Unlocking Plant-level Resource Efficiency Options: A Unified Exergy Measure

AbstractIn this research we propose a physical measure of resource efficiency, based on exergy, which combines energy and material flows in a single dimensionless metric, bounded by 0 and 1. The inclusion of materials in the efficiency metric makes it possible to compare a wide range of industrial devices and processes, and even different sectors, using a consistent framework. Resource efficiencies for steel-making processes were computed as an example and were found to range from 10.0% in sinter plants to72.1% in coke ovens. A unified resource efficiency measure helps identify the drivers of resource consumption and reveal opportunities to reduce carbon emissions

Exergy: A universal metric for measuring resource efficiency to address industrial decarbonisation

© 2019 Institution of Chemical Engineers To achieve agreed targets for reducing global carbon emissions, industry must become more resource-efficient. To this end, two viable strategies exist: energy efficiency and material efficiency. Despite the inherent interdependence of energy and materials in industrial processes, policy and industry treat these two strategies as isolated pursuits, which provides only a partial insight into potential gains from resource efficiency. To resolve this disconnect, we review 34 resource efficiency metrics from the literature and evaluate their effectiveness at driving the sector's low-carbon transition. We then evaluate five selected resource efficiency metrics, in more detail, against the RACER evaluation methodology, using the criteria: Relevance, Acceptance, Credibility, Easiness and Robustness. The results point to the effectiveness of employing a Resource Efficiency metric based on the thermodynamic concept of exergy. Exergy-based Resource Efficiency metrics score highest in Relevance and Robustness, traits which are inherent to the metric and cannot be changed. However, exergy efficiency scores lower for Acceptance, indicating further advocacy is required for it to be accepted as a mainstream measure of resource efficiency. More work is required to provide simple guides, training and software tools, to facilitate wider use of exergy efficiency in the resource efficiency narrative. We hope that this paper, is a first step towards demystifying exergy and will spur further discussion about the use of exergy-based metrics for measuring Resource Efficiency

Creating a Water Quality Scale Methodology Using California as a Case Study

Water availability analysis traditionally has involved understanding how much water enters and leaves a region and how much is used or stored each year. This mass balance of water, or water budget, is useful for tracking quantities of water; however, it offers no insights into the quality of the water. This paper introduces a method for creating a water quality scale that utilizes unique categories for water quality and reserves additional categories for the insertion of local water quality data. The method was tested using California as a case study. A water quality scale applicable to California was created, and data for the city of Paso Robles were inserted to demonstrate the flexibility of the framework to be made location-specific. The resulting scale can be used by water resource engineers to compare different types of water in terms of quality, measure both the quantity and quality of a local water supply simultaneously, and evaluate the most sustainable water supply options available. Furthermore, the scale can be customized for use anywhere in the world

A hybrid traceability technology selection approach for sustainable food supply chains

Traceability technologies have great potential to improve sustainable performance in cold food supply chains by reducing food loss. In existing approaches, traceability technologies are selected either intuitively or through a random approach, that neither considers the trade-off between multiple cost–benefit technology criteria nor systematically translates user requirements for traceability systems into the selection process. This paper presents a hybrid approach combining the fuzzy Analytic Hierarchy Process (AHP) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) with integer linear programming to select the optimum traceability technologies for improving sustainable performance in cold food supply chains. The proposed methodology is applied in four case studies utilising data collected from literature and expert interviews. The proposed approach can assist decision-makers, e.g., food business operators and technology companies, to identify what combination of technologies best suits a given food supply chain scenario and reduces food loss at minimum cost.Cambridge Trust and Commonwealth Scholarship Commission

A marginal abatement cost curve for material efficiency accounting for uncertainty

Comparing costs of measures to mitigate greenhouse gas is challenging as there are many competing notions of costs, and uncertainties associated with cost estimates. In addition, there are many different types of mitigation measures, from supply-side investment solutions to demand-side efficiency improvements, which may interact, risking double-counting of abatement potentials. This paper presents a novel, transparent methodology for building a marginal abatement cost curve that allows abatement costs and potentials to be compared. This curve improves over existing methods as it allows for abatement measures to be pursued in parallel, takes into account the interplay between abatement measures and captures data on cost uncertainty. The method is applied to build the first bottom-up marginal abatement cost curve for greater material efficiency steel use in the UK. This curve is demonstrated via four material efficiency measures which do not require large changes in final uses of products: reusing steel beams in construction, specifying optimal lightweight beams in construction, choosing smaller cars and specifying high strength steel car bodies. The results show that these strategies could reduce UK steel demand and associated global emissions by approximately 12%. 17% of this potential would be viable at the Department for Business, Energy \& Industrial Strategy (BEIS) 2030 carbon price for policy appraisal (79£/tCO2) taking into account emissions savings associated with steel demand only. Once use-phase emissions savings are taken into account this share increases to 60%. These results can be traced directly back to underlying assumptions regarding costs and emissions allocations

Options to make steel reuse profitable: An analysis of cost and risk distribution across the UK construction value chain

Although steel reuse has been identified as an effective method to reduce the carbon and energy impact of construction, it is in effect only a marginal practice. A detailed analysis of the costs and risks of reuse in practice in the uk is lacking. We found that although there is a sufficient spread between the price of steel scrap and new steel, this difference cannot be captured by the demolition contractors. Rather, reused steel is somewhat more expensive than new elements, except in certain circumstances such as when the reused elements are available from a nearby site, or when testing elements can be avoided. Further, we show that neither the costs of steel reuse, nor the risks, nor its benefits are spread equitably throughout the construction industry supply chain: most of the substantial and capital-intensive changes required for the widespread adoption of steel reuse are concentrated on steelwork contractors and stockists. Based on this analysis, we suggest helping the emergence of a specialised stockist.This research was supported by Innovate UK, project ‘Supply Chain Integration for structural steel reuse’, ref. 132106; EPSRC Material demand reduction: NMZL/112, RG82144, EPSRC reference: EP/N02351X/1

Real and perceived barriers to steel reuse across the UK construction value chain

© 2017 Elsevier B.V. Although steel reuse has been identified as an effective method to reduce the carbon and energy impact of construction, its occurrence is shrinking in the UK. This can be partly explained by the many barriers which have been identified in the literature, but a detailed analysis of how these barriers affect different parts of the supply chain is still lacking. We show that there is a contrast between perceived higher costs and time required to employ reused steel and the assessments of realised projects. Using a novel ranking method inspired from the field of information retrieval (tf-idf), we have analysed interviews of actors across the supply chain to determine the acuteness of the perception of each barrier. We show that demolition contractors, stockists, and fabricators face specific barriers which each need to be addressed at their level. This is in contrast with more generic barriers present throughout the value chain which we show are probably more perception than reality. Finally, we suggest how supply chain integration could facilitate reuse and make it economically viable at scale

Leveraging material efficiency as an energy and climate instrument for heavy industries in the EU

Material efficiency is indispensable to reaching agreed targets for industry's energy and carbon emissions. Yet, in the EU, the energy- and emissions-saving potentials of this strategy continue to be framed as secondary outcomes of resource-related policies. Understanding why material efficiency has been overlooked as an energy/climate solution is a prerequisite for proposing ways of changing its framing, but existing studies have failed to do so. This paper fills this gap by triangulating interviews, policy documents and three policy theories: namely, historical and rational choice institutionalism, and multiple streams framework. Factors discouraging material efficiency as an energy and climate strategy include: difficulties in reframing the prevailing rationale to pursue it; the inadequacy of monitored indicators; the lack of high-level political buy-in from DG Energy and Clima; the ETS policy lock-in; uncoordinated policy management across Directorates; the lack of a designated industry lobby. Policy solutions are proposed. Before 2030, these are limited to minor amendments, e.g. guidance on embodied energy calculations or industry standards. Post-2030, more radical interventions are possible, such as introducing new fiscal drivers, re-designing the ETS emissions cap or benchmarks for allowances. This evidence suggests that the transition to a low-carbon industry will require Member State- and industry-level action.Emerson Electric co

A new method to estimate the lifetime of long-life product categories

Increased recycling and reuse rates are a central part of the objectives laid out by the COP21. Nonetheless, the practical implementation of what has been called the circular economy, as well as its true potential are not easily established. This is because the impact and implementation time scales of any intervention depend on knowing the lifetime of products, which is frequently unknown. This is particularly true in construction, responsible for 39% of worldwide emissions, 11% of which are embodied. Most MFA models will simply assume a range of plausible life expectancies when bottom-up data is lacking (e.g. for buildings). In this work, we propose a novel method of identification using the high quality but highly aggregated trade data available, and use it to establish a “mortality curve” for buildings and other long-lasting products. This identification method is intended to provide more reliable inputs to existing MFA models. It is widely applicable due to the general availability of the underlying data. Using it on UK trade data, we identify product classes at 1 year for packaging/home scrap, one around 10 years for vehicles/equipment, and around 50 years for construction. The identification approach was then validated using classical approaches using bottom up data for vehicles

Dynamic exergy analysis: From industrial data to exergy flows

As the power and transport sectors decarbonize, industrial emissions will become the main focus of decarbonization efforts. Exergy analysis provides a combined material and energy efficiency approach to assess industrial plants, both of which are necessary to tackle industrial emissions. Existing studies typically use simulated, static data that cannot inform real plant operators. This paper performs an exergy analysis on data spanning 2 years from 311 sensors of a real ammonia production site. We develop methods to overcome unique data challenges associated with real industrial data processing, visualize resource flows in Sankey diagrams, and estimate exergy indicators for both the steam methane reforming plant and its constituent processes. We evaluate average conventional and transit exergy efficiencies for the plant (71%, 15%), primary reformer (86%, 40%), secondary reformer (96%, 71%), high-temperature shift (99.7%, 77%), combustor (56%, 55%), and heat exchange section (85%, 82%). Overall exergy losses are 80 MW; the primary reformer and combustor are the two processes with the highest losses at 35 and 33 MW, respectively. Such an analysis can inform both improvement projects and performance finetuning of a real plant while being applicable to any industrial site. Increased availability of cheap wireless sensors and a shift to Industry 4.0 can enable higher resolution and real-time performance monitoring