technologyComment of air separation, cryogenic (RER): The main components of air are nitrogen and oxygen, but it also contains smaller amounts of water vapour, argon, carbon dioxide and very small amounts of other gases (e.g. noble gases). The purification and liquefaction of various components of air, in particular oxygen, nitrogen and argon, is an important industrial process, and it is called cryogenic air separation. Cryogenic distillation accounts for approximately 85% of nitrogen and over 95% of oxygen production. It is the preferred supply mode for high volume and high purity requirements (Praxair 2002). Cryogenic air separation is currently the most efficient and cost-effective technology for producing large quantities of oxygen, nitrogen, and argon as gaseous or liquid products (Smith & Klosek 2001). Besides the air needed as a resource the major input for the liquefying process is the electricity to compress the inlet air, which normally comprises 95% of the utility costs of a cryogenic air separation plant. In some plants the amount of processed air (in Nm3) can be up to 5 times larger than the derived liquid products (Cryogenmash 2001). In these plants, the waste gas stream is naturally also much larger (in order to obtain the mass balance). As output of the cryogenic air separation there are three products: liquid oxygen, liquid nitrogen and liquid crude argon. The assumed process includes no gaseous co-products. In reality gaseous products are also processed if there is a demand at the production site. The investigated cryogenic air separation process leads to liquid products in the following quality: - Liquid oxygen: min. 99.6 wt-% - Liquid nitrogen: min. 99.9995 wt-% - Liquid argon, crude: 96-98 wt-% An air pre-treatment section downstream of the air compression (0.7 MPa) and after cooling removes process contaminants, including water, carbon dioxide, and hydrocarbons. The air is then cooled to cryogenic temperatures and distilled into oxygen, nitrogen, and, optionally, argon streams. Alternate compressing and expanding the recycled air can liquefy most of it. Numerous configurations of heat exchange and distillation equipment can separate air into the required product streams. These process alternatives are selected based on the purity and number of product streams, required trade-offs between capital costs and power consumption, and the degree of integration between the air separate unit and other facility units. This process requires very complicated heat integration techniques because the only heat sink for cooling or condensation is another cryogenic stream in the process. Since the boiling point of argon is between that of oxygen and nitrogen, it acts as an impurity in the product streams. If argon were collected and separated from the oxygen product, an oxygen purity of less than 95% by volume would result (Barron & Randall 1985). On the other hand, if argon were collected with the nitrogen product, the purity of nitrogen would not exceed 98.7% by volume. To achieve higher purities of oxygen and nitrogen the elimination of argon is necessary. Commercial argon is the product of cryogenic air separation, where liquefaction and distillation processes are used to produce a low-purity crude argon product. Praxair (2002) Gases > Nitrogen > Production of Nitrogen. Praxair Technology Inc. 2002. Retrieved 16.01.2002 from http://www.praxair.com Smith A. R. and Klosek J. (2001) A Review of Air Separation Technologies and their Integration with Energy Conversion Processes. In: Fuel Processing Technology, 70(2), pp. 115-134. Barron and Randall F. (1985) Cryogenic Systems. 2 Edition. Oxford University Press, New York Cryogenmash (2001) KxAxApx Type Double-Pressure Air Separation Plants. Gen-eral Data. Cryogenic Industries, Moscow, Russia. Retrieved 16.01.2002 from http://www.cryogenmash.ru/production/vru/vru_kgag2_e.htm imageUrlTagReplaceb1f86554-243f-4c79-b3a2-e6a9efa3a7ef
technologyComment of styrene production (RoW): Styrene is mainly produced by the dehydrogenation of ethylbenzene (EBS process) and via ethylbenzene hydroperoxide (POSM process) with propylene oxide as a by-product (James and Castor 2011). This dataset reflects only the dehydrogenation of ethylbenzene (EBS). Close to the entire production of ethylbenzene is produced via the alkylation of ethylene and benzene (Welch et al. 2005). This production route has been used since the mid-nineties (James and Castor 2011). Chemical reaction: C6H6 + C2H4 -> C8H10 C8H10 -> C8H8 + H2 The reaction from ethylbenzene to styrene is reversible. The reaction is endothermic with a heat delta of 600 degrees Celcius and 124.0 kJ/mol (James and Castor 2011). The production of styrene is mostly performed (ca. 75% of production), by running ethylbenzene (the input includes recycled ethylbenzene) through subsequent reactors / reactors beds. Steam is used to dehydrogenate the input product. Steam has been found to ensure a high yield, provide the necessary conditions for the reaction to happen and at the same time cleaning the used catalyst (James and Castor 2011). The use of a catalyst boosts the efficiency of the reaction, otherwise low temperature and low pressure are enough to ensure the reaction but with lower