Sulfate Pulp Research Articles

Researches on the Bleaching of NSSC Pulps With OP Sequences

In this study, to determine optimum bleaching conditions of NSSC pulps with OP sequences 15 oxygen prebleaching trials and 8 hydrogen peroxide bleaching trials were realized. As a result of statistical analysis of the data obtained, optimum oxygen and peroxide bleaching conditions of NSSC pulps were found as indicated below: Oxygen prebleaching; Reaction temperature: 110¼C Reaction time:20 min. NaOH charge:5% Consistency:12 % Magnesium sulfate:0.5 % Oxygen pressure:12 % Hydrogen prebleaching; Reaction temperature: 80¼C Reaction time:90 min. NaOH charge:4% Consistency:1.5 % Magnesium sulfate:10 % Oxygen pressure:1 % Brightness, breaking length, burst and tear index of NSSC pulps bleached with OP sequences were found 83.60%, 4.63%, 48,87% and 20.70% respectively higher than those of unbleached NSSC pulps. It is also possible bleaching NSSC pulps with OP sequences as high as 72 brighthess level. The content of colored and toxic organic material of OP bleaching sequences effluents is lower than those of chlorine based bleachings. The pulps bleached with OP sequences can be used in the production of printing and tissue papers in combination with sulphate and sulphite pulps. Additionally, these pulps may also be used in the production of newspaper.

Statistical properties of emission data in life cycle assessments

The objective of the present paper was to evaluate the statistical properties of emission factors as they are used in life cycle assessment (LCA) studies at present. A group of 26 sulphate pulp mills in Sweden has been used in the study, based on measured emissions to air and water in the period 1986–1993. The study showed large variations in annual emission factors within a group of companies. For most emissions to water, emission factors were independent of annual pulp production rates. Emission factors for an industrial branch can thus be used independent of the size of the plant in LCA studies. When comparing different types of statistical distributions for emission factors, the data set deviated significantly from all the tested distributions. Most emission factors tended to be best represented by a binomial distribution, indicating that emission factors should be square-root transformed before being used in statistical tests. However, not even a square-root transformation resulted in really normally distributed data sets for the emission factors from the pulp mills. The paper discusses several reasons for the large variation in emission factors. Strict regulations from authorities and development of environmental management systems seem to be most efficient in reducing emission factors and annual variations in emission factors.

Degradation of the Polysaccharides in the Woods of Two Provenances ofPinus contortaduring Kraft Pulping

Wood samples from two provenances of Pinus contorta, from plantations in North Scotland, were subjected to sulphate pulping with varying charges of chemicals. Studies were carried out to establish the relationship between the severity of the pulping conditions and the nature and quality of the pulps produced. The pulps were analysed for their main chemical constituents and the composition of their polysaccharides. The monomers in the polysaccharides were determined by gle analysis. All galactose, most of the arabinose and mannose, and about half of the xylose residues present in the woods were lost during sulphate digestion. It is concluded that polysaccharides known as arabinogalactans and others known as glucomannans and galactoglucomannans were almost completely removed. while arabino-(4-O-methyl)glucuronoxylans with a low degree of substitution were relatively resistant to removal. The cellulose losses ranged from 17 to 28%, depending on the charge of chemicals in the cooking liquors. Woods from trees of the inland form of P. contorta showed lower losses of cellulose (17-21% against 21-28% of the coastal form).

Surface area of papermaking woodpulps used by the British paper industry

The surface area was determined for various papermaking woodpulps: bleached eucalyptus globulus sulphate pulp; bleached eucalyptus grandis sulphate pulp; bleached betula verrucosa sulphate pulp; bleached pine/spruce sulphate pulp; bleached pine/spruce sulphate pulp fines. The method of negative adsorption was used which gives an effective ‘wet’ surface area. By looking at negative adsorption data more closely, some inference can be made about the morphology of the substrate.

