A Holistic Methodology for Optimizing Industrial Resource Efficiency

Abstract

Efficient consumption of energy and material resources, including water, is the primary focus for process industries to reduce their environmental impact. The Conference of Parties in Paris (COP21) highlighted the prominent role of industrial energy efficiency in combating climate change by reducing greenhouse gas emissions. Consumption of energy and material resources, especially water, are strongly interconnected and, therefore, must be treated simultaneously using a holistic approach to identify optimal solutions for efficient processing. Such approaches must consider energy and water recovery within a comprehensive process integration framework which includes options such as organic Rankine cycles for electricity generation from low-medium-temperature heat. This work addresses the importance of holistic approaches by proposing a methodology for simultaneous consideration of heat, mass, and power in industrial processes. The methodology is applied to a kraft pulp mill. In doing so, freshwater consumption is reduced by more than 60%, while net power output is increased by a factor of up to six (from 3.2 MW to between 10-26 MW). The results show that interactions among these elements are complex and therefore underline the necessity of such comprehensive methods to explore their optimal integration with industrial processes. The potential applications of this work are vast, extending from total site resource integration to addressing synergies in the context of industrial symbiosis.

An Optimisation Approach for Long-Term Industrial Investment Planning

“…The problem was solved using a novel decomposition algorithm with integer cuts. Similarly, Kermani et al developed a holistic and generic method, which solves heat and mass integration, heat exchanger network design and improves the industrial processes by organic Rankine cycle integration [20]. The method proposed in this work is based on a PI method [21], which introduces location aspects, such as heat losses and piping costs between plants.…”

Optimal Design of Heat-Integrated Water Allocation Networks

“…where, F k is the heat capacity flow rate of stream k and f k,I l is the heat capacity flow rate of stream k towards the inlet of heat exchanger of match (k, l)/(l, k) in the superstructure of stream k. (15) Mass balance at the mixer preceding a heat exchanger of stream k ∈ HCS:…”

“…1. providing systematic holistic methodologies addressing non-water processes [10][11][12][13], thermal utilities [10,14,15], and other energy conversion and heat recovery technologies [15], 2. considering multi-period operations and uncertainty analysis of HIWANs addressing variations of operating conditions, 3. proposing Multi-Criteria Decision Making (MCDM) tools addressing conflicting set of objectives and providing a set of optimal solutions to guide decision-makers in selecting the most appropriate configuration(s) [15], and 4. proposing efficient solution strategies to address the increasing difficulty of solving large-scale cases [16,17].…”

“…Chen and Wang [2] and Kermani et al [5] have highlighted the importance and benefits of multi-objective optimization techniques in HIWAN synthesis problems. Very few research works have considered these techniques in their methodologies [15,25,26]. Boix et al [26] selected four objective functions defined as minimizing the freshwater consumption, energy consumption, number of heat exchangers, and number of water interconnections.…”

“…They further allow practitioners to understand why they are selecting a specific solution and how this solution's performance is compared to the rest. Among these tools, parallel coordinates visualization tool [32] is a powerful and practical way for evaluation and decision-making in high-dimensional spaces with applications in urban planning [33,34] and process integration [15]. This tool has been selected to visualize and further select promising alternatives similar to the approach presented by Kermani et al [15].…”