• Energy Research

Abstract Gate-to-gate process energy consumption is an important metric for sustainability as it affects both costs and environmental impact. As only little process information is available in early phases of chemical process design, a detailed energy consumption calculation is substantially restrained. Therefore, a reliable estimation of energy consumption in early phases of process design is an important alternative. In this work, an index representing process energy consumption was evaluated and tested for 14 organic solvent case studies. By using simplified process models the indices were calculated and compared to literature values for gate-to-gate energy consumption. The predictability of the process energy consumption on the basis of this indicator, including possible modifications in its original definition, was evaluated with the Pearson's and Spearman's correlation coefficients. The results further validated the use of the EI (energy index) in its original form as a proxy indicator of the process energy consumption for decision making in early stages of process design. For assessing the production of new classes of chemicals the EI should be evaluated as shown in this paper in order to establish its practicability. In certain cases an adjustment of the indicator categories may be necessary.

The design of an extraction process is complicated. The key decision here is the selection of extractive solvent, however, is not stand alone. The distillation sequence, which normally follows the extraction unit for solvent recovery and product purification, is entirely influenced by the agent chosen. In many cases, mass throughput of solvents in the extraction unit can be large in order to increase separation performance. This character could raise various concerns in monetary and non-monetary issues such as safety, environment and social aspects. In this work, we propose a structural framework, which facilitates chemical engineers to design extraction processes under sustainable criteria. An activity modeling method, the type-zero method of Integrated DEFinition (IDEF0), is applied for presenting the inter-connected design activities transparently, and for incorporating various sustainability criteria systematically into design. Within the framework, extractive agents and succeeding recovery/purification processes are considered concurrently, which enables rational choices in the entire process. The framework is demonstrated through a case study, where extraction solvents and following separation systems are evaluated under selected sustainability criteria.

Management of emerging technologies may play a significant role in the advancement towards sustainable development. While the development of consistent management policies requires inputs from a wide spectrum of specialists and other stakeholders, current platforms for facilitating their participation are insufficient. In this study, we present a framework for a visualized scenario analysis that comprehensively assesses combinations of multiple technologies. This framework (1) helps our understanding of scenario performance and behaviors of technology‐introduction, (2) identifies the relationships and trade‐offs based on evaluation indices, and (3) allows for visualization of various technology‐introduction scenarios accounting for time frame. The applicability of this methodology is demonstrated using case studies that evaluate scenario performances and behaviors when implementing various power generation technologies in the Japanese electricity supply system. Different scenarios (e.g., renewable energy‐based power generation, operation choice of nuclear power) are visualized to assist stakeholders with evaluation of the trade‐offs. © 2014 American Institute of Chemical Engineers Environ Prog, 34: 832–840, 2015

This paper presents design approaches to induce behavioral shifts toward product sharing through a case study on laundry activities in Japan. Business models involving provision of temporary access to goods are garnering attention as a way to reduce environmental impacts from the current pattern of consumption. However, the success of such business models is a matter of consumer choice, and there exist hurdles for consumers to forego ownership and transfer to product sharing. To understand the forces that affect consumer behavior involving product sharing and to design effective interventions for behavioral shifts, we conducted in-depth interviews and a web survey. From the results, we specified the decision processes in a behavioral shift between home washing and laundromat use, and generated “implementation of a communal laundromat in an apartment building” as a promising way for consumers to shift toward laundromat use. Based on our calculation, the proposed approach has a potential to reduce environmental impact of a hypothetical community by 1.8% in greenhouse gas emissions and 16% in resource use relative to when only home washing is practiced. Our study provides an example of designing interventions for product sharing through reflecting actual usage patterns and consumer motivations.

AbstractIn recent years, many chemical companies have adopted the concept of sustainable development as a core business value. In this context and with focus on early phases, we present a novel design framework that comprises four stages of process modeling and multiobjective evaluation considering monetary and nonmonetary aspects. Each stage is characterized by the available information as a basis for process modeling and assessment. Appropriate modeling approaches, and evaluation indicators for economy, life‐cycle environmental impacts, environment, health, and safety (EHS) hazard, and technical aspects are selected for each defined stage. The proposed framework is demonstrated on the design of a methyl methacrylate (MMA) process: considering 17 synthesis routes, the framework is mimicked step‐by‐step, to select the route with the best multiobjective performances, and to produce an optimized process flowsheet. As a validation of the framework, evaluation profile of six routes over all stages are compared, and crucial points are identified that should be estimated considerably well in early stages of the framework. © 2008 American Institute of Chemical Engineers AIChE J, 2008

Abstract We propose a method for designing a local energy cooperative network (EneCoN) that uses new technologies for heating and power in a combined way. The method comprises six steps, including the generation of different technology options, energy balance modeling of the demand and supply, and multiobjective evaluation and optimization. As a decision-support tool, ternary diagrams are applied to analyze the effect of the mix of energy consumers in an EneCoN (i.e., residents, offices, or hospitals) on the objective function. The overall outcome of applying the method is a suggestion for the technology mix in the EneCoN that minimizes design objectives such as cost and environmental impacts with consideration of the mix of energy consumers as a design parameter. A case study was conducted on the installation of photovoltaic power generators, solar heat collectors, and fuel cells as new energy technologies in the target cities Tokyo, Sapporo, and Naha. Differences in the climate and energy demand profile were well reflected in the calculation, and different suggestions for the technology mix were obtained. The method also allowed good visualization of various complex design options (e.g., consumers, technology types, and the degree of combination) and can serve as a solid basis for designing energy systems.

AbstractThe utilization of biomass is a key technology toward sustainable development. Bioethanol can be used as a substitute for fossil‐based fuel and to produce commodity chemicals, in which the latter has larger benefit returns and wider application. Therefore, switching the use of bioethanol as a feedstock of chemical processes from the conventional fossil‐based one to produce large quantities of chemicals has recently received increasing attention. In this study, we investigate the potential of substituting bioethanol‐based processes for fossil‐based processes to produce ethyl acetate, by considering economic and environmental issues. Different technologies of producing ethyl acetate are considered. One representative fossil‐based process is modeled and compared with three bioethanol‐based processes, with respect to production cost and CO2 emission indicators. The results show that bioethanol‐based processes have better cost saving and less global warming potential. The identification of a feasible bioethanol‐based production process of ethyl acetate will largely contribute to the development of the chemical industry and help ensure the actual sustainability of such an emerging technology. © 2010 American Institute of Chemical Engineers Environ Prog, 2010