MILL LEAKAGE STUDIES REVEAL COSTLY AND UNNECESSARY LOSS OF FIBER, ENERGY AND WATER

Transcription

1 MILL LEAKAGE STUDIES REVEAL COSTLY AND UNNECESSARY LOSS OF FIBER, ENERGY AND WATER Author: Ross Elliot, Tecumseth Filtration Inc. Abstract: Mill Leakage is the significant and unnecessary loss of fiber, energy and water that usually goes unnoticed in most pulp and paper mills. In-mill studies uncover the improvement potential, identify the solutions and provide the business case for remedial action. Examples from studies that are performed using rotary drum microfilter technology quantify the unnecessary losses from mill leakage. Once the extent of possible reduction is demonstrated and its economic value is established, a credible path forward can be put in place. The solutions include saving fiber and energy while reducing fresh water usage and effluent discharge. An extended benefit from the solution is the reduction in demand on the bio treatment processes as well as lower BOD/COD. Application studies that use small-sized production microfilter equipment explore the limits and capability of the technology over various operating conditions in selected process locations. Physical results of the studies establish size and design requirements for equipment acquisition. The evidential results, together with the solid business case, mitigate the risk for making solid capital expenditure decisions. Key Words: microfiltration; improvement; environment; risk; capital expenditure INTRODUCTION Paper mills use water, fiber and energy. The relative quantities of each vary with the product, process and geographic location and these resources have specific costs associated with them. These inputs, as the main ingredients in making paper, are carefully measured and the amounts used are tracked against the amount of quality production that is manufactured. The main outputs from mill operations are the product, residual heat and effluent. Product quantity is measured because it constitutes the commercial value of the operation. Residual heat is not measured but its value is fully recognized and attempts are made to reuse as much of it as possible. Effluent is different it is waste, something that must be dealt with because of regulatory limits and the cost of treatment. But effluent contains the same ingredients as the original inputs, just in a different mix or form. Are useful resources available from effluent and are any of them recoverable? Are the losses of water, fiber and energy contained in effluent merely leakage of these resources from the mill? Leakage can be prevented. Tecumseth Filtration Inc. performs in-mill studies with production filtration equipment to help mills understand the potential for preventing the loss or leakage of fiber, water and energy resources from process operations. Rotary drum microfilter technology is seldom used in North American mills and yet, on a global basis, it has long been proven to be an important piece of process equipment. Microfilters can be positioned in many different parts of an operation and have the capability to reduce fresh water usage, fiber losses and energy consumption at most mills. This equipment can be complementary to currently installed process equipment. However, it also has the advantage of being able to replace other, less efficient, traditional technologies and to provide a lower ongoing cost of operation. LEAKAGE OF WATER, FIBER AND ENERGY Pulp and paper making operations take a solid, either wood or recycled paper, and remake it into a saleable product that can be consumed by several different markets. The processes for doing this require numerous operations where the solid is diluted then thickened again, until the final drying of the product through evaporation. Wherever thickening occurs the liquid that is generated carries with it some of the fiber that was part of the stock. This liquid is largely reused in other parts of the operation but at some stage new water sources, fresh water, must be added to

2 make up for the losses to the sheet and in the effluent. Direct addition of fresh water occurs when makeup volume is required for dilution and as steam that is injected for heating. Fresh water is added indirectly for purposes other than dilution, such as cleaning showers and seals on pumps. Overall, the solids and water that goes into any operation must equal the solids and water that leaves it. Water is the carrier that is required to move fiber through the operation and it is an integral part of operations that transform wood into the final sheet. The amount of fiber that remains with process water at different thickening operations varies greatly depending on the equipment used and the product being made. Table 1 lists examples of the fiber content that has been measured during investigations into a number of applications over many mills. Ideally, this fiber would have more value if it remained with the product stream. As well, most pulp and paper operations run at high temperatures to help improve performance and that means heat energy is also contained in the fluid streams. That energy will be lost as leakage if all of the liquid is not reused. Screw presses are commonly used in pulp mill bleach plants as the final thickening operation prior to the stock entering the bleached stock chest. Filtrate from a screw press, which is hot and contains residual bleaching chemicals, is used back in the bleaching operation for dilution or as part of the washing process. As can be seen in Table 1, screw press filtrates also contain very high amounts of quality fiber, some of which will be lost when it is not completely reused. As a source of leakage this liquid is often at 0.5% consistency. The loss amounts to thousands of tons of fiber worth