Person:
Monte Lara, María Concepción

First Name

María Concepción

Last Name

Monte Lara

URI

https://hdl.handle.net/20.500.14352/76231

Affiliation

Universidad Complutense de Madrid

Faculty / Institute

Ciencias Químicas

Department

Ingeniería Química y de Materiales

Area

Ingeniería Química

Identifiers

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Now showing 1 - 10 of 29

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, Ángeles
Nanocelluloses (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.
Depósitos adherentes en el proceso de fabricación de papel reciclado
(2003) Monte Lara, María Concepción; Tijero Miquel, Julio; Blanco Suárez, Ángeles
La utilización de papel de recuperación como materia prima para la fabricación de papel reciclado presenta numerosas ventajas medioambientales y económicas. Sin embargo, también tien graves inconvenientes, debido a la cantidad de contaminantes que se introducen en el sistema. Los contaminantes que se encuentran en forma de materia disuelta y coloidal no pueden ser eliminados por los procesos mecánicos convencionales y cuando se desestabilizan, por un cambio brusco de las condiciones del sistema, son responsables directos de la formación de manchas y agujeros en el producto final. El objetivo de esta Tesis es el desarrollo de un procedimiento para determinar la tendencia de la materia disuelta y coloidal presente en un agua papelera a la formación de depósitos adherentes, de manera práctica y precisa. El método desarrollado consta de las etapas necesarias para la obtención de las aguas blancas, en condiciones similares a las que se obtienen en el proceso de fabricación de papel reciclado. Las aguas caracterizadas se desestabilizan con un polímero catiónico para favorecer la formación de depósitos utilizando un equipo de deposición diseñado para tal fin, denominado "Rotor de Deposición", que permite llevar a cabo la determinación cuantitativa de los depósitos mediante un sistema de análisis de imagen. Con el método desarrollado, una vez validado y determinada su reproducibilidad, se lleva a cabo un estudio en aguas blancas obtenidas a partir de suspensiones de pasta que contienen los contaminantes propios del proceso de reciclado de papel: adhesivos, compuestos de estucado y jabones de destintado. Se estudia el efecto que jercen distintas variables, como la naturaleza del contaminante, la presencia de aditivos de destintado, la naturaleza de los agentes de desestabilización, la dosis empleada y las características del medio (pH, conductividad y durez de las aguas), sobre la tendencia a la formación de depósitos adherentes. Así mismo, se lleva a cabo un estudio de la depositabilidad de la materia disuelta y coloidal contenida en muestras de dos fábricas que utilizan papel de recuperación como materia prima, con el fin de comparar los resultados de las muestras de laboratorio con los que se obtienen de muestras reales
Extending the limits of paper recycling - improvements along the paper value chain
(Forest Systems, 2013) Blanco Suárez, María Ángeles; Miranda Carreño, Rubén; Monte Lara, María Concepción
Aim of study: The purpose of this study is to analyze how paper recycling activities in Europe can be extended through different improvements along the paper value chain. The importance of this study lies in the identification of the present barriers in paper recycling and how they can be overcome. Area of study: Europe. Material and methods: All the main stages along the paper value chain have been analyzed for possible improvements: collection of recovered paper (availability and quality), sorting of recovered paper, paper production, and printing and converting activities. Main results: To increase paper recycling in Europe the following improvements are necessary. First, it is mandatory to increase the availability of recovered paper through more efficient collection systems (avoiding the use of commingled collection systems) and limiting the competition with energy purposes and the exports. Second, it is necessary to extend sorting activities, which can be achieved by reducing sorting costs by the use of automatized sorting systems. Third, there is a need to increase the recyclability of paper products by the commitment of printing and converting industries to use recycling-friendly printing inks and adhesives. Finally, environmental awareness of the citizens is still an important driver for increasing recycling activities, affecting not only recovery but to all the stages along the paper recycling chain. Research highlights: Although the recycling rate in Europe is already very high (68.9%), there is still room to further extend paper recycling activities through different improvements along the paper value chain.
Comparison of ultrafiltration and dissolved air flotation efficiencies in industrial units during the papermaking process
(APPITA Journal, 2011) Monte Lara, María Concepción; Ordóñez Sanz, Ruth; Hermosilla Redondo, María Daphne; González Sánchez, Mónica; Blanco Suárez, María Ángeles