yield. Usual reaction conditions are 620 degrees Celsius combined with very low pressure, this ensures a yield between 88 and 95% (James and Castor 2011). According to James and Castor (2011) one of the most used catalyst for this reaction is composed by 84.3% iron (Fe2O3), 2.4% chromium (Cr2O3), and 13.3% potassium (K2CO3) (James and Castor 2011). The average lifespan of catalysts for this reaction is assumed to be 2 years (James and Castor 2011). The catalyst in not consider significant in terms of emissions for the reaction and it is therefore not included in this dataset and it is assumed to be taken into consideration in the input of chemical factory. The main source of information for the values for water (process and cooling), nitrogen and chemical factory is industry data from Gendorf. The values are a 5-year average of data (2011 - 2015) published by the Gendorf factory (Gendorf, 2016, Umwelterklärung, www.gendorf.de), (Gendorf, 2015, Umwelterklärung, www.gendorf.de), (Gendorf, 2014, Umwelterklärung, www.gendorf.de). The Gendorf factory is based in Germany, it produces a wide range of chemical substances. The factory produced 1657400 tonnes of chemical substances in the year 2015 (Gendorf, 2016, Umwelterklärung, www.gendorf.de) and 740000 tonnes of intermediate products. Reference(s): Hischier, R. (2005) Establishing Life Cycle Inventories of Chemicals Based on Differing Data Availability (9 pp). The International Journal of Life Cycle Assessment, Volume 10, Issue 1, pp 59–67. 10.1065/lca2004.10.181.7 Gendorf (2016) Umwelterklärung 2015, Werk Gendorf Industriepark, www.gendorf.de James, D.H. and Castor, W.M. 2011. Styrene. In Ullmann's Encyclopedia of Industrial Chemistry, Electronic Release, Vol.34, pp.529-544. Wiley-VCH, Weinheim. Welch, V.A. et al. 2005. Ethylbenzene. In Ullmann's Encyclopedia of Industrial Chemistry, Electronic Release, Vol.13, pp.451-464. Wiley-VCH, Weinheim. technologyComment of styrene production (RER): Styrene is mainly produced by the dehydrogenation of ethylbenzene (EBS process) and via ethylbenzene hydroperoxide (POSM process) with propylene oxide as a by-product (James and Castor 2011). This dataset reflects only the dehydrogenation of ethylbenzene (EBS). Close to the entire production of ethylbenzene is produced via the alkylation of ethylene and benzene (Welch et al. 2005). This production route has been used since the mid-nineties (James and Castor 2011). Chemical reaction: C6H6 + C2H4 -> C8H10 C8H10 -> C8H8 + H2 The reaction from ethylbenzene to styrene is reversible. The reaction is endothermic with a heat delta of 600 degrees Celcius and 124.0 kJ/mol (James and Castor 2011). The production of styrene is mostly performed (ca. 75% of production), by running ethylbenzene (the input includes recycled ethylbenzene) through subsequent reactors / reactors beds. Steam is used to dehydrogenate the input product. Steam has been found to ensure a high yield, provide the necessary conditions for the reaction to happen and at the same time cleaning the used catalyst (James and Castor 2011). The use of a catalyst boosts the efficiency of the reaction, otherwise low temperature and low pressure are enough to ensure the reaction but with lower yield. Usual reaction conditions are 620 degrees Celsius combined with very low pressure, this ensures a yield between 88 and 95% (James and Castor 2011). According to James and Castor (2011) one of the most used catalyst for this reaction is composed by 84.3% iron (Fe2O3), 2.4% chromium (Cr2O3), and 13.3% potassium (K2CO3) (James and Castor 2011). The average lifespan of catalysts for this reaction is assumed to be 2 years (James and Castor 2011). The catalyst in not consider significant in terms of emissions for the reaction and it is therefore not included in this dataset and it is assumed to be taken into consideration in the input of chemical factory. The main source of information for the values for water (process and cooling), nitrogen and chemical factory is industry data from Gendorf. The values are a 5-year average of data (2011 - 2015) published by the Gendorf factory (Gendorf, 2016, Umwelterklärung, www.gendorf.de), (Gendorf, 2015, Umwelterklärung, www.gendorf.de), (Gendorf, 2014, Umwelterklärung, www.gendorf.de). The Gendorf factory is based in Germany, it produces a wide range of chemical substances. The factory produced 1657400 tonnes of chemical substances in the year 2015 (Gendorf, 2016, Umwelterklärung, www.gendorf.de) and 740000 tonnes of intermediate products. Reference(s): Hischier, R. (2005) Establishing Life Cycle Inventories of Chemicals Based on Differing Data Availability (9 pp). The International Journal of Life Cycle Assessment, Volume 10, Issue 1, pp 59–67. 10.1065/lca2004.10.181.7 Gendorf (2016) Umwelterklärung 2015, Werk Gendorf Industriepark, www.gendorf.de James, D.H. and Castor, W.M. 2011. Styrene. In Ullmann's Encyclopedia of Industrial Chemistry, Electronic Release, Vol.34, pp.529-544. Wiley-VCH, Weinheim. Welch, V.A. et al. 2005. Ethylbenzene. In Ullmann's Encyclopedia of Industrial Chemistry, Electronic Release, Vol.13, pp.451-464. Wiley-VCH, Weinheim. Certain data points from a company survey by PlasticsEurope (three companies and four production sites).