several million dollars every year plus heat energy that can have an equal value. In many board or packaging product mills, a decker or similar operation is used to capture fiber from white water off the forming section of the machine. Although most of the wire pit water is recycled for dilution at the fan pump, there is always an excess and it is very rich in fiber. Following the decker or saveall the filtrate solids remain rich in fiber, frequently measured at between 500 mg/l and 1,000 mg/l, and the temperature of the water can be as high as 65 º C (150 º F). Some of this fiber and energy becomes leakage of resources from mill operations. It is worth noting that most pulp and Table 1 - Microfilter Feed Source TSS Examples paper operations have been significantly modified over time to increase production and improve product quality. Whenever changes are made, the original design capacity of equipment and entire parts of operations are compromised and that changes the ideal balance of flows and operations. These changes often result in the need for more water than is available within the process and, although the production improvements are positive, there is also an unplanned increase in the leakage of water, fiber and energy. REDUCTION OF RESOURCE LEAKAGE Mill effluent is the accumulator of all sources of process discharges, stock dumps and spills of fiber and water. Typically there are a number of small contributors that, when combined, result in larger than anticipated fiber and energy leakage to effluent. One containerboard mill recently determined that the yearly loss from its OCC

3 operations is over $800,000 worth of quality fiber as a result of long ignored leakage from normal mill equipment and operations. A specialty paper mill with three paper machines studied the returns they could generate through recovery from their effluent and found the opportunity included fiber, energy, water and chemicals worth several million dollars. Even if the economic factor of potential recoverable resources does not hit home, there are environmental pressures that must be considered. Increasing numbers of pulp and paper operations are being asked by government regulatory agencies to submit plans on how they will reduce mill discharges, often by 30% or more. Environmental factors will continue to impact the need for mill process evolution. It is not unusual that mill bio-treatment facilities run over their design capacity and are constantly pressing against or violating regulatory limits. Both economic and environmental issues are forcing mills to further close discharges from their operations. One way to reduce the amount of solids and excess mill process water that is allowed to leak from operations is to treat this water before it becomes effluent. That implies that the solids will be removed from this flow and that the filtrate will be clear enough to be used somewhere else in the process. The other way to minimize the total discharge is to put effluent through a final process to recover solids and clarify the water sufficiently such that it can be used in place of fresh water. Solutions to improve the retention of water, fiber and energy require a close look at how the operation can be modified to make those improvements. One approach is the redesign of parts of the operation to take advantage of newer technologies. Another is to add equipment that can achieve the desired results without forcing major process reconfiguration. EQUIPMENT ALTERNATIVES TO REDUCE LEAKAGE There are numerous approaches to the reduction of resource leakage from a mill and each situation must be evaluated for the equipment that will provide the best results, as well as the lowest ongoing cost of operation. The most common requirements to clarify process water are: to close the system in order to replace fresh water where possible; to recover quality fiber from specific operations so it is not lost to disposal; to remove fiber and solids for disposal prior to bio-treatment operations; to remove solids from effluent being discharged from the mill after biotreatment. Some of the more common types of equipment used to clarify process water and remove or recover solids include: Various forms of Inclined Screens These use wire mesh or slotted plates to scavenge long fiber and coarse debris from flows; noted for plugging and require operator attention. Commonly used to remove solids from effluent flows or previously dewatered solids but allow passage of quality fiber and fines. Vibrating Screens Wire mesh or slotted plates that scavenge long fiber and coarse debris from flows; some have ongoing maintenance and cleaning requirements. Screen size is not sufficiently fine enough to recover all usable fiber Deckers or Drum Savealls Rotating cylinder filters with screens or perforated shell for dewatering pulp, typically in washing processes; noted for being a coarse filter with high solids in the filtrate. Most often, although some filtrate is reused in the process, much of this water ends up as effluent. Disc Savealls Rotating cylinder filters fitted with screens to remove solids from paper machine white water; require sweetener addition to form filter mat, all of which is returned to the process; vacuum is generated as part of the design for filtering assistance and this pulls significant amounts of fiber and fines into the filtrate; filtrate can be separated into cloudy, clear and, sometimes very-clear portions for appropriate reuse; clear portion is purged if there is excess water in the process. Although disc savealls are one of the most common systems for treatment of whitewater, by today s standards the design and principle of operation is no longer good enough to sufficiently reduce leakage of fiber from excess machine white water.

