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EDITORIAL Circular economy is already here !
TABLE OF CONTENTS
The mineral fertilizer industry has always been based on circular thinking. The integrated production at the typical plant has meant that by-products from one production was used as raw material for another production and vice versa.
Editorial.......................................................................... 3
This brochure is presenting six case studies showing how the circular economy is being put into practice in our industry. They involve recycling of millions of tons of material.
Report............................................................................ 4 Case Studies.................................................................. 8
The brochure also has an appendix listing the common materials which form part of the circular nature of fertilizer production.
1. Ammonium sulfate from nylon production................................................ 8 2. Sulfur and sulfuric acid from natural oil and gas refining.......................... 9 3. Sulfuric acid from metal smelting operations.......................................... 10 4. Horticultural symbiosis based on residual heat and CO2 valorization.... 10 5. CO2 as raw material............................................................................... 11 6. Integrated production of complex fertilizers............................................ 11
The fertilizer industry is already a trail blazer and far ahead down the road of circular economy even if more can be done. The goal of industrial recycling and symbiosis is to improve the industrial system by optimizing resource use, closing material loops and minimizing emissions. The European Union has recognized the potential contribution of industrial recycling and symbiosis to sustainable production and to the competitiveness of the European industry as this is one of the key principles of the EU Circular Economy Package.
Appendix.......................................................................12
We, in the fertlizer industry, are happy to contribute.
Bibliography.................................................................. 15
Jacob Hansen Director General
“The fertilizer industry has always been circular.� Jacob Hansen, Fertilizers Europe
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Figure 2. “Recycling and reuse of products”. Industrial recycling and symbiosis closes the loop in the material and energy flows during manufacturing. Industrial symbiosis intends to avoid wastes and to move to integrated systems in which every product has its use and value.
REPORT Industrial recycling and symbiosis
Keep resources in use for as long as possible
Minimize disposed residual waste
Extract the maximum value from products
Recover and regenerate products and materials at the end of service life
Focus on the role of the European fertilizer industry Industrial recycling and symbiosis closes the loop in the material and energy flows during manufacturing. Industrial symbiosis intends to avoid wastes and to move to integrated systems in which every product has its use and value. One of the key principles of the EU Circular Economy Package is the reuse of raw materials. The European Commission “adopted this ambitious new package to help European businesses and consumers to make the transition to a stronger and more circular economy where resources are used in a more sustainable way. The proposed actions will contribute to “closing the loop” of product lifecycles through greater recycling and re-use, and bring benefits for both the environment and the economy. The plans will extract the maximum value and use from all raw materials, products and waste, fostering energy savings and reducing Green House Gas emissions”.
Figure 1. “Industrial recycle and Industrial symbiosis”.
Industrial recycle
Industrial symbiosis
etc.
The principal objective of industrial recycling and symbiosis is to improve the industrial system by optimizing resource use, closing material loops and minimizing emissions, thereby reducing and possibly eliminating the dependence on non-renewable energy sources. This can be achieved, for example, through focus on industrial networks, both local, regional and on a European level. The European Union has recognized the potential contribution of industrial recycling and symbiosis to sustainable production and to the competitiveness of the European industry. The Roadmap to a Resource Efficient Europe1 indicates that a better reuse of raw materials may save € 1.4 billion per year and may generate € 1.6 billion per year in additional sales. 4
Circular Economy
The fertilizer industry in particular has optimized its production systems for over a hundred years by making use of spent raw materials originating from related production processes. Modern chemical operations started in the second half of the 19th century, many based on coal. Coal was used to produce town gas for lighting purposes. The tar residue or by-product was found to contain a range of chemicals that could be extracted to provide e.g. aniline, the basis for artificial dyes, and ammonia, the basic raw material for modern fertilizers. At the time, the demand for ammonia for use as a component of fertilizers by far exceeded its availability and this intensified the search for an industrial route for making ammonia, leading to the Haber-Bosch process that is the most energy efficient process in use today.
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Figure 3. “Modern chemical operations started from tar”.
Figure 4. “Recycling of effluent streams from abatement in granulation of fertilizers”.
Town gas Coal
Tar-residue residue - Tar
Ammonia
Fertilizers
Aniline Anilin
Modern fertilizer industry started with the use of the by-product ammonia and continued to incorporate a vast range of byproducts from various other processes during the past 100 years. Typical examples are: the use of sulfur from oil and gas refining operations for making sulfuric acid, - the use of ammonium sulfate from nylon synthesis for making sulfate-containing mineral fertilizers, and - the application of used acids in dissolving insoluble rock phosphates for making water-soluble and therefore plant available phosphate fertilizers.
