scispace - formally typeset
Search or ask a question
Author

Ángel Pérez

Bio: Ángel Pérez is an academic researcher from University of Castilla–La Mancha. The author has contributed to research in topics: Ultrafiltration & Biodiesel. The author has an hindex of 26, co-authored 53 publications receiving 3391 citations.


Papers
More filters
Journal ArticleDOI
TL;DR: A triangular graph based on the composition in monounsaturated, polyunsaturated and saturated methyl esters was built in order to predict the critical parameters of European standard for whatever biodiesel, known its composition.

1,667 citations

Journal ArticleDOI
TL;DR: In this article, the authors analyzed the catalytic performance of several heterogeneous catalysts in the transesterification of sunflower oil with methanol, and the results supported the hypothesis of a homogeneous-like mechanism where the alkali methoxide species were leached out.
Abstract: The aim of this study was to analyse the catalytic performance of several heterogeneous catalysts in the transesterification of sunflower oil with methanol. In order to characterize the different catalysts, nitrogen adsorption/desorption and CO 2 temperature programmed desorption were used. The transesterification of sunflower oil was carried out using three different zeolites: mordenite, beta and X, to determine the influence of the kind of zeolite on the methyl ester production. The influence of the metal incorporation technique was studied using both impregnation and ion-exchange methods. Also, the transesterification reaction was carried out using catalysts with different metal loading. Finally, zeolite X was agglomerated with a binder, sodium bentonite, to study how the presence of a binder could change the catalytic performance of the zeolite. A methyl ester content of 93.5 and 95.1 wt% was obtained at 60 °C employing zeolite X with or without sodium bentonite, respectively. All biodiesel synthesized were characterized using the standard UNE-EN 14214. A complete deactivation study was carried out in order to check the sodium leaching from the catalyst. The results supported the hypothesis of a homogeneous-like mechanism where the alkali methoxide species were leached out.

172 citations

Journal ArticleDOI
TL;DR: In this article, the performance of biodiesel quality standards when triacetin is present at different concentrations in the biodiesel was evaluated using reaction stoichiometry, and the results showed that the effect of adding triacetins is different to that of adding glycerol.
Abstract: Triacetin is a byproduct obtained from the reaction between triglycerides and methyl acetate (interesterification) and has a higher added value than that of glycerol. According to the reaction stoichiometry, the final product contains 20 wt % of triacetin and 80 wt % of biodiesel in a single phase. The aim of this work was to test the performance of biodiesel quality standards when triacetin is present at different concentrations in the biodiesel. We therefore measured properties, such as the density, kinematic viscosity, cloud point, pour point, cold filter plugging point, dynamic viscosity, cetane number, heating value, distillation curve, and flash point, for mixtures of triacetin and biodiesel composed of various amounts of triacetin of up to 20 wt % and different biodiesels (palm, soybean, sunflower, high-oleic sunflower, and rapeseed). Current biodiesel fuel standards would limit the triacetin to about 10 wt % (EN 14214) if they considered that the effect of adding triacetin is different to that of ...

141 citations

Journal ArticleDOI
TL;DR: In this work, various techniques are tested, and the best technique is found to be crystallization filtration using methanol, which reduces the CFPP from 17 degrees C to -8 degrees C with a biodiesel loss of 8.93 wt.%.

140 citations

Journal ArticleDOI
TL;DR: In this article, a process for recovery heavy metals from industrial wastewaters has been studied, which is called PSU (Polymer Supported Ultrafiltration), and includes complexation of metallic ions with polymers (polyethyleneimine or poly(acrylic) acid) in order to make this solution flow through an ultrafiltration ceramic membrane and to obtain two different streams: permeate (nearly free of metal) and retentate (with high complex concentration).

115 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: It is evident from the literature survey articles that ion-exchange, adsorption and membrane filtration are the most frequently studied for the treatment of heavy metal wastewater.

6,844 citations

Journal ArticleDOI
TL;DR: In this article, the results of the transesterification of sunflower oil with methanol to produce biodiesel using CaO nanoparticles supported on NaX zeolite as catalyst were reported.
Abstract: Biodiesel is produced by the transesterification of oil triglycerides with methanol or ethanol, in the presence of a homogeneous or heterogeneous catalyst. This study aims to report the results of the transesterification of sunflower oil with methanol to produce biodiesel using CaO nanoparticles supported on NaX zeolite as catalyst. The effect of the CaO nanoparticles concentration on the NaX zeolite surface was studied in the range of 5−25 wt %. The transesterification reaction was carried out at reflux temperature of methanol, atmospheric pressure, a reaction time of 6 h, and with a 6:1 molar ratio of methanol to sunflower oil. Catalyst characterization was carried out by X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. It was concluded that methyl esters content is highly influenced by basicity and that the best catalyst was the one holding 16 wt % CaO nanoparticles. The produced biodiesel was 93.5% methyl esters and was found to fulfill the specifications of Europ...

