Economic evaluation of bio-based supply chains with CO2 capture and utilisation

Carbon capture and storage (CCS) and carbon capture and utilisation (CCU) are acknowledged as important R&D priorities to achieve environmental goals set for next decades. This work studies biomass-based energy supply chains with CO2 capture and utilisation. The problem is formulated as a mixed-integer linear program. This study presents a flexible supply chain superstructure to answer issues on economic and environmental benefits achievable by integrating biomass-coal plants, CO2 capture and utilisation plants; i.e. location of intermediate steps, fraction of CO2 emissions captured per plant, CO2 utilisation plants' size, among others. Moreover, eventual incentives and environmental revenues will be discussed to make an economically feasible project. A large-size case study located in Spain will be presented to highlight the proposed approach. Two key scenarios are envisaged: (i) Biomass, capture or utilisation of CO2 are not contemplated; (ii) Biomass, capture and CO2 utilisation are all considered. Finally, concluding remarks are drawn.Peer ReviewedPostprint (author's final draft

Characterization of cooling loads in the wine industry and novel seasonal indicator for reliable assessment of energy saving through retrofit of chillers

The food sector is a major consumer of energy and growing efforts are being made in the search for solutions that will guarantee the efficient and sustainable use of energy resources. Among the different sectors, wineries are attracting particular interest due to the continuous growth of the global market and production. Surveys conducted in the winemaking sector have highlighted the importance of performing accurate energy audits and have identified the installation of efficient refrigeration systems as a promising solution in a variety of cases. Unfortunately, the savings achievable by efficient cooling technologies are often estimated using simplified approaches which do not take into consideration the actual operating conditions of the equipment typically variable on seasonal and daily bases. In this paper a novel bottom-up procedure is presented, aimed at developing reliable profiles for refrigeration and air-conditioning loads and at assessing the extent to which more efficient chilling units could contribute to reducing electricity consumption. The use of standard Seasonal Energy Efficiency Ratios is critically discussed and a novel customized indicator is proposed. The method is applied to a medium-scale winery producing still red and white wines and sparkling wines, for which only aggregated energy consumption data are available. After deriving detailed load profiles, it is proven that the use of standard seasonal indicators leads to 56.85% and 83.87% overestimation of potential energy savings, respectively, for low and medium temperature cooling energy uses, confirming the importance of adopting seasonal indicators customized on the actual operating conditions of chillers

Quantifying Potential Energy Efficiency Gain in Green Cellular Wireless Networks

Conventional cellular wireless networks were designed with the purpose of providing high throughput for the user and high capacity for the service provider, without any provisions of energy efficiency. As a result, these networks have an enormous Carbon footprint. In this paper, we describe the sources of the inefficiencies in such networks. First we present results of the studies on how much Carbon footprint such networks generate. We also discuss how much more mobile traffic is expected to increase so that this Carbon footprint will even increase tremendously more. We then discuss specific sources of inefficiency and potential sources of improvement at the physical layer as well as at higher layers of the communication protocol hierarchy. In particular, considering that most of the energy inefficiency in cellular wireless networks is at the base stations, we discuss multi-tier networks and point to the potential of exploiting mobility patterns in order to use base station energy judiciously. We then investigate potential methods to reduce this inefficiency and quantify their individual contributions. By a consideration of the combination of all potential gains, we conclude that an improvement in energy consumption in cellular wireless networks by two orders of magnitude, or even more, is possible.Comment: arXiv admin note: text overlap with arXiv:1210.843

Effective sourcing strategies for perishable product supply chains

Purpose – The purpose of this paper is to assess whether an existing sourcing strategy can effectively supply products of appropriate quality with acceptable levels of product waste if applied to an international perishable product supply chain. The authors also analyse whether the effectiveness of this sourcing strategy can be improved by including costs for expected shelf life losses while generating order policies. Design/methodology/approach – The performance of sourcing strategies is examined in a prototype international strawberry supply chain. Appropriate order policies were determined using parameters both with and without costs for expected shelf life losses. Shelf life losses during transport and storage were predicted using microbiological growth models. The performance of the resulting policies was assessed using a hybrid discrete event chain simulation model that includes continuous quality decay. Findings – The study's findings reveal that the order policies obtained with standard cost parameters result in poor product quality and large amounts of product waste. Also, including costs for expected shelf life losses in sourcing strategies significantly reduces product waste and improves product quality, although transportation costs rise. Practical implications – The study shows that in perishable product supply chain design a trade-off should be made between transportation costs, shortage costs, inventory costs, product waste, and expected shelf life losses. Originality/value – By presenting a generically applicable methodology for perishable product supply chain design, the authors contribute to research and practice efforts to reduce food waste. Furthermore, product quality information is included in supply chain network design, a research area that is still in its infancy

