meta data for this page
Differences
This shows you the differences between two versions of the page.
Both sides previous revisionPrevious revisionNext revision | Previous revision | ||
sector:ippu:pulp_paper_food:pulp_and_paper_industry:start [2023/04/11 15:29] – [Sulphite process] kludt | sector:ippu:pulp_paper_food:pulp_and_paper_industry:start [2023/04/19 12:39] (current) – [Paper and carton production] kludt | ||
---|---|---|---|
Line 9: | Line 9: | ||
\\ | \\ | ||
- | The fibre for paper production is produced, via chemical or mechanical processes, either from fresh fibre or from processed recycled paper. A distinction is made between integrated and non-integrated pulp and paper mills. Non-integrated pulp mills solely produce pulp for sale on the open market. | + | The fibre pulp for paper production is produced, via chemical or mechanical processes, either from fresh fibre or from processed recycled paper. A distinction is made between integrated and non-integrated pulp and paper mills. Non-integrated pulp mills solely produce pulp for sale on the open market. |
On the other hand, integrated mills produce both pulp and paper, at integrated sites. A paper mill can either produce paper from fibre material produced at other locations or be integrated within complete pulping processes set up at one site. | On the other hand, integrated mills produce both pulp and paper, at integrated sites. A paper mill can either produce paper from fibre material produced at other locations or be integrated within complete pulping processes set up at one site. | ||
Line 20: | Line 20: | ||
==== Sulphate process ==== | ==== Sulphate process ==== | ||
- | The sulphate or kraft process is the world' | + | The sulphate or kraft process is the world' |
- | This process produces atmospheric emissions in chemical recovery (boilers), in bark combustion, from lime kiln - from the combustion of strong and weak non-condensable gases (NCG) in dedicated burner, in wood-chip storage, in pulp digestion, in pulp washing, in bleaching, in bleach-chemical processing, in evaporation, in sorting and washing, in processing of circulating water and in operation of various types of tanks. Such emissions include fugitive emissions that occur at various processing points – primarily in (liquor)-recovery boilers, lime kilns and auxiliary boilers. The main components of emissions include nitrogen oxides, sulphur-containing compounds, such as sulphur dioxide, and NCG which consists mainly out of reduced sulphur | + | This process produces atmospheric emissions in chemical recovery (boilers), in bark combustion, from lime kiln - from the combustion of strong and weak non-condensable gases (NCG) in dedicated burner, in wood-handling, in pulp cooking, in pulp washing, in bleaching, in bleaching-chemical processing, in evaporation, |
- | The two German sulphate-pulping plants are fitted with a system for post-incineration of NCG equipped with wet scrubbers for SOₓ removal and with systems for NOx-reduced combustion in recovery boilers (>20 % NOₓ reduction; figures of the German Pulp and Paper Association (VDP, September 2004). | ||
- | ==== Sulphite process ==== | + | The two German sulphate-pulping plants are fitted with a system for post-incineration of NCG equipped with wet scrubbers for SOₓ removal and with systems for NOx-reduced combustion in recovery boilers (>20 % NOₓ reduction; figures of the German Pulp and Paper Association (VDP, September 2004). Because of the odours of reduced sulphur compounds, the two relevant plants are practically leak-proof and fitted with an advanced collection and odour abatement technique - otherwise they would not be permitted in Germany. All residues end up in (liquor)-recovery boilers and do not emit in reduced form. |
- | Sulphite | + | ==== Sulphite process |
- | Atmospheric emissions occur especially in recovery (boilers) and in bark combustion. | + | Sulphite pulp is produced in 4 of 6 installations in Germany. In such plants, pulping is based on the use of aqueous sulphur dioxide (SO₂) and a base - calcium, sodium, magnesium or ammonium. The four German mills use the acid bisulphite method. Acid processes are those in which the pH is 1 – 2.5. Sulphite pulping for papermaking derives its name from the use of a bisulphite solution as the delignifying medium. The cation used for papermaking pulp is magnesium (all 4 mills in Germany). The sulphate process and the sulphite process have numerous similarities, |
- | Waste-gas emissions with less-concentrated SO₂ are released in washing and sorting processes, and they are released by ventilation shafts of evaporators and by various tanks. Such emissions | + | Atmospheric emissions occur especially in recovery (boilers) and in bark combustion. Waste-gas emissions with less concentrated SO₂ are released in washing and sorting processes, and they are released by ventilation shafts of evaporators and by various tanks. Such emission |
- | They consist primarily of sulphur dioxide, nitrogen oxides | + | All four sulphite pulping plants in Germany are operated with a collection system for concentrated and less concentrated |
+ | A number of measures are available for reducing consumption of fresh steam and electrical energy and for increasing plant-internal generation of steam and electricity. Sulphite pulp mills can generate their own heat and electricity by using the thermal energy in concentrated liquor, bark and waste wood. The recovery boiler acts as a power station where the concentrated spent sulphite liquor is burnt. Generated heat is utilised for the generation | ||
- | All four sulphite | + | Explanation of the management of process related sulphur and ammonia emissions for pulping |
- | Explanation | + | Emissions |
+ | Exceptions with ammonia emissions are prohibited and actually excluded. Both circumstances are therefore not relevant for Germany. | ||
==== Mechanical pulp ==== | ==== Mechanical pulp ==== | ||
