Examinando por Autor "Vicente, Gemma"

Mostrando 1 - 15 de 15

A successful method for phycocyanin extraction from Arthrospira platensisusing [Emim] [EtSO4] ionic liquid
(Wiley, 2021) Sánchez-Laso, Jennifer; Piera, Alejandro; Vicente, Gemma; Bautista, Luis Fernando; Rodríguez, Rosalía; Espada, Juan J.
Research into the extraction of phycobiliprotein from Arthrospira platensis is currently ongoing. Most traditional methods of phycobiliprotein extraction include the use of organic solvents, which negatively affect the sustainability of the process. Ionic liquids (ILs) are a promising alternative for phycobiliprotein extraction due to their properties as green solvents. In the present work an imidazolium-based IL and sonication were studied for phycobiliprotein and carbohydrate extraction. A factorial experimental design was used to optimize the amount of extracted phycocyanin. The maximum extraction yield was achieved by using low biomass/solvent ratios combined with high IL/water ratios and sonication powers, and long operation times. The recovery of IL was studied under these conditions using a dialysis-based process to separate the IL from the extracted phycobiliproteins. The results reveal the possibility of using the recovered IL for seven consecutive extraction cycles with an acceptable phycocyanin extraction amount, from 75 mg g−1 (fresh IL) to 60 mg g−1 (7 cycles of reused IL). The use of [Emim] [EtSO4] + ultrasound is a promising alternative for phycocyanin extraction, enhancing the results obtained with other IL in terms of extracted phycocyanin and the number of times the IL can be reused.
Biodiesel and biogas production from Isochrysis galbana using dry and wet lipid extraction: A biorefinery approach
(Elsevier, 2020) Sánchez-Bayo, Alejandra; López-Chicharro, Daniel; Morales, Victoria; Espada, Juan José; Puyol, Daniel; Martínez, Fernando; Astals, Sergi; Vicente, Gemma; Bautista, Luis Fernando; Rodríguez, Rosalía
Wet lipid extraction combined with residual biomass anaerobic digestion are alternatives to reduce the overall energy consumption of biodiesel production from microalgae. Solvents with different polarities have been studied to assess dry and wet lipid extraction process from Isochrysis galbana microalga. Ethyl acetate (EA) and a chloroform:methanol (CM) mixture yielded the best lipid extraction results in the dry and wet route with suitable lipid compositions. Fatty acid methyl esters (FAMEs) conversion of dry and wet extracted lipids with these solvents was performed by using both homogeneous (H2SO4) and heterogeneous (resin CT 269) catalysts. FAME production from wet extracted lipids with the EA solvent using the CT-269 resin constitutes an advantageous process because it avoids the water elimination step, and the CT-269 is a heterogeneous commercial catalyst, readily to separate after reaction. Lipid-spent microalga was anaerobically digested, obtaining that waste biomass from the wet extraction with EA had the highest methane yield (310 mL CH4/g volatile solids (VS). Energy balance analysis for FAMEs production with EA solvent (wet route) and heterogeneous catalyst yielded an energy recovery of about 80% in terms of biodiesel and biogas. Therefore, this process constitutes a promising route under an energy-driven microalga biorefinery.