technologyComment of air separation, cryogenic (RER): The main components of air are nitrogen and oxygen, but it also contains smaller amounts of water vapour, argon, carbon dioxide and very small amounts of other gases (e.g. noble gases). The purification and liquefaction of various components of air, in particular oxygen, nitrogen and argon, is an important industrial process, and it is called cryogenic air separation. Cryogenic distillation accounts for approximately 85% of nitrogen and over 95% of oxygen production. It is the preferred supply mode for high volume and high purity requirements (Praxair 2002). Cryogenic air separation is currently the most efficient and cost-effective technology for producing large quantities of oxygen, nitrogen, and argon as gaseous or liquid products (Smith & Klosek 2001). Besides the air needed as a resource the major input for the liquefying process is the electricity to compress the inlet air, which normally comprises 95% of the utility costs of a cryogenic air separation plant. In some plants the amount of processed air (in Nm3) can be up to 5 times larger than the derived liquid products (Cryogenmash 2001). In these plants, the waste gas stream is naturally also much larger (in order to obtain the mass balance). As output of the cryogenic air separation there are three products: liquid oxygen, liquid nitrogen and liquid crude argon. The assumed process includes no gaseous co-products. In reality gaseous products are also processed if there is a demand at the production site. The investigated cryogenic air separation process leads to liquid products in the following quality: - Liquid oxygen: min. 99.6 wt-% - Liquid nitrogen: min. 99.9995 wt-% - Liquid argon, crude: 96-98 wt-% An air pre-treatment section downstream of the air compression (0.7 MPa) and after cooling removes process contaminants, including water, carbon dioxide, and hydrocarbons. The air is then cooled to cryogenic temperatures and distilled into oxygen, nitrogen, and, optionally, argon streams. Alternate compressing and expanding the recycled air can liquefy most of it. Numerous configurations of heat exchange and distillation equipment can separate air into the required product streams. These process alternatives are selected based on the purity and number of product streams, required trade-offs between capital costs and power consumption, and the degree of integration between the air separate unit and other facility units. This process requires very complicated heat integration techniques because the only heat sink for cooling or condensation is another cryogenic stream in the process. Since the boiling point of argon is between that of oxygen and nitrogen, it acts as an impurity in the product streams. If argon were collected and separated from the oxygen product, an oxygen purity of less than 95% by volume would result (Barron & Randall 1985). On the other hand, if argon were collected with the nitrogen product, the purity of nitrogen would not exceed 98.7% by volume. To achieve higher purities of oxygen and nitrogen the elimination of argon is necessary. Commercial argon is the product of cryogenic air separation, where liquefaction and distillation processes are used to produce a low-purity crude argon product. Praxair (2002) Gases > Nitrogen > Production of Nitrogen. Praxair Technology Inc. 2002. Retrieved 16.01.2002 from http://www.praxair.com Smith A. R. and Klosek J. (2001) A Review of Air Separation Technologies and their Integration with Energy Conversion Processes. In: Fuel Processing Technology, 70(2), pp. 115-134. Barron and Randall F. (1985) Cryogenic Systems. 2 Edition. Oxford University Press, New York Cryogenmash (2001) KxAxApx Type Double-Pressure Air Separation Plants. Gen-eral Data. Cryogenic Industries, Moscow, Russia. Retrieved 16.01.2002 from http://www.cryogenmash.ru/production/vru/vru_kgag2_e.htm imageUrlTagReplaceb1f86554-243f-4c79-b3a2-e6a9efa3a7ef
technologyComment of acetylene production (RER): Partial oxidation of natural gas. The flue gas is assumed to be cleaned with electrofilters. References: Pässler, P., Hefner, W., Buckl, K., Meinass, H., Meiswinkel, A., Wernicke, H.-J., Ebersberg, G., Müller, R., Bässler, J., Behringer, H. and Mayer, D. 2011. Acetylene. Ullmann's Encyclopedia of Industrial Chemistry. Althaus H.-J., Chudacoff M., Hischier R., Jungbluth N., Osses M. and Primas A. (2007) Life Cycle Inventories of Chemicals. Final report ecoinvent data v2.0 No. 8. Swiss Centre for Life Cycle Inventories, Dübendorf, CH.