- | Mechanical pulp is produced in 8 plants in Germany. In mechanical pulping, wood fibres are separated from each other via mechanical energy applied to the wood matrix. This process is designed to conserve most of the lignin in the wood, in order to maximise yields while ensuring that the pulp has adequate strength and whiteness. | + | Mechanical pulp is produced in 8 plants in Germany. In mechanical pulping, wood fibres are separated from each other via mechanical energy applied to the wood matrix. This process is designed to conserve most of the lignin in the wood, in order to maximise yields while ensuring that the pulp has adequate strength and whiteness. |
- | * Unordered List Itemthe wood-grinding | + | * the groundwood |
and | and | ||
- | * the refiner | + | * the thermomechanical pulping |
Mechanical-pulp properties can be influenced by increasing the process temperature and, in the case of the refiner process, by chemical pre-treatment of the wood chips. The pulping process in which wood is chemically pre-softened and then broken down into fibres, under pressure, is known as chemical-thermal-mechanical pulping (CTMP). | Mechanical-pulp properties can be influenced by increasing the process temperature and, in the case of the refiner process, by chemical pre-treatment of the wood chips. The pulping process in which wood is chemically pre-softened and then broken down into fibres, under pressure, is known as chemical-thermal-mechanical pulping (CTMP). | ||
Line 51: | Line 52: | ||
==== Paper and carton production ==== | ==== Paper and carton production ==== | ||
- | Paper is made from fibre materials, water and chemical additives. The entire paper-making process consumes large amounts of energy. Electricity is required primarily for operation of various motors and for grinding of fibres. Process heat is used primarily for heating water, other liquids and air, for evaporating water in the drying process of paper machines and for converting steam into electrical energy (with heat/power cogeneration). Large amounts of water are required as process water and for cooling. Various additives are used in the paper production process as process supplies and to enhance product properties (paper additives). | + | Paper is made from fibre materials, water and chemical additives. The entire paper-making process consumes large amounts of energy. Electricity is required primarily for operation of various motors and for grinding of fibres. Process heat is used primarily for heating water, other liquids and air, as steam in the drying process of paper machines and for converting steam into electrical energy (with heat/power cogeneration). Large amounts of water are required as process water and for cooling. Various additives are used in the paper production process as process supplies and to enhance product properties (paper additives). |
- | Most of the waste-gas emissions produced by non-integrated paper mills are produced by steam-production and energy-generation systems. The boilers used in such systems are standard boilers that do not differ from those of other combustion systems. It is assumed that such systems are operated in the same manner as other auxiliary boilers of the same capacity. | + | Most of the waste-gas emissions produced by non-integrated paper mills are produced by steam-production and electricity-generation systems. The boilers used in such systems are standard boilers that do not differ from those of other combustion systems. It is assumed that such systems are operated in the same manner as other auxiliary boilers of the same capacity. |
Overall, most product-specific waste-gas emissions are site-dependent (for example, they depend on the type of fuel used, the size and type of the relevant facility, whether the plant is integrated or non-integrated, | Overall, most product-specific waste-gas emissions are site-dependent (for example, they depend on the type of fuel used, the size and type of the relevant facility, whether the plant is integrated or non-integrated, | ||
Line 61: | Line 62: | ||
==== Activity data ==== | ==== Activity data ==== | ||
- | The figures are available from the base year 1990 onwards and are collected annually by the Association of German Paper Mills compiled in a so-called Performance Report [(and other short statistics: https:// | + | The figures are available from the base year 1990 onwards and are collected annually by the Association of German Paper Mills compiled in a so-called Performance Report [(and other short statistics: https:// |
==== Emissions factors ==== | ==== Emissions factors ==== | ||
Since 2005 real emission factors from German plants for pulp production are available (German contribution to revision of the Best Available Technique Reference Document (BREF) for the pulp and paper industry, 2007). For this reason, in many cases interpolations were carried out between default and country specific values for 1990 and the real, plant-based values (valid from 1995 up to now). | Since 2005 real emission factors from German plants for pulp production are available (German contribution to revision of the Best Available Technique Reference Document (BREF) for the pulp and paper industry, 2007). For this reason, in many cases interpolations were carried out between default and country specific values for 1990 and the real, plant-based values (valid from 1995 up to now). | ||
- | In 2022 the national expert evaluated the used EFs with new figures of the producers [(Figures of facilities: „Data of periodic monitoring“ made available by industry association, | + | In 2022 the national expert evaluated the used EFs with new figures of the producers [(Figures of facilities: „Data of periodic monitoring“ made available by industry association, |
__Table 1: Overview of most recently applied emission factors, in kg/t__ | __Table 1: Overview of most recently applied emission factors, in kg/t__ | ||
Line 79: | Line 80: | ||
A range of measures in sulphite pulp production, carried out on a continual basis, led to reductions of SO₂ emissions. | A range of measures in sulphite pulp production, carried out on a continual basis, led to reductions of SO₂ emissions. | ||
- | EF of NMVOC is confidential since the AD of sulphat | + | EF of NMVOC is confidential since the AD of sulphate |
===== Recalculations ===== | ===== Recalculations ===== |