University Complutense of Madrid

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1 INTEGRAL WATER MANAGEMENT IN THE PAPER INDUSTRY: A CASE STUDY A. Blanco and C. Negro Complutense University of Madrid ablanco@ucm.es cnegro@ucm.es 1 University Complutense of Madrid Origin: 1293 Students: Staff: Budget: 523 millions 2 A. Blanco / C. Negro 1

2 Paper Research Group Its activities are conducted in two lines: Fundamental Research and the Applied Research, in order to enhance the technical and scientific expertise of the industry. The Fundamental Research is devoted to the acquisition of new knowledge and the fundamental understanding of the phenomena taking place during pulp and papermaking. On the other hand, the Applied Research is devoted to the application of these knowledge to solve the needs of the industry and suppliers. 3 SPANISH PAPER SECTOR Production Paper Pulp (t/y) Total Total Consumption Paper Pulp (t/y) Total Total Total 2017 Total 2011 Collection Utilisation Collection rate Utilisation rate Recycling rate ,7 73, ,5 82,1 79,2 Source: ASPAPEL, A. Blanco / C. Negro 2

3 WATER USAGE AND SOURCES Pulp Paper Total water usage (m 3 /t) 35,4 7,9 Effluent (m 3 /t) 29 7 Water Capture per source Million m 3 Well 23 Surface Waters 70 Supply Net 12,5 Recovered Water 3,5 TOTAL WASTE WATER EFFLUENTS Onsite Waste Water Treatments % of Total Primary 8 Primary + Secondary 75 Primary + Secondary 17 + Tertiary Effluent Kg/t Quality COD (pulp) 7,2 COD (paper) 2,2 TSS (pulp) 1,0 TSS (paper) 0,4 Waste Water effluents Million m 3 Rivers and Lakes 34 Sea 36 Urban Sewers 21 Estuaries 2 TOTAL WATER 93 DISCHARGES 6 A. Blanco / C. Negro 3

4 Fresh water reduction Drivers Effluent limits Legislation Social pressure Effluent treatment costs Fresh water costs RM and E savings Image Towards Closed water circuits Closure degree varies with grades 90% reduction of water consumption in 3 decades Minimize water footprint of the paper industry Water quality appropriate for type of use 7 EVERY 2,6 WEEKS THE POPULATION OF MELBOURNE 8 A. Blanco / C. Negro 4

5 10 A. Blanco / C. Negro 5

6 Domestic Agriculture Recreation Energy Industry 11 Vision Water quality appropriate for type of use. Minimize water footprint. Industrial growth decoupled from resource consumption. Symbiotic approach integrating industrial, urban and rural resources Minimum contribution to water stress 12 A. Blanco / C. Negro 6

7 Kalunborg Industry Symbiosis 13 Vision Water quality appropriate for type of use. Minimize water footprint. Industrial growth decoupled from resource consumption. Symbiotic approach integrating industrial, urban and rural resources RETOPROSOST Minimum contribution to water stress 14 A. Blanco / C. Negro 7

8 85 % 30 % 15 Holmen Paper t/y Mill Production Products Madrid t/y Newsprint, Salmon and Improved Newsprint Braviken t/y Newsprint, MF magazine, coloured newsprint, and telephone directory paper Hallsta t/y MF magazine, SC paper, book paper and newsprint, View Product Weight g/m 2 Holmen News Coldset 40* ,8 Holmen News Heatset ,8 Holmen News Flexo 45 Holmen News Salmon Holmen Plus 65 45* 49 52* A. Blanco / C. Negro 8

9 Process & water management 1. HIGH PRODUCTIVITY Formation Retention Drainage Max. production Without breaks Minimum cost WATER MANAGEMENT 2. HIGH QUALITY PRODUCTS Opacity, brightness, strength,. 17 Water Quality- interactions Fibre-Fibre Fibre-agregates Fibre-Fines Fines-DCM DCM-Filler Fibre-DCM Fibre-Filler Fines-Filler Filler-filler DCM-DCM Precipitation Disolution Filler-Agregates 18 A. Blanco / C. Negro 9

10 Wet end Chemistry 19 The Handbook of Environmental Chemistry. Water Reuse Within the Paper Industry A. Blanco, D. Hermosilla and C.Negro, Springer Berlin Heidelberg. June A. Blanco / C. Negro 10

