Board Mills Research Articles

A multi-purpose tool for dynamic simulation of paper mills

A simulation environment for the dynamic simulation of paper or board mills has been developed. APMS (advanced paper mill simulator) provides tools for fast and easy modelling of the plant comprising e.g. stock preparation, approach system, wet end and dry end of the machine. The models are based on the first principles of physics and chemistry whenever it is possible. This mechanistic modelling principle with efficient equation solution techniques ensures fast and accurate simulation for the purposes of process and automation design, analysis and operator training.

Alternative Fiber Resources for Pulp and Paper Industry of Bangladesh: Why and What?

This study has evaluated the factors affecting the utilization of alternative fiber resources and efforts have also been made to outline the possible alternative fiber resources available in the country. Since 1989, paper consumption has exceeded production. Imports of industrial paper have increased and the future of newsprint export is dark. The government sector pulp and paper mills are highly dependent on forest based fiber resources and private sector paper and board mills depend on imported pulps. Uneven distribution of fiber resources has limited the raw material availability of the pulp and paper mills. Shortage of raw materials, irregular procurements, and low installed capacity are the main reasons for low paper production. On the other hand, paper demand will increase tremendously in the near future. But the present raw material availability is not sufficient to cope with the future demand for attaining self sufficiency in paper production. Therefore, immediate action is necessary for utilizing alternative fiber resources. Rangpur region has abundant lower grade jute. Jute cutting is available in Narayangonj area. Available bagasse supply is expected in the northwest regions after the end of this century. These resources are more than enough for supplementing the shortage of present raw materials during the 1997–2006 period.

In line biological water regeneration in a zero discharge recycle paper mill

The recycled paper group of KNP-BT operates in total 12 paper and board mills in Western Europe. All together the output of recycled product is 1.5 million tpy, of which approx. 50% is testliner and corrugated medium. The company has been a pioneer in process water closure for more than 20 years and several of its mills were already operating totally effluent free, long before the term “zero effluent” was invented. Some advantages of this way of operation are energy conservation and no charges for effluent discharge. Disadvantages are amongst others, accumulation of organic compounds, increased salt content, water hardness and volatile fatty acid build up. One of the fluting and testliner mills in the group is Zülpich Papier, which is currently going through an extension phase from 170.000 tpy to 340.000 tpy. This particular mill has been operated under complete effluent free circumstances almost 20 years. However, even though the new machine is to be put into operation in October 1996, a biological process water regeneration plant has been put on stream already in September 1995 in order to collect experience with the internal treatment and to have everything running smoothly by the time the new machine is started. The in line treatment consists of an anaerobic and an aerobic stage. During the first stage the dissolved organic components like carbohydrates and volatile fatty acids are converted into methane gas. At the same time, sulphate reducing bacteria convert sulphate into hydrogen sulphide, which is stripped out by the biogas. During the subsequent aerobic stage, residual organic components are oxidized into carbonate, which precipitates with calcium ions into the aerobic sludge and accumulates as calcium carbonate. These are a few examples of what is being achieved. Due to several favourable reactions in the biological stage, the process water quality has improved drastically for the following criteria: Odour, corrosion properties, salt content (conductivity), hardness, viscosity, COD-level and pH. Also components like stickies, waxes and colloidal material are presumably being degraded during the biological regeneration process. In the paper a description is given of the plant, as well as an overview of the main improvements of the process water quality during the first four months of in line biological treatment.

Experiences of wastewater treatment in Chilean forest industry

The present situation of water treatment facilities in the forest industry of Chile is briefly described. Some data of the Chilean pulp mill production and the present level of water pollution are shown. This paper is the result of five years of applied research conducted to study and evaluate liquid effluent treatment from pulp, paper and board mills. We describe laboratory results corresponding to three industrial mills that we have studied. The first case presented in this paper corresponds to a bleached Kraft pulp mill with a fiber line consisting in a MCC digester, a delignification unit and four steps in bleaching. In this mill the effluents are treated in an extended lagoon and the suspended solids are settled in a primary treatment. Lab scale lagoons were installed to developed start up strategies and to determine optimal operational efficiencies. The second case that we present is a paper mill, with primary treatment in an air flotation unit used for separating suspended solids. A technical economical analysis was necessary to burn solid sludge in order to improve energy balance. Finally, the third case we have studied corresponds to a hardboard mill effluent. In this case, high COD, mainly as colloidal solids, characterize this effluent. Laboratory experiences were made using a system of two sequential aerated lagoons.

