Статті в журналах з теми "Pulp mills Cleaning Australia"

We describe an approach to environmental monitoring that has been developed to deal with future pulp mills in Australia. We propose decision criteria that balance the chance of missing impacts and the chance of falsely accusing a proponent of environmental damage. Rather than focusing on either Type I or Type II statistical errors, we fix the ratio of the two error rates according to perceived costs of making each error. As monitoring is scaled up or down, risks of both errors rise and fall proportionately, in contrast to more traditional approaches, in which one error rate is fixed. We describe the steps necessary to implement a monitoring program using these criteria. Our emphasis is on guidelines that allow the flexibility to deal with monitoring a range of point source discharges in coastal environments that vary widely.

This paper analyzes how a key conflict in Australia's pulp and paper industry became generalized to other sites through environmental action, government regulation, and industry initiative. From 1987–91, Australians debated construction of a new, world-class, export-oriented pulp mill in Tasmania. Rural residents, fishermen, and environmentalists, allied with the Australian Labor Party, succeeded in scuttling the project. Subsequently, the national government launched a major research program, state governments tightened regulations, and industry reduced elemental chlorine use. Any new mills constructed in Australia today would be among the cleanest in the world. This paper is part of a larger, comparative study of technological innovation in the pulp and paper industries of Australia, Indonesia, Malaysia, and Thailand. The author interviewed industry officials, government regulators, research scientists, and environmentalists; visited pulp and paper mills; attended technical conferences; and conducted archival work in these countries during a 12-month period.

Research Highlights: As to fill the current knowledge gap and to deliver important findings to the scientific community, efficient sulfur recovery from black liquor gasifier syngas, comprising both gas cleaning and returning sulfur to the pulping process, was modeled and assessed from a techno-economic viewpoint. This manuscript proves that the associated investment and operational costs cannot be neglected and that they impact the black liquor gasification feasibility significantly. To prove its gasification as a sustainable and more efficient processing route over its combustion in recovery boilers, a substantial process efficiency improvement and operating costs reduction must be targeted in future research. Background and Objectives: Sulfur compounds found in black liquor partly turn into hydrogen sulfide during gasification and exit the gasifier in the syngas. Their efficient recovery in their sulfidic form to the pulping process is of utmost importance. Current studies focus on black liquor gasifier syngas desulfurization only. Materials and Methods: A mathematical model of two H2S absorption units from a 66.7 tDS/h (1600 tons dry solids per day) black liquor gasification process to 20 ppm H2S content in cleaned syngas using either white liquor plus NaOH or N-methyldiethanolamine (MDEA) was created using the Aspen Plus simulation software. Results: The results show that CO2 co-absorption significantly increases the lime kiln load: +20% in the MDEA alternative and +100% in the other one. The MDEA alternative requires almost the same investment costs but by around USD 9.7 million (>50%) lower annual operating costs compared to the other one. Economic evaluation was based on the assumed discount rate of 5% and on the expected plant operation time of 25 years. The estimated total investment cost of the whole plant is around USD 170 million for both alternatives. The whole plant including this alternative exhibits a positive net present value (over USD 19 million), an internal rate of return of 5% and a profitability index of 1.12, whereas that with the other alternative is economically infeasible. Conclusions: The MDEA-based syngas cleaning technology represents a more efficient and economically feasible option of sulfur recovery. A major drawback of both modeled syngas cleaning technologies is that their estimated annual operating costs significantly reduce the expected profit margin of gasification over the traditional black liquor combustion in a recovery boiler. Syngas cleaning and sulfur recovery have to be further optimized to reach a significant cut down in operational costs to improve the economic feasibility of black liquor gasification.

Abstract A large-scale study on bisphenol A (BPA) contamination in Canadian municipal and industrial wastewater and sludge has been completed. A total of about 200 samples were collected, including those from 31 sewage treatment plants and 15 pulp and paper mills across Canada, as well as 13 industrial facilities in the Toronto area. The samples were extracted by previously developed solid-phase and supercritical carbon dioxide extraction procedures and were analyzed by gas chromatography-mass spectrometry. BPA contamination was detected in all of the 72 sewage samples, with concentrations ranging from 0.080 to 4.98 µg/L (median 0.329 µg/L) for the influent, and from 0.010 to 1.08 µg/L (median 0.136 µg/L) for the effluent. Of the 36 influent/effluent sample pairs studied, BPA in the influent is removed by the sewage treatment process at a median reduction rate of 68%. Levels of BPA accumulation in sewage sludge, for the 50 samples tested, ranged from 0.033 to 36.7 µg/g, on a dry weight basis. A wide range of BPA concentrations, from 0.23 to 149.2 µg/L, were observed for the wastewater collected from selected industrial facilities in the Toronto area. The more contaminated samples came from the sectors of chemicals and chemical products, commercial dry cleaning, as well as packaging and paper products. Based on these data, on-site releases of BPA by industrial facilities seem to be much more widespread than the National Pollutant Release Inventory (NPRI) database has suggested. While relatively high levels of BPA were found in some of the primary treated effluent collected from the deinking mills, BPA concentrations in the secondary treated effluent of all pulp and paper mills were low, with a range from < 0.005 to 0.0406 µg/L. Except for the samples derived from a few deinking mills, BPA contaminication in pulp and paper mill sludge was either low or undetected.