The dry recycle and the effluent solutions are recycled within the same installation. This minimizes emissions and makes full use of the initial raw materials. This recycling within an installation at first may seem selfevident; however, if the unit operations show a diverse spatial resolution, this becomes less obvious. Inherently, these abatement systems belong to the very same fertilizer manufacturing installation. Effluent streams from other installations may also be connected. The reference document on Best Available Techniques for the manufacture of Large Volume Inorganic Chemicals – Ammonia, Acids and Fertilizers (LVIC-AAF), given by the European Commission within the scope of Integrated Pollution Prevention and Control shows a number of examples of emission abatement, recycling and reuse of byproducts, and recovery of heat.
Figure 5. The IPPC document on BAT for LVC-AAF (2007)
More details on the above as well as other case studies are presented in this brochure. Many other by-products are used in fertilizer manufacturing processes and some examples are given via the case studies and a non-exhaustive list of recycle bi-products is given in the appendix. Not only chemical products are recycled in the fertilizer industry. Fertilizer manufacturing needs significant amounts of energy (ammonia production) and produces large amounts of energy / heat (nitric acid production) as well. Energy and heat are needed in other manufacturing processes and all processes can be overall optimized for best energetic performance. Fertilizer manufacturing processes have abatement systems installed to minimize emissions into air and water. For example, in the granulation of calcium ammonium nitrate (CAN) or multinutrient NPK fertilizers raw materials and heat are recovered through cyclones, fabric filters and scrubbing systems.
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2: Sulfur and sulfuric acid from natural oil and gas refining Natural oil and gas contain significant amounts of sulfur. If not removed, this sulfur is transformed during the combustion process into sulfur oxides, which contribute to the formation of acid rains. Refining of crude oil to final products requires the desulfurization of the oil. Fuel specifications have become increasingly stringent with respect to the sulfur content. Many petrochemical products likewise are produced to be almost sulfur-free. The removal of sulfur from oil is consequently one of the central conversion requirements in most refineries.
CASE STUDIES 1: Ammonium sulfate from nylon production The synthetic polymer nylon-6 is manufactured through polymerization of caprolactam. Caprolactam based products are applied in fibers and plastics. Caprolactam is made from cyclohexane or cyclohexanone in a stepwise process that cogenerates ammonium sulfate. For each ton of caprolactam approximately 2,0 – 2,2 tons of ammonium sulfate are produced.
Phosphoric acid is an important starting material for the production of granulated phosphate fertilizers. The production of the phosphoric acid requires the solution of the raw material rock phosphate in sulfuric acid. For over 70 years, the by-product sulfur from refineries has been converted into sulfuric acid (by oxidation with air) and this sulfuric acid has subsequently been used for the production of phosphoric acid.
Globally more than 4,5 million tons of caprolactam are produced annually, implicating about 10 million tons of ammonium sulfate. In Europe about 5,1 million tons of ammonium sulfate are produced in the caprolactam manufacturing process, out of a total of about 7,5 million tons of ammonium sulfate annually. The white crystals are used for direct fertilization, particularly on crops that prefer nitrate-free forms of nitrogen, or are incorporated in multi-nutrient fertilizers, such as NPK or in single nitrogen formulations. Ammonium sulfate is a watersoluble component of fertilizers to supply needed sulfur to soils.
Figure 7. Natural Oil & Gas
Close up view of ammonium sulfate crystals
Figure 8. Sulfur production in EU Sulfur in the EU 5,2 million tons of product
Figure 6. “Ammonium sulfate provenances in Europe”.
Production of nylon
Natural Oil & gas
Ammonium sulfate in the EU 5,1 million tons of product
Cyclohexanone
Caprolactam 1 Ton
Waste Sulphur
Sulfuric acid
Germany 24%
Others 34%
Fertilizers
Nylon Poland 14%
Others 11% Spain 10%
Ammonium Sulphate 2,2 Ton
Fuel Oil & gas
NL 8%
Belgium 33%
Italy 10%
Spain 10%
Source: IFA 2013
Poland 13% NL 14%
Germany 19%
Source: IFA 2015
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3: Sulfuric acid from metal smelting operations
5: CO2 as raw material
Ores containing valuable metals, such as silver, copper or iron, are usually treated with reducing agents at high temperature to extract the metal. For economic and environmental reasons, the by-products of such operations are reclaimed. Sulfur dioxide gas, for example, is captured and turned into sulfuric acid, which can be used in fertilizer manufacture. Historically, one observes the presence of fertilizer operations for the manufacture of phosphoric acid and the subsequent finished fertilizers mono- and di-ammonium phosphate (MAP / DAP) often adjacent to copper smelting operations.
