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The conventional Haber–Bosch process (HBP) for NH3 production results in CO2 emissions of almost 400 Mt/y and is responsible for 1–2% of global energy consumption; furthermore, HBP requires large-scale industrial equipment. Green or e-ammonia produced with hydrogen from alkaline water electrolysis using renewable energy and nitrogen from the air is considered an alternative to fossil-fuel-based ammonia production. Small-scale plants with the distributed on-site production of e-ammonia will begin to supplant centralized manufacturing in a carbon-neutral framework due to its flexibility and agility. In this study, a flexible small-scale NH3 plant is analyzed with respect to three steps—H2 generation, air separation, and NH3 synthesis—to understand if milder operating conditions can benefit the process. This study investigates the aspects of flexible small-scale NH3 plants powered by alkaline electrolyzer units with three specific capacities: 1 MW, 5 MW, and 10 MW. The analysis is carried out through Aspen Plus V14 simulations, and the primary criteria for selecting the pressure, temperature, and number of reactors are based on the maximum ammonia conversion and minimum energy consumption. The results show that: (i) the plant can be operated across a wide range of process variables while maintaining low energy consumption and (ii) alkaline electrolysis is responsible for the majority of energy consumption, followed by the ammonia synthesis loop and the obtention of N2, which is negligible. [ABSTRACT FROM AUTHOR]

The optimal combination of distributed generation units in recent years has been designed to improve the reliability of distributed generation systems as well as to reduce losses in electrical distribution systems. In this research, the improved Genetic Algorithm has been proposed as a powerful optimization algorithm for optimizing problem variables. The objective function of this paper includes power loss reduction, hybrid system reliability, voltage profile, optimal size of distributed generation unit, and finally improvement of the construction cost of combined wind and solar power plants. Therefore, the problem variables are subject to reliable load supply and the lowest possible cost during the optimization process. In order to achieve this goal in this study, the IEEE standard 30-bus network is examined. The results of the system simulation show the reduction of total system losses after DG installation compared to the state without DG and the improvement of other variable values in this network. This loss index after installing DG in the desired bus has a reduction of about 200 kWh during the year and has a value equal to 126.42 kWh per year.

In the event of an abrupt sunlight reduction scenario, there is a time window that occurs between when food stores would likely run out for many countries (~6 months or less) and ~1 year when resilient foods are scaled up. A promising temporary resilient food is leaf protein concentrate (LPC). Although it is possible to extract LPC from tree biomass (e.g., leaves and needles), neither the yields nor the toxicity of the protein concentrates for humans from the most common tree species has been widely investigated. To help fill this knowledge gap, this study uses high-resolution mass spectrometry and an open-source toolchain for non-targeted screening of toxins on five common North American coniferous species: Western Cedar, Douglas Fir, Ponderosa Pine, Western Hemlock, and Lodgepole Pine. The yields for LPC extraction from the conifers ranged from 1% to 7.5%. The toxicity screenings confirm that these trees may contain toxins that can be consumed in small amounts, and additional studies including measuring the quantity of each toxin are needed. The results indicate that LPC is a promising candidate to be used as resilient food, but future work is needed before LPCs from conifers can be used as a wide-scale human food.

The increasing implementation of renewable energy sources (RES), along with the diversity of energy source types, has additionally imposed significant operational and management problems in distribution networks. These problems are manifested in voltage regulations, system stability and coordination of protection, both in the distribution and transmission networks. For the medium voltage (MV) network, this includes new energy sources and higher amounts of fault currents, invisibility of several faults in the existing protection scheme, reduction of the range of protection devices and reduction of the possibility of detecting small fault currents with existing protection relays. Such changes significantly reduce the possibility of proper distribution system protection, both in subordinate and superior networks. The subject of this paper is the presentation of a new concept of the use of automation in the management and arrangement of power system protection dependent on the scheme and configuration of an active MV network. The goals of this analysis and research are to find and define the necessary architecture in which the scheme and appearance of the MV network should be automatically detected, and based on network topology to establish new settings of protection devices (ground fault, overcurrent and short circuit protection). The contributions of generation units of RES in the MV network must be considered. This paper specifically analyses the problems of power system management with simultaneous harmonization of protection systems both in the transmission and in the radial distribution network, offering optimization algorithms that have the ability of achieving the optimal solution. The implementation of the proposed technique was tested on a radial connection integrated with a microgrid (MG) which has the possibility of two-way power supply. The obtained results indicate that the proposed technique can solve described problems in the coordination of protection system and network management, even with the dynamic character of operation mode of the networks.

