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

Introduction Classification Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del 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 Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE 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 Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE 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 Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE Introduction Classification Process Consumption Techniques BAT Emerging

Applied Processes and Techniques 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 % of the machine capacity Wet broke: normal operation Dry broke: in finishing operations Introducción Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE Introduction Classification Process Consumption Techniques BAT Emerging

Applied Processes and Techniques 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 Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE Introduction Classification Process Consumption Techniques BAT Emerging

Applied Processes and Techniques 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 Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE 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 Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE 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 Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE 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 materials 1) 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 Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE Introduction Classification Process Consumption Techniques BAT Emerging

Techniques to consider in the determination of BAT 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 Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE Introduction Classification Process Consumption Techniques BAT Emerging

Techniques to consider in the determination of BAT 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 Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE Introduction Classification Process Consumption Techniques BAT Emerging

Techniques to consider in the determination of BAT 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 Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE Introduction Classification Process Consumption Techniques BAT Emerging

Techniques to consider in the determination of BAT 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 Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE Introduction Classification Process Consumption Techniques BAT Emerging

Techniques to consider in the determination of BAT 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 Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE Introduction Classification Process Consumption Techniques BAT Emerging

Techniques to consider in the determination of BAT 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 Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE 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 Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE Introduction Classification Process Consumption Techniques BAT Emerging

BAT: Best Available Techniques 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 Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE Introduction Classification Process Consumption Techniques BAT Emerging

BAT: Best Available Techniques 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 Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE Introduction Classification Process Consumption Techniques BAT Emerging

BAT: Best Available Techniques Measures for reducing emissions to air: 1.Installation of low NO x technology in auxiliary boilers. 2.Reducing SO 2 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 CO 2 (only applicable if papermaking is integrated with virgin pulp production). Introducción Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE Introduction Classification Process Consumption Techniques BAT Emerging

BAT: Best Available Techniques 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 Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE Introduction Classification Process Consumption Techniques BAT Emerging

BAT: Best Available Techniques 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 Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE 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 Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE 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 Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE 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 Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE 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 Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE 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 Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE 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 Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE 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 Departamento de INGENIERÍA QUÍMICA y TECNOLOGÍA del MEDIO AMBIENTE Introduction Classification Process Consumption Techniques BAT Emerging

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