Sustainable Product Portfolio And Process Design Of The Forest Biorefinery

Abstract

INTRODUCTION The North American forestry industry has been challenged in recent years by high energy costs, increasing fibre costs, and aging mill assets that have not been adequately modernized [1]. The so-called forest biorefinery (FBR) has emerged as an interesting candidate for reviving the industry. The FBR may use ligno-cellulosic (woody, agricultural) biomass as raw material and implies full utilization of biomass for the production of fibres, chemicals and/or energy, and thus offers an alternative strategy for its utilization. Its design should consider both the retrofit design of pulp and paper mill processes and the product portfolio [2]. There is an apparent complexity in this development, and therefore a rigorous design framework is needed. The concept of sustainability consists of three dimensions: economic, environmental and social. However, design typically emphasizes economic objectives for decision making between process alternatives, and the environmental and social aspects of alternatives are considered as constraints (e.g. [3; 4]). Multi-criteria decision making (MCDM) methods may be used to consider all sustainability dimensions as objectives. METHODOLOGY Design framework Figure 1 shows a design framework that takes into account the design of the product portfolio and biorefinery production process [7]. It consists of a set of process systems engineering (PSE) tools that together cover all aspects of FBR process and portfolio design. In this framework, an MCDM method is used for design decision making based on the analysis results using the PSE tools. MCDM methods raise the awareness of the decision maker(s) about the problem complexity and they can be used to address decision uncertainty.