EP3931395A1

EP3931395A1 - Deposition reduction

Info

Publication number: EP3931395A1
Application number: EP20707095.4A
Authority: EP
Inventors: Frank DÜRKES; Stefan Franke; Pieter STEENBEEK
Original assignee: Servophil Ag
Current assignee: Servophil Ag
Priority date: 2019-02-25
Filing date: 2020-02-25
Publication date: 2022-01-05
Also published as: WO2020173963A1

Abstract

The present invention relates to a biological process for reducing the level of deposits formed in water bearing systems used in the processing of cellulose, especially water bearing systems used in the production of paper.

Description

Deposition Reduction

FIELD OF THE INVENTION

BACKGROUND OF THE INVENTION

The invention relates to improving the efficiency of water bearing systems by reducing the level of deposits formed in the water bearing system . In a particular embodiment, the invention relates to improving paper production by reducing the level of deposits formed in a water bearing system used during the production of paper.

Paper is available in a variety of types, grades and weights for very different applications, including graphic paper; paper and board for packaging purposes; tissue and hygiene papers; and papers and board for special technical purposes.

In order to be able to cope with the multitude of applications, paper has different properties depending on the desired use. Such properties are obtained by utilising different complex formulations of the paper fibres, fillers and additives during the production process. During such paper production processes, various deposits are formed within the paper manufacturing machinery and can build up on parts of the machinery. The formation of such deposits can result in unpleasant odours being generated, a reduction in the quality of paper produced, as well as a reduction in the efficiency of the production method. Accordingly, such deposits need to be removed from the machines, which can lead to production disturbances and a reduction in the manufacturing efficiencies.

Cellulose is an essential component of paper. It is a polysaccharide, i.e., a macromolecule made up of many sugar molecules. During the production of paper, various cellulose molecules and cellulose-containing fibres having a variety of different lengths are produced. Certain contaminating bacteria are able to digest and use the cellulose molecules and cellulose-containing fibres as an energy source. The contaminating bacteria digest the cellulose molecules and cellulose containing fibres. During this process certain saccharides (e.g., polysaccharides and monosaccharides) are excreted by the contaminating bacteria. The excreted saccharides include one or more of alginates, dextrane, levane, and the monosaccharide components derived from D-Glucoronic-acid, D-Galacturonic-acid and D-Mannuronic-acid. The industrial habitat lacks the necessary nitrogen compounds for the complete utilization of the cellulose derived energy source to build new cells, and hence excess sugars (i.e., the cellulose derived energy source) are excreted as the above recited saccharides. The excreted saccharides form the basis of the deposits.

The excreted saccharides, which can comprise up to 97 weight % water, are sticky and will generally adhere to parts of the water bearing systems; however, some of the saccharides can remain suspended within the water. A wide variety of particles can then adhere to the sticky saccharides, which reduce the flow speeds in the system, impair heat transfer, hinder gas exchange and allow the formation of oxygen-poor/oxygen-free areas where anaerobic bacteria can flourish resulting in unpleasant odours and corrosion to parts of the machinery, for example caused by the formation of corrosive hydrogen sulfide.

In order to try and deal with the issue of deposits forming during cellulose processing, e.g., in paper production, various chemicals and biocides have been added to reduce the levels of contaminating bacteria, and thereby the levels of deposits being formed. Unfortunately, the addition of chemicals and biocides has a negative environmental impact, and does not always successfully reduce the levels of deposit formation for a prolonged period of time. Accordingly, it remains necessary with such treatments to still regularly clean parts of the water bearing system, e.g., paper manufacturing machinery, resulting in a delay in production.

The present disclosure provides a method for reducing deposit formation in a water bearing system used in the processing of cellulose, the method comprising administering a composition comprising bacterial spores and/or bacteria derived from bacterial spores to the water bearing system, wherein the bacteria cannot digest cellulose but can digest one or more of the following saccharides: alginates, dextran, levan and monosaccharide components D-Glucoronic-acid, D-Galacturonic-acid and D-Mannuronic- acid.

The water bearing system can be any water bearing system used in the processing of cellulose wherein deposits are formed on parts of the water bearing system. Suitable water bearing systems include systems involved in wood, and wood pulp processing, and especially water bearing systems used in the production of paper. The water bearing systems can be open or closed systems; however the present method is particularly suitable for reducing deposit formation in substantially closed water bearing systems (i.e., systems where over 80%, over 90% or over 95% of the water is recycled) and fully closed water bearing systems. The present method is particularly suitable for use in reducing deposit formation in water bearing systems used in the production of paper, especially the white water circuit.

The term "paper" as used herein refers to any form of paper including graphic paper; paper and board for packaging purposes; tissue and hygiene papers and papers and board for special technical purposes.