1,687 citations

Journal ArticleDOI
TL;DR: In this paper, the fatty acid (FA) profiles of 12 common biodiesel feedstocks were summarized, and it was shown that several fuel properties, including viscosity, specific gravity, cetane number, iodine value, and low temperature performance metrics are highly correlated with the average unsaturation of the FA profiles.
Abstract: Biodiesel is a renewable transportation fuel consisting of fatty acid methyl esters (FAME), generally produced by transesterification of vegetable oils and animal fats. In this review, the fatty acid (FA) profiles of 12 common biodiesel feedstocks were summarized. Considerable compositional variability exists across the range of feedstocks. For example, coconut, palm and tallow contain high amounts of saturated FA; while corn, rapeseed, safflower, soy, and sunflower are dominated by unsaturated FA. Much less information is available regarding the FA profiles of algal lipids that could serve as biodiesel feedstocks. However, some algal species contain considerably higher levels of poly-unsaturated FA than is typically found in vegetable oils. Differences in chemical and physical properties among biodiesel fuels can be explained largely by the fuels’ FA profiles. Two features that are especially influential are the size distribution and the degree of unsaturation within the FA structures. For the 12 biodiesel types reviewed here, it was shown that several fuel properties – including viscosity, specific gravity, cetane number, iodine value, and low temperature performance metrics – are highly correlated with the average unsaturation of the FAME profiles. Due to opposing effects of certain FAME structural features, it is not possible to define a single composition that is optimum with respect to all important fuel properties. However, to ensure satisfactory in-use performance with respect to low temperature operability and oxidative stability, biodiesel should contain relatively low concentrations of both long-chain saturated FAME and poly-unsaturated FAME.

1,527 citations

Journal ArticleDOI
TL;DR: In this paper, the authors reviewed the source of production and characterization of vegetable oils and their methyl ester as the substitute of the petroleum fuel and future possibilities of Biodiesel production.
Abstract: The world is confronted with the twin crises of fossil fuel depletion and environmental degradation. The indiscriminate extraction and consumption of fossil fuels have led to a reduction in petroleum reserves. Petroleum based fuels are obtained from limited reserves. These finite reserves are highly concentrated in certain region of the world. Therefore, those countries not having these resources are facing a foreign exchange crisis, mainly due to the import of crude petroleum oil. Hence it is necessary to look for alternative fuels, which can be produced from materials available within the country. Although vegetative oils can be fuel for diesel engines, but their high viscosities, low volatilities and poor cold flow properties have led to the investigation of its various derivatives. Among the different possible sources, fatty acid methyl esters, known as Biodiesel fuel derived from triglycerides (vegetable oil and animal fates) by transesterification with methanol, present the promising alternative substitute to diesel fuels and have received the most attention now a day. The main advantages of using Biodiesel are its renewability, better quality exhaust gas emission, its biodegradability and the organic carbon present in it is photosynthetic in origin. It does not contribute to a rise in the level of carbon dioxide in the atmosphere and consequently to the green house effect. This paper reviews the source of production and characterization of vegetable oils and their methyl ester as the substitute of the petroleum fuel and future possibilities of Biodiesel production.

1,250 citations

Journal ArticleDOI
TL;DR: In this critical review, some of the most promising electrochemical tools for the treatment of wastewater contaminated by organic pollutants are discussed in detail and the critical assessment of the reactors that can be used to put these technologies into practice is devoted.
Abstract: Traditional physicochemical and biological techniques, as well as advanced oxidation processes (AOPs), are often inadequate, ineffective, or expensive for industrial water reclamation. Within this context, the electrochemical technologies have found a niche where they can become dominant in the near future, especially for the abatement of biorefractory substances. In this critical review, some of the most promising electrochemical tools for the treatment of wastewater contaminated by organic pollutants are discussed in detail with the following goals: (1) to present the fundamental aspects of the selected processes; (2) to discuss the effect of both the main operating parameters and the reactor design on their performance; (3) to critically evaluate their advantages and disadvantages; and (4) to forecast the prospect of their utilization on an applicable scale by identifying the key points to be further investigated. The review is focused on the direct electrochemical oxidation, the indirect electrochemical oxidation mediated by electrogenerated active chlorine, and the coupling between anodic and cathodic processes. The last part of the review is devoted to the critical assessment of the reactors that can be used to put these technologies into practice.

1,197 citations