Scale formation in the digester during kraft pulping represents a great problem in pulp mills. Scaling reduces pulping control and efficiency, increasing energy costs and leading to cleaning breakdowns, with subsequent losses in productivity. The kraft process promotes CaCO3 scaling due to high calcium ion and carbonate concentrations, as well as high alkalinity and temperature levels, which increase the speed with which liquors reach a state of supersaturation. This work examines the action of diethylene triamine penta(methylene phosphonic acid) (DTPMPA), either alone or combined with commercial anti-scaling agents, as an inhibitor of calcium carbonate precipitation in the kraft pulping of Pinus taeda. The theoretical amount of calcium deposited in the digester was obtained by mass balance. Soluble calcium was stable throughout cooking when using the phosphonates alone or combined with anti-scaling agents. When adding only DTPMPA, calcium stays in the pulp, rather than forming deposits.

Environmental Impact Assessment (EIA) is presented as a specialised tool for project management. Environmental assessment in different phases of the project cycle is discussed. Different approaches to the EIA process in some countries are briefly reviewed, and especially the possibilities for public participation are discussed. A number of examples of EIA in Australia, Canada, France, Germany and Spain are characterised and compared. The comparison includes four kraft pulp mills and one paper mill, and the main features of each EIA are presented.

A number of functions were investigated that related the costs of thermomechanical pulp (TMP) and high-brightness newsprint production, using Pinus radiata D. Don, to important pulp and paper quality (breeding objective) variables, including specific energy consumption and pulp handsheet tear and tensile strength, brightness, and opacity. Pulp handsheet quality traits were considered to be reasonable two-dimensional predictors of paper quality traits in this context. A specific production process that requires the use of a reinforcement kraft pulp and an artificial clay filler to improve the quality of paper produced from the bleached TMP fibres was investigated, similar to the production process used by Australian Newspaper Mills' Boyer Mill in Tasmania, Australia. Pulp and pulp handsheet quality variables could be explained by significant (P > 0.05) wood traits using multiple linear regression equations. This provided a method to predict the economic importance of each wood trait in relation to the thermomechanical production process investigated. The results showed that tracheid length, wood density, wood brightness, and tracheid coarseness were the best predictors of costs. Increases in tracheid length, wood density, and wood brightness and decreases in tracheid coarseness resulted in decreasing the total costs of TMP and high-brightness newsprint production.

The Australasian wood processing industry is poised for a substantial expansion over the next twenty years. Australia, which is presently an importer, is developing plans to become a net exporter of forest products,while New Zealand's wood supply is expected to double over this period. In both countries, the expansion of processing capacity will be required to occur in a sustainable and environmentally sound manner. For example, the Australian Federal government has developed environmental guidelines for new bleached Eucalyptus kraft pulp mills,while the New Zealand government is presently enacting a comprehensive Resource Management Act. The implications of these developments for the Australasian wood processing industry is discussed.

This article examines the Australian Pulp and Paper Mills Ltd. (APPM) dispute which took place in Burnie, Tasmania between March 3 and June 10, 1992. The dispute is placed within the context of major changes in Australian industrial relations, which have been in process since 1986. Management and unions throughout Australia are still experimenting with a variety of industrial weapons to achieve their aims and goals within the parameters of the “Structural Efficiency Principle” and “enterprise bargaining”, constructed in Accords III through VI, from 1986 to the present. It is argued that the crucial change during the past six years has been the ability of companies to re-establish managerial prerogative through litigation. This has provided management with the power to confront secondary issues and agents of change such as the Accord, the Australian Industrial Relations Commission, Structural Efficiency, Enterprise Bargaining and Restructuring with a new vigour, toughness and effectuality. Increasingly docile, debilitated and legally disabled union officials and workers seem to be coming to the view that a union victory occurs if the company agrees to abide by the law while directing its workforce, and recognises the workers' right to be represented by a “third party”.

Paper mills generate large quantities of wastewater and sludge waste depending on the type of paper making processes employed. This poses several problems regarding wastewater treatment, discharge, and sludge disposal. Whenever wastewater is generated, it should be treated in wastewater treatment plants prior to being released to the environment since it can be polluting and dangerous. A study was conducted at Star Paper Mills Ltd. Saharanpur, UP to demonstrate the existing and advanced technologies for wastewater treatment. The mill uses woody raw materials such as eucalyptus, poplar, and veener chips to manufacture a wide range of industrial and cultural grade papers, such as absorbent kraft, maplitho, azure lay, and copier. We observed that the most common excess back water is from paper machines, bleach plant effluent, floor cleaning, and other sources of wastewater. High chemical oxygen demand (COD), biochemical oxygen demand (BOD), and low biodegradability are all characteristics of pulp and paper wastewater. Approximately 85–90% of the fresh water utilized is wasted. We examined the wastewater collected and evaluated from the paper mill by Central Pulp and Paper Research Institute (CPPRI). The Effluent treatment plant (ETP) at Star Paper Mills Ltd. is sufficient to facilitate satisfactory removal of suspended matter in clarifiers and oxidation of biodegradable organic matter in aeration tank. As a matter of fact, if the ETP is operated under optimal conditions, the aeration capacity is sufficient to effectively treat even higher BOD loads than the existing load.