The efficiency of an ultrafiltration unit has been studied and compared with a dissolved air flotation system to get water with a suited quality to be reused in the process. The study was done at a paper mill producing light weight coated paper and newsprint paper from 100% recovered paper. Efficiency was analysed by removal of turbidity, cationic demand, total and dissolved chemical oxygen demand, hardness, sulphates and microstickies. Moreover, the performance of the ultrafiltration unit and the membranes were studied deeply, analysing its variability during the filtration process. As expected, the ultrafiltration gave higher removal efficiencies than the dissolved air flotation cell in parameters like turbidity, cationic demand, dissolved chemical oxygen demand and microstickies. The greatest difference in performance between the units concerned cationic demand and dissolved chemical oxygen demand. Ultrafiltration was influenced by the operating time, decreasing the removal efficiency of the dissolved fraction by 75% and of the colloidal fraction by 30% after 312 of running. Membrane autopsy, carried out to identify the cause of poor membrane performance, showed that the active layer was degraded due to the effect of suspended solids.
Time Variations of Macrostickies and Extractable Stickies Concentrations in Deinking
(Industrial & Engineering Chemistry Research, 2010) MacNeil, Donald; Miranda Carreño, Rubén; Monte Lara, María Concepción; Blanco Suárez, María Ángeles; Sundberg, Anna
The stickies content, both macrostickies and stickies extractable in a solvent, was determined for samples taken at short time intervals from deinking lines, producing deinked pulp for newsprint production. The study was carried out at three mills on different continents, with each having a different source of recycled paper as raw material. The short-term variations in extractable stickies in the incoming raw material were quite extreme, with differences of 100% being seen within hours. Despite this, the final deinked pulp contained fewer sudden variations and had no correlation to the incoming stickies content. While the raw material appeared to affect the incoming stickies content, a well-optimized deinking line was able to buffer the raw material variability, and the final stickies content was more dependent on the deinking process. This result was seen for the two mills examined for this phenomenon, despite a different raw material supply. Macrostickies were found to exhibit the same tendencies, although with smaller and less sudden variations. However, the variations of macrostickies and extractable stickies never correlated, even when both were measured for the same pulp fraction, thus confirming that solvent extraction is not an appropriate method for the determination of macrostickies and is more a reflection of microstickies.
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 Félix
Conventional 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.
Impact of increased collection rates and the use of commingled collection systems on the quality of recovered paper. Part 1: Increased collection rates
(Waste Management, 2011) Miranda Carreño, Rubén; Monte Lara, María Concepción; Blanco Suárez, María Ángeles
The recovery and utilization of recovered paper have increased over past decades all over the world due to economic, environmental, and social issues. However, it is well known that an extended recovered paper collection is detrimental to its quality, either by the exploitation of lower quality sources such as households, or the spreading of commingled systems instead of selective collection systems. The influence of these two factors was assessed by analyzing the quality of different recovered paper grades used as raw material in a mill located in Madrid (Spain) producing newsprint and light weight coated paper from recovered paper. Part 1 of the paper deals with the impact of increased collection rates on the quality of recovered paper and Part 2 with the use of commingled collection systems. Results of Part 1 show that increased collection rates have a large impact on the quality of the recovered paper. The quality, measured as total unusable material and moisture contents, had deteriorated very rapidly in only four years (2005-2008) as a consequence of increased collection rates. Collection rates increased in Spain from 58.5% to 68.6% during this period, resulting in more than 50% increase of total unusable material and 25% of moisture content. The downgrading of the quality of recovered paper is one of the major threats for extending the current limits of paper recycling. Therefore, future challenge is to increase its availability but maintaining its quality.
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 Manuel
Eleven 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.
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 Manuel
Reinforcing 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.
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 Manuel
This 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.