In the event of an abrupt sunlight reduction scenario, there is a time window that occurs between when food stores would likely run out for many countries (~6 months or less) and ~1 year when resilient foods are scaled up. A promising temporary resilient food is leaf protein concentrate (LPC). Although it is possible to extract LPC from tree biomass (e.g., leaves and needles), neither the yields nor the toxicity of the protein concentrates for humans from the most common tree species has been widely investigated. To help fill this knowledge gap, this study uses high-resolution mass spectrometry and an open-source toolchain for non-targeted screening of toxins on five common North American coniferous species: Western Cedar, Douglas Fir, Ponderosa Pine, Western Hemlock, and Lodgepole Pine. The yields for LPC extraction from the conifers ranged from 1% to 7.5%. The toxicity screenings confirm that these trees may contain toxins that can be consumed in small amounts, and additional studies including measuring the quantity of each toxin are needed. The results indicate that LPC is a promising candidate to be used as resilient food, but future work is needed before LPCs from conifers can be used as a wide-scale human food. [ABSTRACT FROM AUTHOR]

Open design and distributed production present potentials for empowering individuals and communities to create, share, access and produce diverse, sustainable designs that can meet their own local needs and the needs of future generations. The literature on distributed production and value creation deploys various sustainable future visions, along with matching assumptions on the roles of various stakeholders who can engage in these open and distributed processes of design, production, and post-use, who operate at varying scales (i.e., individual, local, regional, and global) and with different intentions for creating and recapturing value (i.e., for self and for others). This paper presents the outcomes of a survey conducted as part of a research project on exploring open design-led business models that can establish resilient and adaptive distributed value creation networks and localised circular economy loops, with a particular focus on electrical household appliances. The survey aimed to understand the varying roles stakeholders can take, their existing capabilities, and the kinds of knowledge, skills, and resources they would require to actively participate in such distributed production and value creation networks in Turkey. The results provide comprehensive insights into the types of stakeholders involved in the process, the knowledge, skills, and resources required, and the gaps in accessing them in Turkey. The paper identifies various directions for future research, including exploring secondary raw materials for individual fabrication, individualised post-use practices of reuse, refurbishing and recycling, and codesigning post-use.

Copyright of Control Theory & Applications / Kongzhi Lilun Yu Yinyong is the property of Editorial Department of Control Theory & Applications and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Considering the advantages of 3D printing, intelligent factories and distributed manufacturing, the 3D printing distributed intelligent factory has begun to rise in recent years. However, because the supply chain network of this kind of factory is very complex, coupled with the impact of customized scheduling and environmental constraints on the enterprise, the 3D printing distributed intelligent factory is facing the great challenge of realizing green supply chain networks and optimizing production scheduling at the same time, and thus a theoretical gap appears. This paper studies the hybrid optimization of green supply chain networks and scheduling of the distributed 3D printing intelligent factory. Firstly, according to the green supply chain network architecture of the distributed 3D printing intelligent factory, the cost minimization model is constructed. Secondly, mathematical software is used to solve the model, and the scheduling plan can be worked out. Finally, through the simulation analysis, it is concluded that the influencing factors such as demand, factory size and production capacity complicate the production distribution, and it can be observed that the carbon emission cost has gradually become the main factor affecting the total cost. The study has a reference value for the management decision making of the distributed 3D printing intelligent factory under the background of carbon emissions. [ABSTRACT FROM AUTHOR]

