Browsing by Author "Ripoll Morales, Vanessa"
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Item Anaerobic digestion of slaughterhouse waste in batch and anaerobic sequential batch reactors.(Biomass Conversion and Biorefinery, 2022) Ripoll Morales, Vanessa; Agabo‑García, Cristina; Solera, Rosario; Perez, MontserratThis work focuses on the design of an effective treatment process for slaughterhouse waste management. Four different treatment sequences were proposed, based on aerobic and anaerobic technologies, as well as thermal and centrifugation pre-treatments. Biochemical methane potential tests were carried out to assess the viability in terms of biodegradability and biogas production of the anaerobic digestion units, which involved different substrates for each proposed process (raw slaughterhouse wastewater, thermal pre-treated slaughterhouse activated sludge, supernatant of thermal pre-treated slaughterhouse sludge, and co-digestion mixture of slaughterhouse wastewater and supernatant of thermal pre-treated slaughterhouse sludge). The obtained results showed that thermal pre-treatment is not effective by itself. However, if it is followed by centrifugation, organic matter removal is importantly improved. In addition, removal efficiency reached 76.0% when employing a codigestion mixture. Kinetic analyses showed that the specific constant rate of the mixture was 1.5 times higher than with the sole supernatant. Afterwards, the co-digestion mixture was employed as a substrate for an anaerobic sequencing batch reactor working under a semi-continuous operational mode. The influence of organic load rate (OLR) on organic matter removal and biogas production was studied. The best operational OLR range was 1.16–2.16 kg/m3•d, achieving 87.8% of chemical oxygen demand removal and 0.23 LCH4/ Ldigester·d of methane production rate. A faster organic load rate than 2.88 kg/m3•d led to bioreactor destabilisation. The obtained results were competitive against published studies that employed different anaerobic technologies and made progress towards the industrial implementation of effective technology in slaughterhouse facilities.Item Development of engineering skills in students of biotechnology: Innovation project “From laboratory to industry”.(Education for Chemical Engineers, 2023) Ripoll Morales, Vanessa; Godino Ojer, Marina; Calzada Funes, JavierProfessors of Chemical Engineering often find that students are discouraged by the highly technical nature of the subject, have a poor understanding of how the subject relates to their field and lack the basic engineering skills and competences. This purpose of this paper is to report on a teaching innovation experience in the course in Biochemical Engineering, part of the Degree in Biotechnology at the Universidad Francisco de Vitoria (Madrid, Spain). The aim of the innovation project was to motivate students and overcome the difficulties posed by the course. To this end, a series of practical seminars were designed with individual and group learning activities, for the acquisition of engineering competences, developing higher-order thinking skills and transversal competences. The evaluation of the project was based on the learning-teaching experience of professors, the academic performance of students and student surveys at the end of the course. All indicators showed that the new methodology had a positive impact both on the attitudes of students and on learning outcomes. Furthermore, students had a more precise and positive vision of the interrelation between Chemical Engineering and Biotechnology in general, favourably influencing their learning in other courses within the degree program.Item High 2,3-butanediol production from glycerol by Raoultella terrigena CECT 4519.(Bioprocess and Biosystems Engineering, 2020) Ripoll Morales, Vanessa; Rodríguez, Alberto; Ladero, Miguel; Santos, Victoria E.Bioconversion of biodiesel-derived glycerol into 2,3-butanediol has received recently much attention due to its increasing surplus and its multiple uses in industry as bulk chemical. The influence of initial glycerol concentration on 2,3-butanediol production in batch runs has been studied. A concentration higher than 140 g/L produces an inhibitory effect on the final 2,3-butanediol concentration and its production rate. In batch mode, the highest yield respect to the theoretical maximum yield (71%) was reached employing 140 g/L as initial concentration 140 g/L. Based on these results, a high 2,3-butanediol production has been achieved through a fed-batch strategy. The reached 2,3-butanediol concentration was 90.5 g/L from pure glycerol and 80.5 g/L from raw glycerol. The 2,3-butanediol yield respect to the theoretical maximum yield was also improved through the fed-batch operation (90%). To date, this concentration is the highest produced amount employing as biocatalyst a non-pathogenic bacterium (level 1).Item Highly efficient carbon catalysts for the green synthesis of 1,5-benzodiazepines: Experimental and theoretical study.