Experiences of wastewater treatment in chilean forest industry

The present situation of water treatment facilities in the forest industry of Chile is briefly described. Some data of the Chilean pulp mill production and the present level of water pollution are shown. This paper is the result of five years of applied research conducted to study and evaluate liquid effluent treatment from pulp, paper and board mills. We describe laboratory results corresponding to three industrial mills that we have studied. The first case presented in this paper corresponds to a bleached Kraft pulp mill with a fiber line consisting in a MCC digester, a delignification- unit and four steps in bleaching. In this mill the effluents are treated in an extended lagoon and the suspended solids are settled in a primary treatment. Lab scale lagoons were installed to developed start up strategies and to determine optimal operational efficiencies. The second case that we present is a paper mill, with primary treatment in an air flotation unit used for separating suspended solids. A technical economical analysis was necessary to bum solid sludge in order to improve energy balance. Finally, the third case we have studied corresponds to a hardboard mill effluent. In this case, high COD, mainly as colloidal solids, characterize this effluent. Laboratory experiences were made using a system of two sequential aerated lagoons.

In line biological water regeneration in a zero discharge recycle paper mill

The recycled paper group of KNP-BT operates in total 12 paper and board mills in Western Europe. All together the output of recycled product is 1.5 million tpy, of which approx. 50% is testliner and corrugated medium. The company has been a pioneer in process water closure for more than 20 years and several of its mills were already operating totally effluent free, long before the term “zero effluent” was invented.Some advantages of this way of operation are energy conservation and no charges for effluent discharge. Disadvantages are amongst others, accumulation of organic compounds, increased salt content, water hardness and volatile fatty acid build up.One of the fluting and testliner mills in the group is Zulpich Papier, which is currently going through an extension phase from 170.000 tpy to 340.000 tpy. This particular mill has been operated under complete effluent free circumstances almost 20 years. However, even though the new machine is to be put into operation in October 1996, a biological process water regeneration plant has been put on stream already in September 1995 in order to collect experience with the internal treatment and to have everything running smoothly by the time the new machine is started.The in line treatment consists of an anaerobic and an aerobic stage. During the first stage the dissolved organic components like carbohydrates and volatile fatty acids are converted into methane gas. At the same time, sulphate reducing bacteria convert sulphate into hydrogen sulphide, which is stripped out by the biogas. During the subsequent aerobic stage, residual organic components are oxidized into carbonate, which precipitates with calcium ions into the aerobic sludge and accumulates as calcium carbonate. These are a few examples of what is being achieved. Due to several favourable reactions in the biological stage, the process water quality has improved drastically for the following criteria:Odour, corrosion properties, salt content (conductivity), hardness, viscosity, COD-level and pH. Also components like stickies, waxes and colloidal material are presumably being degraded during the biological regeneration process.In the paper a description is given of the plant, as well as an overview of the main improvements of the process water quality during the first four months of in line biological treatment.

Employment- and Wage-Consumption Ratios for Montana's Forest Products Manufacturers

Abstract This article presents information on employment and payroll generated per unit volume of timber or wood fiber processed by the various manufacturing sectors of Montana's forest products industry for 1987-1989. Average employment ranged from a high of 117 workers per million cubic feet (mmcf) of wood fiber processed at house log plants, to a low of 12 workers per mmcf at stud mills. Employment-consumption ratios for cedar products plants and producers of utility poles and posts and small poles were 48, 47, and 34 workers per mmcf respectively. At sawmills, employment-consumption ratios ranged from 23 workers per mmcf for board mills to 12 workers per mmcf for stud mills. Plywood plants are slightly more labor intensive than board mills, employing 26 workers per mmcf of wood fiber processed. The processing of mill residue from sawmills and plywood plants by such users as the pulp and paper industry adds substantially to the employment per unit volume of timber processed. Because different components of the industry often use timber of different sizes, species, and quality, changes in the kind of timber available can have considerable influence on the structure of the industry and related employment. West. J. Appl. For. 8(2):54-57.

Differentiation of dairy strains of the Bacillus cereus group by phage typing, minimum growth temperature, and fatty acid analysis

A total of 130 Bacillus strains were isolated from dairy products, the dairy environment and from packaging boards and board-producing machines. Ninety-eight of these were members of the B. cereus group (B. cereus, B. mycoides and B. thuringiensis) as determined by whole cell fatty acid composition. Fatty acid composition did not differentiate between the three species. Of the 98 strains, which were indistinguishable by biochemical tests, 87 could be assigned into 21 different phage types (11 strains remained untypable) when tested with 12 B. cereus, B. mycoides and B. thuringiensis phages. The distribution of phage types between strains from different sources showed that the source of contamination of the dairy products was of milk origin and not from the packaging materials. Most strains isolated from the dairy products were able to grow below 10 degrees C, whereas strains from the dairy environment and from board mills had higher minimum growth temperatures.