AbstractThe pulp and paper industry represents an industry sector which is characterised by its already high degree of sustainability. Biomass is a renewable input material, and typically highly developed recovery cycles minimise the loss of chemicals used in the pulping process. However, certain parts of the recovery cycle are still operated on fossil fuels. This study deals with the substitution of the fossil-based gaseous fuel with product gas from biomass gasification.Gasification experiments have shown that bark available at pulp and paper mills is suitable to produce a product gas via dual fluidised bed steam gasification as a promising substitute for natural gas. Based on the comparison of process layouts regarding the separation of non-process elements, separation efficiency is derived for different setups. To ensure operational security of the chemical recovery cycle, comprehensive gas cleaning including heat exchangers, a particle filter, and a liquid scrubber unit is advised. The gas flow of fuel gas into the gas burner is increased as the heating value of the product gas is accordingly lower in comparison to natural gas. Furthermore, adaptions of the gas burner might be necessary to address the earlier ignition of the H2-rich product gas compared to natural gas.

Цель исследования – разработка алгоритма расчета технологических показателей отдельно по видам выпускаемой продукции для интегрированного целлюлозно-бумажного комбината при сбросе сточных вод после очистки сточных вод на единых очистных сооружениях промышленных стоков. Использован балансовый метод расчёта значений масс загрязняющих веществ, образующихся на тонну выпускаемой продукции ЦБК на основе масс загрязняющих веществ, образующихся во вспомогательных технологических процессах, с учетом очистки сточных вод на общепроизводственных очистных сооружениях. Технологические показатели установлены отдельно для продукции, нормируемой по беленой или небеленой целлюлозе. Если фактические значения технологических показателей превысят значения технологических показателей НДТ, то необходимо разработать водоохранные мероприятия по достижению этих показателей и, до момента их достижения, оплачивать негативное воздействие на водные объекты со стократным повышающим коэффициентом. Разработан алгоритм и функциональные зависимости расчета технологических показателей для ЦБК, выпускающих продукцию, содержащую в композиции беленую и небеленую целлюлозу. Алгоритм рассмотрен на примере условного ЦБК, выпускающего первичные небелёные и беленые волокнистые полуфабрикаты и продукцию полного цикла. К первичным волокнистым полуфабрикатам небеленым отнесены: хвойная и лиственная целлюлоза, ТММ, ХТММ; к первичным волокнистым беленым полуфабрикатам отнесены: беленая хвойная и лиственная целлюлоза, БХТММ; к продукции полного цикла отнесены бумага, картон и продукция их переработки. Алгоритм расчета состоит из пяти этапов: 1 – построение балансовой схемы расчета технологических показателей; 2 – расчет технологических показателей для первичных волокнистых полуфабрикатов небеленых; 3 – расчет технологических показателей для первичных волокнистых полуфабрикатов беленых; 4 – расчет технологических показателей для продукции полного цикла; 5 – расчет значений технологических показателей для каждого вида продукции с учетом очистки на общепроизводственных очистных сооружениях. The purpose of the study is to develop an algorithm for calculating technological indicators separately by types of products for an integrated pulp and paper mill when discharging wastewater after wastewater treatment at unified industrial wastewater treatment plants. A balance method was used for calculating the values of the masses of pollutants formed per ton of output from the pulp and paper mill based on the masses of pollutants formed in auxiliary technological processes, taking into account wastewater treatment at general industrial treatment facilities. Technological indicators are set separately for products rated for bleached or unbleached pulp. If the actual values of technological indicators exceed the values of technological indicators BAT, then it is necessary to develop water protection measures to achieve these indicators and, until they are reached, to pay for the negative impact on water bodies with a hundredfold increasing coefficient. An algorithm and functional dependencies for calculating technological indicators for pulp and paper mills producing products containing bleached and unbleached cellulose in the composition have been developed. The algorithm is considered on the example of a conventional pulp and paper mill, which produces primary unbleached and bleached fibrous semi-finished products, and full-cycle products. Primary unbleached fibrous semi-finished products include: coniferous and deciduous cellulose, ТМP, CТМP; primary fibrous bleached semi-finished products include: bleached softwood and hardwood pulp, BCTMP; full cycle products include: paper, cardboard and their processing products. The calculation algorithm consists of five stages: 1 – building a balance sheet for calculating technological indicators; 2 – calculation of technological indicators for primary fibrous semi-finished products, unbleached; 3 – calculation of technological indicators for primary fibrous semi-finished products bleached; 4 – calculation of technological indicators for full cycle products; 5 – calculation of the values of technological indicators for each type of product, taking into account cleaning at general production treatment facilities.