Manufacturing machines is a challenging task. High-volume sales can offset costs of production, but niche products struggle with viability. Distributed production--having people build their own niche products--is a possible alternative. We examine the Jubilee project, an Open Source Hardware machine with tool changing capability and multiple end effectors designed for distributed production using off-the-shelf and digitally fabricated parts. Since Jubilee's 2019 release, we track its adoption, its online community, and people who have successfully built it. Through analysis of the Jubilee project including 170+ Jubilees built in the wild, interviews with 12 Jubilee builders, and its Github, Discord server, and Wiki, we investigate what aspects helped people produce complex hardware on their own and how they strengthened the design of the product in turn. We find that while self-production is challenging, it can be a viable alternative to traditional hardware manufacturing. Finally, we discuss recommendations for selfproduced Open Source Hardware projects. [ABSTRACT FROM AUTHOR]

Goal: This scientific research article focuses on understanding the new manufacturing paradigm of Industry 4.0 called social manufacturing. The study aims to consolidate the concept of social manufacturing by characterizing and evaluating its theoretical potential, identifying its main practical trends, and correlating its state-of-the-art with its state-of-the-practice. Design / Methodology / Approach: The first step was the consolidation of the concept of social manufacturing through bibliographic analysis. Then, real-world cases were identified and classified under the optics of social manufacturing to define the current practice. Lastly, confronting the concept of social manufacturing with existing methods depicted a clear panorama, including academic and practical opportunities. Results: The results show a trend towards social manufacturing. New challenges, including the COVID-19 pandemic, are pushing forward social collaboration initiatives related to manufacturing. The most advanced conceptualized stage occurs theoretically, as mass individualization is still not a reality. New scenarios of limited resources and challenging environments such as the COVID-19 pandemic will impose the broader dissemination and application of mass customization concepts, practices, and tools. Limitation of the investigation: This research only considered articles published in English. Practices were analyzed using third-party content available. Practical implications: New scenarios of limited resources and challenging environments such as the COVID-19 pandemic impose the broader dissemination and application of mass customization concepts, practices, and tools. Originality / Value: The term social manufacturing in the literature has yet to be consolidated. In addition, no comparison between theory and practice was available. [ABSTRACT FROM AUTHOR]

Manufacturing machines is a challenging task. High-volume sales can offset costs of production, but niche products struggle with viability. Distributed production—having people build their own niche products—is a possible alternative. We examine the Jubilee project, an Open Source Hardware machine with tool changing capability and multiple end effectors designed for distributed production using off-the-shelf and digitally fabricated parts. Since Jubilee’s 2019 release, we track its adoption, its online community, and people who have successfully built it. Through analysis of the Jubilee project including 170+ Jubilees built in the wild, interviews with 12 Jubilee builders, and its Github, Discord server, and Wiki, we investigate what aspects helped people produce complex hardware on their own and how they strengthened the design of the product in turn. We find that while self-production is challenging, it can be a viable alternative to traditional hardware manufacturing. Finally, we discuss recommendations for self-produced Open Source Hardware projects.

Future energy systems must be clean, efficient and profitable. Previous cases have shown that incorporating local production into district heating networks is often unprofitable due to high temperature levels. This article suggests a new way of determining areas in existing networks suitable for low temperature district heating, which makes investments by real estate owners into local production profitable. A simulation of district heating network is used together with an investment optimization model to analyse the spatial potential of local production. The results show that some local production was profitable at current temperature levels, but it could be increased significantly if supply temperatures are decreased. This was shown to decrease losses and emissions of the system. Spatial optimization models are needed to increase knowledge on the effects of local production and lower network temperatures in district heating networks. Furthermore, new pricing models for customers have to be developed. [ABSTRACT FROM AUTHOR]

H 2 is an important commodity chemical that can also be used as an alternative fuel. The way how H 2 is currently produced and distributed, however, is not compatible with this usage. This is primarily due to the high costs associated with storing and delivering H 2 from the centralized production facilities to the end-use sites like H 2 stations that will be distributed throughout a region. Here, we propose a methodology for configuring the distributed H 2 production system that minimizes the overall cost in delivering H 2 to demand sites while meeting the safety requirements. The methodology also takes into account changes in costs with respect to production volume by applying the concept of economy of scale. The proposed methodology is applied to a hypothetical case involving H 2 supply to three stations. The results demonstrate significant reduction in the overall cost when adopting the optimal solution found by our methodology compared to the traditional, centralized production system. Insights on the cost structures associated with producing and delivering H 2 are provided, as well as specific improvements required to make H 2 affordable at the level defined by the international society. • A new methodology for configuring sizes and layout of distributed H 2 production system. • Comparative analysis between the centralized and distributed H 2 production system. • Costs of various H 2 production technologies and sensitivity analyses of key parameters. [ABSTRACT FROM AUTHOR]