technologyComment of ethylene oxide production (RER): Ethylene is directly oxidized with air or oxygen in the presence of a catalyst to ethylene oxide (EO). About 40% of all European EO production is converted into glycols, globally the figure is about 70%. Usually, EO and MEG are produced together at integrated plants. Industrial production started in 1937 with a union Carbide process based on ethylene and air. In 1958 oxygen rather than air was instroduced by Shell Development Company, and today most processes are based on oxygen. Total European production was 3.4 million tons per year in 1997, while the US produced 5.2 million tons per year. Further production capacity of at least 1.2 million tons is reported from Saudi Arabia, Kuwait, Japan and South Korea giving a total of at least 9.8 million tons of ethylene oxide production worldwide. Ethylene oxide is a hydrocarbon compound made from ethylene and oxygen. Major manufacturers include Hoechst Celanese, Shell Chemical, and Union Carbide, among many others. EO is produced by passing a mixture of ethylene and oxygen over a solid silver-containing catalyst. Selectivity is improved by the addition of chlorine compounds such as chloroethane. Reaction conditions are temperatures of about 200 - 300 °C and a pressure of 10 – 30 bar. The main by-products are carbon dioxide and water, formed when ethylene is fully oxidised or some of the EO is further oxidised. Ethylene glycols are formed when the reactor gases are absorbed into chilled water. C2H4 + 1/2 O2 C2H4O (1) C2H4 O + H2O HO-C2H4-OH (2) C2H4 + 3 O2 2 CO2 + 2 H2O (3) (1) production of ethylene oxide (2) production of MEG from EO and water (3) production of carbon dioxide and water from oxidation of ethylene The carbon dioxide is removed from the scrubber by absorption with hot aqueous potassium carbonate, the resulting solution is steam stripped to remove the carbon dioxide, which is vented to air. The potassium carbonate is regenerated. The carbon dioxide can be reused for inerting, or is sold, or is vented to atmosphere. References: IPPC Chemicals, 2002. European Commission, Directorate General, Joint Research Center, “Reference Document on Best Available Techniques in the Large Volume Organic Chemical Industry”, February 2002. Wells, 1999. G. Margaret Wells, “Handbook of Petrochemicals and Processes”, 2nd edition, Ashgate, 1999
technologyComment of chlor-alkali electrolysis, diaphragm cell (RER): In the diaphragm process, all reactions take place in only one cell. A diaphragm is used to separate the feed brine (anolyte) and the chlorine formed at the anode from the sodium hydroxide containing solution (catholyte) and the hydrogen formed at the cathode. Without the diaphragm being present during electrolysis, chlorine and hydrogen would form an explosive mixture and sodium hydroxide and chlorine would react to form sodium hypochlorite (NaOCl). Diaphragms used to be made from asbestos but up-todate technology allows for asbestos-free polymer-based diaphragms. Purified brine is fed to the anode compartment and percolates through the diaphragm into the cathode compartment. The percolation rate is controlled by a difference in liquid level between both compartments. At the anodes (metal oxide coated titanium), chlorine gas is formed which is collected and directed to further processing. Cathodes, where water decomposition takes place, are made of activated carbon steel. Catholyte leaving the cell, also called cell liquor, is a mixture of 10-12 wt.-% sodium hydroxide and 15-17 wt.-% sodium chloride in water. This solution is usually evaporated to 50 wt.-% NaOH. In this process, simultaneously most of the salt is removed by precipitation to a final residual of 1 wt.-%. The resulting salt is typically recirculated to brine preparation. The advantage of diaphragm cells is that the quality requirements for the brine and the electrical energy consumption are low. Disadvantageous are the high amount of thermal energy necessary for sodium hydroxide concentration and the comparably low quality of the produced sodium hydroxide and chlorine. References: Euro Chlor (2013) An Eco-profile and Environmental Product Declaration of the European Chlor-Alkali Industry, Chlorine (The chlor-alkali process). technologyComment of chlor-alkali electrolysis, membrane cell (RER): In the membrane cell process, the anode and cathode compartments are separated by a perfluoropolymer cation-exchange membrane that selectively transmits sodium ions but suppresses the migration of hydroxyl ions (OH-) from the catholyte into the anolyte. Saturated brine flows through the anode compartment, where chlorine gas is produced at the anode. The electric field in the electrolysis cell causes hydrated sodium ions to migrate through the membrane into the cathode compartment. The cathode compartment is fed with diluted sodium hydroxide solution. Water is electrolysed at the cathode releasing gaseous hydrogen and hydroxyl ions, which combine with the sodium ions and thus increase the concentration of sodium hydroxide in the catholyte. Typically, the outlet concentration of sodium hydroxide is around 32 wt.