Reducing deposit formation refers to lowering the amount and/or size of deposits formed on surfaces of the water bearing system. The deposits are formed by the action of contaminating bacteria on cellulose molecules and cellulose containing fibres resulting in the production of saccharides that adhere to surfaces of water bearing systems. A wide variety of particles (e.g. additional polysaccharides, starch, glues, alkyl ketene dimers (AKD) and other organic or polymer-like deposits) can then adhere to the deposited saccharides and form the deposits. The present method reduces the formation of deposits on the surface of the water bearing system, so that at least 10%, 50% or 90% fewer deposits are formed on the surface of the water bearing system when the composition comprising the bacterial spores and/or bacteria derived from bacterial spores is administered to the water bearing system.

The composition used in the method comprises: (1) bacterial spores that germinate and producederived bacteria; and/or (2) bacteria that are derived from bacterial spores. The term "derived bacteria" as used herein refers to both bacteria derived from the bacterial spores present within the composition, and bacteria that have previously been derived from bacterial spores and are present within the composition. The derived bacteria do not need to be directly derived from a bacterial spore but include subsequent generations of bacteria. The derived bacteria can be any suitable bacteria that can breakdown the saccharides formed by the contaminating bacteria (i.e., the saccharide-producing bacteria) and thereby destabilize and at least partially break down the deposits.

The derived bacteria can digest one or more of the following saccharides: alginates, dextran, levan and monosaccharide components D-Glucoronic- acid, D-Galacturonic-acid and D-Mannuronic-acid. In certain embodiments the derived bacteria can digest at least two, three, four or more of the saccharides. In a particular embodiment the derived bacteria can digest all the saccharides.

The derived bacteria are not able to break down cellulose, and therefore will not contribute to forming the saccharides that form the basis of the deposits.

For safety reasons is it desirable that the bacterial spores and the derived bacteria are not pathogenic, i.e., they belong to risk group 1 (§ 3 of the Ordinance on Biological Substances).

It is further desirable that the derived bacteria are genetically stable and therefore will not develop atypical characteristics during use in the water bearing system.

The spores and the derived bacteria are used in a water bearing system during the processing of cellulose, in particular during the production of paper, and therefore need to tolerate the conditions within such water bearing systems. For example, the bacteria will need to tolerate temperatures from 10-60°C, pH values from 5-8, and salt densities of 3-5 weight %).

It will be appreciated that the derived bacteria should remain stable in an aqueous solution and be able to multiply within the water bearing system. The derived bacteria should also be able to colonise surfaces of the water bearing system, and, in certain embodiments, form a biolayer on surfaces of the water bearing system. It is also desirable that the derived bacteria use oxygen for metabolism (i.e., are aerobic) and are actively mobile. The use of oxygen prevents formation of corrosive hydrogen sulfide and sulfide-related material destruction. The ability to move actively enables active movement and spreading on the surfaces of the water bearing system.

The use of bacterial spore derived bacteria provides the advantage of being able to produce, store and transport stable spore compositions. Accordingly, the bacterial spores can be stored for a prolonged period of time (i.e., for many months), and transported without any special requirements (e.g., temperature, nutrients, etc.). When the bacterial spores are to be used in the water bearing system, the spores can be directly added to the system resulting in the production of the derived bacteria in the system. As those skilled in the art will appreciate the spores can also be formulated into a suitable composition/suspension (e.g., aqueous composition/suspension) prior to administration to the water bearing system.

The term "bacterial spores" as used herein encompasses all bacterial spores, and especially includes endospores.

Particularly suitable derived bacteria include bacteria of the genus Bacillus. a genus of bacteria with more than 200 species.

Particularly suitable bacterial spores and/or bacteria derived from bacterial spores for use in the method include:

Bacillus altitudinis (e.g., deposited strain DSM21631);

Bacillus amyloliquefacies (e.g., deposited strains DSM 7, ATCC 23350);

Bacillus coagulans (e.g., deposited strain DSM 2314);

Bacillus kokeshiiformis (e.g., deposited strains MO-04, JCM 19325);

Bacillus licheniformis (e.g., deposited strains DSM 13, ATCC 14580, DSM 46308, DSM 8785);

Bacillus megaterium (e.g., deposited strains DSM 32, ATCC 14581);

Bacillus pumilus (e.g., deposited strains DSM 27, ATCC 7061);

Bacillus subtiHs (e.g., deposited strains DSM 10, ATCC 6051, DSM 5749, DSM17299); and

Bacillus thermoamylovorans (e.g., deposited strain DSM 28625).

In one embodiment, particularly suitable bacterial spores and/or bacteria derived from bacterial spores for use in the method include:

Bacillus amyloliquefacies (e.g., deposited strains DSM 7, ATCC 23350);

Bacillus licheniformis (e.g., deposited strains DSM 13, ATCC 14580); Bacillus megaterium (e.g., deposited strains DSM 32, ATCC 14581);

Bacillus pumilus (e.g., deposited strains DSM 27, ATCC 7061); and

Bacillus subtiHs (e.g., deposited strains DSM 10, ATCC 6051, DSM 5749, DSM17299).