11 Sustainable water management Conservation 10-12% Fresh water consumtion Time 21 The Handbook of Environmental Chemistry. Water Reuse Within the Paper Industry A. Blanco, D. Hermosilla and C.Negro, Springer Berlin Heidelberg. June A. Blanco / C. Negro 11

12 Loops Separation Fresh Water Effluent Counter-current flow K1 Efficiency of fresh water use in the paper machine. >1 K2 Efficiency of loop separation >1 K1/K2 = 1 Good counter-current flow 23 Process optimization 24 A. Blanco / C. Negro 12

13 Sustainable water management Conservation 10-12% Fresh water consumtion Process optimization 25-30% Time 25 The Handbook of Environmental Chemistry. Water Reuse Within the Paper Industry A. Blanco, D. Hermosilla and C.Negro, Springer Berlin Heidelberg. June A. Blanco / C. Negro 13

14 Process optimization UF 27 Sustainable water management Conservation 10-12% Fresh water consumtion Process optimization 25-30% Internal treatments UF: 12-15% Time 28 A. Blanco / C. Negro 14

15 Improve water management A MUST! DAF DAF COD mg/l Sustainable water management Conservation 10-12% Fresh water consumtion Process optimization 25-30% But there is a limit! Internal treatments UF: 12-15% New alternatives SWM R&D Time 30 A. Blanco / C. Negro 15

16 The Handbook of Environmental Chemistry. Water Reuse Within the Paper Industry A. Blanco, D. Hermosilla and C.Negro, Springer Berlin Heidelberg. June TERTIARY LOOP SECONDARY LOOP Fresh Water QUATERNARY LOOP Fresh Water Treatment Sludge Long circuit PRIMARY LOOP Short Circuit White Waters I Pulp Preparation Paper Machine Excess Water Lodos PAPER Fiber Recovery and Water Clarification White Waters II Fiber Recovery Excess Water Biological Treatment of Effluent Biosludge Final Effluent mwwtp 32 A. Blanco / C. Negro 16

17 Fresh water uses Showers Chemicals Boilers Hydraulic sealing 60% 14% 7% 9% Freshwater Evaporation 7 m 3 /t (12%) Recovered paper LOOP 1 LOOP 2 LOOP 3 Recycled paper DAF DAF DAF Dried sludge (2%) Gravity table WWTP Effluent (86%) 34 Water uses & quality Minimum quality required for showers PARAMETER VALUE Hardness, mgcaco3/l <200 Alkalinity, mgcaco3/l <100 Suspended solids <5 (TSS), mg/l COD, mg/l <5 Deposits of CaCO 3 Deposits, biofilms, abrasion Conductivity, µs/cm <500 Iron, mg/l <0,1 Aluminium, mg/l 0,1 Magnesium, mg/l <15 Scaling, corrosion, odours Chloride, mg/l <50 Sulfates, mg/l <100 Microorganisms, <1 CFU/100mL Aerosols 35 A. Blanco / C. Negro 17

18 Selection of technologies Absence of microorganisms at final consumption Removal of salts (<0,5 ms/cm) and microorganisms To ensure an optimal performance of RO (LSI<3) To reduce organic matter (fouling) and SO 4- (legal limits) Chlorine/Chloramines/UV RO MF/UF BIOLOGICAL TREATMENT Ordoñez R et al. Water Sci Tech 2010 (62.7): Multi-barrier double membrane systems LSI = Langelier Saturation Index 37 Effluent reclamation Freshwater ALTERNATIVE LOOP 1 LOOP 2 LOOP 3 Gravity table DAF COD: mgl Sulphates: mg/l Si: mg/l Anaerobic + aerobic Coagulation Flocculation Limit: silica MF/UF RO Limit: concentrates Coagulation + softening + flocculation 38 A. Blanco / C. Negro 18