4 Dissolved Air Flotation (DAF) Solids flotation technology that removes solids from the flow being treated; requires compressed air equipment and polymer addition to aid solids flocculation; particularly useful in deink operations to remove fines, fillers and coating materials; also used to remove solids from effluent flows and to clarify water for reuse in process operations. DAFs can provide very low solids clarified water that has both long and short fibers remaining in it. They can be designed to handle any flow volume but are sensitive to flow variations and are known to occasionally create a heavy mat that collapses into the clarified water which then contaminates clarified water users and can damage internal apparatus. Further cleaning of the clarified water is required before use in high pressure showers. The biggest negative factor is the ongoing cost of polymer addition. Rotary Drum Microfilters Often referred to as gentle filtration that recovers solids and clarifies process water; self-cleaning that uses its own filtrate; selectable microfilter media down to 10 microns for high clarity and maximum shower reuse. Units are sized to flow-through requirements. Sweetener can be added as an option. Speed control allows surge management. Rotary drum microfilters are often used to replace disc savealls and DAFs to get better, more consistent water clarity; frequently used after screw presses, after savealls and DAFs, and on effluent streams. Backwash Filters Tubular filters with screens or perforated plates that are typically used to remove additional solids from previously clarified water; backwashing is required; do not handle surges; noted for providing clear water to sensitive applications such as trim squirts. Membrane Technologies treatment of clarified effluent water to reduce suspended and dissolved solids; can be used as a primary or a final stage of bio-treatment of effluent for discharge. With the requirement for continuing cost reduction and improved environmental performance every effort should be made to determine the best solution for the long term viability of each operation. Technologies that were once good enough need to be evaluated against what current equipment can offer. Comparisons of capital expenditure costs must be weighted with the ongoing cost of operation (COO) that includes any additives, maintenance, parts replacement, energy usage, additional support services such as air, vacuum, steam, water and, of course, operator loading. RESOURCE LEAKAGE STUDIES In order to determine what solution will achieve the objectives, whether they are economic or environmentally driven, there is a whole process that must be initiated. This begins with the generation of ideas on what to do and requires the expertise of personnel who have a thorough understanding of process operations. In most mills major change is made by a project champion who can drive a concept through initial investigation and on to installed reality. This person must thoroughly understand what impact the project changes will have on the process, people and production, as well as the entire scope of potential benefits. In order for this to happen it is necessary to create a plan that uncovers the possibilities offered by technology, what options might be available, the financial and operating benefits that can be generated and the risk factors in adopting the changes. If all of these are worked through and the result looks positive then a capital allocation request can be put forward for acceptance and funding. If approved, then a project is designed and the equipment is installed and commissioned. The project champion drives the idea, and then the project, from start to finish and performs a follow-up audit as a measure of success against the original plan. Although this process is pretty standard, there is one very large hurdle that must be addressed. The most critical and challenging part of the plan is to get it accepted and then funded. The issue is RISK. Ideas are great and it is nice to be enthusiastic but there is the reality of determining whether or not the technology in question will actually work in a particular process and how well it will work. For almost all capital equipment expenditure programs, existing installations are used as references to help mitigate risk and they are a very important part of acceptance of the