The bacteria used in the method can be obtained from numerous commercial sources, including official strain collections (DSMZ, ATCC etc.). The example strains indicated above are given as examples only. One skilled in the art will appreciate that any strain of the recited Bacillus species can be used in the methods described herein.

The composition comprising the bacterial spores and/or bacteria derived from the bacterial spores, may include just the spores or just the derived bacteria, or a mixture of the spores and the derived bacteria. In view of the high stability of the bacterial spores, in certain embodiments it is desirable that the composition comprises the bacterial spores, and is substantially free of the derived bacteria, i.e., comprises less that 1%, or less than 0.1% of the derived bacteria.

The composition comprising the bacterial spores and/or bacteria derived from bacterial spores, may include a mixture of different types of spores and/or derived bacteria, e.g., different species, or just one type (i.e., a single species). For example, the composition can comprise one or a plurality of the Bacillus bacterial species listed above. In some embodiments the composition comprises 3, 4 or 5 different Bacillus species selected from the bacterial species listed above. In one embodiment the composition comprises 5 different Bacillus species. The 5 species can be any combination of the Bacillus species listed above, and in one particular embodiment the 5 different species are Bacillus amyloliquefacies (e.g., deposited strains DSM 7, ATCC 23350); Bacillus licheniformis (e.g., deposited strains DSM 13, ATCC 14580); Bacillus megaterium (e.g., deposited strains DSM 32, ATCC 14581); Bacillus pumilus (e.g., deposited strains DSM 27, ATCC 7061); and Bacillus subtilis (e.g., deposited strains DSM 10, ATCC 6051, DSM 5749, DSM17299).

An advantage of including a mixture of different types of spores and/or derived bacteria is that the derived bacteria may have a variety of characteristics to enable a broader range of functionality, e.g., can function to breakdown a greater variety of saccharides and/or can function to breakdown the saccharides under a variety of different conditions (e.g., temperature, pH, salt concentrations, etc.).

The composition comprising the bacterial spores and/or derived bacteria may additional comprise one or more additives. Suitable additives include the necessary media components to ensure that the spores and/or derived bacteria are maintained functionally. The media requirements for the spores and derived bacteria are well known to those skilled in the art. The composition may additionally comprise an energy source for the derived bacteria to ensure that there is a sufficient initial energy source available for the derived bacteria on addition to the water bearing system. In one embodiment the composition comprising the bacterial spores and/or derived bacteria does not allow multiplication of the bacteria (e.g., due to the presence of only a minimal amount of an energy source). By preventing multiplication the concentration of the bacterial spores and/or derived bacteria is maintained. A further addition component may be a pH modifying agent such as limewater (calcium hydroxide).

The present method reduces the level of deposit formation in water bearing systems, especially in water bearing systems used in the production of paper. Accordingly the method provides an improvement in paper productivity and in the ability to consistently produce quality paper. The method can also reduce odours and damage to the water bearing system by reducing the level of anaerobic bacterial growth and the production of corrosive hydrogen sulphide. In particular, by reducing the level of deposits forming in the water bearing sytem, water flow in the system is not disrupted thereby avoiding the formation of areas where anaerobic bacterial growth can occur.

The composition comprising the bacterial spores and/or derived bacteria can be administered to the water bearing system in any suitable manner. The bacterial spores and/or derived bacteria containing composition maybe administered directly into the water bearing system. Such direct administration may be made at one site or at multiple sites within the water bearing system. The administration may be made continuously or batch wise by any suitable method, such as a controllable and adjustable pump. The bacterial spores and/or derived bacteria are generally suspended in an aqueous solution, and then administered to the water bearing system.

For the addition of the bacterial spores and/or derived bacteria in a water bearing circuit, one or more suitable dosing points should be selected. The added suspension should be mixed with the circulating water as quickly as possible in order to achieve successful dispersion within the water bearing system. Addition of the bacterial spores and/or derived bacteria should be managed so that there is an energy source available for the spore forming bacteria. Accordingly, it is generally not recommended to add the bacterial spores and/or derived bacteria shortly after the water bearing system has been cleaned, since a sufficient amount of saccharide deposits must be present to act as an energy source for the derived bacteria. However, if it is desirable to add the bacterial spores and/or derived bacteria to a clean water bearing system, an additional energy source for the spore forming bacteria can be added. Addition of the bacterial spores and/or derived bacteria in a water bearing system that has already built up large deposits should also be avoided, as even successful growth and high degradation activity cannot degrade the deposit uniformly without the formation of large shreds. The formation of such large shreds risks affecting quality of the product being produced in the water bearing system, e.g., paper quality. The amount of bacterial spores and/or spore forming bacteria to be administered will depend on the size of the water bearing system, the level of deposits present within the system, and the expected rate of deposit generation. The required amount can be determined by one skilled in the art and adjusted over time.