19 Performance of biological systems Anaerobic treatment PP-A UASB PP-B EGSB PP-A Actived sludge PP-B MBR b COD, % BOD5, % SO4 2- % 45 ± 8 72 ± ± 16 Aerobic treatment 54 ± 8 68 ± 9 30 ± 16 1,5 kw h/m 3 treated water COD, % BOD5, % 60 ± ± ± 7 95 ± 2 Biogas profitability 0,25 Nm 3 biogas/m 3 treated water Effluent quality: PARAMETER ACTIVATED SLUDGE MBR ph 7,91 7,82 TSS, mg/l dcod, mg/l BOD 5, mg/l SO 4, mg/l Irreversible fouling Hollow fibre membranes with Monash fibre deposits Univ, 16 August Reverse osmosis SiO2 (mg/l)/flow (L/h) /01/09 12/01/09 19/01/09 26/01/09 SiO 2 RO-1 Permeate RO-1 Reject RO-2 Permeate RO-2 Reject 02/02/09 09/02/09 16/02/09 23/02/09 02/03/09 SILICA IS A LIMITATION FOR RO b scaling Silica Permeate Excelent quality to substitute fresh water Recovery of 20% Limitation Concentrate PARAMETER VALUES LAW ph 8 - Conductivity, ms/cm 9,1 7,5 tcod, mg/l >20% >30% 43 A. Blanco / C. Negro 19

20 Treatment of RO concentrates Optimum coagulant: PAC Dose (2-2,5-3 g/l) Lime softening: ph (8, 9,5 y 10,5) Flocculation Flocculant type (apam, cpam) Dose (3-5-7 g/l) Coagulant (mg/l) Lime (ph) Floculant (mg/l) COD removal (%) Conductivity removal (%) 2500 PAC NO NO % NO 5 (apam) % +45% (apam) (apam) 60 = (apam) = +10% 44 Mill effluent treatment and reuse Water recovery in RO units is limited by silica 20-40% RO recovery Anaerobic + MBR + RO 80% RO recovery if silica is removed. Limitation MBR permeate can be reuse Showers and preparation of some chemicals X Not suitable to prepare cpambentonite retention system due to its anionic nature which reduce their efficiency. Limitation Important fresh water savings can be achieved There is a limit: m 3 /t still necessary This solution is not sustainable in water stress areas! 45 A. Blanco / C. Negro 20

21 TERTIARY LOOP SECONDARY LOOP Fresh Water QUATERNARY LOOP Fresh Water Treatment Sludge Long circuit PRIMARY LOOP Short Circuit White Waters I Pulp Preparation Paper Machine Excess Water Lodos PAPER Fiber Recovery and Water Clarification White Waters II Fiber Recovery Excess Water Biological Treatment of Effluent Biosludge Final Effluent mwwtp 46 Pilot Plants (1.5 m 3 /h) Pilot plant trials during 3 months at Cuenca Media-Alta of Arroyo Culebro mwwtp 47 A. Blanco / C. Negro 21

22 Pre-treatments performance COD (mg/l) Fe COD Fe (mg/l) Tertiary treated water!!! TMP (bar) 23/10 06/11 20/11 04/12 18/12 01/01 15/01 29/01 12/02 1,5 1,2 0,9 0,6 0,3 0,0 TMP Flux Flux (LMH) Pressurized MF 100% SS removal 25% DBO 5 removal 23/10 06/11 20/11 04/12 18/12 01/01 15/01 29/01 12/02 50 Reverse osmosis performance Flux (LMH) 32 RO-1 RO-2 28 RO Parameter RO-1 RO-2 RO-3 Limit Conductivity, µs/cm <500 tcod, mg/l <5 <5 <5 <5 SO4, mg/l <3 <3 <3 < TSS, mg/l <2 <2 <2 <5 Hardness, mg/l <7 <7 <7 <200 23/10 06/11 20/11 04/12 18/12 01/01 15/01 29/01 12/02 Membrane change in RO-2. Chloramines addition in this line. NO3, mg/l 0,69 0,23 0,24 <1 P, mg/l 0,07 0,06 0,06 <0,2 Uncontrolled dumping of free chlorine within the tertiary treatment increased flux & did not oxidized the membrane. Ordoñez R et al. CEJ, A. Blanco / C. Negro 22

23 In 2012 CYII built a WWRP, based on this multi-barrier membrane system, to supply Holmen Paper Madrid with reclaimed water instead of drinking water Limits/barriers: Quality of the municipal waste water effluent Legislation Aceptation Water price 52 Conducción a HPM PRFV 500 Ø PN16 Lenght m 53 A. Blanco / C. Negro 23

24 55 Sustainable Process-Water-Product Management Where are you? m 3 /t =?? Fresh water consumtion DF Closure has consequences Problems? Process change with time Optimised water circuit? Reduced maintenance costs Water effects? DF Where do you want to be? m 3 /t =?? Driven force? 56 A. Blanco / C. Negro 24

