PULP AND PAPER INDUSTRIES Group 4 Cynthia Alcántara Lucía Escorial Sara Gómez Michael Moreau Marta Pérez

PULP AND PAPER INDUSTRIES

Group 4Cynthia Alcántara

Lucía EscorialSara Gómez

Michael MoreauMarta Pérez

Introduction

Classification

Departamento deINGENIERÍA QUÍMICA y TECNOLOGÍAdel MEDIO AMBIENTE

• Main consumer of natural resources:– Wood (as raw material)– Fossil, fuel, electricity (as energy)– Water

• Wood contains: – 50% water– 45% cellulose– 25% hemicelluloses– 25% lignin– 5 % other organic a inorganic materials

General Information

Process

Consumption

Techniques

BAT

Emerging

Classification of pulp and paper mills

•Kraft pulping process• Sodium sulphate

•Sulphite pulping process:• Magnesium sulphite pulping

•Mechanical and chemi-mechanical• mechanical energy applied to the wood

matrix•Recycled fibre processing (recovered fibre)•Non integratepaper mills

• paper manufacturing independently from pulp manufacturing.

Introducción


Introduction

Classification

Process

Consumption

Techniques

BAT

Emerging

Non integratepaper mills• Paper and board manufacturing is described independent from pulp manufacturing.•Most paper mills in Europe are non-integrated mills.•All types of paper and board-making processes have the following basic units:

• Stock preparation• Approach flow system• Paper and board machine• Calenders, coaters, a coating colour kitchen,

winders, rewinders and a roll wrapping station.

Introducción


Introduction

Classification

Process

Consumption

Techniques

BAT

Emerging

Applied Processes and Techniques

• Stock preparation• Is conducted to convert raw stock into finished

stock• The pulp is prepared for the paper machine• Including the blending of different pulps,dilution and the addition of chemicals• Is based on the removal of impurities

•Paper machine• The paper is formed• Most of the properties of the paper are

determined.

Introducción


Introduction

Classification

Process

Consumption

Techniques

BAT

Emerging


•Water circuits and fibre recovery • 3 process water circuits in a paper mill: • primary circuit (short circulation)• secondary circuit (long circulation)• tertiary circuit (excees water from secondary)

• Broke system• Return the paper fibre back to the process• The amount of broke produced during

papermaking is normally 5 - 20 % of the machine capacity

• Wet broke: normal operation• Dry broke: in finishing operations

Introducción


Introduction

Classification

Process

Consumption

Techniques

BAT

Emerging


•Sizing (optional)• agents are applied to the fibre matrix to

increase the strength of the base paper• and tomodify the surface properties with

respect to liquid uptake during writing, printing or coating

•Coating (optional)• application of a mixture of water, white

pigments, binder…to create specific surface qualities

•Dyeing (optional)• For coloured papers

Introducción


Introduction

Classification

Process

Consumption

Techniques

BAT

Emerging


•Addition of chemicals• To achieve certain paper properties• To improve operations in the production

process•Calendering (optional)

• The objective is to produce a smooth paper surface that meets the printing and writing requirements for the intended use.

Introducción


Introduction

Classification

Process

Consumption

Techniques

BAT

Emerging

Consumption and emission levels• Consumption of major raw material–Fibres, water and chemical additives

• Water use–Cleaning water, solvent, cooling …

• Use of additives• Energy demand• Wastewater emissions:–Rejects from stock cleaning–Temporary and accidental discharges–Cooling and sealing waters

Introducción


Introduction

Classification

Process

Consumption

Techniques

BAT

Emerging

Consumption and emission levels

•Solid waste generation wastewater:–Rejects from stock preparation–Sludge from water treatment

•Atmospheric emissions:–Air emissions from paper machines–Air emission from energy generation–Odour from vapours and from wastewater treatment

•Noise from paper machines (local)

Introducción


Introduction

Classification

Process

Consumption

Techniques

BAT

Emerging

Techniques to consider in the determination of BAT

•Techniques currently commercially available for prevention or reduction of:

– emissions/waste–reducing consumption of energy –reducing consumption of raw materials1) Internal treatment of white water by use of membrane filtration and recycling of treated process water–Micro-filtration–Ultra-filtration–Nano-filtration (NF) –Reverse osmosis (RO)

Introducción


Introduction

Classification

Process

Consumption

Techniques

BAT

Emerging


2) Water management and minimising the use of water for different paper grades–Efficient separation of cooling waters from process water.–The shower water system is usually the biggest consumer of fresh water: most of the fresh water must be replaced by clarified white water.–Recycling part of the vacuum pump sealing water.–Design and maintenance of piping and storage chests.

Introducción


Introduction

Classification

Process

Consumption

Techniques

BAT

Emerging


3) Reduction of fibre and filler losses–Tuning of the pulp refining and screening just ahead of the feed to the paper machine to maintain proper balance of different types of fibres in pulp.–Efficient control of paper machine headbox–Sufficient use of paper chemicals to reach improved fibre retention in order to get a good paper web formation.

Introducción


Introduction

Classification

Process

Consumption

Techniques

BAT

Emerging


4) Recovery and recycling of coating colour-containing effluent–The pigments are expensive, so the recovery of a part of the coating colour for reapplication and minimisation is cost-effective–One method is ultra-filtration: water and chemicals are separated from each other by using a semi-permeable membrane.

Introducción


Introduction

Classification

Process

Consumption

Techniques

BAT

Emerging


5) Energy savings through energy efficient technologies

•There are opportunities for energy saving in many stages of the process.•Example: Energy savings through heat recovery systems–The purpose: to lower the mill' s consumption of primary energy by using waste energy from the process

Introducción


Introduction

Classification

Process

Consumption

Techniques

BAT

Emerging


6) Measures for noise reduction– For internal noise sources:

• Installations of a new closed hood with higher sound insulation

– For external noise control:• Installation of absorptive silencers • Installation of pipe resonators to reduce noise

levels from exhaust air fans and vacuum pumps,• Silencers and sound insulation hoods for the fans

on the building roof.

Introducción


Introduction

Classification

Process

Consumption

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BAT

Emerging


7) Others techniques are:• Control of potential disadvantage of closing up the water systems • Separate Pre-treatment of Coating Wastewaters• Measures to reduce the frequency and effects of accidental discharges• Measurement and automation• Installation of an equalisation basin and primary treatment of wastewater• Secondary or Biological Treatment - Aerobic Methods• Chemical precipitation of wastewater from paper mills• Substitution of potentially harmful substances by use of less harmful alternatives• Pre-treatment of sludge (de-watering) before final disposal or incineration• Options for waste treatment.• Installation of low NOx technology in auxiliary boilers (oil, gas, coal)•Use of combined heat and power generation•Optimisation of de-watering in the press section of the paper machine

Introducción


Introduction

Classification

Process

Consumption

Techniques

BAT

Emerging

BAT: Best Available Techniques

• General measures:1.Training, education and motivation of staff and operators.2.Process control optimisation.3.Sufficient maintenance has to be ensured.4.Environmental management system which clearly defines the responsibilities for environmentally relevant aspects.

Introducción


Introduction

Classification

Process

Consumption

Techniques

BAT

Emerging


• Measures for reducing emissions to water:1.Minimising water usage for different paper grades by increased recycling of process waters.2.Control of potential disadvantages of closing up the water systems.3.Construction of a balanced white water, filtrate and broke storage system and use of constructions, design and machinery with reduced water consumption when practicable.4.Measures to reduce frequency and effects of accidental discharge.