Without being bound by the following theory, it is believed that after administration the bacterial spores and/or derived bacteria bind to the deposits and/or surfaces of the water bearing system. The bacteria then multiply and the spores germinate and produce derived bacteria. The saccharides forming the basis of the deposits are metabolized by the derived bacteria. As the derived bacteria grow and multiply, the deposits on the surfaces in the water bearing system are colonised and reduced by the activity of the bacteria. The bacteria can penetrate the deposits and degrade them below the surface. This can result in the detachment of small shreds of the degraded deposits.

Depending on the conditions within the water bearing system, the rate of growth of the derived bacteria may vary. In view of this, the conditions within the water bearing system can be adjusted to achieve a desired level of bacterial growth. Where this is not possible it may be necessary to add additional bacterial spores and/or derived bacteria to the system.

If the energy sources for the derived bacteria are exhausted, the bacteria will form spores (i.e., endospores). Accordingly, in order to compensate for any loss of the bacteria, e.g., via discharge from the water bearing system, and/or spore formation, the bacterial spores and/or derived bacteria material can be replenished. Such replenishment can occur continuously, batch wise, or when deemed necessary, i.e., when odour and/or significant deposit levels are detected.

One way to determine the effectiveness of the method is to measure the amount and/or rate of deposit formation in the water bearing system. Suitable methods for making such a measurement are well known to those skilled in the art. For example, a probe can be positioned within the water flow and measurements made to determine the amount and/or rate of deposit formation on the probe. Electrical capacity, heat exchange, ultrasonic, optical density, and weight measurements can be made to determine the amount and rate of deposit formation. It should be noted that when measuring the thickness of the deposits, the thickness seems to increase following exposure to the bacterial spores and/or spore forming bacteria, and then decreases. The reason for this contradictory signal is believed to be due to the initial loosening of the deposit resulting in an increase in water penetration temporarily swelling the deposit.

Depending on the amount and/or rate of deposits being formed in the water bearing system, the amount of bacterial spores and/or derived bacteria added to the system can be adjusted. For example, if the amount of deposits is increasing, the amount of bacterial spores and/or derived bacteria added to the system can be increased. Alternatively, if the level of deposits is maintained at an acceptably low level, then the amount of bacterial spores and/or spore forming bacteria can be maintained. As those skilled in the art will appreciate such a feedback loop can be automated. When the water bearing machine is a paper manufacturing machine, the measurement of the deposits is preferably made in the white water circuit of the paper manufacturing machine. Accordingly, when a probe is used to make the measurement it is preferred that the probe is positioned within the white water circuit of the paper manufacturing machine.

The present invention is also directed to a composition comprising bacterial spores and/or bacteria derived from the bacterial spores for administration into a water bearing system, wherein the bacteria cannot digest cellulose but can digest one or more of the following saccharides: alginates, dextran, levan and monosaccharide components D-Glucoronic-acid, D-Galacturonic- acid and D-Mannuronic-acid, and wherein the composition further comprises a stabilising agent and/or a non-biocidal-active quaternary ammonium compound.

The bacterial spores and/or bacteria derived from the bacterial spores are as defined above. Furthermore, and as indicated above, the composition comprising the bacterial spores and/or bacteria derived from the bacterial spores, may include just the spores or just the derived bacteria, or a mixture of the spores and the derived bacteria. In view of the high stability of the bacterial spores, in certain embodiments it is desirable that the composition comprises the bacterial spores, and is substantially free of the derived bacteria, i.e., comprises less that 1%, or less than 0.1% of the derived bacteria.

In addition, and as indicated above, the composition comprising the bacterial spores and/or bacteria derived from bacterial spores, may include a mixture of different types of spores and/or derived bacteria, e.g., different species, or just one type (i.e., a single species). The bacterial spores and/or bacteria derived from bacterial spores, as well as the mixtures thereof, are as defined above.

The stabilising agent can be any suitable stabilising agent such as glycerine. Suitable non-biocidal-active quaternary ammonium compounds are well know to those skilled in the art.

