Reducing water and energy consumption in chemical industry by sustainable production approach: a pilot study for polyethylene terephthalate production Emrah Alkaya a ,G € oksel N. Demirer b, * a Technology Development Foundation of Turkey, Cyberpark Cyberplaza B-Blok Kat: 5-6, 06800 Bilkent, Ankara, Turkey b Department of Environmental Engineering, Middle East Technical University, Dumlupinar Bulvari No: 1, 06800 Ankara, Turkey article info Article history: Received 5 June 2014 Received in revised form 28 December 2014 Accepted 28 February 2015 Available online 7 March 2015 Keywords: Cleaner production Resource efficiency Polyester production Water saving Energy efficiency abstract In this study, a polyethylene terephthalate manufacturing plant was subjected to environmental per- formance evaluation and analyses/benchmarking of water consumption. The objective was to determine processes/practices where significant water and related energy saving potential was present. Based on evaluations and analyses, a technology change was realized in heat transfer systems from water-to air- cooled process. As a result of the applications, soft cooling water consumption of the company was reduced by 46.7% which corresponds to water saving of 151,428 m 3 /year. Moreover, 117,848 kWh/year of energy was saved due to electricity saving in electric motors of pumps of heat transfer systems as well as pumps/fans of cooling towers. Owing to the improved energy efficiency, total carbon emissions of the company was reduced by 69,530 kg CO 2 /year. Auxiliary material consumption was also reduced since the maintenance requirements of heat transfer pumps were minimized. The total cost saving was 104,905 $/ year, while the payback period was calculated as 6 months. This study was conducted to be used as a successful model to increased water and energy efficiency in manufacturing industries based on sys- tematic environmental performance evaluations and benchmarking. Furthermore, it could serve as a building block in Turkey for the integration of cleaner and sustainable production approach into national agenda which is currently being structured by the European Union harmonization efforts of this country. © 2015 Elsevier Ltd. All rights reserved. 1. Introduction Chemical industry is indispensable for the growing economy of Turkey during current shift from agricultural-to industrial-based development. In Turkey, with more than 13 billion $ of export, chemical industry has a share of 9.7% in total export of the country (MOSIT, 2012). In terms of created added-value, the chemical in- dustry is in the 4th place among other manufacturing sectors. In addition to its export capacity and created added-value, the chemical industry is also very important when its contribution to employment (more than 230,000 employees) is taken into consideration (MOSIT, 2012). Turkish chemical industry has a product portfolio composed of variety of products including organic/inorganic chemicals, synthetic fibers, soaps/detergents, pharmaceuticals, fertilizers, essential oils, petrochemicals, paints, cosmetics and personal care products (MOE, 2013). Although the chemical industry is of utmost importance in terms of its contribution to the national economy, its negative environmental impacts draw particular attention. According to Turkish Statistical Institute, chemical industry produces 378,341 tons of hazardous waste annually which makes it the single most hazardous waste producer industry in Turkey or 33.3% of total (TSI, 2008a). When the total solid waste production is of concern, the chemical industry is in the 4th place after basic metal, other non- emetal mineral products and food industries, being responsible for 6.7% (830,039 tons/year) of total industrial solid waste generation (TSI, 2008b). Apart from hazardous and solid waste production, chemical industry is one of the major water consuming industries. In 2008, chemical industry consumed 67.5 million m 3 of water, corresponding to 5.1% of total industrial water consumption as the 4th most water consuming industry in Turkey (TSI, 2008c). Inten- sive energy consumption and associated greenhouse gas emissions are other important environmental issues associated with the * Corresponding author. Tel.: þ90 312 210 58 67; fax: þ90 312 210 26 46. E-mail addresses: ealkaya@ttgv.org.tr (E. Alkaya), goksel@metu.edu.tr (G.N. Demirer). Contents lists available at ScienceDirect Journal of Cleaner Production journal homepage: www.elsevier.com/locate/jclepro http://dx.doi.org/10.1016/j.jclepro.2015.02.087 0959-6526/© 2015 Elsevier Ltd. All rights reserved. Journal of Cleaner Production 99 (2015) 119e128