Scheduling in distributed production system has become an active research field in recent years. This paper investigates the distributed assembly blocking flow-shop scheduling problem (DABFSP), which consists of two stages: production and assembly. The first stage is processing jobs in several identical factories. Each factory has a series of machines no intermediate buffers existing between adjacent ones. The second stage assembles the processed jobs into the final products through a single machine. The objective is to minimize the maximum completion time or makespan of all products. To address this problem, a constructive heuristic is proposed based on a new assignment rule of jobs and a product-based insertion procedure. Afterwards, an iterated local search (ILS) is presented, which integrates an integrated encoding scheme, a multi-type perturbation procedure containing four kinds of perturbed operators based on problem-specific knowledge and a critical-job-based variable neighborhood search. Finally, a comprehensive computational experiment and comparisons with the closely related and well performing methods in the literature are carried out. The experimental and comparison results show that the proposed constructive heuristic and ILS can solve the DABFSP effectively and efficiently. [ABSTRACT FROM AUTHOR]

The need for a sustainable society has grown rapidly. This trend requires new production system concepts following an era of mass customization. As one of these new concepts, "crowdsourced manufacturing" has attracted noticeable attention. In such systems, each participant shares their manufacturing resources for ecosystem co-prosperity, providing new value for the next society. To realize such a concept, it is important to (1) match resource requests and resource offers so as to achieve high efficiency, and (2) induce participants to act in a fair way. Previously, some studies showed production efficiency improvements. Nevertheless, relatively few studies have been conducted on induction mechanisms. The purpose of this study is to develop induction mechanisms for participants. Concerning induction mechanisms, we focus on two viewpoints: (a) matching stability, and (b) "strategyproofness." These viewpoints are well-known concepts in the market design research field. We previously proposed a resource matching stability analysis method and mechanism for inducing participants to accept matching plans. Formally, a matching method is "strategyproof" when it is a dominant strategy for all participants to submit their true information. However, it is hard to satisfy this condition. Practically, it would be useful to evaluate the strength of an induction, even if the matching method is not strategyproof. In this study, we propose indices for showing the strength of induction ("strength of strategyproofness"). Subsequently, we evaluate matching methods, and show that participants will state false information to maximize their profit in a system with resource matching methods for the profit maximization of the entire system. As the resource providers, they can obtain greater profit by submitting false information regarding resource usage fees. Then, the profits of the resource requesters are unfairly impaired. Furthermore, we propose a new resource matching method, inspired from the "nucleolus" concept in cooperative game theory. The proposed method reduces the maximum dissatisfaction (i.e., profit loss) of resource requesters and resource providers, based on profit sharing. The computational results show that the proposed method induces participants to submit true information, while maintaining high production efficiency. [ABSTRACT FROM AUTHOR]

Agricultural food production systems are essential to face current and future climate, food security and nutrition challenges. Several novel urban agriculture production concepts are utilizing symbiotic production and distributed/urban production principles to address these challenges. Life cycle engineering can support the planning and design of production systems and help to identify hotspots and avoid problem shifting. In this work the authors identify the factors resulting from symbiotic, distributed and enclosed food production, influencing life cycle inventory modelling for life cycle assessment. Based on the influencing factors a life cycle inventory modelling framework is proposed and the application pathway is illustrated by an in-development production system called CUBES Circle. [ABSTRACT FROM AUTHOR]

