Person: Monte Lara, María Concepción
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First Name
María Concepción
Last Name
Monte Lara
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Químicas
Department
Ingeniería Química y de Materiales
Area
Ingeniería Química
Identifiers
18 results
Search Results
Now showing 1 - 10 of 18
Item Industrial Application of Nanocelluloses in Papermaking: A Review of Challenges, Technical Solutions, and Market Perspectives(Molecules, 2020) Balea Martín, Ana; Fuente González, Elena de la; Monte Lara, María Concepción; Merayo, Noemi; Campano Tiedra, Cristina; Negro Álvarez, Carlos Manuel; Blanco Suárez, ÁngelesNanocelluloses (NC) increase mechanical and barrier paper properties allowing the use of paper in applications actually covered by other materials. Despite the exponential increase of information, NC have not been fully implemented in papermaking yet, due to the challenges of using NC. This paper provides a review of the main new findings and emerging possibilities in this field by focusing mainly on: (i) Decoupling the effects of NC on wet-end and paper properties by using synergies with retention aids, chemical modification, or filler preflocculation; (ii) challenges and solutions related to the incorporation of NC in the pulp suspension and its effects on barrier properties; and (iii) characterization needs of NC at an industrial scale. The paper also includes the market perspectives. It is concluded that to solve these challenges specific solutions are required for each paper product and process, being the wet-end optimization the key to decouple NC effects on drainage and paper properties. Furthermore, the effect of NC on recyclability must also be taken into account to reach a compromise solution. This review helps readers find upscale options for using NC in papermaking and identify further research needs within this field.Item Improving deposition tester to study adherent deposits in papermaking(Chemical Engineering Research and Design, 2012) Monte Lara, María Concepción; Sánchez, Mónica; Blanco Suárez, María Ángeles; Negro Álvarez, Carlos Manuel; Tijero Miquel, Julio FélixConventional methods used for the quantification of adherent material contained in a pulp suspension propose either filtration of the sample, which may lead to loss of sticky material in the filtrate, or dilution of the pulp, which may cause destabilization of the dissolved and colloidal material; thus, leading to unreliable results. In 1998, the Cellulose and Paper Group of University Complutense of Madrid developed a deposition tester which aimed to quantify the adherence of material (microstickies and secondary stickies from dissolved and colloidal material) that was present in white waters generated during papermaking processes. In this paper, an improved deposition tester capable of directly studying the deposition tendency of total stickies in pulps without dilution is described and validated. The design of this device prevents the rotor system from being clogged and blocked by pulps, hence, being able to quantify deposits without having to apply any filtration and/or dilution stages. In addition, the study provides determination of the equipment optimum operating conditions as well as comparison between the improved deposition tester and the one previously developed. Results show that this deposition tester can determine the adherent material contained in pulps with a consistency up to 1%. The comparison of results obtained after applying both deposition quantification methods shows that the quantities of deposits that were measured with the improved tester are slightly lower than those obtained with the application of the conventional method; however, they are in the same order of magnitude. Therefore, it is possible for the improved tester to determine total stickies in all cases, including cases that it is not convenient to apply a filtration and/or a dilution stage.Item Waste management from pulp and paper production in the European Union(Waste Management, 2009) Monte Lara, María Concepción; Fuente González, Elena De La; Blanco Suárez, María Ángeles; Negro Álvarez, Carlos ManuelEleven million tonnes of waste are produced yearly by the European pulp and paper industry, of which 70% originates from the production of deinked recycled paper. Wastes are very diverse in composition and consist of rejects, different types of sludges and ashes in mills having on-site incineration treatment. The production of pulp and paper from virgin pulp generates less waste but the waste has similar properties to waste from the production of deinked pulp, although with less inorganics. Due to legislation and increased taxes, landfills are quickly being eliminated as a final destination for wastes in Europe, and incineration with energy recovery is becoming the main waste recovery method. Other options such as pyrolysis, gasification, land spreading, composting and reuse as building material are being applied, although research is still needed for optimization of the processes. Due to the large volumes of waste generated, the high moisture content of the waste and the changing waste composition as a result of process conditions, recovery