High Intensity Drying of M.G. Paper

ABSTRACT The technological properties of paper are strongly influenced by the drying conditions. This is the case in particular with M.G. paper and machine performance is limited largely for quality reasons. Therefore, the question as to which extent the drying conditions influence the process of drying and the paper quality is of major importance for industry. Unlike the results already published, tests were carried out with a laboratory machine operating on a continuous basis, with high drying rates, short retention time and application of combined contact/ convectional drying. The kinds of stock used were waste paper containing wood, bleached long-fiber magnefite pulp and unbleached long-fiber sulphate pulp with a basis weight ranging between 37 and 75 g/m2.

The American Pulp and Paper Industry, 1900–1940: Mill Survival, Firm Structure, and Industry Relocation by Nancy K. Ohanian

870 Book Reviews TECHNOLOGYAND CULTURE The American Pulp and Paper Industry, 1900-1940: Mill Survival, Firm Structure, and Industry Relocation. By Nancy K. Ohanian. Westport, Conn.: Greenwood Press, 1993. Pp. xv+217; tables, notes, appendixes, bibliography, index. $49.95. In this book about the U.S. pulp and paper industry the focus is on the relocation of production that took place between 1900 and 1940. Around 1900 the industry was centered in the Northeast and the Great Lakes region. During the interwar years, the Pacific Coast and the South became the most important producers, with the southern pine and the Douglas fir and the softwoods on the Pacific Coast offering favorable conditions to pulp and papermaking. According to Nancy K. Ohanian, this relocation was among the most influential shifts of industrial production in the 20th century: “In fact, the extent of outmigration of the pulp and paper industry from the Northeast ranks second only to the widely studied exit of the cotton textile industry” (p. 1). The theme of the book ought, then, to be of interest to students of history of technology. The author has drawn information from the annual Lockwood’ s Directory ofthe Paper and Allied Trades, which provides information about each mill. Stating that this information enabled her to carry out unique research because individual mills are followed over time, she applied modern methods of economic analysis in dealing with the data. The book contains a multitude of tables and figures that describe the changes in industry structure. The analysis is concentrated on vertical integration and mill survival. But to what extent does this shed light on the reasons for the relocation? The pulp and paper industry is highly dependent on the location of raw material. As new technology made possible the use of new materials, location and the international division of labor changed accordingly. In her introduction, Ohanian states that the discovery of the sulfate pulping process in the early 20th century was responsible for the growth of production in the southern states (p. 6). She accounts here as well for the challenge from foreign competition, in particular sulfate pulps and newsprint from Canada and Sweden. Clearly, new technology and foreign competition were among the main reasons for the relocation of the industry in the United States. The models used provide us with data about patterns ofintegration in the industry, and the author finds that the larger the mill size and the greater the market concentration, the higher the probability of integra­ tion. She also finds that surviving mills consistendy were larger than failing mills (p. 148) and that there was generally a higher rate of net entry to the southern and Pacific regions. The findings are thus consistent with a technology-induced relocation. Although models used are appropriate to test economic assumptions about the behavior of firms, they focus litde on reasons why relocation took place. Historians of technology who seek information about factors relevant to the TECHNOLOGYAND CULTURE Book Reviews 871 adoption, adaption, and diffusion of new technology will find litde about these processes here. (However, an appendix addresses the technology of papermaking.) The author’s economic approach overlooks questions such as why American producers were comparatively late in starting the production ofsulfate pulp and kraft paper. In Scandinavia, the production ofsulfate pulp started in the 1880s and the production of kraft paper in the 1890s. In die United States, sulfate pulp did not get started until about 1910, according to Ohanian. In spite of its shortcomings as technological history, the book nonetheless contains accurate and detailed informa­ tion about industry structure during a crucial period in the history of the American pulp and paper industry. Eli Moen Ms. Moen is a research fellow in the History Department of the University of Oslo. She is the author of “Norway’s Entry into the Age of Paper,” in Technology Transfer and Scandinavian Industrialisation, ed. Kristine Bruland (Oxford, 1991). To Reclaim a Divided, West: Waler; Law, and Public Policy, 1848-1902. By DonaldJ. Pisani. Albuquerque: University of New Mexico Press, 1992. Pp. xx+487; illustrations, notes, bibliography, index. $40.00 (cloth); $19.95 (paper). In the past two decades, western water has become a highly active...