(Catalysis Today, 2024) Godino Ojer, Marina; Ripoll Morales, Vanessa; Pastrana-Martínez, Luisa M.; Morales-Torres, Sergio; Maldonado-Hódar, Francisco J.; Pérez-Mayoral, ElenaA family of sustainable carbon catalysts with different chemical surface, active and selective for the synthesis of benzodiazepine 1 (BDZ), from o-phenylendiamine (OPD) 2 and acetone 3, under mild conditions, is reported. Catalysts were prepared by acids treatments with H2SO4 or H3PO4 of an activated carbon doped with ZnO at 3% wt (N3Zn) and, subsequently, submitted to additional thermal treatment in air. Simultaneously to the ZnO leaching, surface C-SO3 groups were generated by treatment of N3Zn with H2SO4 (N3Zn-S) whereas treatment with H3PO4 led to C-PO3 functions (N3Zn-P sample). The thermal treatment partially removes the C-SO3 groups (N3Zn-S-C sample) while C-PO3 functions were partially oxidized to C-OPO3 groups (N3Zn-P-C). Our results suggest that these chemical surface modifications of the catalysts are key on catalytic performance, pointed out the importance of the nature and distribution of acid sites at the surface. Remarkably, investigated carbon catalysts (N3Zn-S samples) were more active than the NS catalyst obtained by direct treatment of AC with H2SO4, this last mainly functionalized with C-OSO3 groups. Although the catalysts resulting of the H3PO4 treatment showed both a similar activity, some differences on selectivity to BDZ 1 were observed, attributed to certain specificity of P-functions at the surface depending on the acid strength of active sites and the reaction conditions. These results were supported by DFT calculations.Item Improvement of biomethane potential of sewage sludge anaerobic co-digestion by addition of “sherry-wine” distillery wastewater.(Journal of Cleaner Production, 2020) Ripoll Morales, Vanessa; Agabo-García, Cristina; Perez, Montserrat; Solera, RosarioCo-digestion of sewage sludge (SS) with other unusually treated residues has been reported as an efficient method to improve biomethane production. In this work, Sherry-wine distillery wastewater (SW-DW) has been proposed as co-substrate in order to increase biomethane production and as a breakthrough solution in the management of both types of waste. In order to achieve this goal, different SS:SW-DW mixtures were employed as substrates in Biomethane Potential (BMP) tests. The biodegradability and biomethane potential of each mixture was determined selecting the optimal co-substrate ratio. Results showed that the addition of SW-DW as a co-substrate improves the anaerobic digestion of SS in a proportionally way in terms of CODs and biomethane production The optimal co-substrates ratio was 50:50 of SS:SW-DW obtaining %VSremoval = 54.5%; YCH4 = 225.1 L CH4/kgsv or 154 L CH4/kgCODt and microbial population of 5.5 times higher than sole SS. In this case, %VSremoval = 48.1%; YCH4 = 183 L CH4/kgsv or 135 L CH4/kgCODt. The modified Gompertz equation was used for the kinetic modelling of biogas production with successful fitting results (r2 = 0.99). In this sense, at optimal conditions, the maximum productivity reached at an infinite digestion time was () = 229 ± 5.0 NL/kgSV; the specific constant was K = 25.0 ± 2.3 NL/kgSV·d and the lag phase time constant was (λ) = 2.49 ± 0.19.Item Kinetic modelling of 2,3-butanediol production by Raoultella terrigena CECT 4519 resting cells: Effect of fluid dynamics conditions and initial glycerol concentration.(Biochemical Engineering Journal, 2021) Ripoll Morales, Vanessa; Ladero, Miguel; Santos, Victoria E.Biodiesel-derived glycerol was biologically converted to 2,3-butanediol, an organic compound with multiple industrial applications. Recent studies showed that Raoultella terrigena CECT 4519 is an effective biocatalyst for the bioprocess under conventional growing conditions. In the present work, a novel biocatalyst composed by R. terrigena resting cells was evaluated for the first time. Fluid dynamic conditions has been optimized to maximize 2,3-butanediol production in terms of titre, yield, and selectivity. Regarding the effect of initial glycerol concentration in batch runs, no substrate inhibition was detected in the studied conditions (concentrations between 45 and 250 g/L were used). Employing pure glycerol as carbon source, 82.0 g/L 2,3-butanediol titre was achieved, whereas 76.5 