The composition comprising the bacterial spores and/or derived bacteria may, as indicated above, additional comprise one or more additional additives. Suitable additives include the necessary media components to ensure that the spores and/or derived bacteria are maintained functionally. The media requirements for the spores and derived bacteria are well known to those skilled in the art. The composition may additionally comprise an energy source for the derived bacteria to ensure that there is a sufficient initial energy source available for the derived bacteria on addition to the water bearing system. In one embodiment the composition comprising the bacterial spores and/or derived bacteria does not allow multiplication of the bacteria (e.g., due to the presence of only a minimal amount of an energy source). By preventing multiplication the concentration of the bacterial spores and/or derived bacteria is maintained. A further addition component may be a pH modifying agent such as limewater (calcium hydroxide). A further aspect of the present invention is a water bearing system for use in processing cellulose, and having a biolayer of bacterial spores and/or bacteria derived from the bacterial spores formed on a surface of the system, wherein the bacteria cannot digest cellulose but can digest one or more of the following saccharides: alginates, dextran, levan and monosaccharide components D-Glucoronic-acid, D-Galacturonic-acid and D-Mannuronic-acid.

The bacterial spores and/or bacteria derived from the bacterial spores are as defined above.

As indicated above, the water bearing system can be any water bearing system for processing cellulose, and in certain embodiments is a water bearing system used in the manufacture of paper. In one embodiment the water bearing system is a white water circuit used in the production of paper.

The water bearing system having the biolayer can be formed by administering a composition of the bacterial spores and/or bacteria derived from the bacterial spores, and allowing the biolayer to form. The biolayer can form on a surface of the system where deposits have or are expected to form.

The following examples are set forth as being representative of the present disclosure. These examples are not to be construed as limiting the scope of the present disclosure as these and other equivalent embodiments will be apparent in view of the present disclosure, Figures and accompanying claims.

Figure 1 shows a schematic representation of the mode of action of the method for reducing deposits using the bacterial spore composition disclosed herein.

Figure 2 shows the effect of the bacteria on the level of polymer build up.

Figure 3 shows the effect of the bacteria on deposit formation within the water bearing system of a paper mill.

Figure 4 shows the level of organic acids measured in the system overtime.

Figure 5 shows the effect of the bacteria on the disc filters within the paper mill.

Figure 6 shows the level of deposits on the walls of a paper mill measured using a heat exchange sensor.

Figure 7 shows a headspace gas chromatography of a tissue demonstrating that the level of volatile odour producing compounds within the tissue is reduced when bacteria are present within the water bearing system of the paper mill.

Figure 8 shows the effect of the bacteria on various parts of the paper mill.

Figure 9 shows chromatography of the headspace in the paper mill demonstrating that with the bacteria the odour level is reduced. Figure 10 shows the effect of including the bacteria in the water cooling sytem of a paper mill.

Statements

Deposits in paper machine circuits

are typically difficult to avoid and lead to:

^■ Stains and clumps in the paper, unplanned shutdow

^■ Sheetstrength problems, corrosion, reduced dewaterering

Odour problems (in the product, in the environment)

Lower runability, machine availability etc.

In order to prevent deposits, various strategies and tools are available, depending on the type of deposit:

Biocides

^■ If deposits are predominantly of microbial origin

^■ Preservation of additives and fresh water disinfection Combinations

^■ Biocides against micro-organisms and dispersants against organic deposits

Cleaning

■ Continuous prevention of deposit build-up

Use of sticky control agents, fixing, hardness stabilisation, ultrasound

^■ Organic and inorganic deposits

Functional Bacteria successfully in use in :

Coolingwater circuits

Foodstorage

Animal care and animal sheds

Hardsurface cleaning, hospitals and much more

Use in the paper industry?

Declining number of biocidal tools (BPR)

Occupational safety always comes first ^■ Reduction of hazardous substances

^■ Further reduction of the effect on the environment (AOX)

^■ Less storage & handling options for hazardous substances Examples

Example 1

Polymer build up

Problem statement

■ Deposits in tanks

Previous approaches to a solution

• Periodic cleaning

• Biocide treatment not possible (WWTP)

Solution administering bacteria

^■ Intensive dosing in ongoing process, later converted to maintenance dosing Result

• Reduced organic deposits; less cleaning

• Remaining deposits present can be removed more easily

The results of the experiment are shown in Figure 2. The Figure shows deposit build up with and without the functional bacteria. It can be seen that the inclusion of the bacteria significantly reduced the level of deposit build up in the tanks.

Example 2

Testliner paper mill

Problem

Odour in the paper mill and in the surrounding area

100% waste paper and dosed cycle; therefore strong

Pollution by organic acids

Previous approaches

Organic biocide treatment led to little success

Use of oxidative biocides is uneconomical Solution by functional bacteria

Thorough system cleaning, water exchange

Intensive dosing of functional bacteria

12/2016 Use of the biological material in the fresh water system to solve the odour problem and the too high proportion of organic acids in the system. So far only use of limewater.