To Reclaim a Divided, West: Water; Law, and Public Policy, 1848–1902 by Donald J. Pisani

TECHNOLOGYAND CULTURE Book Reviews 871 adoption, adaption, and diffusion of new technology will find litde about these processes here. (However, an appendix addresses the technology of papermaking.) The author’s economic approach overlooks questions such as why American producers were comparatively late in starting the production ofsulfate pulp and kraft paper. In Scandinavia, the production ofsulfate pulp started in the 1880s and the production of kraft paper in the 1890s. In die United States, sulfate pulp did not get started until about 1910, according to Ohanian. In spite of its shortcomings as technological history, the book nonetheless contains accurate and detailed informa­ tion about industry structure during a crucial period in the history of the American pulp and paper industry. Eli Moen Ms. Moen is a research fellow in the History Department of the University of Oslo. She is the author of “Norway’s Entry into the Age of Paper,” in Technology Transfer and Scandinavian Industrialisation, ed. Kristine Bruland (Oxford, 1991). To Reclaim a Divided, West: Waler; Law, and Public Policy, 1848-1902. By DonaldJ. Pisani. Albuquerque: University of New Mexico Press, 1992. Pp. xx+487; illustrations, notes, bibliography, index. $40.00 (cloth); $19.95 (paper). In the past two decades, western water has become a highly active subject ofAmerican historical inquiry. A host of scholars have used this topic as a point of departure to set a great deal of the agenda for environmental studies and to pose fresh perspectives on the transMississippi West. Since the control, use, and allocation of water were central to western settlement, this focus is both appropriate and laudatory. From this gush of literature have come new insights into the social and institutional process ofhuman habitation and the interplay of politics, culture, values, and technology in making the arid region “blossom as the rose.” To Reclaim a Divided West is both monumental and provocative in its approach, assumptions, and findings. What emerges from Donald Pisani’s prodigious labors and trenchant analysis is a view of western water from the ground up, rather than the top down—a fragmented, complex mosaic rather than the more symmetrical waterscapes fash­ ioned byJohn Ganoe, Stanley Roland Davison, Samuel P. Hays, Donald Worster, and others. Certainly no other scholar has looked at this subject with more depth, care, and thoughtfulness from the standpoint of law, economics, and government. The book passes through well-known themes and eras including the evolution of water law, the private and corporate allocation of water, the trials of various state irrigation ventures, struggles to define the appropriate federal role, and the movement that culminated in the 1902 Reclamation Act. 872 Book Reviews TECHNOLOGY AND CULTURE The portrait that emerges is rich in chaos and conflict. Pisani seems to have few impressionistic visions to flesh out, victims to lament, or ideological axes to grind. What he lays out is a mix of personalities, institutions, policies, desires, and expectations that varied intraregionally from community to community, state to state, and basin to basin. The book is meticulous, traditional natural-resource history in the tradition of Paul Wallace Gates, to whom the author pays homage in his acknowledgments (p. xx). The underlying theme is fragmentation. The author upholds this leitmotiv by postulating that the social and economic dynamics of western mercantilism fostered a region ablaze with conflict at all levels of government rather than consensus. Furthermore, there seems to have been no orderly transition from chaos, provincialism, and inefficiency to the more centralized, rational promise of the 1902 Reclamation Act. In fact, Pisani argues that in this watermark fed­ eral law “the decentralizers won a signal victory in 1902, one destined to have a profound influence on water policy in the twentieth cen­ tury” (p. 325). The book departs sharply from much of the current scholarship on western water by downplaying the importance of geography and aridity. Even though this assumption is more implied than stated, Pisani’s West is shaped much more by traditional American values, culture, institu­ tions, and economic realities than its setting and environment. Perhaps this course correction will be a helpful tonic to current scholarly directions that place too little or a distorted emphasis on the political economy of the region. To...

Testing of the cytotoxic effects of sulfate pulp mill waste waters.

