José Francisco Colom

• Full Professor in Pulp and Paper Technology
• Retired at Polytechnic University of Catalonia

A new biotechnological procedure using laccase in combination with a hydrophobic phenolic compound (lauryl gallate) for the hydrophobization of cellulose fibres and internal sizing of paper was developed. Cellulose fibres from hardwood kraft pulp were incubated with laccase (Lac), in combination with lauryl gallate (LG). The Lac-LG treatment result...

A study was conducted to demonstrate enzymatic treatments of pulp using laccase hydrophobic compounds. The enzymatic treatments were performed in the Easydye® reactor, using small metal vessels of 250ml. The study was conducted to assess the internal sizing capability of a series of nine hydrophobic compounds and to investigate the treatment condit...

Paper surface roughness is an important consideration in paper and board destined for printing. The amount of coating and method of application depend on the roughness of the base paper. We present a method to measure the roughness of the paper based on analysis of speckle pattern on the surface. Images are captured by means of a simple configurati...

Flax soda/AQ pulps were treated with different fungal laccase-mediator combinations followed by physical and chemical characterization of the pulps to obtain a thorough understanding of the laccase/mediator effects on hexenuronic acid (HexA) removal and the coupling of mediator onto pulps for fiber functionalization. Large differences were found an...

Flax and sisal pulps were treated with two laccases (from Pycnoporus cinnabarinus, PcL and Trametes villosa, TvL, respectively), in the presence of different phenolic compounds (syringaldehyde, acetosyringone and p-coumaric acid in the case of flax pulp, and coniferaldehyde, sinapaldehyde, ferulic acid and sinapic acid in the case of sisal pulp). I...

Roughness of paper surface is an important parameter in paper manufacturing. Surface roughness measurement is one of the central measurement problems in paper industry. Surfaces are often coated and the amount of coating and method of application used depends on the roughness of the base paper [1], [2]. At the moment, air leak methods are standardi...

An oxygen delignified eucalyptus Kraft pulp was bleached in a totally chlorine-free (TCF) sequence using an ozone stage (Z) followed by a hydrogen peroxide stage (P). Ozone treatments were carried out at a laboratory scale with new automated equipment. The Z stage was modeled using a four-variable sequential statistical plan over the following rang...

Laccase–mediator systems have the disadvantage that the mediator is expensive and potentially toxic. In this work, we used N-hydroxyacetanilide (NHA) in combination with laccase for the first time to bleach eucalypt pulp and found it to be a very promising, advantageous alternative to 1-hydroxybenzotriazole (HBT) as mediator. Thus, NHA is efficient...

The phenols syringaldehyde (SA), acetosyringone (AS) and p-coumaric acid (PCA) were used as natural laccase mediators in combination with a laccase from Pycnoporus cinnabarinus to bleach flax fibres. Their performance was compared with 1-hydroxybenzotriazole (HBT) in terms of enzyme stability, and pulp and effluent properties. HBT and PCA were foun...

The effects of laccase-natural mediator systems (LMS) on sisal pulp and their potential for either biobleaching or functionalizing (via radical-coupling) its fibres were investigated. The enzyme treatment (L stage) was followed by extraction with hydrogen peroxide in order to determine whether observable effects could be enhanced by removing LMS-mo...

The way how sterols, the main lipophilic compounds present in eucalypt kraft pulp, are eliminated by an enzymatic stage using the laccase-mediator system was evaluated. With this purpose laccase-mediator stage (L) was applied on an Eucalyptus globulus pulp under different operation conditions following a three-variable (laccase dose, mediator dose...

Wild and recombinant hydrolases and oxidoreductases with a potential interest for environmentally sound bleaching of high-quality paper pulp (from flax) were incorporated into a totally chlorine free (TCF) sequence that also included a peroxide stage. The ability of feruloyl esterase (from Aspergillus niger) and Mn2+-oxidizing peroxidases (from Pha...