5/2017 Odour has improved, organic acids remained high, otherwise no problems and abnormalities

7/2017 Stabilisation of the pH-value by adding limewater, odour of organic acids no longer detectable

From 5/2018 onwards Dosage of biological material: 0.4 I to 19.5 m3 fresh water when limewater is added to the system

Result

For years successful odour reduction and deposit control with the help of functional bacteria

Clean retention agent system through the use of the biological material in the fresh water A paper mill producing 100% recycled paper from waste paper was found to produce a strong odour. The closed water system was found to be heavily contaminated with a variety of organic acids.

Previous treatment with organic biocide treatment led to little success.

The system was cleaned, and the water changed. After operating for 7 days, 4.8 L/d of a bacterial spore mixture was administered to the system. The bacterial spore mixture comprises bacterial spores of the following bacterial species Bacillus amyloliquefacies ; Bacillus licheniformis ; Bacillus megaterium,· Bacillus pumiius ; and Bacillus subtiiis.

After operating the system for 5 months, the odour levels improved, and there were no problems or abnormalities.

During a subsequent dosage of 6 L/d of the bacterial spore mixture, limewater (calcium hydroxide) was also added to stabilise the pH, and this resulted in no odour being detected.

The bacterial spore mixture was added to the system a year after the initial addition at a concentration of 5 L/d. The system has been operated continuously for 2 years without any odour and without any detrimental levels of deposits forming.

Results of the test are shown in Figure 3. Example 3

Problem

100% waste paper and dosed cyde

Substitution of bioddes as hazardous substances

Odour from oxidative biocides, odour from organic acids

Previous approaches

Fresh water with oxidative biocide (BCDMH)

Circuit with chlorine bleaching lye

Solution by functional bacteria

Intensive dosing in running process, maintenance dosing

12/2018 Start with biological material, dosing in Krofta overflow, 4.8 L/d 12/2018 Odour becomes noticeably better, pH-value drops slightly, is increased by adding limewater

03/2019 Dosage now adjusted to 6 L/d, addition of limewater for pH stabilisation, no more use of biocides in the factory

4/2019 Massive reduction and dissolution of slimy deposits

8/2019 Addition of biological material at 5 L/d levelled out

12/2019 Dosage biological material + limewater dosage, no more use of biocides, no more abnormalities

Result

Increase of occupational safety

Reduced odour (no more "chemical odour")

Less deposits, organic acids sink

A cylinder wet machine having a 98% closed circuit was used in the manufacture of cardboard from 100% waste paper continuously for 6 days a week.

Oxidative biocide l-Bromo-3-chloro-5,5-dimethylhydantoin (BCDMH) was used in the system to try and reduce odour and deposit formation. Chlorine bleaching lye was also used to try and reduce odour and deposit formation. Both approaches had limited success. 2 L of the bacterial spore mixture used in Example 2 was introduced into the Krofta overflow at a rate of 4.8 L/d. Within a few weeks the odour became noticeably better and the pH value dropped slightly. Limewater was added to increase the pH to a range from 6.3 to 7.3.

The bacterial spore mixture was added at a concentration of 4.5el l spores/L at a rate of 6 L/d, with the controlled addition of limewater to increase the pH to a range from 6.3 to 7.3. Biocides are no longer used in the factory.

After 4 months of use there was a massive reduction and dissolution of slimy deposits on the surfaces of the machine.

After 8 months of use the rate of bacterial spore addition levelled out to 5 L/d, without any abnormalities or problems.

Figure 4 shows the level of organic acids in system overtime. Without bacterial spores the amount of organic acids rises up to 7500 and 7300 mg/L. After addition bacterial spores the amount of the organic acids decreased to 6000 mg/L.

Example 4

Problem

Batches and holes in the tissue

Deposits in the white water and on the disc filter

Processing problems due to stains in the tissue Previous approaches

Process water must often be replaced during shutdowns

No success with biocides

Solution by functional bacteria

Intensive system cleaning

6/2018 Start with biological material in the clear water of the machine

Dosing of biological material into the clear water: 24 dosing pulses of 17 min each, 2 L/d Result

No lumps, holes = Clean machine Increased runability without the use of hazardous substances

A paper mill producing 3.5 tonnes tissue/day, and having an almost closed cycle, was found to have quality issues. In particular, batches of tissue were produced with holes in the tissue and with stains on the tissue. In addition, deposits in the white water and on the disc filter found.

The use of biocides was not found to be effective and the process water had to be frequently replaced resulting in many shutdowns.

The system was intensively cleaned and 2L of the bacterial spore mixture used in Example 2 was introduced in the clean water of the machine: 24 dosing pulses of 17 min each, 3.46 L/d. Bacterial spores are added at a concentration of 4.5el l/L.

This treatment resulted in the tissue product being reliably produced without any holes or stains.