Biodiesel Production (FAEEs) by Heterogeneous Combi-Lipase Biocatalysts Using Wet Extracted Lipids from Microalgae
(MDPI, 2019) Sánchez-Bayo, Alejandra; Morales, Victoria; Rodríguez, Rosalía; Vicente, Gemma; Bautista, Luis Fernando
The production of fatty acids ethyl esters (FAEEs) to be used as biodiesel from oleaginous microalgae shows great opportunities as an attractive source for the production of renewable fuels without competing with human food. To ensure the economic viability and environmental sustainability of the microbial biomass as a raw material, the integration of its production and transformation into the biorefinery concept is required. In the present work, lipids from wet Isochrysis galbana microalga were extracted with ethyl acetate with and without drying the microalgal biomass (dry and wet extraction method, respectively). Then, FAEEs were produced by lipase-catalyzed transesterification and esterification of the extracted lipids with ethanol using lipase B from Candida antarctica (CALB) and Pseudomonas cepacia (PC) lipase supported on SBA-15 mesoporous silica functionalized with amino groups. The conversion to FAEEs with CALB (97 and 85.5 mol% for dry and wet extraction, respectively) and PC (91 and 87 mol%) biocatalysts reached higher values than those obtained with commercial Novozym 435 (75 and 69.5 mol%). Due to the heterogeneous nature of the composition of microalgae lipids, mixtures with different CALB:PC biocatalyst ratio were used to improve conversion of wet-extracted lipids. The results showed that a 25:75 combi-lipase produced a significantly higher conversion to FAEEs (97.2 mol%) than those produced by each biocatalyst independently from wet-extracted lipids and similar ones than those obtained by each lipase from the dry extraction method. Therefore, that optimized combi-lipase biocatalyst, along with achieving the highest conversion to FAEEs, would allow improving viability of a biorefinery since biodiesel production could be performed without the energy-intensive step of biomass drying.
Can mild alkaline pretreatment simultaneously enhance the antioxidant capacity of Beta-carotene extracts and biomethane yields in a sustainable Dunaliella salina biorefinery?
(Elsevier, 2024-12) Águila-Carricondo, Pilar; García-García, Raquel; Roche, Juan Pablo de la; Galán, Pedro Luis; Bautista, Luis Fernando; Vicente, Gemma
This research aims to assess the effect of alkaline pretreatments on the antioxidant potential of β-carotene-rich extracts from the microalga Dunaliella salina and the cumulative biomethane production from its spent biomass, within the framework of a circular economy approach using four biorefineries. A solvent screening was performed, with ethyl acetate achieving the maximum β-carotene extraction yield (5.3% ± 0.03%). Alkaline pretreatments were applied to the initial biomass (direct) and extracts after a extraction with ethyl acetate (indirect), using two matrices: water (W) and a mixture water:ethanol (WE). Direct alkaline pretreatments (D) offered extracts with higher potential than indirect pretreatments (I) in terms of: i) antioxidant capacity, as measured by ABTS•+ assay (0.69±0.1 and 0.61±0.1 mmolTE/gDW for W-D and WE-D, respectively, and 0.55±0.1 and 0.53±0.1 mmolTE/gDW for W-I and WE-I, respectively) and •OH scavenging activity (1.89±0.2 and 2.05±0.5 mmolTE/gDW for W-D and WE-D, respectively, and 0.48±0 and 1.2±0.3 mmolTE/gDW for W-I and WE-I, respectively), ii) biomethane production from their spent biomass (301±14 mLCH4/gVS and 289±9.0 mLCH4/gVS for W-D and WE-D, respectively, compared to 235±57 mLCH4/gVS without alkaline pretreatment), and iii) sustainability analysis, which includes the assessment of the biomass exploitation for β-carotene extraction and biomethane production. The most sustainable biorefinery was W-D as it achieved the highest biomass exploitation (33.8%), compared to WE-D (29.1%), W-I (33.1%) or WE-I (32.8%). This underscores the novelty and effectiveness of direct alkaline pretreatments for enhancing both antioxidant potential and energy recovery from D. salina biomass in a biorefinery context
Cultivation of Microalgae and Cyanobacteria: Effect of Operating Conditions on Growth and Biomass Composition
(MDPI, 2020) Sánchez-Bayo, Alejandra; Morales, Victoria; Rodríguez, Rosalía; Vicente, Gemma; Bautista, Luis Fernando