5 technology. However, if senior management is to grant project approval, the understanding of risk must be fully explored and developed people s careers are at stake as well as the performance of the operation. In-mill studies that use representative production equipment is the ideal way to bridge the gap between the idea and acceptance of the plan. As performed by Tecumseth Filtration Inc. for the application of rotary drum microfilter technology, studies establish credibility based on demonstrated proof of concept and economic viability. When properly designed and executed the study will show what results can be obtained from reducing the leakage of resources and this can be used to calculate the economic value that exists from a fully designed installation. At the same time, issues related to process operation can be identified and the liabilities posed by the implementation of new technology can be investigated. There are four key benefits to mill leakage studies. 1. The first positive benefit is the human aspect related to understanding the technology and the reasons it works so well. The old adage seeing is believing is just one part of what in-mill studies provide. 2. Next is the panorama of operating conditions, cause-and-effect relationships, disruption response characteristics and quality of output that can affect and be achieved with the technology. 3. Third is what can be determined from the data that is collected in terms of design requirements, process improvement and return on investment. 4. Lastly, the trial operation can specifically identify conditions or situations in the process that may be causing stability problems, opportunities for additional improvement or other associated issues. Regardless of the type of equipment that is being investigated, these four categories are a critical part of reducing the risk when making a capital investment decision. For rotary drum microfilter technology, the smallest production unit manufactured by Algas Fluid Technology Systems AB makes an ideal test stand for an in-mill trial of the equipment. Because of the simplicity of the concept and minimal requirement for support services, it is easy to arrange and put into action. A unit is moved into a mill location on a skid and a feed line is connected this may require installation of a take-off line from the process flow to be tested if it does not already exist. Typically the feed line is a two inch (~50 mm) flexible hose that connects to a two inch (~50 mm) Figure 1 - Rotary Drum Microfilter Trial Unit inlet pipe. It is additionally useful to have a flowmeter inserted on this line. Outlet flows from the trial unit can be allowed to run to the floor or can be piped to drainage channels or collector tanks. A power source is connected to an accompanying transformer (480V, 3-phase or 550V, 3-phase) and, as long as there is a mill water hose in the vicinity, the unit is ready to operate. Testing then captures a range of operating conditions and test equipment setup. Because the trial unit used for studies is production equipment, the test data can be used to directly calculate the size of unit that is needed to manage the entire process flow being considered. The results will be the same as what is measured during the study and sizing is a direct scale-up based on the area of filtration required. The physical placement of the test unit allows mill personnel to gain perspective on where the equipment can be located and its small footprint is a plus for fitting into tight mill areas where space is a premium. The ability to see the magnitude of results that can be obtained allows calculation of the return on investment to be done with confidence. The fact that the numbers have been generated with actual production equipment provides a degree of credibility that is not typical of most experimental trials that involve only part of the concept being

6 investigated. Where large capital investments are often looked at as career make-or-break decisions, the presence of critical data and visibility of the results ahead of time makes a lot of sense. The fourth key benefit was to identify conditions that may affect the success of the technology. An example of this is a study where the filter medium blinded over after 12 hours of operation. The filter has strong cleaning showers on both sides of the fabric but the nature of the fines in the effluent flow that was being processed created a gelatinous film that significantly reduced the flow-through. This is an issue specific to the pulp characteristics in this mill. The situation was partially resolved during the remainder of the study but a modified operational practice would need to be instituted for the microfilter to get the desired results for continuing operation. Some of the options available to correct such issues include: addition of a polymer to aid drainage by providing flocculation of the fines; add sweetener to the inlet flow to change the drainage characteristics and how the fines accumulate in a mat; use a more open filter medium to allow the gelatinous fines to pass through; take the feed after further dilution and at a lower temperature; or use other chemical additives to reduce the nature of gelatinous characteristic. There