g/L were reached using raw glycerol. These numbers involve an achieved yield respect to maximal theoretic yield of 79% and 77%, respectively. A successful kinetic modelling of the bioprocess was developed and it is able to describe both the evolution of concentrations of relevant components with time and the rates calculated at experimental time values. Estimated specific 2,3-butanediol production rate was 0.034 g2,3-BDO/gX⋅h, while the estimated empirical pseudo-stoichiometric coefficient glycerol/2,3-butanediol was 2.52 gGly/g2,3-BDO. The obtained results showed that R. terrigena resting cells is a promising biocatalyst, which provides new opportunities for developing and scaling-up glycerol biorefineries.Item Kinetic modelling of anaerobic co-digestion of sewage sludge and Sherry-wine distillery wastewater: Effect of substrate composition in batch bioreactor.(Fuel, 2022) Ripoll Morales, Vanessa; Solera, Rosario; Pérez, MontserratBatch thermophilic anaerobic co-digestion of sewage sludge (SS) and Sherry-wine distillery wastewater (SW-DW) was investigated through biochemical methane potential tests (BMP). The results pointed out that biodegradability and biomethane potential were enhanced proportionally to the percentage of SW-DW of the feedstock, whose soluble biodegradability fraction is 10-fold higher than SS. Specifically, organic matter removal increases from 37 % (employing sole SS as feedstock) to 60 % (employing sole SW-DW as feedstock). SW-DW almost doubles methane yield in comparison to SS (302 ± 15 and 175 ± 9 NL/kg, respectively). A structured kinetic model was developed considering hydrolysis, acidogenic and methanogenic steps of anaerobic digestion. A non-linear multiple-response regression was employed to estimate the kinetic parameters for each feedstock (0%(v/v) SW-DW, 25%(v/v) SW-DW, 50%(v/v) SW-DW, 75%(v/v) SW-DW, and 100%(v/v) SW-DW). The first-order kinetic parameter estimated of the hydrolysis step varies inversely proportional to the percentage of SW-DW content in the feedstock. Whereas, there is no significant influence of feedstock composition on kinetic parameters value regarding acidogenesis and methanogenesis. These results showed that rate–limiting step switched during the fermentation and the addition of SW–DW favours acidogenic and methanogenic steps. In summary, the proposed kinetic model was able to predict batch experimental data, supporting the application of biogas production from anaerobic co-digestion of SS and DW-DW.Item Modelling of the anaerobic semi-continuous co-digestion of sewage sludge and wine distillery wastewater.(Environmental Science: Water Research & Technology, 2020) Ripoll Morales, Vanessa; Agabo García, Cristina; Solera, Rosario; Pérez, MontserratThe semi-continuous mesophilic anaerobic co-digestion of sewage sludge and wine distillery wastewater was investigated. In this sense, the effects of reducing the hydraulic retention time (HRT, from 20 d to 8 d) on the degradation of organic matter and methane production were determined. The experimental results showed that anaerobic co-digestion enhanced the biodegradability of the mixture in terms of VS and CODT (7–8% higher) for HRT = 8 d. The methane productivity at HRT = 8 d (18.0 LCH4 kgVS−1 d−1) was also enhanced (30% higher) compared to that obtained in the control experiment. In addition, a mathematical kinetic model was proposed to determine the rate-limiting step of the process. Stoichiometric parameters obtained for SS : WDW (0.115 kgCH4 kgCOD−1) was higher than SS (0.094 kgCH4 kgCOD−1), which means that co-digestion increased the rate of consumption because of the higher amount of biodegradable compounds. The kinetic study showed that anaerobic co-digestion favoured the methane production rate enhancing the acetate consumption step and making methanogenesis the rate-limiting step in this process.Item P-Doped carbon catalyst highly efficient for benzodiazepine synthesis. Tires valorisation.(Catalysis Today, 2023) Godino Ojer, Marina; Ripoll Morales, Vanessa; López Peinado, Antonio J.; Bernardo, María; Lapa, Nuno; Ferraria, Ana María; Botelho do Rego, Ana María; Fonseca, Isabel M.; Matos, Inés; Pérez Mayoral, ElenaCarbon catalysts prepared from pyrolysis of spent tires are found to efficiently catalyse the synthesis of benzodiazepine 1, from o-phenylendiamine 2 and acetone 3, with high conversions and selectivity, under mild reaction conditions, according to Scheme 1. The most acidic catalyst, CPN_H3PO4, obtained by chemical activation with H3PO4, resulted on the most efficient catalyst affording conversion values higher than 90 %, after 4 h of reaction time, and selectively leading to benzodiazepine 1 (90 %). On