The purpose of this work is to define optimal growth conditions to maximise biomass for batch culture of the cyanobacterium Arthrospira maxima and the microalgae Chlorella vulgaris, Isochrysis galbana and Nannochloropsis gaditana. Thus, we study the effect of three variables on cell growth: i.e., inoculum:culture medium volume ratio (5:45, 10:40, 15:35 and 20:30 mL:mL), light:dark photoperiod (8:16, 12:12 and 16:8 h) and type of culture medium, including both synthetic media (Guillard’s F/2 and Walne’s) and wastewaters. The results showed that the initial inoculum:culture medium volume ratio, within the range 5:45 to 20:30, did not affect the amount of biomass at the end of the growth (14 days), whereas high (18 h) or low (6 h) number of hours of daily light was important for cell growth. The contribution of nutrients from different culture media could increase the growth rate of the different species. A. maxima was favoured in seawater enriched with Guillard’s F/2 as well as C. vulgaris and N. gaditana, but in freshwater medium. I. galbana had the greatest growth in the marine environment enriched with Walne’s media. Nitrogen was the limiting nutrient for growth at the end of the exponential phase of growth for C. vulgaris and N. gaditana, while iron was for A. maxima and I. galbana. The growth in different synthetic culture media also determines the biochemical composition of each of the microalgae. All species demonstrated their capability to grow in effluents from a wastewater treatment plant and they efficiently consume nitrogen, especially the three microalga species.
Environmental analysis of Spirulina cultivation and biogas production using experimental and simulation approach
(Elsevier, 2018-12) Rodríguez, Rosalía; Espada, Juan José; Moreno, Jovita; Vicente, Gemma; Bautista, Luis Fernando; Morales, Victoria
Microalgae is constituted by different compounds, interesting for the production of a wide range of endproducts by using different technologies. Many potential possibilities have been developed under the context of a biorefinery. The aim of this work is to evaluate the environmental performance of biogas production from Spirulina (Arthrospira maxima) through LCA using experimental and simulation results. For this purpose, kinetic models for batch cultivation and anaerobic digestion (AD) were determined from experimental data. Thus, Monod kinetic model and a first order model describe well microalgal biomass growth and AD, respectively. This model was used to simulate growth of Spirulina in a continuous system by using SuperPro Designer 9.5. Calculated results were compared to continuous experimental ones, obtaining good agreement in all cases. On the other hand, the whole process (cultivation, dewatering and AD of Spirulina biomass) was also simulated and the obtained results (material and energy balances) were used to construct LCA inventory data. Thereafter, environmental impacts were quantified through CML-2001 methodology using software Gabi 6.0. LCA results show that abiotic depletion of fossil resources (ADFR) category presents the highest impact, being biomass cultivation the most important contributor (about 56%). This result is directly related to the high energy consumption required for nutrient production, which also leads to increase remarkably the global warming potential (GWP) category. Main conclusion of the work is that the total/partial substitution of mineral fertilizers as nutrient source is the key to improve the environmental performance of the studied process. In this sense, a potential alternative could be the use of nutrients from wastewater or other wast
Hydrothermal Liquefaction of Microalga Using Metal Oxide Catalyst
(MDPI, 2020) Sánchez-Bayo, Alejandra; Rodríguez, Rosalía; Morales, Victoria; Nasirian, Nima; Bautista, Luis Fernando; Vicente, Gemma
The yield and composition of the biocrude obtained by hydrothermal liquefaction (HTL) of Nannocloropsis gaditana using heterogeneous catalysts were evaluated. The catalysts were based on metal oxides (CaO, CeO2, La2O3, MnO2, and Al2O3). The reactions were performed in a batch autoclave reactor at 320 C for 10 min with a 1:10 (wt/wt) microalga:water ratio. These catalysts increased the yield of the liquefaction phase (from 94.14 wt% for La2O3 to 99.49 wt% for MnO2) as compared with the thermal reaction (92.60 wt%). Consequently, the biocrude yields also raised in the metal oxides catalysed HTL, showing values remarkably higher for the CaO (49.73 wt%) in comparison to the HTL without catalyst (42.60 wt%). The N and O content of the biocrude obtained from non-catalytic HTL were 6.11 wt% and 10.50 wt%, respectively. In this sense, the use of the metal oxides decreased the N content of the biocrude (4.62–5.45 wt%), although, they kept constant or increased its O content (11.39 –21.68 wt%). This study shows that CaO, CeO2 and Al2O3 can be promising catalysts based on the remarkable amount of biocrude, the highest values of C, H, heating value, energy recovery, and the lowest content of N, O and S.