Measures for Energy-Efficient Process Chains

Energy efficiency is an essential factor for promoting sustainable manufacturing. Various types of energy consumption occur in modern process chains. This includes usage of electrical energy, e.g. for machine tools or air compression, but also energy consumption through use of resources (such as raw materials and supplies). In this paper, a process chain from the automotive industry is considered with the purpose of identifying energy saving potentials of various kinds. The process chain is used for the production of an axle component. In order to evaluate saving potentials, the current state of the process chain is analyzed. Then, the impact of process parameter optimization on the energy demand is examined. It was found that small energy savings through parameter optimization are possible. However, this can be problematic since process parameters are closely linked to process reliability, so energy savings might be achieved at the expense of product quality. Furthermore, it turns out that the reduction of the process energy is not sufficient for a broad energetic optimization of the process chain and base load reducing measures are required instead. Therefore, further analysis is focused on energetic effects of such measures as machine design, recycling, adjustments of process chain and product design. These were found to be an effective lever for minimizing energy demand of the process chain. A combination of feasible measures adds up to a potential energy saving of 11.5% in the investigated scenario

Estimation of Energy Intensity in Wood Processing Sawmills based on Analysis of Product, Process and System parameters

Energy costs have risen immensely in the recent past and have strained US industrial sectors. The forest products sector is considered as an energy intensive industry group and energy use has an important impact on sawmill\u27s financial integrity. Energy intensity or specific energy consumption (SEC) is an important aspect to wood products producing sawmills since it also represents production efficiency to some extent. This research focuses on developing SEC profiles for the manufacture of hardwood lumber in sawmills and estimating energy intensity based on product, process and system parameters. Energy benchmarking will help the sawmill industry to know their level of performance and opportunities to improve their energy efficiency and productivity. Process, production and energy data were gathered by visiting three sawmills with single sawing lines and two sawmills with double sawing lines in West Virginia.;Initially SEC was calculated in the traditional way as total energy consumption by total board feet sawn and the average SEC for all the sawmills was around 100 kWh per thousand board feet of lumber sawn. Effect of lumber sizes sawn on energy consumption was analyzed and a method to calculate SEC based on surface area sawn was developed. Sawmills\u27 SEC developed based on surface area sawn yielded better results than traditionally calculated SEC since it exposed production bottle necks.;Data from four sawmills was used to develop three estimation models to estimate SEC of the fifth sawmill based on product, process and system parameters. The parameters that were included in the model were: species and lumber sizes for product, sawing time and maintenance schedule for process, and motor horse power, availability of resaw and production line configuration for system. The model which had \u27motor horse power x minutes\u27 as one of the estimator variables was better than the other two models in terms of both R2 and ability to estimate SEC of the fifth sawmill. One estimation model was developed to predict total energy consumption and although this model had the highest R2, it didn\u27t estimate the fifth sawmill that well. Sensitivity analysis was conducted to find the effect of different widths of lumber sawn on energy consumption and also the parameters used in the estimation model were analyzed for their sensitivity towards the energy consumption. Energy consumption of Sawmill 3 was highly sensitive to estimator variables \u27motor horse power\u27 and \u27grade lumber sizes\u27. Energy consumption of sawmill motors were compared and the highest energy consumer of sawmill 2 and 4 motors was main saw and carriage feed, since there was no resaw or a gang saw in them. The energy consumption of sawmill 1 motors was similar to sawmill 3 and energy consumption of sawmill 2 motors was similar to sawmill 4.;The \u27Sawmill Energy Estimation Program\u27 that takes the inputs from the user and estimates sawmill\u27s energy intensity based on sawmill parameters and analyzes sawmill\u27s efficiency and gives recommendations with estimated savings to improve sawmill\u27s energy efficiency and productivity was also developed to help sawmill owners to analyze their sawmill

Ono: an open platform for social robotics

In recent times, the focal point of research in robotics has shifted from industrial ro- bots toward robots that interact with humans in an intuitive and safe manner. This evolution has resulted in the subfield of social robotics, which pertains to robots that function in a human environment and that can communicate with humans in an int- uitive way, e.g. with facial expressions. Social robots have the potential to impact many different aspects of our lives, but one particularly promising application is the use of robots in therapy, such as the treatment of children with autism. Unfortunately, many of the existing social robots are neither suited for practical use in therapy nor for large scale studies, mainly because they are expensive, one-of-a-kind robots that are hard to modify to suit a specific need. We created Ono, a social robotics platform, to tackle these issues. Ono is composed entirely from off-the-shelf components and cheap materials, and can be built at a local FabLab at the fraction of the cost of other robots. Ono is also entirely open source and the modular design further encourages modification and reuse of parts of the platform