Sustainability assessment of biorefinery strategies under uncertainty and risk using multi-criteria decision-making (MCDM) approach

摘要

The overall objective of this thesis is to illustrate a design-based methodology for strategic decision-making under uncertainty while quantifying risk attitude of decision makers, in order to identify sustainable biorefinery strategies. The proposed methodology has been demonstrated by two case studies addressing (a) the triticale-based greenfield agriculture biorefinery, and (b) the forest biomass-based biorefinery in retrofit to a kraft pulp mill. In order to mitigate risk, a phased approach has been considered for candidate biorefinery strategies, to be implemented over the near and then longer-term.;The methodology presented in this thesis assesses biorefinery alternatives from economic, market competitiveness and environmental perspectives, using systems analysis tools including classical techno-economic assessment. The results of these assessments are incorporated into a set of "intelligent" sustainability criteria. In contrast to conventional analyses which generally use only short-term profitability metrics for decision-making, this work defines multidisciplinary criteria representing profitability and business-oriented economic performance, potential environmental footprint, market competitiveness, as well as technology and market risks - as indicators of biorefinery sustainability. These criteria are inevitably conflicting, and thus they need to be aggregated into a unique sustainability score for each biorefinery strategy, through conducting a multi-criteria decision-making (MCDM) by a multi-disciplinary panel with various backgrounds to ensure that expertise in the critical dimensions that should be considered in strategic decision making is captured. MCDM approach offers certain advantages over the other available methods, including: (a) reflecting the preferences of decision makers regarding the relative importance of the criteria, (b) consensus building among project stakeholders and (c) a focus on criterion interpretation.;In this thesis, a practical and systematic methodology is developed and demonstrated whose goal is to make more "intelligent" decisions at strategic level of design, by assessing sustainability of biorefinery strategies under both uncertainty and risk. The data uncertainty has been quantified by a stochastic risk analysis method (Monte Carlo analysis) in the form of probability distribution functions of sustainability criteria. In addition, panel uncertainty has been addressed in terms of the level of consensus among the panel members for making the final decision. Moreover, the risk attitude of decision-makers has been measured using a lottery approach and applying risk aversion theory, by which the preference of decision-makers is quantified for decision making. As a consequence of quantifying uncertainty and risk, decision-makers were provided with improved understanding resulting in more robust decisions. One of the achievements in this thesis is showing that addressing risk attitude of decision makers on top of involving uncertainty in strategic decision making could help to more differentiate between the alternatives and consequently enabled decision makers to screen out more options at the strategic level with more confidence.;The results in this thesis illustrate the importance of applying a systematic approach for making a strategic design decision, considering sustainability criteria and involving uncertainty and decision makers' risk attitude in multi-criteria decision-making. Once these concepts are understood by the senior management of companies, then consensus building can be objectively and systematically accounted for, in decision making and a better decision can be made. (Abstract shortened by UMI.).