New green biorefineries from cyanobacterial-microalgal consortia: Production of chlorophyll-rich extracts for the cosmetic industry and sustainable biogas
(Elsevier, 2023) Águila-Carricondo, Pilar; Roche Cadavid, Juan Pablo de la; Galán, Pedro Luis; Bautista, Luis Fernando; Vicente, Gemma
Microalgae are promising and sustainable candidates for developing biorefineries to obtain valuable bioproducts and bioenergy. However, key challenges, such as low biomass production, high-cost harvesting, and non-efficient extractions, are restricting its large-scale production. Symbiotic relationships between microalgae and cyanobacteria can simultaneously mitigate these technical and economic restrictions. This research aims to develop sustainable and cost-effective biorefineries from two microalgae-cyanobacteria consortia to produce valuable ingredients for the cosmetic field (chlorophylls) and bioenergy (biogas). Solvent screening and cell disruption experiments were carried out to optimise the chlorophyll extraction protocols. Green solvents were chosen for both consortia. The mildness method (vortexing) was enough to achieve the maximum extraction level of chlorophylls (4.8 ± 0.2 mg/g) using 96% ethanol from a consortium composed of Chlorella vulgaris, Tetraselmis sp., and Kamptonema sp. The use of bead-beating was even more effective using water in the case of the consortium of C. vulgaris and Arthrospira platensis (13.5 ± 1.1 mg/g). High-potential antioxidant chlorophyll extracts were obtained for the cosmetic sector. As ethanol traces were found in the residual biomass of the C. vulgaris, Tetraselmis sp., and Kamptonema sp. consortium, the highest cumulative biomethane production (472 ± 32 mLCH4/gVS) was achieved with this residual biomass, the corresponding value for the initial consortium being significantly lower (239 ± 32 mLCH4/gVS). The study concludes through the overall mass balances of the best biorefineries that it is possible to recover up to 100% of both consortia weight as cosmetic ingredients, biogas, and fertilisers or cultivation media.
Novel Biorefinery Approach for Phycocyanin Extraction and Purification and Biocrude Production from Arthrospira platensis
(ACS, 2023) Sánchez-Laso, Jennifer; Espada, Juan José; Rodríguez, Rosalía; Vicente, Gemma; Bautista, Luis Fernando
A new biorefinery from Arthrospira platensis was proposed to obtain phycocyanin (PC) and a biocrude by hydrothermal liquefaction (HTL). PC is a high-added-value phycobiliprotein widely used as a food colorant and in the nutraceutical and pharmaceutical industries. However, the use of conventional solvents in the extraction process and the purity grade of the extract are shortcomings in bioproduct production. PC was extracted using a reusable ionic liquid [EMIM][EtSO4], achieving a PC purity of the lowest commercial grade. Therefore, two downstream processes were applied: (1) dialysis + precipitation and (2) aqueous two-phase system (ATPS) + dialysis + precipitation. After the second purification process, the PC purity increased remarkably to reach the analytical grade for pharmaceutical and nutraceutical applications. The waste biomass (WB) obtained in the PC extraction was valorized by hydrothermal liquefaction (HTL) to produce a biocrude. The biocrude yield and composition remarkably enhanced using isopropanol at 350 °C as a cosolvent.