The effect of 22 technological waste water samples and of some standards was tested on bacteria, fungi, chlorococcal algae, flagellata, plant cells, cells of Tubifex tubifex, hamster cells V79 and the fish Lebistes reticulatus. Of these 22 samples, some inhibition of cell life processes was displayed by the black liquor formed in the production of paper pulp and viscose pulp, by the waste solution produced during the preparation of bleaching agents for paper pulp and viscose pulp, and by the residual liquor after hypochlorite treatment of paper pulp.

Xylanases in bleaching: From an idea to the industry

The utilization of hemicellulases in bleaching of kraft (sulphate) pulp is considered as one of the most important new large-scale industrial applications of enzymes. This is partly due to the great potential of an environmentally safe method. This method has in a short period also proven to be economically realistic. The main enzymes needed in the enzyme-aided bleaching have been shown to belong to the group of endo-/gb-xylanases. Xylanases act mainly on the relocated, reprecipitated xylan on the surface of the pulp fibres. Enzymatic hydrolysis of this specific type of xylan renders the structure of the fibres more permeable. The hydrolysis of xylan or mannan in the inner fibre layers may also enhance the bleachability. In practical process conditions, properties of the enzymes such as substrate specificity and the pH and temperature optima are of utmost importance. The benefits obtained by enzymes are dependent on the chemical bleaching sequence used as well as on the residual lignin content of pulp. The main goals in the enzyme-aided bleaching of kraft pulps have been the reduction of consumption of chlorine chemicals in the bleaching process and consequently lowering the AOX of the effluents. Enzymes have been applied as a pretreatment both in conventional (C/D)EDED and in ECF (elementary chlorine-free) bleaching sequences. In the production of TCF (totally chlorine-free) pulps, enzymes have also been successfully used for increasing the brightness of pulp.

Kinetic Models for Describing Degradation of AOX in the Waste Water of a Mill Producing Bleached Sulphate Pulp

In the study, submodels for describing degradation of organic chlorine (measured as AOX) coming from a mill producing bleached sulphate pulp were developed. The submodels coupled to a hydrodynamic model can then be used in assessing the behaviour of AOX in receiving waters. The data used in developing the models was based on mesocosm-scale experiments carried out in two lakes. Waste waters of two mills were used at two dilutions (2% and 10%). Part of the mesocosms were darkened in order to study the effect of light on degradation. In the first phase of the modelling first-order kinetics with a constant coefficient were used. The next steps were to include the effect of temperature and light in the model. Including temperature and light did not much contribute to the modelling results. It was found that more than half of the degradation was caused by the light-dependent component of the degradation reaction. The reaction obeys first order kinetics satisfactorily. However, the reaction coefficient is greater in the beginning of the experiment than later. A correction function describing the decrease of the reaction coefficient was included in the model. The correction function is based on the idea that the most readily decaying components of AOX disappear from the solution in the beginning and therefore the apparent reaction coefficient decreases. Only data on AOX was available in this study but the approach can be applied for different chloro- organic compounds and also for other organic substances.