HPLC, SEM and XRD techniques have been proposed as methods for ascertaining the changes occurring in polysaccharides (cellulose and xylans) and fibres during the xylanase bleaching processes. TCF and ECF bleached pulps with and without enzyme pretreatment were analysed. The ratio of carbohydrates present in the pulp, observation of changes occurrin...

Referencia OEPM: P200102804.-- Fecha de solicitud: 17/12/2001.-- Titulares: Consejo Superior de Investigaciones Científicas (CSIC), Universidad Politécnica de Cataluña, Institut National de la Recherche Agronomique-France. Esta invención describe un procedimiento para el blanqueo de pastas de papel de alta calidad obtenidas a partir de plantas herb...

High-quality flax pulp was bleached in a totally-chlorine-free (TCF) sequence using a laccase-mediator system. Three fungal laccases (from Pycnoporus cinnabarinus, Trametes versicolor and Pleurotus eryngii) and two mediators, 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) and 1-hydroxybenzotriazole (HBT), were compared. P. cinnabarinus and T...

Eucalyptus globulus kraft pulp was bleached in a totally chlorine-free (TCP) sequence (OXZP). The P stage was modelled using a four-variable sequential statistical plan over the following ranges: 0.5 to 2.5% hydrogen peroxide on o.d. pulp, 1 to 3 h reaction time, 70 to 90°C temperature, and 0.2 to 2.2% sodium hydroxide on o.d. pulp. The models defi...

Two nonwood raw materials, Hibiscus cannabinus (kenaf) and Miscanthus sinensis (elephant grass), are analysed and compared with other papermaking species. With this purpose, their chemical compositions are compared with those to different raw materials. Subsequently, a microscopic study allows to identify the elements which form the vegetal structu...

The influence of pH on pulp properties was studied by the kinetic analysis of ozone bleaching of Eucalyptus Kraft pulp. The crystallinity of the pulps was also evaluated by XRD. The rate constants of delignification and chromophore removal decreased with the increase in pH, while the rate constant of cellulose degradation increased. The selectivity...

Mixed office waste has become a really important source of secondary fibre. The most interesting characteristic of this waste paper grade is the potential to produce excellent visual appearance papers because of their high brightness. However, the deinking of this paper grade is a rather difficult task. In this study, the effect of a novel cellulas...

Environmental pressure has led the pulp and paper industry to develop new technologies in order to reduce or suppress the presence of various pollutants in effluents from bleaching plants. One of the choices for this purpose is enzyme-based biotechnology. This study deals with the effect of using a xylanase-based enzymatic pretreatment, in a TCF (T...

The XOAZRP TCF sequence was applied to bleach wheat straw pulp. Following each bleaching stage, the properties of the pulp (viz. kappa number, standard viscosity, borohydride viscosity and brightness) and of the resulting effluents were determined. The performance of the reagents was analyzed through the studies of xylanase treatment and crystallin...

The reaction kinetics of ozone bleaching of wheat straw pulp has been studied for the first time. The results were compared with eucalyptus pulp in order to know that both raw materials have a similar behaviour. Ozone treatments were carried out in a special reactor at low consistency (0.5% o.d.p.). The main variables were consumption of ozone by t...

This study shows that oxalic acid is a very effective additive for the ozone treatments compared with other additives. The required concentration is very small and even lower than the concentration formed during the stage itself. Several different mechanisms for the action of oxalic acid as an additive during the ozone bleaching are examined. He is...

A device has been designed for off-line optical paper inspection and quality control of stripes and holes in the cigarette paper. Hardware description is first presented including main paper characteristics to be measured. Typical paper stripe and holes structures are then discussed with image processing and analysis considerations to discriminate...

The reaction kinetics of ozone bleaching of wheat straw pulp has been studied for the first time. The results were compared with eucalyptus pulp in order to know that both raw materials have a similar behaviour. Ozone treatments were carried out in a special reactor at low consistency (0.5% o.d.p.). The main variables were consumption of ozone by t...

Ozone appears to be an effective choice for developing new totally chlorine free (TCF) sequences. One of the goals of current research into the use of ozone as a pulp-bleaching agent is to increase the selectivity of the process. In this work, various reagents were used as additives in the ozone bleaching stage (Z) with a view to raising its select...

Various totally chlorine-free sequences with a Z stage (XOZP, XOAZP, XOZRP, and XOAZRP) were implemented with a view to examining the individual and combined effects of using an additive (A), consisting of oxalic acid and a post-treatment (R) based on sodium borohydride on the properties of the resulting pulp and effluents. The performance of the r...

Flax pulp obtained by anthraquinone-soda pulping, resulting in a kappa number of 11.1, a viscosity of 950 ml/g and 36.7 % ISO brightness, was bleached in a totally chlorine-free sequence using the enzyme laccase from the fungus Pycnoporus cinnabarinus and 1-hydroxybenzotriazole (HBT) as redox mediator (stage L), followed by a hydrogen peroxide stag...

Analysis of the sugars present in wood pulp using HPLC has been proposed as a method for ascertaining the changes occurring in polysaccharides (cellulose and xylans) during the bleaching process. Preliminary, adaptation and optimisation of the method to be used were required. Once the most suitable method was found, TCF and ECF pulps with and witho...

Ozone appears to be an effective bleaching agent for the TCF process. However, bleaching sequences involving a Z stage require optimisation to overcome low selectivity. In this work, various reagents were used in treatments preceding the ozone bleaching stage in order to increase its selectivity. Eight reagents were used under different conditions...

Environmental pressure has led the pulp and paper industry to develop new technologies with a view to reducing or suppressing the presence of various pollutants in effluents from bleaching plants. One of the choices for this purpose is enzyme-based biotechnology (particularly that using xylanases). This paper deals with the effect of using a xylana...

The effect of different Z stage post-treatments on the selectivity of bleaching processes using ozone has been studied. There are some contradictions in the literature as to the ideal post-treatment to increase the selectivity of ozone bleaching. The agents used as post-treatments in this study were formamidine sulfinic acid, sodium borohydride, so...

Enzymatic bleaching of flax alkaline pulp is intended here by using laccase-mediator systems (LMS) based on Pleurotus eryngii, Trametes versicolor and Pycnoporus cinnabarinus laccases and two mediators. The efficiency of the different LMS treatments was compared in terms of brightness, kappa number and viscosity modifications. Furthermore, changes...

The production of bleached cellulose pulps from elephant grass (Miscanthus sinensis) via a two-stage soda pulping process and a TCF bleaching sequence is evaluated in this work. The impregnation rapid steam pulping process (IRSP) involves impregnating of the lignocellulosic material with the pulping liquor, withdrawing the excess liquor and rapidly...

The effect of two different cellulases on the hornification phenomenon,in which drainability (Schopper–Riegler method) and mechanical propertiesdiminish when pulps are dried, was studied. The enzyme applications testedincluded a commercial enzyme named ComC (Pergalase A40 from CIBA) and alaboratory enzyme from Paenibacillus sp. strain BP-23namedCel...

The rising utilization Mixed Office Waste (MOW) as a source of secondry fiber makes necessary to develop news tecnologies to make this secondary fiber grade suitale for the manufacturee of higgh brightness printing paper. Deinking this kind of paper is necessary to achieve the required properties. But the deinking operation is as impotant as the pr...

The traditional paper surface characterisation methods, for example based on air-stream leakage (Bendtsen, Parker print surf), are facing severe limitations. These traditional methods are better suited as indicators of erroneous production than for grading paper samples with respect to his print quality potential. It has been acknowledged that this...

Formation is the measure of variations due to non-uniform fibre distribution in a sheet of paper. Paper formation is one of the most important properties of paper and is still difficult to measure. A method for determining this property has been developed. This method, based on light transmission image analysis, uses features of the power spectrum...

Ozone seems to be a good choice to develop new TCF bleaching sequences. One objective in the ozone application as a bleaching chemical of pulp is to increase the selectivity of the process. In this paper, different reagents have been applied as additive in Z-stage, to obtain a better selectivity. 16 reagents at different conditions have been employ...