methods are usually expensive and their environmental impact is still uncertain. For this reason, it is necessary to continue research on different applications of wastes, while taking into account the environmental and economic factors of these waste treatments.Item Recycled Fibers for Sustainable Hybrid Fiber Cement Based Material: A Review(Materials, 2021) Balea Martín, Ana; Fuente González, Elena De La; Monte Lara, María Concepción; Blanco Suárez, María Ángeles; Negro Álvarez, Carlos ManuelReinforcing fibers have been widely used to improve physical and mechanical properties of cement-based materials. Most fiber reinforced composites (FRC) involve the use of a single type of fiber to improve cement properties, such as strength or ductility. To additionally improve other parameters, hybridization is required. Another key challenge, in the construction industry, is the implementation of green and sustainable strategies based on reducing raw materials consumption, designing novel structures with enhanced properties and low weight, and developing low environmental impact processes. Different recycled fibers have been used as raw materials to promote circular economy processes and new business opportunities in the cement-based sector. The valuable use of recycled fibers in hybrid FRC has already been proven and they improve both product quality and sustainability, but the generated knowledge is fragmented. This is the first review analyzing the use of recycled fibers in hybrid FRC and the hybridization effect on mechanical properties and workability of FRC. The paper compiles the best results and the optimal combinations of recycled fibers for hybrid FRC to identify key insights and gaps that may define future research to open new application fields for recycled hybrid FRC.Item Polymeric Branched Flocculant Effect on the Flocculation Process of Pulp Suspensions in the Papermaking Industry(Industrial & Engineering Chemistry Research, 2009) Blanco Suárez, María Ángeles; Fuente González, Elena De La; Monte Lara, María Concepción; Cortés, Noelia; Negro Álvarez, Carlos ManuelThis paper presents the effect of the structure of cationic polyacrylamides (CPAMs) on flocculation of pulpsuspensions and floc properties. A focused beam reflectance measurement (FBRM) probe was used to monitor flocculation, deflocculation, and reflocculation processes in real time. To carry out the study, 1% elemental chlorine free (ECF) eucalyptus kraft pulp containing 20% ground calcium carbonate (GCC) was used. Results show that the effect of the CPAM structure depends on charge density and polymer dose. Floc size does not always decrease with branching degree, whereas floc stability and reflocculation ability increased when highly charged and branched CPAM was used. These findings indicate that the use of highly branched CPAMs with very high molecular weight is very promising as a retention aid method to improve the papermaking process.Item Pitch adsorption on natural and modified talcs(Journal of Pulp and Paper Science, 2009) Tijero Cruz, Antonio; Monte Lara, María Concepción; Blanco Suárez, María Ángeles; Negro Álvarez, Carlos Manuel; Tijero Miquel, Julio FélixTalc is used traditionally for pitch control in papermaking. The effectiveness of talcs as control agent of dissolved and colloidal pitch depends on its structural and surface characteristics of minerals. Talcs are modified by thermal and surface treatments to obtain different properties e.g specific surface, surface energy, surface charge and ratio lypophilic/hydrophilic surface. Five commercial talcs have been tested to determine its capacity to adsorb the lypophilic contaminants by experiments of adsorption isotherms. The talcs correspond to two groups of different mineralogical compositions: one with high concentration of talc and some dolomite; and the other, with medium concentrations of talc and chlorite. Colloidal dispersions of extractives were obtained by extraction of Eucalyptus globulus wood at pilot plant scale with acetone, evaporation of the solvent and reextraction with hexane to increase the selectivity of lypophillic compound extraction. The isotherms of adsorption of the pitch dispersions were carried out at 50ºC on the different talcs. The adsorption took place by a mechanism of colloidal adsorption and the results obtained were adjusted to the Langmuir equation. Results show that talc addition to bleaching waters or process waters can produce high reductions of colloidal pitch concentrations, at comparatively low doses.Item Interaction of dissolved and colloidal material during the mixing of different pulps(Holzforschung, 2010) Monte Lara, María Concepción; MacNeil, Donald; Negro Álvarez, Carlos Manuel; Blanco Suárez, María ÁngelesMixtures of stickies-containing and stickies-free pulps were investigated for their deposition potntial in an attempt to better understand the interactions of dissolved and colloidal material (DCM) when mixing two different pulps. The filtered pulp mixtures were tested in a deposition apparatus which measures both the dynamic fluid as well as impact deposition by an established optical scanning method. A pulp filtrate of model stickies led to deposition