Experimental Study on the Control of Nutrients in Activated Sludge Treatment

Laboratory experiments were conducted to determine the need for addition of phosphorus during the treatment of pulp and paper mill waste waters by the activated sludge method. The study also included the testing of different modifications of the activated sludge method (a completely mixed, three completely mixed reactors in series, anaerobic/aerobic) to see how different forms of phosphorus and nitrogen (total-N, NH+4 - N, NO-2 - N, NO-3 - N) are present in the influent and effluent. The tests were conducted using waste water from two newsprint/magazine paper mills and from a bleached sulphate pulp mill. Different loadings and levels of phosphorus addition were applied. When paper mill waste water was treated at normal loading (sludge load was c. 0.3 kgBOD/(kgMLVSS*d)), a small phosphorus addition was needed to secure efficient operation. The optimum BOD:P ratio was about 100:0.4, in which case the treated effluent had a total phosphorus content of c. 0.5 mg/l (about 70% reduction), a soluble phosphorus content of c. 0.3 mg/l and a phosphate phosphorus content of well below 0.1 mg/l. Larger phosphorus additions produced no further improvement in treatment results (BOD reduction c. 90% and COD c. 75%). Doubling the loading gave poorer results and the situation could not be rectified by adding phosphorus. Addition of phosphorus was not needed when treating pulp mill waste water, as has also been found when running activated sludge treatment plants at several mills. The BOD reduction (c. 95%) was excellent under all conditions. The COD reduction was 30-55%, AOX 30-35% and chlorophenols 90-95%. The total phosphorus content of the treated effluent was 0.3-0.7 mg/l when no phosphorus was added. This treatment also resulted in extremely low phosphate phosphorus levels. The biosludge contained 0.5-1.9% phosphorus, 0.5-0.8% when pulp mill waste waters were treated and occasionally around 2% for the paper mill. The experiments showed that it might be possible to operate the pulp mill treatment plant with even less phosphorus in relation to BOD compared with the BOD level of waste waters to which no phosphorus has been added. The mill could consider removing the excess phosphorus originating from lime mud neutralization before the waste water arrives at the treatment plant. In treating both these waste waters there is the risk of really high phosphorus discharges if care is not taken with the phosphorus addition. A typical situation of this type arises if the plant is run on the old "textbook rule" of BOD:P=100:1. The nitrogen was added as urea resulting in the BOD:N ratio of 100:(2.5-4.5). Total-N in the paper mill untreated waste water was in the range of 8.5-13 mg/l and in the effluent 2.5 - 5.0 mg/l, i.e. the removal was 55-75%. NH+4 - N in the influent was in the range of 1.5-3.0 mg/l and was totally removed in most of the runs. The concentration of (NO-2 - N + NO-3 - N) was only 40-50 µg/l, the removal was 0-85 % depending on the conditions. The activated sludge modification "three completely mixed reactors in series" yielded the best results when all parameters were taken into account.

Application of the cell growth and DNA-inhibition tests for characterizing sulfate pulp mill waste waters.

The evaluation of cytotoxic and genotoxic effects of selected technological samples from sulfate pulp mill waste waters by using the growing activity method for pseudodiploid fibroblasts V79 from lungs of the Chinese hamster and from human heteroploid fibroblasts EUE has been described along with the DNA-inhibition test for studying the synthesis of DNA after it has been influenced by the above-mentioned samples. Both the waste solution produced during the preparation of bleaching agents and the liquor generated after using hypochlorite (1st stage) as a fourth filter (after the production of paper pulp) are cytotoxic waste waters. Black liquor generated during the production of viscose pulp may have mutagenic effects and black liquor obtained from the production of paper pulp is characterized by mutagenic as well as carcinogenic effects.

Adsorption Characteristics of a Biotreated Pulp Mill Effluent

Spent bleaching effluents from the chlorination and extraction steps of a sulfate pulp mill were subjected to activated carbon treatment to investigate the elimination of nonbiodegradable matter. For this purpose the biotreated waste water containing mainly nonbiodegradable matter was treated with different activated carbon types. The elimination degree of nonbiodegradable matter was determined and adsorption isotherms were generated in terms of the parameters COD, DOC, Color436 and UV254. The removal level was over 90% when the carbon dosage exceeded 10 000 mg/l. AOX compounds could be eliminated over 90%. The isotherms could be expressed by the Freundlich equation. It was shown that the shape of the isotherms was strongly dependent on the carbon dosage employed. According to carbon dosage three different adsorption regions were distinguished and for each region the corresponding Freundlich constants K and n were determined. Carbon addition led to a change in the composition of wastewater as shown by decreasing COD/DOC, UV254/DOC and Color436/DOC ratios. Further it was shown that the relatively fast color and UV analyses were accurate enough to characterize the adsorptivity.