First industrial-scale Power-to-Methanol plants are starting to be deployed in various geographic locations to tackle the problem of high greenhouse gas emissions of the predominantly fossil-based production of methanol. With the aim to speed up the deployment by streamlining their engineering and construction, we explore the potential of reducing the complexity of designs to be distributed across locations with different renewable energy conditions. A multi-objective optimization-based method incorporating a broad process network for early-stage process synthesis is proposed, which by determining the installed capacities of technologies from the chemical production, utility and storage subsystems, identifies alternative designs with different levels of complexity along two dimensions: 1) the number of different technologies used, 2) standardization of designs across different locations. The method was applied to case studies, which paired together design locations with either wind- or solar-dominant renewable resource conditions in the US and Chile for standardization. As per the method, the increases of methanol production costs due to reduced design flexibility, inherently bound to complexity reduction, were quantified and Pareto fronts were constructed. These uncovered the possibility to significantly reduce the complexity of the designs with only small increases of the production costs. By comparing the results of the case studies under different cost and operation scenarios, we characterized general aspects, which need to be considered for such design simplification. One of the main outcomes were the quantified cost-increases due to standardization, which were around 7 and 15 % relative to the specifically designed plants for each location in the US and Chile case studies respectively. A subsequent analysis of the economies of numbers through learning rates reported in academic literature suggested that the proposed standardization, even across extremely different locations, could compensate these cost-increases and be economically beneficial. Yet, more specific data on achievable cost-reductions are needed, requiring more interaction with the industry and further research, for which we highlighted promising directions. [Display omitted] • Method to identify standard and simple design of Power-to-Methanol processes. • Standardization across locations can affect technology selection. • Transfer of the complexity of design into the complexity of fluctuating operation. • Pareto-optimal design with thermal energy storage parabolic troughs, heat pump. • Important to consider the locations, which should share a standard design. [ABSTRACT FROM AUTHOR]

Makerspaces – open access design and fabrication workshops – provide new contexts for design practice through ‘distributed production’. The global community of makerspaces has evolved quickly and in turn, substantial hype is attributed to its potential for radical sustainable innovation. In this article, we explore this potential in the context of the new ‘circular economy’ agenda. We focus the research on the critical role of makerspace managers/founders who are recognised as gatekeepers to circular practices. The research method is action-led including expert interviews (academics and founders/managers) as well as two generative context-mapping workshops, run at selected makerspaces in collaboration with their founders/managers. We unearth everyday ‘how-to’ guidance to interweave circular practices within makerspaces from the outset by: fostering an enabling culture; building local connections; nurturing individual/community capacities; and stimulating practical know-how. However, while the research reveals immense opportunities to cultivate circular literacy from within makerspaces, the prospects to ask more profound questions about our economy, through makerspace practices, are found to be compromised by day-to-day concerns. The insights from this research can act as a starting point for future work in this emerging research area.

This article studies the issues of storage in the planning of low voltage (LV) networks. An algorithm of advanced automation function is developed to illustrate the maximum economic value of storage, from the distribution system operator (DSO) point of view, in the long‐term planning of LV networks, compared to a conventional reinforcement method. In order to model the randomness that characterises the new actors of the network (distributed production and storage), a stochastic planning study with uncertainties concerning the connection nodes of the batteries and the photovoltaic production in the network is conducted. The results show that compared to reinforcement, storage can present an economic benefit for the DSO, based on a limited but crucial set of elements: cost of remuneration for using storage, topology, and constraints on the network, and characteristics of the equipment presenting the constraints. For the third‐party storage facility owner, the presented benefits constitute the maximal envelop within which a cost benefit analysis should be restricted to be economically viable, as likely to be used to provide services to the DSO. These points are illustrated with two real networks in order to validate the proposed planning tool. [ABSTRACT FROM AUTHOR]

Copyright of Técnica Industrial: Revista Cuatrimestral de Ingeniería, Industria e Innovación is the property of Fundacion Tecnica Industrial and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Since the beginning of the New Millennium, increasingly widespread availability of the Internet and digitally enabled tools have made production processes more accessible to private individuals, introducing new opportunities for personal fabrication and social manufacturing. Yet scant sustainability research has been conducted on this important sector. We argue that research barriers, particularly relating to confusing terminology and lack of individual-centric analytical tools, are largely responsible for this void. The objective of this study is to overcome these barriers by (1) providing an integrating framework that can improve transferability, to other conceptual analyses, of the results of sustainability research conducted from a particular conceptual viewpoint, and (2) suggesting how some firm-centric analytical tools can be modified for effective use in studies of individual-level phenomena. We base our framework on the emerging concept of social manufacturing, first eliciting its main aspects and dimensions with a conceptual literature study, and then discovering its central properties with an empirical case study. We conclude by using the new social manufacturing framework to suggest modifications of three common sustainability analysis tools to make them more applicable to research on individual-level production. By making future investigation in this area more accessible our work contributes to both sustainability research and to the emerging field of research on social manufacturing. [ABSTRACT FROM AUTHOR]