according to the proportion of stickies-containing pulp in the mixture. Other mixtures of pulps, however, led to deposition that differed from the predicted value. It is theorised that pulp fibres present in the mixture could adsorb the polysaccharides that would otherwise keep the colloidal system electrostatically stable. This destabilisation was most prominent at lower proportions of the stickies-free pulp suspensions used for mixing. These results show that care must be taken when mixing different pulps for paper and board production, as even a small amount of replacement pulp can lead to destabilisation of DCM and formation of deposits. Furthermore, special care must be taken when mixtures of pulps are used to validate stickies measurements.Item Corn stalk from agricultural residue used as reinforcement fiber in fibercement production(Industrial Crops and Products, 2013) Jarabo, Rocío; Monte Lara, María Concepción; Fuente González, Elena De La; Santos, Sérgio Francisco; Negro Álvarez, Carlos ManuelIn the last few years an increasing high interest has been drawn to the potential use of agricultural waste as raw material to produce structural reinforcement fibers for building materials, due to environmental and economical aspects. Corn is the world's most produced cereal in terms of quantity, what entails the generation of large quantities of waste. Despite this fact, only a few research works concerned with the use of fibers from waste corn stalks in the production of fiber-cement have been published and there is a complete lack of data on the characterization of these fibers. The objective of this research is to study the feasibility of using fibers obtained from corn stalk as reinforcement fibers in the production of fiber-cement through new environmentally friendly cooking methods. This study encompasses the morphological characterization of the fibers and the study of the effects that the use of these fibers has on the flocculation, retention and drainage of the fiber-cement suspensions and on the mechanical and physical properties of the final product. The results obtained in the tests confirmed the high potential of the corn stalk as a source of fibers for the manufacture of a fiber-cement capable of meeting the requirements of demanding applications.- Project number: 120
Item CHEM-E-CAR: De la teoría a la práctica. Construcción de un prototipo(2017) Monte Lara, María Concepción; Balea Martín, Ana; López Expósito, Patricio; Campano Tiedra, Cristina; Cortijo Garrido, Luis; Plaza Rodriguez, Jesus; Barndok, Helen; Miranda Carreño, Rubén; Tijero Cruz, Antonio; Ladero Galán, Miguel; García-Ochoa Soria, Félix; Senit Velasco, Juan José; Velasco Conde, Daniel; Alcalá Penades, Germán; Mato Díaz, Sonia; Pérez Trujillo, Francisco Javier; Santos Barahona, Héctor; Lasanta Carrasco, María Isabel; de Miguel Gamo, María Teresa; García Martín, Gustavo; Illana Sánchez, Andrea; Alberola Sánchez, Raúl; Arsuaga Cao, Pablo; Ara Jimeno, Pablo; Avila Palomares, Alberto; Bolívar Tejedo, Pilar; Carlucci, Maurizio Antonio; del Amo Salgado, Pablo; Espinosa García, Lucía; Fernández Rodríguez, Gemma; Galán Galán, Alicia; Márquez Negro, Alejandro; Martín Jiménez, Diego; Morona Murillo, Lorena; Pedregal Sáez, Antonio; Resino Guirao, Jesús; Negro Álvarez, Carlos Manuel; Fuente González, Elena De La; Blanco Suárez, María ÁngelesEl proyecto consiste en construir un prototipo de coche “Chem-E-Car” y constituir a la UCM como una de las primeras universidades españolas que participa en dicha competición internacional. Item Development of a methodology to predict sticky deposits due to dissolved and colloidal material destabilization in papermaking - Application to different systems(Chemical Engineering Journal, 2004) Monte Lara, María Concepción; Blanco Suárez, María Ángeles; Negro Álvarez, Carlos Manuel; Tijero Miquel, Julio FélixDue to trends in papermaking like closed water systems or higher use of recovered paper as raw material, a large number of contaminants are accumulated in the system as dissolved and colloidal material (DCM). When the DCM is destabilized by a sudden change in the system conditions, it produces sticky deposits called secondary stickies that affect the papermaking processes and the quality of the final product. The laboratory methods existing to predict DCM destabilisation have limitations as low reproducibility or they do not distinguish between sticky and non-sticky materials and/or high volumes are necessary to perform the test, etc. In order to solve these problems, a methodology to predict the depositability potential of DCM has been developed by the Complutense University of Madrid. The methodology is based, first, on the destabilisation of the DCM by polymer addition, second, on its deposition on the collector surfaces and, third, on the quantification of the formed deposits by image analysis. Results show that the methodology has a good reproducibility with an error below 10%. Validation was carried out by application of the method to different cases. Results demonstrate that the developed methodology is a useful tool for researchers and papermakers to predict deposit problems due to the destabilisation of DCM in papermaking.