycles, yielding biocatalyst productivities of 56 and 122 kg NPGDL/kg biocatalyst using Novozym® 40086 and Novozym® 435, respectively. The final choice will be based on both economic and sustainability criteria. Green metric values using both biocatalysts are similar but the product obtained using Novozym® 40086 is 20% cheaper, making this alternative the best option.
- PublicationOpen AccessInfluence of the operating conditions on lipase-catalysed synthesis of ricinoleic acid estolides in solvent-free systems(Elsevier, 2008-12-25) Bódalo, A.; Bastida Rodríguez, Josefa; Máximo, María Fuensanta; Montiel Morte, María Claudia; Murcia Almagro, María Dolores; Ortega Requena, Salvadora; Ingeniería QuímicaIn this work, the synthesis of ricinoleic acid estolides, also named polyricinoleic acid (PR), in two different solvent-free reaction systems, catalysed by immobilised Candida rugosa lipase is described. First, the esterification was performed in an open air jacketed batch reactor and the influence of amount of enzyme, temperature and initial water content was tested. The best results were obtained when 5 g of soaked immobilised derivative was used as biocatalyst, and the reaction was carried out at 40 °C. It was observed that environmental relative humidity plays an important role in the enzymatic synthesis of ricinoleic acid estolides and, given that this parameter takes on a wide range of values depending on the season, it is considered the main cause of the poor reproducibility achieved in the open air reactor. To solve this problem, the ricinoleic acid estolides were synthesised under controlled atmosphere in a vacuum reactor with dry air intake. The optimum drying time of 7 h was selected. In these conditions, PR with an acid value of 57.5 mg KOH/g was synthesised in 48 h of reaction and the results were entirely reproducible.
- PublicationOpen AccessSolvent-free polyglycerol polyricinoleate synthesis mediated by lipase from Rhizopus arrhizus(2011-02-04) Gómez, J.L.; Bastida Rodríguez, Josefa; Máximo Martín, María Fuensanta; Montiel Morte, María Claudia; Murcia Almagro, María Dolores; Ortega Requena, Salvadora; Ingeniería Química
- PublicationOpen AccessSustainable Biocatalytic Procedure for Obtaining New Branched Acid Esters(MDPI, 2021-11-13) Montiel, M.C.; Asensi, M.; Gimeno-Martos, S.; Máximo, F.; Bastida, J.; Ingeniería QuímicaBiocatalytic synthesis of 2-ethylhexyl 2-methylhexanoate is described in this work for the first time. This branched-chain ester is suitable for use at low temperatures in numerous applications. The immobilized lipase Novozym® 435 has demonstrated its ability to catalyze the ester synthesis from 2-ethylhexanol and 2-methylhexanoic acid in a solvent-free medium. The high reaction times that are required result in a loss of alcohol by evaporation, which must be compensated for with an excess of this substrate if high conversions are to be achieved. Therefore, two strategies are established: 70 ◦C with a 10% excess of alcohol, which requires a longer operating time and provides conversions of 97%, and 80 ◦C with a 20% excess of alcohol, which allows for the achievement of a 99% conversion in a shorter time. The optimal reaction conditions have been chosen based on reusability of the enzyme, process productivity, green metrics and preliminary economic study. When the synthesis is carried out under the best conditions (70 ◦C, 10% molar excess of alcohol and six uses of the immobilized enzyme) a productivity of 203.84 kg product × kg biocatalyst−1 is attained. The biocatalytic procedure matches many of the objectives of “green chemistry” and is suitable to be scaled up and used in industrial manufacturing
- PublicationOpen AccessSustainable Biocatalytic Synthesis of a Second-Generation Biolubricant(2024-02-15) Montiel, M.C.; Gómez, M.; Murcia, M.D.; Ortega Requena, Salvadora; Máximo, F.; Bastida, J.; Ingeniería QuímicaBackground: Biolubricants represent a category of lubricating substances derived from sustainable sources such as vegetable oils, animal fats, and other bio-based materials. They are considered more environmentally friendly than mineral-based lubricants because they are biodegradable and nontoxic. Biolubricants derived from vegetable oils or animal fats were used as first-generation biolubricants. They have limited performance at extreme temperatures, both high and low, as well as low oxidative stability. Substitution of the double bonds by branching improves the performance and stability of the resulting second-generation biolubricants. Methods: In the past, the production of these compounds has relied on the chemical pathway. This method involves elevated temperatures and inorganic catalysts, leading to the necessity of additional purification steps, which decreases environmental sustainability and energy efficiency. A more environmentally friendly alternative, the enzymatic route, has been introduced, in accordance with the principles of “Green Chemistry”. Results: In this paper, the esterification of 2-methylhexanoic acid with 2-octyl-1-dodecanol and its optimization were developed for the first time. The synthesis was conducted within a jacketed batch reactor connected to a thermostatic bath in a solvent-free reaction medium and using Lipozyme® 435 as biocatalyst. Conclusions: The high viscosity index value of this new hyperbranched ester (>200, ASTM D2270) suggests that it may be an excellent biolubricant to be used under extreme temperature conditions. Regarding sustainability, the main green metrics calculated point to an environmentally friendly process.
- PublicationOpen AccessSustainable synthesis of branched-chain diesters(Elsevier, 2020-11-11) Serrano-Arnaldos, M.; Ortega Requena, Salvadora; Sánchez, J.A.; Hernández, A.; Montiel, M.C.; Máximo, F.; Bastida, J.; Ingeniería QuímicaEsters from branched alcohols and dicarboxylic linear acids are widely used as lube bases due to their good performance at low temperatures. This work proposes a new process to synthesize bis(2-ethylbutyl) adipate and bis(2-ethylbutyl) sebacate by using the lipase-based catalyst Novozym® 435 in a solvent-free system. Different reaction strategies have been tested in order to minimize 2-ethyl-1-butanol losses due to its evaporation and optimum operation conditions have been determined: 2.5 % of biocatalyst, 50 °C and a molar excess of alcohol of 15 % for the adipic diester and of 25 % for the sebacic one. It has also been proven that the immobilized enzyme can be reused in seven successive reaction cycles, achieving high yields without an appreciable reduction of activity. This biocatalytic pathway is a promising basis for the development of a more sustainable large scale process for obtaining biodegradable lubricants, as it is pointed out by productivity, economic and green metrics calculations.