are many different ways to get the positive results that have been anticipated and are available. REPORTING ON A MILL LEAKAGE STUDY The study report is the record and analysis of what occurred and was accomplished during the operation of the trial equipment while processing mill water. It is the summary of activities and the results of testing that will lead to a mill leakage reduction plan. A study, like any project, must have a statement of objective that embodies the where, what and why for the activities. One example would be: Determine how much fiber can be saved and the clarity of polished water produced through filtering DAF clarified accepts using a rotary drum microfilter. The report will become a reference document and must include the context of the study, starting with a description of the process area in which the study is performed, where the feed from the process is taken and what it is. Further discussion must include the operational issues that are investigated and where the outlet products of the equipment can be used if the anticipated filtrate has the desired properties. The next part of the technical discussion is a description of the testing and data collection that takes place flows, consistencies, drum speeds, filter medium type, temperatures. This leads into an examination of the equipment used, its set-up and operation and how it is manipulated. The rotary drum microfilter has the following parameters that can be adjusted: Figure 2 - Mill Leakage Study Report Table Of Contents Flow to the unit affects level in the drum Speed of the rotating drum affects filtrate clarity and throughput Level differential across the filter affects throughput Filter medium used (30 micron, 80 micron or 120 micron fabric) affects filtrate clarity and throughput Amount of cleaning shower and knock-off shower water Proportion of super-clear or super-clear with some less-clear Figure 3 - Mill Leakage Study Technical Discussion

7 filtrate extracted As well, the unit can be set up to add sweetener stock or polymers to enhance filtration if needed. From start-up with fresh water, the microfilter unit reaches steady-state operation within an hour. As changes are made to its operation a new equilibrium occurs within half an hour. The major impact of most changes is visible within 10 minutes. Throughout all the testing a Trial Log is maintained to capture the circumstances around each test with clarification comments recorded to capture details. Table 2 - Excerpt From Trial Log A Summary of Findings identifies the key results obtained, along with the conditions and situation analysis. This includes the observations about what happened through the trial, the notable cause and effect relationships, any difficulties or surprise events encountered, data analysis and plots, and the results that are identified or derived. Technical findings lead directly to recommendations that can be made based on the results of testing. The recommendations indicate how successfully a rotary drum microfilter will operate in the process and the appropriate source of process water if that is in question. Most importantly this will identify the size and design of the unit that would be most effective for the flow to be treated and filtrate that is needed. The Technical Discussion is followed by a summary of the savings that can be generated through implementation of the recommended unit. The savings calculations are typically based on dollar values that are considered to be conservative for the product or services involved. The model (Figure 2) includes inputs and calculations that provide specific determination of the savings from each area of contribution - fiber, energy, water, production, chemicals and waste disposal. ECONOMICS OF REPAIRING MILL LEAKAGE Following recognition that there are savings and improvements available from addressing mill leakage, the next important step is to develop the business case for successful funds appropriation. Most mills already realize they can make improvements to their usage of fresh water and energy but the path leading to the solutions is definitely cloudy. A technical remedy may make sense but this must be supported with the economics. Part of the study process for rotary drum microfilter technology includes the use of a Savings Calculator to point directly at where the results will be generated and their financial magnitude. This calculator is a model that requires inputs of process measurements and cost factors. Broad scope numbers can be calculated using some basic or best-guess estimates in order to get an order of magnitude value for the savings available. The study develops actual numbers which make the calculations much more exact. These are values that can then be included in the mill leakage project justification.