the other hand, the CPN and CPN_CO2 catalysts reached high conversions of 2 although diminished selectivity to 1, confirming that the carbon matrix is involved in the first steps of the reaction mainly catalyzing the formation of intermediate 4 as the main reaction product. Note that all the investigated catalysts are macroporous materials with pore size distribution large enough to favor diffusion of reactants and products. Therefore, the catalytic performance is mainly governed by the chemical surface, in particular by the presence of acid functions as phosphate groups anchored to the carbon surface or as SiP2O7 supported phase. Finally, considering both experimental and theoretical results, it seems that the most probable catalytic centers comprise phosphate functions in SiP2O7 catalyzing the last cyclization step to 1. Although electrophilicity of carbon acceptor (Cdouble bondN moiety) in the presence of model simulating phosphate groups anchored to the carbon surface was slightly superior, transition structure in the presence of model simulating SiP2O7 showed the smallest free energy barrier.Item Study on the Operational Modes Using Both Growing and Resting Cells for Succinic Acid Production from Xylose Kinetic Modelling.(Fermentation, 2023) Escanciano, Itziar A.; Ripoll Morales, Vanessa; Ladero, Miguel; Santos, Victoria E.Succinic acid (SA) is one of the most prominent C4 biomass-based platform chemicals that can be biologically obtained. This article verifies, for the first time, the possibility of producing succinic acid with fed-batch or repeated batch operations with Actinobacillus succinogenes in a resting state, that is, in the absence of a nitrogen source. In this work it is possible to optimise separately the stages of cell growth and production in the fed-batch or repeated batch modes, minimising the costs associated with the nitrogen source and facilitating the subsequent purification of SA. These experiments were carried out with xylose, the most abundant monosaccharide in hemicelluloses, with the results subsequently being compared to those obtained in equivalent operations carried out with cells in a state of growth. First, a cost-effective synthetic growth medium was proposed and successfully employed for SA production. Biocatalysts’ reutilisation showed that the bioprocess can be carried out successfully in repeated batch and fed-batch modes. The best mode for growing cells is repeated batch, achieving a maximum productivity of 0.77 g‧L−1‧h−1, a selectivity of 53% and a yield of 51% with respect to xylose consumed. In contrast, the fed-batch mode was found to be the most convenient mode with resting cell biocatalyst, reaching a maximum productivity of 0.83 g‧L−1‧h−1, a selectivity of 0.78 g‧g−1 and a yield of 68% with respect to the xylose consumed. In addition, by-product formation is significantly reduced when employing resting cells. An unstructured non-segregated kinetic model was developed for both biocatalysts, capable of simulating cell growth, xylose consumption, SA production and by-product generation, with successful estimation of kinetic parameters supported by statistical criteria.Item Teaching chemical engineering to biotechnology students in the time of COVID-19: Assessment of the adaptation to digitalization.(Education for Chemical Engineers, 2021) Ripoll Morales, Vanessa; Godino Ojer, Marina; Calzada Funes, JavierWith the global outbreak of COVID-19 in March 2020, there was an immediate shutdown of face-to-face classes and a sudden shift to on-line learning. Confinement required finding innovative approaches to teaching and student assessment. This paper aims to share the experience of adapting the course in Biochemical Engineering, part of the Biotechnology program at Francisco de Vitoria University (Madrid, Spain), to remote learning. A sequence of collaborative learning activities, with active student participation, was designed to replace the traditional mid-term exam. Activities were carefully implemented, considering the range of learning styles. Engineering skills, transversal competences and higher-order thinking skills were fostered through these activities. The analysis of the teaching/learning experience was based on teacher observations, academic performance and student surveys. All indicators showed that the adopted methodology had a positive impact of student performance. Student participation, especially among those repeating the course, also improved. Furthermore, students gained a more accurate and positive perception of the link between Chemical Engineering and Biotechnology, which may have a favourable impact on the teaching of Bioreactors in the coming academic year.