Novel Biorefinery Approach for Phycocyanin Extraction and Purification and Biocrude Production from Arthrospira platensis
(ACS, 2023) Sánchez-Laso, Jennifer; Espada, Juan J.; Rodríguez, Rosalía; Vicente, Gemma; Bautista, Luis Fernando
A new biorefinery from Arthrospira platensis was proposed to obtain phycocyanin (PC) and a biocrude by hydrothermal liquefaction (HTL). PC is a high-added-value phycobiliprotein widely used as a food colorant and in the nutraceutical and pharmaceutical industries. However, the use of conventional solvents in the extraction process and the purity grade of the extract are shortcomings in bioproduct production. PC was extracted using a reusable ionic liquid [EMIM][EtSO4], achieving a PC purity of the lowest commercial grade. Therefore, two downstream processes were applied: (1) dialysis + precipitation and (2) aqueous two-phase system (ATPS) + dialysis + precipitation. After the second purification process, the PC purity increased remarkably to reach the analytical grade for pharmaceutical and nutraceutical applications. The waste biomass (WB) obtained in the PC extraction was valorized by hydrothermal liquefaction (HTL) to produce a biocrude. The biocrude yield and composition remarkably enhanced using isopropanol at 350 °C as a cosolvent.
Optimisation of FAME production from waste cooking oil for biodiesel use
(ELSEVIER, 2009) Bautista, Luis Fernando; Vicente, Gemma; Rodríguez, Rosalía; Pacheco, María
This study consists of the development and optimisation of the potassium hydroxide-catalysed synthesis of fatty acid methyl esters (FAME) from waste cooking oil. A factorial design of experiments and a central composite design have been used. The variables chosen were fatty acid concentration in the waste cooking oil, temperature and initial catalyst concentration by weight of waste cooking oil, while the responses were FAME purity and yield. The initial catalyst concentration is the most important factor, having a positive influence on FAME purity, but a negative one on FAME yield due to the positive influences of the yield losses (triglyceride saponification and methyl ester dissolution in glycerol). Fatty acid concentration in the waste cooking oil is the second factor in importance, having negative influences in FAME purity and yield. Temperature has an insignificant effect on FAME purity, but it has a significant negative influence on FAME yield due to the positive effect of temperature on the yield losses. Second-order models were obtained to predict the responses analysed as a function of these variables.
Optimised phycoerythrin extraction method from Porphyridium sp. combining imidazolium-based ionic liquids
(Elsevier, 2024-07-30) Piera, Alejandro; Espada, Juan J.; Morales, Victoria; Rodríguez, Rosalía; Vicente, Gemma; Bautista, Luis Fernando
Phycoerythrin (PE) extraction from Porphyridium sp. was studied employing ultrasound-assisted extraction combined with aqueous mixtures of two imidazolium-based ionic liquids (ILs) simultaneously, marking a significant novelty. A face-centred central composite design and response surface optimised PE yield (EPE), considering the effects of ionic liquid concentration (IL), [Emim][EtSO4]/[Bmim][EtSO4] mass ratio (E/B), biomass concentration (BM), and time (t). Improvements in EPE by 300 % and 115 % were achieved compared to a phosphate buffer solution and the freeze-thaw method, respectively. Temperature and pH effects were examined independently, leading to the determination of optimal operating conditions: BM = 10 mg mL−1, IL = 18.6 wt%, E/B = 0.78/0.22, t = 10 min, T = 35 °C, and pH = 7.5. Results indicated the potential for reusing the ILs for at least five consecutive extraction cycles, maintaining an EPE of 94.2 % compared to fresh ones. This underscores the success and innovation of the developed technology in enhancing PE extraction from Porphyridium sp
Oxygenated compounds derived from glycerol for biodiesel formulation: Influence on EN 14214 quality parameters
(ELSEVIER, 2010) Melero, Juan A.; Vicente, Gemma; Morales, Gabriel; Paniagua, Marta; Bustamante, Javier