Evaluation of Purification Efficiency of Activated Sludge Treatment Plants for Pulp and Paper Industry Wastewaters in Finland

Since 1984, when the first activated sludge treatment plant (ASTP) was built to treat pulp and paper industry wastewaters in Finland, twenty more plants have been introduced by 1989. An evaluation was undertaken to find out the actual performance of the ASTPs in BOD7, CODc r and phosphorus removal. The evaluation included all the 12 ASTPs in operation in the pulp and paper industry at the beginning of 1987. The highest average BOD7 removals were about 90 % at pulp mills as well as paper and board mills. CODc r removal was generally higher at paper and board mills (about 40-70 %) than at pulp mills (about 25-55 %). Phosphorus was added to wastewater in most plants. In some ASTPs, phosphorus concentrations were lowered by 20-40 % compared with wastewater from the mill. In some plants phosphorus load on the recipient was higher than the load coming from the mill. In treated wastewater, correlations between suspended solids and BOD7, CODc r, phosphorus and nitrogen were significant in most plants. This indicated that low removal efficiencies resulted from poor suspended solids removal in the secondary clarification. Volumetric and sludge CODc r loading rates could not explain removal efficiencies when all plants were included in the comparison. In plants treating chemical pulping effluents, higher removal efficiencies were normally achieved with lower loading rates. When the plants were studied separately, the influence of loading rate was generally significant.

Enzymatic characterization ofBacilli from food packaging paper and board machines

Aerobic spore-forming bacteria were found dominant in the microflora of food packaging paper and board. Twenty-five strains of bacteria belonging to the genusBacillus were isolated from these paper and board machines, papermaking chemicals, and final products of papermaking. Nineteen strains were analyzed for production of α-amylase, α-glucosidase, glucoamylase, pullulanase, β-glucanase, carboxymethyl cellulase, and caseinase, and also for resistance towards industrial biocides. pH and temperature optima for the activity of the enzymes were determined. All strains were found to produce one or more of the enzymes studied. The amylolytic enzymes of most strains had high temperature optima for activity. Vegetative cells of all strains were found very resistant towards the different commercial slimicides used in paper and board mills. This property together with the ability to survive through the dry end of the machine to the final board and paper, and the production of enzymes degrading papermaking chemicals makes these bacteria potentially harmful in paper and board mills.

Use of Phage Typing and Fatty Acid Analysis for the Identification of Bacilli Isolated from Food Packaging Paper and Board Machines

Summary Fourty-eight Bacillus reference strains representing 17 different species and 22 Bacillus isolates from paper and board (carton) mills were characterized by phage sensitivity and whole cell fatty acid analysis. On the basis of phage sensitivity patterns obtained with 44 phages of 10 different Bacillus species, the strains could be divided into 27 different phage types. Whole cell fatty acid profiles allowed classification of strains into 20 different fatty acid biovars. These two approaches together allowed the identification of 19 out of the 22 paper and board mill isolates in agreement with results obtained by classical identification methods based on the biochemical and physiological properties.

A mortality study of Finnish pulp and paper workers.

Mortality among workers in the Finnish pulp and paper industry was evaluated in a retrospective cohort study of 3520 workers who had been employed continuously for at least one year between 1945 and 1961. Six subcohorts were formed according to six work areas: sulphite, sulphate, paper, and board mills, maintenance department, and power plant. National mortality rates were used for comparison. The mortality of a cohort of 1290 sawmill workers was also studied in order to have a socially, geographically, and occupationally similar group without the exposures typical of the pulp and paper industry for comparison. Smoking habits were surveyed. Mortality was followed up until 31 December 1981. Overall mortality for the entire cohort did not differ from that expected (1044 obs, 1029.4 exp, SMR 101), but there was an excess of deaths from diseases of the circulatory system among the men (489 obs, 404.9 exp, SMR 121). This was due to the excess of deaths from ischaemic heart disease found among the men at the sulphite, sulphate, and paper mills, maintenance department, and power plant, but not at the sawmill. The existing smoking data did not explain this finding and it may therefore be associated with occupational exposures.