Introducción


Introduction

Classification

Process

Consumption

Techniques

BAT

Emerging


• Measures for reducing emissions to water:5.Collection and reuse of clean cooling and sealing waters or separate discharge.6.Separate pre-treatment of coating wastewaters.7.Substitution of potentially harmful substances by use of less harmful alternatives.8.Effluent treatment of wastewater by installation of an equalisation basin and primary treatment.9.Secondary or biological treatment of wastewater

Introducción


Introduction

Classification

Process

Consumption

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BAT

Emerging


• Measures for reducing emissions to air:1.Installation of low NOx technology in auxiliary boilers.2.Reducing SO2 emissions from steam boilers by using low sulphur oil and coal or controlling S emissions.3.Use of combined heat and power generation. 4.Using renewable sources like wood or wood waste to reduce the emissions of fossil CO2 (only applicable if papermaking is integrated with virgin pulp production).

Introducción


Introduction

Classification

Process

Consumption

Techniques

BAT

Emerging


• Noise attenuation:–BAT is the reduction of noise levels audible in the vicinity of paper mills.–The measures applied will depend to a large extent on the specific noise problem of a mill and the targets set. –Usually they will be much stricter when the mill is located adjacent to a residential area.

Introducción


Introduction

Classification

Process

Consumption

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BAT

Emerging


• Chemical usage:1.Ensure the availability of a database for all used chemicals and additives .2.Application of the principle of substitution: less hazardous products are used when available.3.Measures to avoid accidental discharges to soil and water from handling and storage of chemicals. 4.Design and operation of facilities in such a way that dangerous substances cannot escape.

Introducción


Introduction

Classification

Process

Consumption

Techniques

BAT

Emerging

Emerging Techniques

• Some “promising techniques” are addressed that can not (yet) be considered BAT due to the stage of development of these techniques.• The paper mill of the future can be probably described by the following characteristics:

–Decrease in paper mill water consumption and specific emissions by means of increasing water re-use, closed water loops and internal water treatment–Increase in electricity consumption (specific to production)–Decrease in paper mill noise level

Introducción


Introduction

Classification

Process

Consumption

Techniques

BAT

Emerging

Emerging Techniques

• Minimum effluent paper mills - optimised design of water loops and advanced wastewater treatment technologies.• Impulse technology for dewatering of paper.• Condebelt ® process.• Internal heat pumps.• Total site integration tools.

Introducción


Introduction

Classification

Process

Consumption

Techniques

BAT

Emerging

Emerging Techniques

• Minimum effluent paper mills - optimised design of water loops– To apply a combination of membrane filtration, ozonation and evaparation–Can reduce fresh water consumption– Are only applied in pilot-scale.– Full scale expierences are limited to a few examples in the world– There are still operation problems and relatively high costs

Introducción


Introduction

Classification

Process

Consumption

Techniques

BAT

Emerging

Emerging Techniques

• Impulse technology for dewatering of paper– Dryness levels of 55-65% before the drying section (15-25 % more than ordinary press section)– Decrease the heat consumption– The development work is still at an early stage.

Introducción


Introduction

Classification

Process

Consumption

Techniques

BAT

Emerging

Emerging Techniques

• Condebelt ® process–The Condebelt ® drying process is a new way to dry paper and board. –The paper web coming from the press section is dried between two steel belts instead of traditional steam cylinders.– In 1999 there was two Condebelt ® drying processes in commercial operation– More square meters from the same amount of fibres can be manufactured without loosing product quality– Higher potential for energy recovery

Introducción


Introduction

Classification

Process

Consumption

Techniques

BAT

Emerging

Emerging Techniques

• Internal heat pumps– Are used for pumping heat from one medium (air) to another (for example water)– Investment costs are quite high

Introducción


Introduction

Classification

Process

Consumption

Techniques

BAT

Emerging

Emerging Techniques

• Total site integration tools– Try to combine the whole energy, water, fibre, chemicals, system to create a good integration of the mill– Lower emissions to air and water and at the same time to reduce the formation of solid waste and energy– The total site integration tool software is not a big investment.

Introducción


Introduction

Classification

Process

Consumption

Techniques

BAT

Emerging

Thank you for your attention!

Documents

PULP AND PAPER INDUSTRIES Group 4 Cynthia Alcántara Lucía Escorial Sara Gómez Michael Moreau Marta Pérez