Example 5

Problem

Odour in tissue

Deposits

Previous approaches

None

Solution by functional bacteria

Intensive system cleaning

Dosing of biological material into the clear water: 24 dosing spurts of 18 min each , 3.46 L/d

Result

Fewer deposits

Fewer odorous substances in the tissue A paper mill producing 44 tonnes of tissue/day, and having an almost closed cycle, was found to have quality issues. In particular, batches of tissue were found to have an odour, and deposits where identified in the machine.

The system was intensively cleaned and the bacterial spore mixture used in Example 2 was introduced in the clean water of the machine: 24 dosing pulses of 18 min each, 3.46 L/d.

This treatment resulted in a reduction in odour in the produced tissue and fewer deposits on the water bearing system.

Figure 6 shows measurments of the thickness of the deposits using heat exchange measurements (i.e., the amount of heat that is conducted through the walls of the water bearing system is measured, wherein the presence of deposits reduces the amount of heat conducted). Electrical capacity, ultrasonic, optical density, and weight measurments can also be used to determine the amount and rate of deposit formation. It should be noted that when measuring the thickness of the deposits, the thickness seems to increase following exposure to the bactierial spores and/or spore forming bacteria, and then decreases. The reason for this contradictory signal is believed to be due the initial loosening of the deposit resulting in an increase in water penetration temporarily swelling the deposit.

Figure 7 shows a headspace gas chromatography of tissue produced in the absence of the spore derived bacteria and a tissue produced in the presence of the spore derived bacteria. The result shows that the level of volatile odour producing compounds in the tissue is reduced when the bacteria are present within the water bearing system of the paper mill .

Example 6 - Tissue Production

Problem statement

• Stains and holes in the tissue

■ Deposits in the white water and disc filter

Previous approaches to a solution

^■ No results Solution involving functional bacteria

• Thorough system cleaning

• After initial intensive dosing, switched to regular dosing Result

■ No stains, holes and a clean machine

^■ Increased runability without the use of hazardous substances

^■ Reduced odours in the tissue

^■ Permanent use was successful and lead to sustainable robust

system. Figure 8 shows the effect of the addition of the bacterial spore mixture on various parts of the paper mill . In particular, the heavy contamination of the white water and the disc filters can be seen, as well as the significantly cleaner surfaces obtained after running the system with the bacteria derived from the bacterial spores.

Tissue obtained from the paper mill operated with and without the addition of the bactierial spore mixture was tested using headspace gas chromatography. Figure 9 shows that the level of volatile odour producing compounds in the tissue is reduced when the derived bacteria are present within the water bearing system of the paper mill.

Example 7 - Cooling Water System Problem statement

■ Reduced cooling capacity due to deposits

^■ Need for substitution of biocides as hazardous substance

^■ Odour due to biocides , and process water odour

Previous approaches to a solution

■ Organic biocides (CIT/MIT)

^■ Regular manual cleaning

Solution involving functional bacteria

• Intensive dosing while system in operation, followed by a regular dosing program

• If necessary, intermittent disinfection (oxidative biocides) for

Legionella Control

Result

^■ Reduced occupational hazard and cooling capacity restored ■ Reduced odours

^■ Less deposits and no cleaning required

Figure 10 shows the effect of the spore derived bacteria on the level of deposits in the cooling water system of a paper mill . In particular, prior to dosing with the bacterial spore mixture used in Example 2, the functionality of the cooling water system was reduced due to the presence of significant deposits on the walls of the cooling water sytem and in the water itself. The addition of the bacterial spore mixture resulted in significantly reduced deposits on the wall of the cooling water system and in the water itself. In addition the functionality of the cooling water system was significantly improved.

Conclusion The examples demonstrate that the addition of bacterial spores and/or bacteria derived from bacterial spores to water bearing systems significantly reduces the level of deposits formed, and also reduces odour, and structural flaws (e.g., holes, etc.) in the derived paper product.

Clauses

1. Process for preventing or reducing surface deposits and/or odours in water-bearing systems, in particular in all water-bearing systems in paper production (paper, board and cardboard for packaging purposes; hygiene and tissue papers and papers and cardboard for special technical uses), comprising the steps

(a) providing an aqueous solution containing biological material, such as spores and/or bacteria;

b) determining one or more dosing points in a water-bearing circuit; c) dosing the aqueous solution containing the biological material into the water-bearing circuit;

d) germination of the biological material in the water-bearing circuit; e) metabolizing organic material in water-bearing circuits, in particular on their surfaces by the biological material;

f) colonization of surfaces in the water-bearing circuits by the biological material.

2. The process according to clause 1, characterized in that the added biological material is functional bacteria, such as probiotic bacteria and in particular bacteria germinated from spores.

3. The process according to clause 1 or 2, characterized in that the germination of the biological material takes place within the water- bearing circuit.