-%. A part of the product stream is diluted with demineralised water to about 30 wt.-% and used as catholyte inlet. In some units, a more diluted 23 wt.-% NaOH solution is produced. In these cases, the inlet concentration is adjusted to 20-21 wt.-%. Usually the NaOH solution is evaporated to the marketable concentration of 50 wt.-% using steam. Depleted brine leaving the anode compartment is saturated with chlorine and is therefore sent to a dechlorination unit to recover the dissolved chlorine before it is resaturated with salt for recirculation. The advantages of the membrane cell technique are the very high purity of the sodium hydroxide solution produced and the comparably low energy demand. Disadvantages comprise the high requirements on brine purity, the need for sodium hydroxide evaporation to increase concentration, and the comparably high oxygen content in the produced chlorine. In general, multiple cell elements are combined into a single unit, called electrolyser, of whom the design can be either monopolar or bipolar. In a monopolar electrolyser, the anodes and cathodes of the cells are connected electrically in parallel, whereas in the bipolar design, they are connected in series. Therefore, monopolar electrolysers require high current and low voltage, whereas bipolar electrolysers require low current and high voltage. Since bipolar systems allow higher current densities inside the cells, investment and operating costs are usually lower than for monopolar systems. References: Euro Chlor (2013) An Eco-profile and Environmental Product Declaration of the European Chlor-Alkali Industry, Chlorine (The chlor-alkali process). technologyComment of chlor-alkali electrolysis, mercury cell (RER): The mercury cell process comprises an electrolysis cell and a decomposer. Purified and saturated brine (25-28 wt.-% NaCl in water) is fed to the electrolysis cell on top of a film of mercury (Hg) flowing down the inclined base of the cell. The base of the cell is connected to the negative pole of a direct current supply forming the cathode of the cell. Anodes consisting of titanium coated with oxides of ruthenium and titanium are placed in the brine without touching the mercury film. At the anodes, chlorine gas is formed which is collected and directed to further processing. Due to a high overpotential of hydrogen at the mercury electrode, no gaseous hydrogen is formed; instead, sodium is produced and dissolved in the mercury as an amalgam (mercury alloy). The liquid amalgam is removed from the electrolytic cell and fed to a decomposer, where it reacts with demineralised water in the presence of a graphite-based catalyst to form sodium hydroxide solution and hydrogen. The sodium-free mercury is recirculated back into the cell. Cooling of hydrogen is essential to remove any water and mercury. The sodium hydroxide solution is very pure, almost free from chloride contamination and has usually a concentration of 50 %. Further treatment comprises cooling and removal of catalyst and mercury traces by centrifuges or filters. Advantages of the mercury cell process are the high quality of chlorine and the high concentration and purity of sodium hydroxide solution produced. The consumption of electric energy for electrolysis is, however, higher than for the other techniques and a high purity of the feed brine is required. Inherently, the use of mercury gives rise to environmental releases of mercury. References: Euro Chlor (2013) An Eco-profile and Environmental Product Declaration of the European Chlor-Alkali Industry, Chlorine (The chlor-alkali process). technologyComment of potassium hydroxide production (RER): Potassium hydroxide is manufactured by the electrolysis of potassium chloride brine in electrolytical cells. Hydrogen and chlorine are withdrawn from the cell. The rest of the reaction mixture contains KOH, water, and unreacted potassium chloride. This reaction mixture is then concentrated in an evaporator. Most of the potassium chloride crystallizes by evaporation, and is recycled. After evaporation, the potassium hydroxide is precipitated. Potassium hydroxide, chlorine and hydrogen are obtained from potassium chloride brine according to the following reaction: 2 KCl + 2 H2O -> 2 KOH + Cl2 + H2 Reference: Jungbluth, N., Chudacoff, M., Dauriat, A., Dinkel, F., Doka, G., Faist Emmenegger, M., Gnansounou, E., Kljun, N., Schleiss, K., Spielmann, M., Stettler, C., Sutter, J. 2007: Life Cycle Inventories of Bioenergy. ecoinvent report No. 17, Swiss Centre for Life Cycle Inventories, Dübendorf, CH. technologyComment of sodium chloride electrolysis (RER): Sodium chloride electrolysis
