Closing the Waste Loops: Australian Newsprint Mills
The manufacture of newsprint is a process which generates both solid and liquid wastes. Australian Newsprint Mills Ltd Albury has given increasing attention to waste issues in recent years and has succeeded in closing or partially closing some of the ëwaste loopsí, especially in the areas of waste paper recycling, waste water, and solid waste.
Background
Australian Newsprint Millsí (ANM) integrated pulp and paper mill at Albury, New South Wales, was established in 1981. The facility currently manufactures approximately 210,000 tonnes of newsprint annually using thermomechanical and recycled fibre (RCF) pulping processes. This represents around 35 percent of Australiaís newsprint requirements. ANM is Australiaís only domestic manufacturer of newsprint.
The Process
Waste paper
Prior to the establishment of its Albury recycled fibre plant in 1993, ANM was not involved in waste paper recycling. Until that time, much of the waste paper generated in Australia ended up in landfills. The ANM project significantly raised the Australian old newsprint recovery rate from 37 percent of annual consumption in 1991 to 60 percent in 1996.
Waste water
While the Albury mill has always been a low consumer of water by paper industry standards, it nonetheless draws all its water requirements from the Murray River and is the largest industrial user on the river, taking 4,490 ML annually for paper maunfacture.
Solid waste
The major solid waste product produced by the mill is a biosolid derived from two main sources: unincorporated wood fibre and activated sludge; and unincorporated recycled fibre, waste ink and magazine fillers.
One dry tonne of water treatment biosolid contains the nutritional equivalent of 1.6 kg of double superphosphate and 3.5 kg of urea. Traditionally, these biosolids have been landfilled.
Cleaner Production Initiative
ANM made a number of major modifications to its newsprint manufacturing process during the mid 1990s. These modifications have not only altered the quality and type of newsprint produced but have also had an impact on the waste products generated by the plant.
Waste paper recycling
In 1993, ANM constructed Stage 1 of its waste paper recycling plant. The plant allowed the company to produce newsprint with a 25 percent recycled fibre component. In 1995, Stage 2 commenced operations, more than doubling plant capacity. The construction cost of both stages amounted to $100 million and raised the recycled component of ANM Albury newsprint to 40 percent.
The newsprint manufacturing process at Albury now requires the purchase of over 48,000 tonnes of old magazine and 112,000 tonnes of old newsprint annually. Wastepaper is sourced from all eastern Australian cities and also from many rural areas. Wastepaper is transported to the mill on trucks used for the delivery of finished product, thus improving the efficiency of both newsprint distribution and wastepaper delivery.
Waste water
Management of waste water has always been an important issue at Albury. Water is used for two main purposes - paper making and cooling.
Cooling water (around 4 ML per day) is used to cool machinery eg hydraulic oil units, refiners and motors. It is kept separate from other water sources and uses, and remains uncontaminated by the paper making process. This water is not treated (other than in cooling towers) but is monitored for contamination. After being recycled several times, it is returned to the Murray River. Return water is utilised by a golf course and race course.
Paper making water (around 8 ML per day) is added to wood and recycled pulp until a dilute solution of wood fibre (1 percent solids) is created. This pulp solution is sprayed onto a rotating plastic mesh fabric, where water is then removed leaving behind a matted web of fibres - paper.
The water used in this process becomes contaminated with wood fibres not incorporated in the paper, with chemical residues from the raw materials used, and from chemicals added to control pulp pH and brightness. The water is treated to recover wood fibres and remove contaminants before being reused in the pulping process. Excess water and unrecoverable fibre is treated in a tertiary water treatment process.
After treatment, the waste water is used to irrigate a 330 hectare plantation (largely consisting of radiata pine) established by ANM in 1993 on land adjacent to the paper mill.
Solid waste
Prior to trials conducted by ANM in 1992, experimentation with paper mill waste in Australia had been minimal. The trials on both pasture and croplands close to the mill demonstrated that beneficial agronomic effects could be obtained under a range of conditions and that farmer acceptance in using biosolids was high.
ANM has now developed a full scale land spreading operation on privately owned land within 25 km radius of the mill. Careful selection and classification of potential land spreading sites and soil types has meant that the operation can continue well into the winter period with minimal impact on soils, farm tracks etc.
In addition to the biosolids, a solid waste in the form of bark, sawdust and tree branch material is produced during timber processing operations at the mill. This material is used to fire boilers in the generation of steam for the paper making process. Approximately 10,500 tonnes of oven-dried bark are produced annually. 10 percent of this is sold for landscaping and horticultural purposes. The remainder is burnt and provides an alternative to the use of gas in the steam generation process. This gas substitution may have a value of up to $0.5 million per annum and may meet up to 40 percent of the millís steam generation requirements.