8 A business case for any project must include a complete prospectus on what is involved. This includes the objective, the equipment involved, the gains to be made, the design changes, engineering, construction, ongoing cost of operation implications and the return on investment. The in-mill study creates confidence and credibility in many of these areas: Allows mill personnel first-hand experience with the equipment Shows actual results that can be achieved Demonstrates the economics Provides perspective on the process design, engineering changes and implementation scope that is required. The business case is further advanced in the study report by including a financial analysis with Figure 4 - Summary Of Savings representative determinations of Net Present Value (NPV), Internal Rate of Return (IRR) and Return On Investment (ROA). If the fiber that is removed from the flow stream can be reused in the process or sent forward as quality fiber, this provides a rich source of saving. The replacement of fresh water has very significant implications, particularly in more northern climates where shower water or other process make-up water must be heated to process temperature before it is used. Steam must be generated to heat this water and the temperature increase required can easily average over 25ºC (77ºF). If fresh water is purchased from a municipality or treatment center the cost is high because of the volumes consumed. Process water that is recycled also contains chemicals that will not need to be replaced when fresh water no longer purges these elements. Acceptable savings along with cost estimates are then run through an economic analysis model that outputs values that can be used as guides to the return on investment. In most places this analysis points to a must-do project because of the high rate of return. NPV, IRR and ROA values are a necessary part of getting funds appropriation and when these numbers are very positive, as in the example in Table 2, it makes them difficult to ignore. Table 3 - Financial Analysis Summary EXAMPLE CASE STUDIES In-mill studies that use actual process equipment have proven to be exceptionally effective at generating the right information needed to identify a mill leakage solution that can improve the bottom line while it alleviates existing operating constraints and reduces the impact on the environment. In many cases, the results indicate that rotary

9 drum microfilter technology has a double impact that was not expected cost reduction together with reduced environmental impact. Many mills experience severe mill leakage issues related to their effluent. Some are pushing against the regulatory limits on their solids, others on their BOD or COD, while some are just plain overloading the primary treatment facilities with excess volume, good fiber and fines. This becomes the key driving force behind interest in the technology. This interest ramps up when it is realized that not only can rotary drum microfilters alleviate the environmental concerns but they can, as part of the solution, create some very significant savings and improve machine performance. A number of mills have gained the value of recovering quality fiber from their effluent streams and later realized they also saved on not having to dig out their settling ponds nearly as often. Following are some results from recent mill leakage studies that were done in North America. Tissue Mill Consumer and industrial products. Issue: overflow of whitewater directly to effluent. Objective: recover useful fiber; reduce effluent flow; and replace fresh water in paper machine showers with recycled process water. Study: testing with 30 micron filter medium indicated >95% removal of fiber from the flow to effluent. Filtrate had no solids that can plug shower nozzles. Estimated yearly savings potential >$450,000. Tissue Mill Industrial products. Issue: the DAF used to remove solids from effluent does a very poor job of clarifying water that is discharged to a municipal system. Objective: reduce solids being discharged to keep within set limits and determine if any of the treated water could be reused in the process. Study: inlet flow to DAF ranged from 60 mg/l to >1000 mg/l of fiber and outlet from the DAF ranged from 20 to >600 mg/l. For the trial period, the rotary drum microfilter treated a portion of the flow going into the DAF, and produced filtrate with solids of between 1 mg/l and 7 mg/l. Average solids removal was over 99% and the water was clear enough to be reused in the process DAF vs Microfilter Solids Removal From Effluent Inlet Flow PPM DAF PPM RDM Filtrate PPM Figure 5 Tissue Mill DAF Versus Rotary Drum Microfilter Solids Removal From Same Effluent Stream Feed Packaging Mill Corrugating Medium from virgin fiber. Issue: high fresh water usage and high fiber loss. Objective: off-load primary treatment facility and retain fiber in whitewater.