Effect of the presence of lignin on the structure and reactivity to hydrolysis of lignincarbohydrate complexes of poplar wood obtained by sulfate pulping

Lignincarbohydrate complexes (LCC) of poplar wood obtained by sulfate pulping and containing lignin in amounts of 0.9–8.3% have been studied by X-ray diffractometry. Heterogeneous hydrolysis methods have been used to determine their reactivity. The content of the crystalline fraction in LCC depends on the lignin removal and increases with the decrease of the lignin content. The degree of crystallinity of cellulose in sawdust and in LCC is fairly high and changes slightly with the lignin removal. The presence of lignin plays a blocking role in the heterogeneous hydrolysis and decreases the rate constant. It is suggested that lignin is bonded to cellulose on the outer surfaces of the crystalline part of the cellulose fibril. Some possible variants of these bonds are discussed.

Trichloroacetic acid in pine needles in the vicinity of a pulp mill

Trichloroacetic acid (TCA) concentrations in Scots pine needles in the vicinity of a sulphate pulp mill, urban and rural areas were studied. TCA was analyzed by GC/NCI-MS/SIR -method as its methyl ester. TCA levels were 2–50 and 5–135 ng g −1 in the first-year and third-year needles, respectively. No differences with TCA concentrations between the study areas were observed. However, low values under the most common plume direction from the pulp mill, as well as the low average TCA concentration in the vicinity of the mill area suggest that reactions with the pulp mill emissions may inhibit TCA formation.

Ind

the study is aimed to find the isolation techniques and properties al lignin component of black Liquors from pulp industry. The samples were taken from Basuki Rahmat pulp industry, namely black liquor of sulfate pulping from evaporator (with pH 13. 52) and from digester (pH 10.58), and from Basuki Teguh, namely neutral sulfite semi chemical pulping (pH 6.85). The isolation was conducted by using two kinds of acid i.e. sulphuric acid 2 N and chloric 2 N each at pH 3. and pH 5. The result revealed that the yield and quality of lignin isolated at pH 2 was higher than other pH levels. At this pH level, the lignin produced from sulfate pulping black liquor of exporator was 21.04%, and from digester was 7.47 %, and of neutral sulfide semi chemical pulping was 0.57%. the lignin properties of each black liquor were as the following : pure lignin content was 70.41 %, 72. 55 % and 68. 29 % , respectively ; methoxyl content was 5. 62 %, 11.17 % and 8. 95 % respectively, and particle surface area was 33.87 m3/g, 29.81 m2/g and 28.03 m2/g, respectively, Different from other lignin properties, highest acidity and water absorption capacity of lignin was produced by one which was isolated by chloric acid at pH level 5. the water absorption capacity and lignin acidity of sulfate pulping black liquor of evaporator was 122.45% and pH 6; and of digester was 119. 17 % and pH 6.03; and of neutral sulfide semi chemical pulping was 116.60 % and pH 5.53.

Pulp and paper from certain fast-growing plant species

Abstract Three species of fast-growing plants, Gmelina arborea, Callicarpa arborea and Ficus fistulosa, were evaluated for their pulp- and paper-making properties. Data on proximate chemical analyses of raw material, unbleached and bleached pulp yields, fibre dimensions and physical-strength properties of paper sheets were obtained. The unbleached pulp yields were 47.8–51.2% with Sulphate pulping, while with Soda-anthraquinone pulping the yields were 48.0–51.7%. The average fibre lengths and diameters of the unbleached pulps were within the ranges 0.80–0.96 mm and 14–22 μm respectively. Laboratory hand-made paper sheets with adequate strength properties were obtained.