The use of a novel “xylanase A” enzyme was found beneficial in the elemental chlorine free (ECF) bleaching of oxygen delignified Eucalyptus kraft pulps. The application of the enzyme made possible production of fully bleached pulps with high brightness (89% ISO) and viscosities (above 800 cm3/g), without elemental chlorine (XDnEpD and DnEpD sequenc...

The effects of xylanase on pulp properties and fibre morphology in a TCF (totally chlorine free) bleaching sequence has been studied. Enzymatic treatment is usually applied after oxygen delignification, but in this paper the effect of xylanase treatment before the oxygen delignification bleaching stage was studied. The application of xylanases in T...

The effect of oxalic acid on the reaction kinetics of ozone with a Eucalyptus globulus kraft pulp was studied. Xylanase treatment (X) and oxygen delignification (O) were carried out on the pulp before the kinetic study. Ozone treatment was carried out in a special batch reactor at low consistency (0.5% o.d.p.). The main variables were ozone consump...

Ozone seems to be a good choice in TCF bleaching. However, it is necessary to study the ozone bleaching optimization due to its poor selectivity. In this paper, different reagents have been applied as pretreatment before Z-stage, to obtain a better selectivity. 8 reagents at different conditions have been employed, therefore 24 pretreatments were c...

Ozone seems to be a good choice in TCF bleaching. However, it is necessary to study the ozone bleaching optimization due to its poor selectivity. In this paper, different reagents have been applied as pretreatment before Z-stage, to obtain a better selectivity. 8 reagents at different conditions have been employed, therefore 24 pretreatments were c...

The paper formation is one of the most important properties of the paper but remains a difficult property to determine. A method for determining this property has been developed. This method based on light transmission image analysis uses the power spectra of the Fourier transform to analyze the floc distribution. The method has been tested for var...

Paper formation is an important quality parameter, but it has been difficult to measure satisfactorily. A fast, convenient, quantitative measurement is important for automatic inspection of sheet formation. A new index of formation was developed using an image analysis method based on wavelet theory. It provides a multi-resolution analysis that is...

The paper begins with an introduction about the possibilities of utilization of enzymes in the pulp and paper industry. This paper is a presentation of a research carried out in the School of Engineers of Terrassa. It deals with stripping off colour in waste paper. The aim of the research is to obtain white papers with adequate optical characterist...

The use of xylanase in eucalypt kraft pulp bleaching improves bleachability in subsequent stages. Sequences ODPD and XODPD were compared. At the same final brightness of 88% ISO enzyme treatment pulp can save 34 % in chlorine dioxide or 47 % in hydrogen peroxide consumption. Other optical and physical properties are similar for both sequences. Enzy...

Environmental pressures are forcing the pulp and paper industry to develop new technologies that reduce or eliminate the presence of various contaminants in bleaching plant effluents. Oxygen delignification techniques, replacement of elemental chlorine with chlorine dioxide, ozone, hydrogen peroxide and new bleaching agents as well as the use of xy...

The use of xylanase in Eucaliptus kraft pulp bleaching improves bleachability in subsequent stages. Sequences ODPD and XODPD were compared. At the same final brightness of 88% ISO, the enzymatic treated pulp can save 40% in chlorine dioxide or 75% in hydrogen peroxide consumption. Other optical and physical properties are similar for both sequences...

Xylanase A from the recently isolated Bacillus sp. strain BP-23 was purified to homogeneity. The enzyme shows a molecular mass of 32 kDa and an isoelectric point of 9.3. Optimum temperature and pH for xylanase activity were 50 degrees C and 5.5 respectively. Xylanase A was completely inhibited by N-bromosuccinimide. The main products of birchwood x...

En este trabajo se ha llevado a cabo un estudio del destintado por flotación de una impresión flexográfica en blanco y negro. Las variables estudiadas fueron temperatura, pH y tipo de tensoactivo (no iónico y catiónico). Para realizar el estudio se diseñó un plan experimental factorial 2 3 , al que se le incluyó el tiempo de flotación a 4, 8 y 12 m...