Production of 1 ton of ammonia produces on average about 2 tons of CO2. Part of that CO2 is captured during the production process and purified for use in a wide range of applications, including beverages.
Figure 9.“Di-ammonium phosphate from phosphoric acid / spent sulfuric acid”. The volumes of the by-product sulfuric acid, mainly used in the manufacture of phosphate fertilizers, are significant. About 40 % of the sulfur dioxide used to make 22 million tons of sulfuric acid annually in EU-25 arise from non-ferrous metal operations (2004).
Sparkling water is made with CO2 from ammonia production
4: Horticultural symbiosis based on residual heat and CO2 valorization
6: Integrated production of complex fertilizers
Intensive greenhouse horticulture is a key pillar of the agricultural economy of the Netherlands. Dutch greenhouses are worldwide recognized for their high-tech innovation, resource-efficiency, and year-round supply of premium horticultural products. Energy use, however, is a major challenge, accounting for some 30 % of total operating costs. Residual heat and CO2 from ammonia operations were once considered as waste. However, the use of available residual heat from neighboring industries is a promising option to reduce energy costs. This industrial symbiosis option could be realized using a new pipeline network, supplying both residual heat and CO2, byproducts from an adjacent ammonia manufacturing plant, to the greenhouses6. In this case, in The Netherlands, 60 kilotons (kT) of CO2 are now used annually in horticulture, whereas the use of the residual heat avoids the emission of another 135 kT of CO2 annually. It is a successful example of an industrial symbiosis, on a large scale, implementing benefits to the environment, horticulture and the fertilizer industry, in spite of significant challenges and costs. Greenhouse in the Netherlands using CO2 from a neighboring ammonia plant
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http://www.circulary.eu/sectors/fertiliser
Circular Economy
Complex mineral fertilizers can be produced via various processes or production routes. An important production step is the conversion of the insoluble phosphate contained in the mined natural rock phosphate into a plant available form. One of the possible processes to do so is the nitrophosphate route including the so-called ODDA process. The advantage of the integrated ODDA process is that not only the conversion of phosphate into plant-available forms is achieved but also the co-product calcium nitrate is used for the production of nitrate containing straight fertilizers.
Figure 10.“Flow chart for the nitrophosphate process”.
In this integrated process, no solid waste is produced and, importantly, the by-product calcium carbonate (lime) can be obtained, which is the starting raw material for the synthesis of calcium ammonium nitrate, a highly efficient straight nitrogen fertilizer. In the formation of lime, CO2 from adjacent plants, such as an ethylene oxide, a waste incineration or an ammonia plant, is consumed. The process is exemplary of an integrated production, using and avoiding by-products.