technologyComment of epoxy resin production, liquid (RER): Commercial epoxy resin can be produced by reacting bisphenol-A and epichlorohydrin in presence of a base catalyst (here represented by sodium hydroxide) (Guichon Valves n.d. and Pham and Marks 2005). Epoxy resins are in liquid form if n is from 0 to 1. When n is larger than 1 the resin in solid (Licare and Swanson, 2011). As the product here representes epoxy resin in liquid form, n is set to 1. 2C15H16O2 + 3C3H5ClO + 3NaOH -> C39H44O7 + 3Na+ + 3Cl- + 3H2O Pham, H.Q. and Marks, M.J. 2005. Epoxy Resins. In Ullmann's Encyclopedia of Industrial Chemistry, Electronic Release, Vol.13, pp.155-244. Wiley-VCH, Weinheim. Guichon Valves, n.d. Epoxy resins – Manufacturing process of Epoxy resins. Retrieved from: http://guichon-valves.com/faqs/epoxy-resins-manufacturing-process-of-epoxy-resins/, accessed 13th February 2017 For more information on the model please refer to the dedicate ecoinvent report, access it in the Report section of ecoQuery (http://www.ecoinvent.org/login-databases.html) The process is carried out in a reactor where a solution of sodium hydroxide is added (20 to 40% concentration). The product is brought to boiling temperature and a solvent is added. Solvents are not included in the inventory as it is assumed that solvents are closed-loop recycled. The unreacted epichlorohydrin is collected and recycled back into the system. The epoxy resin in then washed; this gives the final product in liquid form. Epoxy resin can also be produced in solid form. To do so, curing with, for example secondary amines, is necessary. Epoxy resins can have different characteristics, these depend on additional products that can be added to the liquid resin. The required characteristics depend on the final use of the product (Guichon Valves n.d.) This inventory representing production of a particular chemical compound is at least partially based on a generic model on the production of chemicals. The data generated by this model have been improved by compound-specific data when available. The model on production of chemicals is using specific industry or literature data wherever possible and more generic data on chemical production processes to fill compound-specific data gaps when necessary. The basic principles of the model have been published in literature (Hischier 2005, Establishing Life Cycle Inventories of Chemicals Based on Differing Data Availability). The model has been updated and extended with newly available data from the chemical industry. In the model, unreacted fractions are treated in a waste treatment process, and emissions reported are after a waste treatment process that is included in the scope of this dataset. For volatile reactants, a small level of evaporation is assumed. Solvents and catalysts are mostly recycled in closed-loop systems within the scope of the dataset and reported flows are for losses from this system. The main source of information for the values for heat, electricity, water (process and cooling), nitrogen, chemical factory is industry data from Gendorf. The values are a 5-year average of data (2011 - 2015) published by the Gendorf factory (Gendorf, 2016, Umwelterklärung, www.gendorf.de), (Gendorf, 2015, Umwelterklärung, www.gendorf.de), (Gendorf, 2014, Umwelterklärung, www.gendorf.de). The Gendorf factory is based in Germany, it produces a wide range of chemical substances. The factory produced 1657400 tonnes of chemical substances in the year 2015 (Gendorf, 2016, Umwelterklärung, www.gendorf.de) and 740000 tonnes of intermediate products. Reference(s): Hischier, R. (2005) Establishing Life Cycle Inventories of Chemicals Based on Differing Data Availability (9 pp). The International Journal of Life Cycle Assessment, Volume 10, Issue 1, pp 59–67. 10.1065/lca2004.10.181.7 Gendorf (2016) Umwelterklärung 2015, Werk Gendorf Industriepark, www.gendorf.de Licari, J.J. and Swanson, D.W. 2011. Chemistry, Formulation, and Properties of Adhesives. In Adhesives Technology for Electronic Applications (Second Edition), 2011
technologyComment of Mannheim process (RER): Production of sodium sulfate and HCl by the Mannheim process. This process can be summarized with the following overall stoechiometric reaction: 2 NaCl + H2SO4 → Na2SO4 + 2 HCl technologyComment of allyl chloride production, reaction of propylene and chlorine (RER): based on industry data in the US and Europe technologyComment of benzene chlorination (RER): Clorobenzenes are prepared by reaction of liquid benzene with gaseous chlorine in the presence of a catalyst at moderate temperature and atmospheric pressure. Hydrogen chloride is formed as a by-product. Generally, mixtures of isomers and compounds with varying degrees of chlorination are obtained, because any given chlorobenzene can be further chlorinated up to the stage of hexa-chlorobenzene. Because of the directing influence exerted by chlorine, the unfavoured products 1,3-dichlorobenzene, 1,3,5-trichlorobenzene and 1,2,3,5-tetrachlorobenzene are formed to only