4. The process according to one of the above clauses, characterized in that the water-bearing circuit is a circuit on a paper machine. 5. The process according to one of the above clauses, characterized in that the biological material in particular forms a thin protective film on the surfaces. 6. The process according to any of the above claims, characterized in that the biological material is dosed continuously or shockwise into the water-bearing circuit. 7. The process according to one of the above clauses, characterized in that the biological material is prepared under specified conditions as regards concentration, pH, temperature and/or nutrient supply before dosing. 8. The process according to any of the above clauses, characterized in that the deposits are at least partially organic in nature.

9. The process according to one of the above clauses for use in water cycles in paper production, in particular in the manufacture of paper, cardboard, paperboard, tissue and the like.

Claims

1. A method for reducing deposit formation in a water bearing system used in the processing of cellulose, the method comprising administering a composition comprising bacterial spores and/or bacteria derived from bacterial spores to the water bearing system, wherein the bacteria cannot digest cellulose but can digest one or more of the following saccharides: alginates, dextran, levan and monosaccharide components D-Glucoronic- acid, D-Galacturonic-acid and D-Mannuronic-acid.

2. The method of claim 1, wherein the water bearing system is a water bearing system used in the manufacture of paper.

3. The method of claim 1 or claim 2, wherein the derived bacteria can digest alginates, dextran, levan and monosaccharide components D- Glucoronic-acid, D-Galacturonic-acid and D-Mannuronic-acid.

4. The method of any one of claims 1 to 3, wherein the bacterial spores and/or derived bacteria are not pathogenic.

5. The method of any one of claims 1 to 4, wherein the bacterial spores and/or derived bacteria are members of the genus Bacillus.

6. The method of any one of claims 1 to 5, wherein the bacterial spores and/or derived bacteria are selected from the following bacterial species:

Bacillus altitudinis ;

Bacillus amyloliquefacies ;

Bacillus coagulans ;

Bacillus kokeshiiformis ;

Bacillus lichen iformis ;

Bacillus megaterium,·

Bacillus pumilus ;

Bacillus subtiHs ; and

Bacillus thermoamylovorans.

7. The method of any one of claims 1 to 6, wherein the bacterial spores and/or derived bacteria comprise one or more of the following bacterial species: Bacillus amyloliquefacies,· Bacillus licheniformis ; Bacillus megaterium,· Bacillus pumilus,· and Bacillus subtiHs.

8. The method of any one of claims 1 to 7, wherein the bacterial spores and/or derived bacteria comprise the following bacterial species: Bacillus amyloliquefacies,· Bacillus licheniformis,· Bacillus megaterium,· Bacillus pumilus ; and Bacillus subtilis.

9. The method of any one of claims 1 to 8, wherein the composition additionally comprises an energy source for the bacterial spores and/or derived bacteria.

10. The method of any one of claims 1 to 9, wherein the composition additionally comprises a pH modifying agent.

11. The method of any one of claims 1 to 10, wherein the composition is administered to the water bearing system at a single site or at multiple sites.

12. The method of any one of claims 1 to 11, wherein the composition is administered to the water bearing system continuously or batch wise.

13. The method of any one of claims 1 to 12, wherein the composition is administered to the water bearing system when there are sufficient saccharide deposits present in the water bearing system to act as an energy source for the bacterial spores and/or derived bacteria.

14. The method of any one of claims 1 to 13, wherein the composition comprises the bacterial spores and the spores germinate after administration within the water bearing system and produce derived bacteria.

15. The method of any one of claim 1 to 14, wherein the derived bacteria colonise surfaces of the water bearing system.

16. The method of claim 15, wherein the derived bacteria form a biolayer on surfaces of the water bearing system.

17. The method of any one of claims 1 to 16, wherein the amount and/or rate of deposit formation in the water bearing system is monitored and the amount of bacterial spores and/or derived bacteria administered to the system is adjusted to keep the amount of deposit formation at a desirable level.

18. The method of claim 17, wherein a probe for measuring the amount and/or rate of deposit formation is positioned within the water bearing system and used to monitor the amount and/or rate of deposit formation.

19. A composition comprising bacterial spores and/or bacteria derived from the bacterial spores for administration into a water bearing system, wherein the bacteria cannot digest cellulose but can digest one or more of the following saccharides: alginates, dextran, levan and monosaccharide components D-Glucoronic-acid, D-Galacturonic-acid and D-Mannuronic- acid, and wherein the composition further comprises a stabilising agent and/or a non-biocidal-active quaternary ammonium compound.

20. A water bearing system having a biolayer of bacterial spores and/or bacteria derived from the bacterial spores formed on a surface of the system, wherein the bacteria cannot digest cellulose but can digest one or more of the following saccharides: alginates, dextran, levan and monosaccharide components D-Glucoronic-acid, D-Galacturonic-acid and D-Mannuronic-acid.

21. The water bearing system of claim 20, wherein the water bearing system is a water bearing system used in the manufacture of paper.