Advantages of the Process
Waste paper
Recycling of waste paper at Albury has not only helped overcome the growing problem of paper waste, but enabled ANM to provide better newsprint, increase marketing opportunities and reduce pulp processing costs (see further under Cleaner Production Incentive).
The financial benefits from waste paper recycling are relatively small at the present time. Indeed the cost of producing thermomechanical pulp from pine thinnings is less than the cost of purchasing, transporting and reprocessing recycled fibre. The main advantages to ANM of recycled fibre production are superior paper quality and maintenance of market share.
Waste water
The Albury mill has always been a low consumer of water by paper industry standards. This has been achieved through original mill design and improvements to operations, which allow for the recycling of water used in the papermaking process. Current water usage at ANM Albury is around 20 KL per tonne of paper, compared with 100 KL per tonne for older mills and less than 10 KL per tonne for more modern mills.
An important result of the waste water initiatives is that ANM will not discharge any treated waste water into the Murray River except in the very wettest years (1 year in 10). Water within the mill is recycled up to 18 times before it is released for treatment. Further internal recycling may be possible in the future, but is currently limited by the effects on treated process water quality (notably dissolved salts) and hence on the effluentís suitability for irrigation.
The timber grown by the irrigated plantation appears suitable for papermaking and offers the prospect of having a significant commercial pulpwood resource immediately adjacent to the mill
The financial benefits of wastewater reuse at the Albury mill are difficult to quantify. The annual operating cost of wastewater reuse is estimated at more than $500,000, which the company regards as an additional cost of making paper in the Murray Darling Basin. Under current regulatory philosophies and licensing arrangements, ANM would not have been able to recycle wastepaper and continue to discharge wastewater into the river. Wastewater recycling has therefore enabled wastepaper recycling operations to be introduced and maintained at Albury.
The financial returns from the irrigated plantation will cover some of its annual operating costs. However the $10 million establishment cost of the project had to be funded from paper making operations, resulting in reduced profits for the establishment and loan repayment period.
Cleaner production Incentive
Waste paper recycling
Recycled fibre was adopted as a source of newsprint for a number of reasons:
- Government and community pressure - in being the only domestic manufacturer of newsprint, ANM was subject to significant government and community pressure concerned with wise use of resources, a growing volume of wastepaper and declining landfill space. As a manufacturer of this product, ANM was seen by many to have a responsibility for its disposal or reuse.
- Better newsprint - by incorporating magazine pulp (a pulp produced by chemical means) into the newsprint furnish, the paper produced by ANM has improved in quality, notably in tensile strength and caliper (sheet thickness).
- Better marketing opportunities - by having a significant recycled component in its product, ANM has gained improved marketing opportunities and a greater customer acceptance of the product.
- Reductions in pulp processing costs - the power consumption associated with repulping recycled fibre is about 20 percent that of virgin pulp manufacture.
Waste water reuse
The wastewater reuse scheme was adopted due to community concerns about river water quality; government and regulatory pressure to phase out in-river discharges; and the potential to grow a significant pulpwood resource on land adjacent to the mill.
Solid waste reuse
The land spreading of biosolids was chosen as the preferred method of reuse because the material proved useful as an agricultural soil conditioner, providing organic matter, nutrients and calcium as a lime substitute. Landspreading conserves current landfill space and avoids the need to develop a new landfill in the future.
The use of wood waste in the production of steam means that it is possible to reduce gas consumption and costs.
Barriers
The development and operation of waste reuse activities at ANM Albury suggests that waste issues in large scale manufacturing operations may be difficult, expensive and complex. Solutions to waste problems often involve years of research and planning. The most successful solutions to waste problems are those that view waste products as 'wasted' products. The Albury experience suggests that there is always room for improvement in any waste reuse scheme.
The main barriers were regulatory and technological. Recycling and wastewater reuse required an Environmental Impact Statement (EIS), which in 1993 cost over $1 million to prepare and guide through the various stages to approval.
The installation of the recycled fibre plant in 1993 involved significant technical risk. RCF technology has advanced rapidly in recent years.
Knowledge about effluent irrigated plantations has also advanced considerably in recent years. The initiative at Albury virtually doubled the area of irrigated plantation in Australia. The technology needed and the size of the project meant that there were no benchmarks to compare against or build upon.
Wastewater reuse continues to involve a level of uncertainty and technical risk in regard to the long term potential impacts on soil and groundwater. Because of this an intensive monitoring programme has been established in order to test for and avoid any negative long term impacts.
Reference
This case study has been adapted from a paper presented at the 12th National Waste Disposal and Water Management Conference, March 1997, Brisbane, Queensland.
Case study coordinated by the Environment Management Industry Association of Australia (EMIAA), June 1998.
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