10 Consistency mg/l Study: wire pit whitewater was combined with sweetener and filtered using 120 micron medium. Whitewater solids ranged from 6000 mg/l to 9800 mg/l before sweetener was added at fractions of 6% to 15%. Solids removal ranged from 82% to 92% for the various speeds and set-ups. Clarified water averaged around 1100 mg/l with no particle sizes greater than 50 microns as determined by third party analysis. Estimated yearly savings potential >$7 million if all the filtrate could be reused. Packaging Mill Kraft Linerboard from virgin fiber. Issue: high flow and high solids loss to primary treatment. Objective: determine the efficiency of solids removal and clarity of filtrate that could be obtained from treating decker whitewater overflows to effluent. Study: whitewater flow had solids that ranged from 335 mg/l to 1115 mg/l, the rotary drum microfilter had a 30 micron filter medium. Efficiency of solids removal ranged from 40% to 97% with gelatinous fines blinding the filter during one early trial run. Of about 10 tonnes per day of fiber being sent to the clarifier, over 75% of that could easily be removed by rotary drum microfilter technology. Estimated yearly savings potential from removal of these solids was >$1.1 million. Packaging Mill Linerboard and corrugating medium from 100% recycle. Issue: high cost of water purchase and effluent discharge to municipality. Objective: determine the solids removal capability from effluent stream and applicability of filtrate for reuse in machine showers. Study: whitewater from effluent discharge treated with 30 micron filter medium. Inlet solids averaged about 500 mg/l. Average particle size of solids in filtrate <25 micron. Estimated yearly savings potential >$960,000 and a much happier municipality. Newsprint Mill Newsprint from virgin fiber. Issue: high fresh water usage and fiber loss to effluent. Objective: determine efficiencies of fiber removal and filtrate clarity that could be obtained. Study: whitewater filtrate from a disc saveall was fed to the rotary drum microfilter. Solids from the saveall ranged from 21 mg/l to 220 mg/l but were typically around 150 mg/l. Efficiencies in excess of 90% fiber removal could be sustained using a 30 micron filter medium with filtrates having less than 10 mg/l. Third party analysis of filtrate showed no solids larger than 60 microns (2.4 mils) while the feed whitewater had solids larger than 1900 microns (75 mils). Estimated yearly savings potential >$1 million Saveall Clear Feed To Rotary Drum Microfilter Sample number Inlet - from Saveall RDM Clear (10%) RDM Super-Clear (90%) Figure 6 Rotary Drum Microfilter Solids Removal From Clear Saveall Filtrate

11 SUMMARY AND CONCLUSIONS I believe that if you show people the problems and you show them the solutions they will be moved to act. Bill Gates once asserted. Few people go looking for problems, but that is exactly what innovators do and why they are celebrated for their successes. Once the solution has been identified the step to acceptance and implementation becomes the major challenge. Where large capital expenditures are involved, project approval requires justification for taking the investment risk and this hurdle is typically and logically difficult to conquer. Studies into mill leakage that use the actual equipment under consideration provide the information needed to address capability issues and mitigate risk. As well, such studies help to quantify the potential benefits and identify other process issues that may require attention. Rotary drum microfilter technology can be beneficially implemented in every mill. This is a solution that can be demonstrated by Tecumseth Filtration Inc. through in-mill studies that also serve to uncover the many problems they can solve. If the studies are done properly then they will allow people to act by providing visible results with the background data needed to get project approval. The mill leakage problems and solutions are specifically related to fresh water usage, effluent solids discharge and discharge rates, energy usage, fiber recovery, shower nozzle plugging, environmental limitations and operational issues. Study reports become the reference documentation that is used for project justification. Studies on mill leakage quantify the unnecessary fiber, water and energy losses that occur in pulp and paper mills. Through the use of in-mill applications of production technology, the proper collection of relevant test data and a thorough analysis of the results, a very complete perspective on the opportunities available to reduce such losses are made clear. In studies carried out using rotary drum microfilter technology, the capability of these units has been shown to provide solutions for mill leakage problems that include fiber loss, excess effluent flow, high fresh water usage, over-taxed primary clarifier treatments and environmental limit violations. The results potential from tackling mill leakage includes larger than expected energy savings, very significant replacement of fresh water use, reduction in solids going to clarifiers that also reduces BOD and COD, and the potential for higher and more consistent sheet temperatures into the presses and dryer sections. Business case development through in-mill studies that use rotary drum microfilter technology uncovers and identifies the benefits of mill leakage abatement. This technology can benefit every mill, often in unexpected ways, and that proof is available and can be demonstrated.