A HIERARCHICAL ACTIVITY MODEL OF CHEMICAL PROCESS DESIGN BASED ON LIFE CYCLE ASSESSMENT H. SUGIYAMA 1,2 , M. HIRAO 1 , R. MENDIVIL 2 , U. FISCHER 2 and K. HUNGERBU ¨ HLER 2 1 Department of Chemical System Engineering, The University of Tokyo, 113-8656 Tokyo, Japan 2 Institute for Chemical and Bioengineering, Swiss Federal Institute of Technology (ETH), 8093 Zurich, Switzerland A business model of simulation-oriented process design is presented, including life cycle assessment (LCA) and related activities such as multi-objective decision making. Type-zero method of integrated definition language (IDEF0) is employed as an activity modelling tool to describe the entire business model. The whole design procedure is described hierarchically with focus on LCA related activities i.e., perform LCA is defined as a sub-activity of evaluate processes which is further a part of the top level activity, design chemical process. The economic evaluation is defined as an activity concurrent to LCA, enabling multi-objective evaluation and optimization of the process. The roles of decision-support activities such as sensitivity or uncertainty analysis are discus- sed in detail. Use of IDEF0 enabled detailed and at the same time transparent definition of the whole design procedure. A case study is performed on the design of chemical recycling processes of beverage PET bottles, which is currently an important topic in Japan. The proposed design procedure is demonstrated step by step, with focus on the multi-objective process assessment. Among several alternatives the Pareto-optimal ones are identified. Keywords: environmentally benign process design; life cycle assessment; activity modelling; business model; IDEF0; PET bottle recycling. INTRODUCTION In recent years, many chemical companies have adopted the concept of sustainable development as a core business value. Here the basis of decision-making is extended to cover various aspects in addition to the economic perform- ance. Chemical companies need to reflect such paradigm shift in the business models throughout their entire research, development and production activities. The pro- cess design phase is of major importance because decisions made here determine most of the performance of the process. Hence the inclusion of sustainable development criteria is crucial, in particular consideration of the poten- tial environmental impacts, among other issues such as safety or workers’ health (Cano-Ruiz and McRae, 1998). As a method to quantify environmental impacts, life cycle assessment (LCA) (ISO 14040–14043, 1997–2000) is gaining more and more acceptance. While LCA was initially developed for the products evaluation and improvement, process-oriented uses of LCA are found in several case studies from both academia (e.g., Stefanis et al., 1995, 1997; Kniel et al., 1996) and industry (e.g., Bretz and Frankhauser, 1997). As a methodological deve- lopment, Azapagic and Clift (1999) described the use of LCA in the process optimization with mathematical approaches, and formed up a theoretical multi-objective optimization framework together with an economic objective. In the introduction of BASF’s ‘eco-efficiency method’, Saling et al. (2002) illustrated industrial practice of LCA for evaluating non-monetary performance of the technology options. Combined with economic evaluation, the overall result is applied in the improvement of the existing process. In all these publications, retrofitting design cases were presumed, e.g., cases where the process information that is needed for LCA was available. More recently, some authors proposed the practice of LCA even with limited amount of available process information, which is typically the case in grassroots design. Hoffmann et al. (2004) proposed a method to treat uncertain design variables as probability distributions, and to incorporate them into the result of LCA and the net present value for multi-objective optimization. Stewart et al. (2003) presented the use of different levels of life cycle impact assessment results in different design phases according to the available amount of the process information.  Correspondence to: H. Sugiyama, Institute for Chemical and Bio- engineering, Swiss Federal Institute of Technology, ETH Ho ¨nggerberg, CH-8093 Zurich, Switzerland. E-mail: hirokazu.sugiyama@chem.ethz.ch 63 0957–5820/06/$30.00+0.00 # 2006 Institution of Chemical Engineers www.icheme.org/journals Trans IChemE, Part B, January 2006 doi: 10.1205/psep.04142 Process Safety and Environmental Protection, 84(B1): 63–74