a small extent if at all. The velocity of chlorination for an individual chlorine compound depends on the compound's structure and, because of this, both the degree of chlorination and also the isomer ratio change continuously during the course of reaction. Sets of data on the composition of products from different reactions are only comparable if they refer to identical reaction conditions and materials having the same degree of chlorination. By altering the reaction conditions and changing the catalyst, one can vary the ratios of different chlorinated products within certain limits. Lewis acids (FeCl3, AlCl3, SbCl3, MnCl2, MoCl2, SnCl4, TiCl4) are used as principal catalysts. The usual catalyst employed in large scale production is ferric chloride, with or without the addition of sulfur compounds. The ratio of resulting chlorobenzenes to one another is also influenced by the benzene:chlorine ratio. For this reason, the highest selectivity is achieved in batch processes. If the same monochlorobenzene:dichlorobenzene ratio expected from a batch reactor is to result from continuous operation in a single-stage reactor, then a far lower degree of benzene conversion must be accepted as a consequence of the low benzene:chlorine ratio). The reaction is highly exothermic: C6H6 + Cl2 --> C6H5Cl + HCl ; delta H = -131.5 kJ/mol Unwanted heat of reaction can be dissipated either by circulating some of the reactor fluid through an external heat exchanger or by permitting evaporative cooling to occur at the boiling temperature. Circulation cooling has the advantage of enabling the reaction temperature to be varied in accordance with the requirements of a given situation. Evaporative cooling is more economical, however. Fractional distillation separates the products. Iron catalyst is removed with the distillation residue.Unreacted benzene is recycled to the reactor. technologyComment of hydrochloric acid production, from the reaction of hydrogen with chlorine (RER): HCl can be either directly prepared or generated as a by-product from a number of reactions. This dataset represents the production of HCl via the combustion of chlorine with hydrogen gas. The process involves burning hydrogen gas and chlorine in a gas combustion chamber, producing hydrogen chloride gas. The hydrogen chloride gas then passes through a cooler to an absorber where process water is introduced, producing aqueous hydrochloric acid. H2 + Cl2 -> 2 HCl (exothermic reaction) References: Althaus H.-J., Chudacoff M., Hischier R., Jungbluth N., Osses M. and Primas A. (2007) Life Cycle Inventories of Chemicals. ecoinvent report No. 8, v2.0. EMPA Dübendorf, Swiss Centre for Life Cycle Inventories, Dübendorf, CH. technologyComment of tetrafluoroethylene production (RER): The production of fluorochemicals and PTFE monomers can be summarized with the following chemical reactions (Cedergren et al. 2001): CaF2 + H2SO4 -> CaSO4 + 2HF (1) CH4 + 3Cl2 -> CHCl3 + 3HCl (2) CHCl3 + 2HF -> CHClF2 + 2HCl (3) 2 CHClF2 + heat -> CF2=CF2 + 2 HCl (4) This dataset represents the last reaction step (4). Parts of the production are carried out at high pressure and high temperature, 590 ºC – 900 ºC. The first reaction (1) takes place in the presence of heat and HSO3 - and steam. The inventory for the production of hydrogen fluoride can be found in the report (Jungbluth 2003a). Reaction (2) is used to produce trichloromethane. Reaction 3 for the production of chlorodifluoromethane takes place in the presence of a catalyst. The production of PTFE (4) takes place under high temperature pyrolysis conditions. Large amounts of hydrochloric acid (HCl) are generated as a couple product during the process and are sold as a 30% aqueous solution. A large number of other by-products and emissions is formed in the processes (benzene, dichloromethane, ethylene oxide, formaldehyde, R134a, and vinyl chloride) and small amounts of the highly toxic perfluoroisobutylene CF2=C(CF3)2. The by-products in the production of monomers can harm the processes of polymerisation. Because of this, the refinement of the production of monomers has to be very narrow. This makes the process complex and it contributes to a high cost for the PTFE-laminates. (Cedergren et al. 2001). References: Althaus H.-J., Chudacoff M., Hischier R., Jungbluth N., Osses M. and Primas A. (2007) Life Cycle Inventories of Chemicals. Final report ecoinvent data v2.0 No. 8. Swiss Centre for Life Cycle Inventories, Dübendorf, CH.
technologyComment of aniline production (RER): Production of aniline from benzene by nitrobenzene as an intermediate input with a process yield of 99%. References: Hischier R. (2007) Life Cycle Inventories of Packagings & Graphical Papers. ecoinvent report No. 11. Swiss Centre for Life Cycle Inventories, Dübendorf, 2007. Kahl, T., Schröder, K.-W., Lawrence, F. R., Marshall, W. J., Höke, H. and Jäckh, R. 2011. Aniline. Ullmann's Encyclopedia of Industrial Chemistry.