25 Closure limits Fresh water costs $$ m 3 /t Problem 2 Problem 3 Problem 1 $$ $$ Long term losses Discharge costs Loss of opportunities Total costs Chemicals costs Product 1 g/l mg/l COD Starch Sizing CMC Defoamers 100/ Sustainable Process-Water-Product Management Water audit Water quality Problems Mapping: ph, ʎ, COD,... Critical contaminants/areas Sources of problems Critical operation conditions Water capacity Water reuse: K 1, Q stock /Q wastewater Counter current flow: K 1 /K 2 Loop separation: K 2 Water fit for use WWTP efficiency Chemical treatments Loss of opportunities Benchmarking Improvement opportunities Knowledge Critical water issues Goals Awareness Integral P W P management Prevention is key Training program: new procedures Monitoring water quality: checking day list Low retention time: 2 3h Optimize water treatment Chemical treatments Improve treatments efficiency: DAF Maintaining water quality Operation conditions P W P Maintenance program Avoid anaerobic condition Water quality use/quality needed Identify domino effects Reorganization of circuits? Separation of loops Thickeners? Internal treatments kidneys? Effluent treatment and reuse? Model based evaluations? Prioritized list of actions Housekeeping Chemistry $-$ Investments $-$$$ 59 A. Blanco / C. Negro 25

26 Kidney technologies 60 Silica maybe a limitation in deinking plants! [SiO 2 ] reject (mg/l) Saturation R: 40% R: 60% R: 80% Removal [SiO 2 ] feed (%) Modification of ph Conductivity! ph = 8,6 and 2500 mg/l PACl5 60% Viable RO >80% recovery [SiO 2 ] removal (%) Silica removal > 85% PACl3 at ph=10.5 PACl3 at ph=8.6 PACl4 at ph=10.5 PACl4 at ph=8.6 PACL5 at ph=10.5 PACL5 at ph=8.6 RO recovery ~ 40% Monash dosage Univ, (mgl 16 August -1 ) A. Blanco / C. Negro 26

27 SILICA REMOVAL EFFLUENT PROCESS WATER Prescreening SOLUBLE Mg COMPOUNDS COMMERCIAL Al SALTS KINETICS/ MECHANISM MgCl 2 6H 2 O COMMERCIAL PAM AND PA HYBRIDS NEWLY DEVELOPED PA PADADMAC HYBRIDS COAGULATION SPARINGLY SOLUBLE Mg COMPOUNDS KINETICS/ MECHANISM MgO INFLUENCE OF SS IN DAF COAGULATION CHITOSAN DERIVATES Prescreening ACTIVATED ALUMINA HYDROTALCITE SILICA REMOVAL DURING SOFTENING ADSORPTION I. Latour Doctoral thesis TREATMENT SELECTION Characteristics of the treatments to achieve high silica removal rates (>90%) for the treatment of high silica content ( mg/l) and low hardness waters (2-7 mg/l) COAGULATION SILICA REMOVAL DURING PRECIPITATIVE SOFTENING ADSORPTION ADDITIVE Hybrid Soluble Mg Sparingly soluble Mg Calcined coagulant compounds compounds hydrotalcite (PANS PA2) (MgCl 2 6H 2 O) (MgO) TEMPERATURE 25ºC 25ºC 35ºC 25ºC 50ºC ph DOSAGE 2500 mg/l 1500 mg/l 500 mg/l 1500 mg/l (50ºC) 2500 mg/l(25ºc) COD REMOVAL FINAL CONDUTIVITY SLUDGE GENERATION COST Monash Univ, 16 August A. Blanco / C. Negro 27

28 H1 CONCLUSIONS How far can we go? Board/packaging 0-3 m 3 /t Liner m 3 /t Graphic paper 6-15 m 3 /t 100% Reclaimed water Tissue 6-12 m 3 /t Optimal SWM = SPWPM Global approach but local solutions Look outside your fence! Pre-treatments are essential and cheaper Limits are further that what we expect R&D studies focus Concentrates Scaling / Fouling Energy Post-treatments are available if needed Barriers: legal, acceptation Costs 68 INTEGRAL WATER MANAGEMENT IN THE PAPER INDUSTRY: A CASE STUDY A. Blanco and C. Negro Complutense University of Madrid 69 A. Blanco / C. Negro 28

29 Diapositiva 68 H1 HP, 14/08/2018