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APPENDIX Materials commonly used in the production of fertilizers and their source process (non-exhaustive). Material
Process
Gypsum (calcium sulfate dihydrate) Gypsum Gypsum Calcium sulfate (hydrates) Hexafluorosilicic acid (H2SiF6) Nitric acid (HNO3) Diluted nitric acid (diluted HNO3) Ammonia (NH3) Ammonia (NH3) Ammonia (NH3) Ammonia (NH3)
Hydrofluoric acid Phosphoric acid production Electricity production from coal burning Gas scrubbing Phosphoric acid production Nitrite production Nitric acid operations Melamine Caprolactam Urea Stripped ammonia (water) from municipal wastewater and manure treatment plants and biogas installations Oil and gas industry, fuel oil methanation Melamine Scrubbing of hot combustion gases Scrubbing of fertilizer granulation off-gas Ammonia abatement (stripping) in sewage treatment, from municipal wastewater and manure treatment; biogas installations Manganese nitrate Acidic absorption of ammonia Water demineralization Wet dust abatement in fertilizer manufacturing Various operations (pigment production, e.g. titanium dioxide - TiO2)
Sulfur and derived products Ammonium nitrate (NH4NO3) Ammonium nitrate (NH4NO3) Ammonium nitrate (NH4NO3) Ammonium nitrate (NH4NO3) Ammonium nitrate (NH4NO3) Ammonium nitrate (NH4NO3) Inorganic salts Mixed inorganic salts Internal stabilizers, e.g. magnesium oxide (MgO), magnesium sulfate (MgSO4), magnesium nitrate (Mg(NO3)2), aluminium sulfate (Al2(SO4)3), iron sulfate (Fe(SO4)) Carbon dioxide (CO2) Carbon dioxide (CO2) Urea 12
Ethylene-oxide Ammonia - NH3 CO2 from ammonia production
Material
Process
Ammonium sulfate ((NH4)2SO4) Ammonium sulfate ((NH4)2SO4) Ammonium sulfate ((NH4)2SO4) Ammonium sulfate ((NH4)2SO4) Ammonium sulfate ((NH4)2SO4) Ammonium sulfate ((NH4)2SO4) Ammonium sulfate ((NH4)2SO4) Ammonium sulfate ((NH4)2SO4) Ammonium sulfate ((NH4)2SO4)
Gas scrubbing Titanium dioxide (TiO2) pigment production Flue gas desulphurization Caprolactam, formic acid Methyl methacrylate Acrylonitrile Steel Ammonia gas scrubbing in fertilizers production Ammonia recovery (stripping) from municipal wastewater and manure treatment; biogas installations ODDA process
Calcium carbonate (CaCO3, lime) Wastewater treatment Calcium nitrate (Ca(NO3)2) Sulfuric acid (H2SO4) Sulfuric acid (H2SO4) Sulfuric acid (H2SO4) Sulfuric acid (H2SO4) Diluted sulfuric acid (H2SO4) Magnesium nitrate (Mg(NO3)2) Magnesium sulfate (MgSO4) Magnesium sulfate (MgSO4), sulfur and derived products Ash Ash Ash Ash Ash Slag Struvite (MgNH4PO4) Potash Natural gas Iron sulfate (FeSO4) Iron sulfate (FeSO4 x H2O) Iron sulfate (FeSO4 x H2O) Potassium sulfate (K2SO4) Spent sulfuric acid (H2SO4) Spent sulfuric acid (H2SO4) / phosphoric acid (H3PO4) Ammonium thiosulfate Ammonium carbonate ((NH4)2CO3) Nitrous oxide (laughing gas, N2O)
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NP/NPK ODDA process Titanium dioxide (TiO2, rutile mineral) Caprolactam From by-product pyrite (copper/zinc mines) Titanium dioxide (TiO2) pigment production Concentrated nitric acid production Titanium dioxide (TiO2) pigment production Flue gas desulphurization Sewage sludge Bone meal Incineration of wood and its products (chips, saw dust, bark) Dust burning Coal fired power station Dust burning Wastewater treatment Salt production Fermentation processes Titanium dioxide (TiO2) pigment production Titanium dioxide (TiO2) pigment production Titanium dioxide (TiO2) pigment production Various industries Various industries Aluminum treatment Gas treatment in energy industry Production of baking agents (e.g. E 503), specific scrubbing Adipic acid 13
Material
Process
Carbon monoxide / hydrogen (CO/H2) mixture Biotite Waste streams to recover Cu and Zn as micronutrients Calcium ammonium nitrate (CAN) Ammonium chloride (NH4Cl)
Acetylene off gas Secondary mineral from mining Various industries
Potassium hydroxide (KOH) Potassium nitrate (KNO3) Mono calcium- phosphate (MCP) / Di-calciumphosphate (DCP) Ca-phosphates H2 Coating agents Off specs (physical characteristics, nutrient(s) content) Lignosulphonates
Nitro-phosphate NPK production Solvay process for the production of sodium carbonate Chlorine operations Feed industry Some P-recovery technologies Various industries (petrochemical / refineries) Various industry by-products Fertilizer manufacturing processes (e.g. urea, NPK, AN) Wood-pulp production
BIBLIOGRAPHY EC, Roadmap to a Resource Efficient Europe, 2011. EC, A stronger European Industry for Growth and Economic Recovery, 2012. EC, Circular Economy Package, 2015. EC, Press release, 02.12.2015, “Closing the loop: Commission adopts ambitious new Circular Economy Package to boost competitiveness, create jobs and generate sustainable growth�. EC, IPPC, LVIC-AAF, August 2007.
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