technologyComment of phenol production (RER): This dataset models the Hock process, which is the main process that is used for the production of phenol. In this process, cumene is transformed into phenol in two stages: (i) oxidation of the cumene, and (ii) cleavage into phenol and acetone. The oxidation happens in large reactors at a temperature of about 90-120°C and 0.5-0.7 MPa pressure. The whole reaction is autocatalytic and exothermic, releasing about 800 kJ per kilogram of cumene hydroperoxide to the environment by active cooling systems, mainly water. The second reaction – the cleavage – is an acid-catalyzed reaction, using almost exclusively sulphuric acid as catalyst. Two different ways are used within industry – called homogeneous phase (using 0.1-2% sulphuric acid) rsp. heterogeneous phase (40-45% sulphuric acid at a concentrate-acid ratio of 1:5). Also this second step is strongly exothermic – releasing ca. 1680 kJ per kilogram of cumene hydroperoxide cleaved. After the cleavage, further cleaning steps are used to achieve in the end a phenol purity of >99.9%. This includes neutralization and removing of sulphuric acid, followed by distillation processes. The overall yield of the production of phenol for this case here is assumed to be in the order of 95%. The inventory is based on stoechiometric calculations. The emissions to air (0.2 wt% of raw material input) and water were estimated using mass balance. Treatment of the wastewater in an internal wastewater treatment plant is assumed (elimination efficiency of 90% for C). References: Althaus H.-J., Chudacoff M., Hischier R., Jungbluth N., Osses M. and Primas A. (2007) Life Cycle Inventories of Chemicals. ecoinvent report No. 8, v2.0. EMPA Dübendorf, Swiss Centre for Life Cycle Inventories, Dübendorf, CH. technologyComment of phenol production, from cumene (RER): This process consists first in the production of cumene from the reaction of benzene and propylene. Cumene then reacts with oxygen to give phenol and acetone. For each kilogram of phenol produced, 0.63 kg of acetone are obtained. For the process 0.6 MJ/kg of electricity and 9.1 MJ/kg of steam are required per kg of phenol and 0.2 MJ/kg of electricity and 9.8 MJ/kg of steam required per kg of acetone (Saygin 2009). Chemical reaction: C9H12 + O2 -> C6H6O + C3H6O This inventory representing production of a particular chemical compound is at least partially based on a generic model on the production of chemicals. The data generated by this model have been improved by compound-specific data when available. The model on production of chemicals is using specific industry or literature data wherever possible and more generic data on chemical production processes to fill compound-specific data gaps when necessary. The basic principles of the model have been published in literature (Hischier 2005, Establishing Life Cycle Inventories of Chemicals Based on Differing Data Availability). The model has been updated and extended with newly available data from the chemical industry. In the model, unreacted fractions are treated in a waste treatment process, and emissions reported are after a waste treatment process that is included in the scope of this dataset. For volatile reactants, a small level of evaporation is assumed. Solvents and catalysts are mostly recycled in closed-loop systems within the scope of the dataset and reported flows are for losses from this system. The main source of information for the values for heat, electricity, water (process and cooling), nitrogen, chemical factory is industry data from Gendorf. The values are a 5-year average of data (2011 - 2015) published by the Gendorf factory (Gendorf, 2016, Umwelterklärung, www.gendorf.de), (Gendorf, 2015, Umwelterklärung, www.gendorf.de), (Gendorf, 2014, Umwelterklärung, www.gendorf.de). The Gendorf factory is based in Germany, it produces a wide range of chemical substances. The factory produced 1657400 tonnes of chemical substances in the year 2015 (Gendorf, 2016, Umwelterklärung, www.gendorf.de) and 740000 tonnes of intermediate products. Reference(s): Hischier, R. (2005) Establishing Life Cycle Inventories of Chemicals Based on Differing Data Availability (9 pp). The International Journal of Life Cycle Assessment, Volume 10, Issue 1, pp 59–67. 10.1065/lca2004.10.181.7 Gendorf (2016) Umwelterklärung 2015, Werk Gendorf Industriepark, www.gendorf.de Gallardo Hipolito, M. 2011. Life Cycle Assessment of platform chemicals from fossil and lignocellulosic biomass scenarios LCA of phenolic compounds, solvent, soft and hard plastic precursors. Master in Industrial Ecology. Norwegian University of Science and Technology Department of Energy and Process Engineering. Retrieved from: http://daim.idi.ntnu.no/masteroppgaver/006/6362/tittelside.pdf, accessed 6 January 2017 SRI consulting. In: Gallardo Hipolito, M. 2011. Life Cycle Assessment of platform chemicals from fossil and lignocellulosic biomass scenarios LCA of phenolic compounds, solvent, soft and hard plastic precursors. Master in Industrial Ecology. Norwegian University of Science and Technology Department of Energy and Process Engineering. Retrieved from: http://daim.idi.ntnu.no/masteroppgaver/006/6362/tittelside.pdf, accessed 6 January 2017 Gallardo Hipolito, M. 2011. Life Cycle Assessment of platform chemicals from fossil and lignocellulosic biomass scenarios LCA of phenolic compounds, solvent, soft and hard plastic precursors. Master in Industrial Ecology. Norwegian University of Science and Technology Department of Energy and Process Engineering. Retrieved from: http://e-archivo.uc3m.es/bitstream/handle/10016/14718/Life%20Cycle%20Assessment%20of%20platform%20chemicals%20from%20fossil%20and%20lignocelulose%20scenarios.%20Martin%20Gallardo.pdf?sequence=2, accessed 6 January 2017 Saygin, D. 2009. Chemical and Petrochemical Sector Potential of best practice technology and other measures for improving energy efficiency. IEA information paper. IEA/OECD. Retrieved from: https://www.iea.org/publications/freepublications/publication/chemical_petrochemical_sector.pdf, accessed 6 January 2017 For more information on the model please refer to the dedicate ecoinvent report, access it in the Report section of ecoQuery (http://www.ecoinvent.org/login-databases.html)