コロナ放電処理によるセルロース繊維シート物性の変化

Whatman # 1 filter paper, handsheet from softwood bleached sulfate pulp (abbreviated as NBKP hereafter), handsheet from thermomechanical pulp (abbreviated as TMP hereafter) and regenerated cellulose film were treated with 401 watts/m2 of corona discharge for the duration of 0 to 180 min. Some changes were examined in the SEM images of the cellulose fibre sheets, in the sheet strength and in the sheet porosity by the increase in the duration of the corona treatment. The following results were obtained.(1) The SEM images changed with the Whatman # 1 filter paper, the handsheet from NBKP and the handsheet from TMP. That is, perforation or boring occurred in the case of the higher duration of 30 min. and 60 min. But, no changes occured with the regenerated cellulose film, as the duration of the corona treatment increased.(2) The tensile index and Young's modulus of the fibre sheets decreased gradually but significantly with the increase in duration of the corona discharge treatment. At that time, the zero span tensile strength also decreased slightly. The tensile index and tensile modulus decreased also in the case of regenerated cellulose film with the increase in the duration.(3) As the duration of corona treatment increased, the cellulose fibre sheets became more permeable. The porosity and mean pore radius obtained by the mercury intrusion method also increased with the increase in the duration. However, no changes occured in permeability with the regenerated cellulose film, even in the duration of 180 min.From the above-described facts, the corona-induced defects is considered to partly bring about the decrease in the cellulose fibre sheet strength.Another mechanism should be considered further from the fact that the tensile strength and the tensile modulus decreased with the increase in the duration for the regenerated cellulose film. A certain fraction of the more microscopical framework which resists against an external force, must be degradated by the oxidation processes. Both mechanism are proposed to affect the reduction in cellulose sheet strength by the corona treatment for a long duration. At the present state, the importance of the two mechanisms cannot be estimated for the reduction in the sheet strength.

Analysis of the Functional Groups Formed on the Corona-Treated Cellulose Fibre Sheet Surface by Means of Chemical Modification in Gas Phase-ESCA Technique.

The surfaces of corona-treated cellulose fibre sheets were characterized by a chemical modification in gas phase-ESCA technique. Whatman #1 filter paper, handsheets from softwood bleached sulfate pulp (N•BKP), handsheets from hardwood bleached sulfate pulp (L•BKP) and handsheets from thermomechanical pulp (TMP) were prepared as cellulose fibre sheet samples. The following results were obtained. (1) Corona-treated cellulose fibre sheets were chemically modified (derivatized) in gas phase by pentafluorophenylhydrazine (PFPH) or trifluoroethanol (TFE), and ESCA spectra of the derivatized sheets were examined. The results show that carbonyl and carboxyl groups were formed on the surface of the cellulose fibre sheets. (2) The quantity of the introduced carbonyl and carboxyl groups, which were obtained by derivatization in gas phase, was larger than those obtained by derivatization in liquid phase. Furthermore, the quantities of the functional groups formed on the surface of the sheets by derivatization in gas phase after washing with some organic solvents and those by washing with organic solvents after derivatization were found to be less than those derivatizing only in gas phase. These results suggest that carbonyl and carboxyl groups were introduced onto the framework or main chain in the surface layer of the sheets. At that time, depolymerization occurs in the framework and the resulting fragmental low molecular compounds have carbonyl and carboxyl groups. (3) The total concentration of the carbonyl and carboxyl groups in the ethanol extracts from the corona-treated sheet were determined by oxime formation and hydroxamic acid-Fe chelate complex formation method, respectively. The increase of 0.98% in the carboxyl group for Whatman #1 filter paper and that of 0.58% for TMP handsheet were found, compared with those of untreated sheets. The increase of 0.02% in the carboxyl group for the Whatman #1 filter paper and that of 0.04% for the TMP handsheet were also found. These results indicate that the low molecular compounds were formed by corona discharge and the compounds possess carbonyl or carboxyl groups.

Pulping innovations in Germany

The dynamic growth in world paper demand in conjunction with ever-increasing environmental restrictions is responsible for recent pulping innovations. Although sulfate pulping will maintain its dominant position, alternative, environmentally-compatible pulping processes will appear on the industrial scene in the next two decades. This is true for West Germany, in particular, where the pulp industry has always been based exclusively on sulfite pulping. Leading this development is the Organocell process which is to be implemented on an industrial scale in 1992. Other processes (ASAM, Acetosolv) will follow and generally accept a broad raw material basis, including annual plant fibres. The suitability for pulping of the latter was proved experimentally, especially for ASAM pulping. The potential contribution of agricultural residues (e.g. straw), fast-growing plantation species (e.g. poplar and eucalypts) or China grass, often called Elephant grass or Giant grass ( Miscanthus sinensis ‘Giganteus’), to the raw material basis of the pulp and paper industry of the future appears to be rather more dependent on political, economic and competitive import conditions.