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
4 results
Search Results
Now showing 1 - 4 of 4
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 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 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.