Ammonia is a critical chemical to fertilize plants and feed the world. Recently, a first of its kind renewable ammonia plant has been built in Morris, MN, powered by wind energy. A broader deployment of such renewable plants will require careful selection of location and unit sizing to keep costs low and optimize the entire ammonia supply chain. In this paper, a 48-h receding horizon optimization problem is developed to optimally schedule unit set points for the system in order to minimize annual operating costs. This optimization formulation is then used to examine how the optimal operating cost depends on the key design parameters of location and unit size. Using the results obtained, simple correlations are developed which capture the dependence of operating costs on ratios of unit capacities, properly scaled to remove the dependence on location. [ABSTRACT FROM AUTHOR]

Chemical companies are constantly seeking new, high-margin growth opportunities, the majority of which lie in high-grade, specialty chemicals, rather than in the bulk sector. To realize these opportunities, manufacturers are increasingly considering decentralized, flexible production facilities: large-scale production units are uneconomical for innovative products with a short lifespan and volatile markets. Small modular plants have low financial risks, are flexible and can respond rapidly to changes in demand. Logistics costs can be also reduced by moving production closer to customers and/or sources of raw materials. Moreover, stricter safety regulations can in many cases be more easily met using smaller distributed facilities. Modularization of chemical production can thus have potentially significant economic and safety benefits. In this article, several drivers for modular production are reviewed, and modular production architectures are evaluated based on a new metric, the value density of feedstock resources and markets for the products of a process. The links between modularization and process intensification are also discussed. Several industrial examples are provided and used to highlight challenges and future directions for this area. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4262-4272, 2017 [ABSTRACT FROM AUTHOR]

Makerspaces – open access design and fabrication workshops – provide new contexts for design practice through ‘distributed production’. The global community of makerspaces has evolved quickly and in turn, substantial hype is attributed to its potential for radical sustainable innovation. In this article, we explore this potential in the context of the new ‘circular economy’ agenda. We focus the research on the critical role of makerspace managers/founders who are recognised as gatekeepers to circular practices. The research method is action-led including expert interviews (academics and founders/managers) as well as two generative context-mapping workshops, run at selected makerspaces in collaboration with their founders/managers. We unearth everyday ‘how-to’ guidance to interweave circular practices within makerspaces from the outset by: fostering an enabling culture; building local connections; nurturing individual/community capacities; and stimulating practical know-how. However, while the research reveals immense opportunities to cultivate circular literacy from within makerspaces, the prospects to ask more profound questions about our economy, through makerspace practices, are found to be compromised by day-to-day concerns. The insights from this research can act as a starting point for future work in this emerging research area. [ABSTRACT FROM PUBLISHER]

Fab Labs, fabrication laboratories, are shared workshops where citizens can access digital fabrication equipment to design and make their own objects. They are proliferating rapidly and represent an alternative to mass production and consumption, an ideology whose environmental and social benefits their “makers” like to espouse. A longitudinal ethnographic study in a Fab Lab in a European design school examined the Lab’s ideology building, how ideals were enacted and where compromises were visible. Environmental issues were intertwined with other ideological concerns, but they were rarely promoted in their own right. Engagement with sustainability-oriented makers and stakeholders is recommended. [ABSTRACT FROM AUTHOR]

