styrene production, UPR, ecoinvent 3.6, Undefined
Location: RER - Europe
This activity produces 1 kg of styrene. Styrene is an unsaturated aromatic monomer. Styrene is used in the production of polymers. Styrene is used in the following production processes in approximately the following shares: 60% for polystyrene production, 18% styrene – acrylonitrile copolymer (SAN) and terpolymers of acrylonitrile, butadiene, and styrene (ABS), 5% for styrene – butadiene rubber elastomers (SBR), 6% styrene – butadiene latexes, 5 % to producer unsaturated polyester resins (James and Castor 2011). Global production of styrene for the year 2008 was of 26 million tonnes (James and Castor 2011).
Reference(s):
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.
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)
Undefined unit processes (UPRs) are the unlinked, multi-product activity datasets that form the basis for all of the system models available in the ecoinvent database. This is the way the datasets are obtained and entered into the database by the data providers. These activity datasets are useful for investigating the environmental impacts of a specific activity (gate-to-gate), without regard to its upstream or downstream impacts.
Styrene is mainly produced by the dehydrogenation of ethylbenzene (James and Castor 2011). 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.
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
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.
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)
ecoinvent EULA