The methyl esters of fatty acids (biodiesel) obtained via transesterification of vegetable oils or animal fats are an alternative to current fossil fuels. A large amount of glycerol as a by-product is generated in this process and new applications for this surplus need to be found. Thus, the transformation of glycerol into branched oxygen-containing compounds could be an interesting solution to provide an outlet for increasing glycerol stocks. In this work, several oxygenated compounds, obtained by transformation of glycerol via etherification, esterification and acetalisation, have been assessed as components for biodiesel formulation. Different quality parameters have been evaluated following the procedures listed in the EN 14214 European Standard for biodiesel specifications. These parameters have been correlated with the amount of oxygenated derivate present in the biodiesel. The best performance as component for biodiesel formulation has been achieved by the mixture of ethers produced via etherification of glycerol with isobutylene. The addition of these compounds has not only improved the low temperature properties of biodiesel (i.e. pour point and cold filter plugging point) and viscosity, but also did not impair other important biodiesel quality parameters analyzed. Although most of the studied oxygenated derivates do not significantly improve any biodiesel property, they do not exert a significant negative effect either. Furthermore, all of them allow an enhancement of overall yield in the biodiesel production. Nevertheless, further improvement could be addressed with a better purification to reduce the presence of non-desired impurities such as diisobutylenes and unreacted acetic acid, which have a negative influence especially in acid number and oxidation stability.
Synthesis of oxygenated compounds for fuel formulation: Etherification of glycerol with ethanol over sulfonic modified catalysts
(ELSEVIER, 2011-12) Melero, Juan A.; Vicente, Gemma; Paniagua, Marta; Morales, Gabriel; Muñoz, Patricia
The present study is focused on the etherification of glycerol with anhydrous ethanol over arenesulfonic acid-functionalized mesostructured silicas to produce ethyl ethers of glycerol that can be used as gasoline or diesel fuel components. Within the studied range, the best conditions to maximize glycerol conversion and yield towards ethyl-glycerols are: T = 200ºC, ethanol/glycerol molar ratio = 15/1, and catalyst loading = 19 wt.%. Under these reaction conditions, 74% glycerol conversion and 42% yield to ethyl ethers have been achieved after 4 h of reaction but with a significant presence of glycerol by-products. In contrast, lower reaction temperatures (T=160ºC) and moderate catalyst loading (14 wt.%) in presence of a high ethanol concentration (ethanol/glycerol molar ratio = 15/1) are necessary to avoid the formation of glycerol by-products and maximize ethyl-glycerols selectivity. Interestingly, a close catalytic performance to that achieved using high purity glycerol has been obtained with low-grade water-containing glycerol.
The effect of the lipid extraction method used in biodiesel production on the integrated recovery of biodiesel and biogas from Nannochloropsis gaditana, Isochrysis galbana and Arthrospira platensis
(Elsevier, 2020) Mendoza, Álvaro; Morales, Victoria; Sánchez-Bayo, Alejandra; Rodríguez, Rosalía; Fernández-González, Cristina; Bautista, Luis Fernando; Vicente, Gemma
The integrated production of biodiesel and biogas has been explored by using N. gaditana, I. galbana and A. platensis as substrate. Three fatty acid ethyl ester (FAEE) production approaches were assessed, namely an indirect process with previously extracted lipids (IPPEL), an indirect process with extracted lipids as free fatty acids (IPELFFA) and a direct process (DP) without a previous lipid extraction stage. Besides de FAEE production, these approaches are considered as pre-treatments of the microbial biomasses evaluated in this study with the objective of increasing the methane yield during the anaerobic digestion. Biogas yields of the residues generated under the three FAEE production methodologies were compared to the biogas yield of the raw feedstock. In all cases, the biodiesel and biogas yields were higher after the FAEE production process from the previously extracted lipids as free fatty acids (IPELFFA). Therefore, this constitutes an interesting and promising route in the joint production of biodiesel and biogas.