Being "carbon efficient" is always one of the missions for suppliers to stay competitive. Production and distribution are the core sections of the supply chain, and integrated scheduling of production and distribution has received increasing research interest because of its great potential to enhance operational performance. Distributed production has gained popularity in recent years. However, distribution strategies compatible with distributed production have not been considered. In this paper, we investigated carbon-efficient integrated scheduling of distributed production and distribution considering shared transportation resource. Particularly, the shared transportation resource strategy, which allows vehicles to serve customers from various depots, enables a more flexible distribution than the traditional method. A bi-objective model is constructed to minimize total carbon emission and completion time simultaneously. To address the computational challenge, an enhanced multi-objective teaching–learning-based optimization (EMTLBO) algorithm is proposed. In EMTLBO, several heuristic rules are introduced to obtain high-quality initial solutions and neighborhood structures are designed for efficient neighborhood search. The comprehensive experiments have demonstrated that (1) the proposed enhancement strategies are effective, (2) the overall performance of EMTLBO is superior to seven well-known algorithms in solving this problem, and (3) the shared transportation resource strategy considerably reduces carbon emission during distribution stage, leading to average decreasing of 41.0 %, 70.6 %, and 41.5% for the instance sets. This work presents significance in promoting a clean and efficient modern supply chain. • The proposed scenario is of great significance for a cleaner supply chain. • Decision relevance of distributed production and distribution is highlighted. • A bi-objective mixed-integer programming model is proposed. • A multi-objective algorithm with enhanced performance is developed. • Effectiveness of proposed shared transportation resource strategy is demonstrated. [ABSTRACT FROM AUTHOR]

Ammonia synthesis is the most important step for nitrogen-fertilizer production and consumes approximately 1% of the world’s energy production and energy-related greenhouse gas emissions. In addition to the concomitant emissions caused by ammonia and nitrogen fertilizer synthesis, centrally produced fertilizer that must be distributed to farms also harms the environment because of the embodied energy of transportation. An environmentally-optimal nitrogen fertilizer system would be distributed on farms themselves using only renewable inputs. Recent developments in solar photovoltaic technology and subsystems for ammonia production have made non-organic on-site ammonia production physically possible. This study provides a technical evaluation of the process for on-site nitrogen-fertilization of corn using solar photovoltaic electricity as the energy input. The system consists of a water electrolysis system to generate hydrogen and a membrane system to generate nitrogen needed as material inputs. Total power consumption for syngas preparation to generate a unit of ammonia is calculated. System total energy consumption is calculated while compensating syngas preparation with heat recovery. Five case-study locations are evaluated to determine their suggested nitrogen fertilizer addition (N-rate) for corn growth and the energy consumption for suggested N-rate is calculated. The System Advisor Model (SAM) is then used to simulate the PV system output for those five locations. Finally, the PV land use required as a fraction of the corn field area is determined. The results indicate that because PV is so much more efficient at solar energy conversion than organic methods, even the worst case evaluated in Indiana requires less than 1% of the corn field converted to a PV system to provide enough energy to generate sufficient amounts of ammonia for fertilizer for the remaining corn. The system was modeled to provide ammonia to fertilize for corn fields larger than 1079 acres with the worst soil conditions, the area of which applies to more than half of cropland in the U.S. in 2011. As the finiteness and emissions of fossil fuel production of nitrogen become more important, this renewable system should become economical and future investigations into its overall viability are warranted. [ABSTRACT FROM AUTHOR]

This paper presents an integrated literature review on how the environmental sustainability of distributed production is studied in a variety of disciplinary sources. The notion of distributed production suggests an alternative to mass production that differs in scale, location and consumer–producer relationship. Understanding its environmental implications (and thereby dematerialization potential) is regarded pertinent and timely. Key themes in the review included how distributed production can promote product longevity and closed material loops, as well as localizing production. New and closer ties between producer and consumer seemed central discussions but were underdeveloped with regard to sustainability potential. Empirical work was seen especially in research on Additive Manufacturing Processes, while the bulk of the studies were conceptual explorations with little testing in the real world as yet. This affirms the emerging nature of the topic and points to a clear need for more (and more diverse) empirical research. The review summarizes the opportunities for greater environmental sustainability as well as potential threats that could serve to guide and improve these novel practices today. It sets the stage for ‘distributed production’ to be examined as its own phenomenon by proposing how it can be characterized and suggests that a research agenda could build upon the work initiated here. [ABSTRACT FROM AUTHOR]