Application of the UASB-Reactor for Anaerobic Treatment of Paper and Board Mill Effluent

Within the holding of Bührmann-Tetterode NV, 7 Dutch paper and board mills are operating, all of them using mainly waste paper as raw material. While three of them completely closed their watercircuits, two other mills put into practice biological waste water treatment namely anaerobic and anaerobic/aerobic. Number 6 is realising an anaerobic plant this year and for number 7 research is still being carried out, dealing with several unfavourable aspects. In September 1981 research for anaerobic treatment (UASB reactors) was started. After good results had been achieved on laboratory scale (301), further investigations were started on semitechnical scale (50 m3). In both cases the anaerobic seed sludge granulated after a while and loadings up to 20 kg COD/m3.d could be handled. COD-removal was 70 per cent, even when the hydraulic retention time was only 2.5 hours. In April 1983 a 70 m3 practical scale UASB reactor was started up at the solid board mill of Ceres. In October 1983 a full scale plant was started up at Papierfabriek Roermond. This plant consists of a 1,000 m3 UASB reactor and a 70 m3 gasholder. It has been designed and constructed by Paques BV and is used for pretreatment of effluent, in order to reduce the loading of the activated sludge plant. Besides energy savings on the oxygen input, about 1 million m3/year of biogas is being generated and is used for steamproduction. Both plants are working satisfactorily. Investment costs appeared to be relatively low. At Ceres, pay-out time is 1.5 year, while at Papierfabriek Roermond waste water treatment is cheaper than before, although capacity is doubled.

Wastewater Characteristics

Forceful measures have been taken in the past decade to reduce the pollution loads of pulp and paper mills. Besides more effective external waste water treatment, internal arrangements have been made to reduce pollution loads, e.g. by closing water systems. New processes and technically improved machines and equipment have made it possible to utilize raw materials and chemicals more efficiently. This has also reduced the pollution loads of the mills. In the 1970s, pollution loads were restricted by environmental laws and regulations in many countries, and the restrictions will become tighter during the 1980s. This will require much research and development. In this paper, characteristics of effluents (BOD, suspended solids, colour, TOC, COD, toxicity) discharged from chemical and mechanical pulping processes and from paper and board mills are presented in general terms and by mill department. Process developments and effects of these developments on pollution loads are described and future trends are discussed.

An investigation into the occurrence of sewage fungus in rivers containing papermill effluents—II. Chemical analysis of mill effluents

This is the second in a series of four articles describing research undertaken at PIRA during 1978–1980 on the causes and prevention of sewage fungus growth in rivers receiving paper and board mill effluents. This paper describes the sampling and analytical programme at three U.K. paper and board mills, the objective of which was to characterise the dissolved organic matter in final effluents and component wastewater streams. The analyses conducted were dissolved organic carbon (DOC), carbohydrate, glucose, gelatin, melamine, hydrolysed sugars and molecular weight distribution. The results are related to the raw materials and manufacturing processes used at each mill site.

Utilization of the white‐rot fungus Sporotrichum pulverulentum for water purification and protein production on mixed lignocellulosic wastewaters

AbstractA process has been developed that allows a direct conversion of lignocellulosic materials into fungal biomass. The thermotolerant white‐rot fungus Sporotichum pulverulentium has been used in continuous laboratory fermentations as well as in a 25 m3 batch fermentation. Fungal cell mass for feeding trials was produced and the economics of the process were estimated. The investigation shows that the process works satisfactorily on the small continuous scale as well as in the large batch culture. The process also seems easy to scale up. The economic evaluations show the conversion of solid lignocellulosic materials to protein feed is not feasible by our process unless the material to be fermented has a certain negative value. A mixed wastewater, such as the white water system in paper and fiber board mills, containing both water soluble mono‐ and oligosaccharides and solid lignocellulosic material, can, however, be fermented in an economically feasible way due to the combined effect of protein production and water purification. Data on the nutritional value of the product are presented in an accompanying paper.

Paper mill sludge production in the North‐West of England

Abstract The results of a questionnaire distributed to paper and board mills in the North‐West of England concerning the quantity of sludge produced and its current method of disposal are presented. The results of a laboratory investigation into the composition of sludges from five dissimilar mills in the area are also presented. The suitability of present disposal practices and the potential for resource recovery are discussed in the light of this data.

Pollution Abatement in Fiber Building Board Mills - 1974

Pollution Abatement in Fiber Building Board Mills - 1974

Dust Control in Board Mills

Dust Control in Board Mills

An end to slavishness? a note on Alli v. Okulaja

“At present, indeed, the Nigerian courts tend slavishly to follow any English decision”. This recent decision of the High Court of Lagos State, however, appears to be the first example of a judicial refusal to follow an English precedent, other than in cases involving the measure of damages, or interpretation of statutes similar to those in force in Nigeria, but not identical. BECKLEY, J., said of Edmeades v. Thomas Board Mills Ltd.: