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National energy systems require flexibility to accommodate increasing amounts of variable renewable energy. This flexibility can be provided by demand-side management (DSM) from industry. However, the flexibility potential depends on the characteristics of each industrial process. The enormous diversity of industrial processes makes it challenging to evaluate the total flexibility provision from industry to sector-coupled energy systems. In this work, we quantify the maximum cost reductions due to industrial DSM in the net-zero sector-coupled Swiss energy system, and the relationship between cost reductions and various industrial process characteristics. We analyze the flexibility of industrial processes using a generic, process-agnostic model. Our results show that industrial DSM can reduce total energy system costs by up to 4.4%, corresponding to 20% of industry-related energy costs. The value of flexibility from industrial DSM depends not only on the process characteristics but also on the system's flexibility alternatives, particularly for flexibility over seasonal time horizons. As one specific option for industrial DSM, we find that thermal energy storage (TES) technologies available today could realize between 28% and 61% of the maximum cost reductions from industrial DSM, making TES a promising DSM solution and showing that industrial DSM isan accessible and cost-effective flexibility option. [ABSTRACT FROM AUTHOR]

In the pursuit of climate change mitigation, the chemical industry is developing carbon capture and utilization (CCU) processes to eliminate fossil carbon feedstock. Life Cycle Assessment (LCA) of CCU processes is crucial to verify climate change mitigation and identify potential burden shifting to other areas of environmental damage. Preferentially, this knowledge would be available already in early process development. However, LCA expertise is sparse and LCA studies are often data-intensive and complex, limiting the accessibility to non-LCA experts. To bridge this accessibility gap, we present ESTIMATe, an open-source Excel tool automating LCA assumptions and using estimation methods to streamline the LCA of CCU processes. ESTIMATe, designed for non-LCA experts, quickly provides simplified early-stage LCA results before a comprehensive LCA would usually be conducted. Our case studies demonstrate how ESTIMATe guides process development at different levels of process maturity by assessing climate change mitigation potentials, analyzing environmental impacts along the course of process development, and comparing the environmental performance of process alternatives. ESTIMATe is thus designed to complement rather than replace comprehensive LCA software, providing early access to LCA results and enabling process developers to incorporate environmental perspectives into their decision-making. The ESTIMATe tool is available for download at https://doi.org/10.5281/zenodo.11060469. [ABSTRACT FROM AUTHOR]

Carbon capture and storage (CCS) is broadly recognised as having the potential to play a key role in meeting climate change targets, delivering low carbon heat and power, decarbonising industry and, more recently, its ability to facilitate the net removal of CO2 from the atmosphere. However, despite this broad consensus and its technical maturity, CCS has not yet been deployed on a scale commensurate with the ambitions articulated a decade ago. Thus, in this paper we review the current state-of-the-art of CO2 capture, transport, utilisation and storage from a multi-scale perspective, moving from the global to molecular scales. In light of the COP21 commitments to limit warming to less than 2 °C, we extend the remit of this study to include the key negative emissions technologies (NETs) of bioenergy with CCS (BECCS), and direct air capture (DAC). Cognisant of the non-technical barriers to deploying CCS, we reflect on recent experience from the UK's CCS commercialisation programme and consider the commercial and political barriers to the large-scale deployment of CCS. In all areas, we focus on identifying and clearly articulating the key research challenges that could usefully be addressed in the coming decade.

Discussions on Consequential Life Cycle Assessment (CLCA) have relied largely on partial or general equilibrium models. Such models are useful for integrating market effects into CLCA, but also have well-recognized limitations such as the poor granularity of the sectoral definition and the assumption of perfect oversight by all economic agents. Building on the Rectangular-Choice-of-Technology (RCOT) model, this study proposes a new modeling approach for CLCA, the Technology Choice Model (TCM). In this approach, the RCOT model is adapted for its use in CLCA and extended to incorporate parameter uncertainties and suboptimal decisions due to market imperfections and information asymmetry in a stochastic setting. In a case study on rice production, we demonstrate that the proposed approach allows modeling of complex production technology mixes and their expected environmental outcomes under uncertainty, at a high level of detail. Incorporating the effect of production constraints, uncertainty, and suboptimal decisions by economic agents significantly affects technology mixes and associated greenhouse gas (GHG) emissions of the system under study. The case study also shows the model's ability to determine both the average and marginal environmental impacts of a product in response to changes in the quantity of final demand.

Several theoretical studies have predicted that refrigerant mixtures with glides of more than 20 K can yield COP improvements in heat pumps for operating conditions where the temperature difference between the heat source and heat sink is large, but experimental validations and quantifications are scarce. The application of high-glide mixtures (>20 K) in industrial heat pumps in the field is, therefore, still hampered by concerns about the behavior and handling of the mixtures. This study experimentally investigates hydrocarbon (HC) mixtures R-290/600 (propane/butane) and R-290/601 (propane/pentane) and compares them to previously tested mixtures of synthetic refrigerants. Comprehensive evaluations are presented regarding COP, compressor performance, pressure drop, heat transfer, and the possibility of inline composition determination. The mixtures were tested over a range of compositions at a source inlet temperature of 60 °C and a sink outlet temperature of 100 °C, with the heat sink and heat source temperature differences controlled to 35 K. R-290/601 at a mass composition of 70%/30% was found as the best mixture with a COP improvement of 19% over R-600 as the best pure fluid. The overall isentropic compressor efficiency was similar for HC and synthetic refrigerants, given equal suction and discharge pressures. Pressure drops in heat exchangers and connecting lines were equal for synthetic and HC mixtures at equal mass flow rates. This allows higher heating capacities of HC mixtures at a given pressure drop (mass flow rate) due to their wider vapor dome. A previously developed evaporator heat transfer correlation for synthetic refrigerant mixtures was applicable to the HC mixtures. A condenser heat transfer correlation previously fitted for synthetic refrigerants performed significantly worse for HC mixtures. Composition determination during operation and without sampling was possible with a deviation of at most 0.05 mass fraction using simple temperature and pressure measurements and REFPROP for thermodynamic property calculations. Overall, high-glide HC mixtures, just like mixtures of synthetic refrigerants, showed significant COP improvements for specific operating conditions despite a decreased heat transfer coefficient. Potential problems like composition shift or poor compressor performance were not encountered. As a next step, testing high-glide mixtures in pilot-plant installations is recommended. [ABSTRACT FROM AUTHOR]

The environmental costs and benefits of introducing a new technology depend not only on the technology itself, but also on the responses of the market where substitution or displacement of competing technologies may occur. An internationally accepted method taking both technological and market-mediated effects into account, however, is still lacking in life cycle assessment (LCA). For the introduction of a new technology, we here present a new approach for modeling the environmental impacts within the framework of LCA. Our approach is motivated by consequential life cycle assessment (CLCA) and aims to contribute to the discussion on how to operationalize consequential thinking in LCA practice. In our approach, we focus on new technologies producing homogeneous products such as chemicals or raw materials. We employ the industry cost-curve (ICC) for modeling market-mediated effects. Thereby, we can determine substitution effects at a level of granularity sufficient to distinguish between competing technologies. In our approach, a new technology alters the ICC potentially replacing the highest-cost producer(s). The technologies that remain competitive after the new technology's introduction determine the new environmental impact profile of the product. We apply our approach in a case study on a new technology for chlor-alkali electrolysis to be introduced in Germany.