Ecocostos

Process Safety and Environmental Protection 9 0 ( 2 0 1 2 ) 27–37

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Process Safety and Environmental Protection
journal homepage: www.elsevier.com/locate/psep

Environmental and eco-costs life cycle assessment of an acrylonitrile process by capacity enlargement in Mexico
M.A. Morales-Mora a,∗ , E. Rosa-Dominguez b,1 , N. Suppen-Reynagac,2 , S.A. Martinez-Delgadillo d
a

PEMEX-Petroquímica, Jacarandas 100, Col. Rancho Alegre I, CP. 96558 Coatzacoalcos, Veracruz, Mexico Central University Marta Abreu de Las Villas, Chemistry-Pharmacy Faculty, Camajuaní Road km 51/2, Santa Clara, Villa Clara ZP: 54 830, Cuba c Centro de Análisis de Ciclo de Vida y Diseno Sustentable. Bohemia 2-9, Bosques del Lago, Cuautitlán Izcalli, Edo. México,C.P. 54766, ˜ Mexico d Depto. Ciencias Básicas. Universidad Autónoma Metropolitana-Azcapotzalco. Av. San Pablo 180. Azcapotzalco. C.P. 02200. Mexico D.F, Mexico
b

a b s t r a c t
Life cycle assessment and marginal prevention costs (eco-costs method) for an acrylonitrile plant were carried out estimating the environmental impact and the eco-costs, due to the increment in the productioncapacity. This study compares the old plant’s operative performance (old design) at 50,000 ton/year where the by-products were incinerated, with the current operation at 60,000 ton/year where those by-products in the waste stream will be treated to take advantage of its substance content, to generate profitable products. In addition, the effect of a wastewater flow rate with cyanide was evaluated on thebiological wastewater treatment process. The redesign showed a high reduction percentage in eleven of eighteen midpoint impact categories. The reduction of 36% in the global impacts in the redesign was obtained when these ones were calculated based on the impacts of the year of 2005. The CO2 emissions equivalents (CO2 eq) had a reduction of 46% (from 6.55 to 3.50 kg CO2 eq/kg of acrylonitrile). Thetotal of marginal prevention costs (eco-costs) are 1.28 USD/kg for acrylonitrile old design and the 0.735 USD/kg for acrylonitrile redesign, i.e. 42.5% lower than the old design. This means that 94.5% are costs for pollution and the use of energy and 5.4% by depletions of material resources. This study proved that the redesign is environmentally most favorable and economically affordable method.Eco-costs method should be incorporated as part of the financial indicators of a project, but with the respective adaptation to the environmental and economic conditions of a region. © 2011 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved. Keywords: Acetocyanhydrine; Acrylonitrile; Eco-costs; Methyl methacrylate monomer; Morelos Petrochemical Complex

1.Introduction

Acrylonitrile is used for the manufacture of acrylic fibers for clothing industry (sweaters, socks and yarn) and materials manufacture for blankets and tapestry; polymers for automotive industry: acrylonitrile–butadiene–styrene (ABS),

styrene–acrylonitrile (SAN) and for the nitrile rubber sector, due to it is resistance to high temperatures, oils and solvents. Acrylonitrile is amaterial manufactured from petrochemical products; propylene and ammonia particularly. World annual production in the year 2005 was 6 million tons, just less than the half of that coming from the United States. In Mexico,

Corresponding author. Tel.: +52 921 21 11337. E-mail addresses: miguel.angel.moralesmo@pemex.com (M.A. Morales-Mora), erosa@uclv.edu.cu (E. Rosa-Dominguez),nsuppen@centroacv.com.mx (N. Suppen-Reynaga), samd@correo.azc.uam.mx (S.A. Martinez-Delgadillo). Received 10 July 2011; Received in revised form 17 October 2011; Accepted 19 October 2011 1 Tel.: +53 42 281100. 2 Tel.: +52 55 2602 9694. 0957-5820/$ – see front matter © 2011 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved. doi:10.1016/j.psep.2011.10.002

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