The challenges for energy efficient casting processes

Casting is one of the oldest, most challenging and energy intensive manufacturing processes. A typical modern casting process contains six different stages, which are classified as melting, alloying, moulding, pouring, solidification and finishing respectively. At each stage, high level and precision of process control is required. The energy efficiency of casting process can be improved by using novel alterations, such as the Constrained Rapid Induction Melting Single Shot Up-casting process. Within the present study the energy consumption of casting processes is analyzed and areas were great savings can be achieved are discussed. Lean thinking is used to identify waste and to analyse the energy saving potential for casting industry

A concept of water usage efficiency to support water reduction in manufacturing industry

Increasing pressures on freshwater supplies, continuity of supply uncertainties, and costs linked to legislative compliance, such as for wastewater treatment, are driving water use reduction up the agenda of manufacturing businesses. A survey is presented of current analysis methods and tools generally available to industry to analyze environmental impact of, and to manage, water use. These include life cycle analysis, water footprinting, strategic planning, water auditing, and process integration. It is identified that the methods surveyed do not provide insight into the operational requirements from individual process steps for water, instead taking such requirements as a given. We argue that such understanding is required for a proactive approach to long-term water usage reduction, in which sustainability is taken into account at the design stage for both process and product. As a first step to achieving this, we propose a concept of water usage efficiency which can be used to evaluate current and proposed processes and products. Three measures of efficiency are defined, supported by a framework of a detailed categorization and representation of water flows within a production system. The calculation of the efficiency measures is illustrated using the example of a tomato sauce production line. Finally, the elements required to create a useable tool based on the efficiency measures are discussed

A review of the lighting performance in buildings through energy efficiency

As developing countries including Malaysia, are now moving towards sustainable development is in line with the Ninth Malaysia Plan, 9th MP, the development should be built to meet current and future needs for achieving sustainability of economic development, social and environmental responsibility for the prosperity without compromising the future generations‘ needs. Over the past five years, there has been a move away from constructing new buildings to refurbishing older and historic ones. Thus, the purpose of this paper is to review and evaluate the approach for the refurbishment of lighting as well as the existing energy efficiency policy and measures in Malaysian historical building for the energy efficiency improvement in the future. The paper takes the form of a review of literature. The main sources of this literature research are based on the articles, journals, and internet search. This study perhaps can add to the breadth of knowledge of lighting performance in the historical building from the perspective of energy efficiency. This study offers new and valuable insights to Malaysia in achieving optimum energy efficiency, saving in financial as well as reducing environmental impact.This paper has been presented at 2nd International Conference on Research in Science, Engineering and Technology (ICRSET’2014) March 21-22, 201

An optimization-based control strategy for energy efficiency of discrete manufacturing systems

In order to reduce the global energy consumption and avoid highest power peaks during operation of manufacturing systems, an optimization-based controller for selective switching on/off of peripheral devices in a test bench that emulates the energy consumption of a periodic system is proposed. First, energy consumption models for the test-bench devices are obtained based on data and subspace identification methods. Next, a control strategy is designed based on both optimization and receding horizon approach, considering the energy consumption models, operating constraints, and the real processes performed by peripheral devices. Thus, a control policy based on dynamical models of peripheral devices is proposed to reduce the energy consumption of the manufacturing systems without sacrificing the productivity. Afterward, the proposed strategy is validated in the test bench and comparing to a typical rule-based control scheme commonly used for these manufacturing systems. Based on the obtained results, reductions near 7% could be achieved allowing improvements in energy efficiency via minimization of the energy costs related to nominal power purchased.Peer ReviewedPostprint (author's final draft

Australia’s Resource Use Trajectories

Australia’s export oriented large natural resources sectors of agriculture and mining, the ways in which large scale services such as nutrition, water, housing, transport and mobility, and energy are organized, as well as the consumption patterns of Australia’s wealthy urban households, create a unique pattern of overall resource use in Australia. In an attempt to contribute to a new environmental information system compatible with economic accounts, we represent Australia’s resource use by employing standard biophysical indicators for resource use developed within the OECD context. We are looking at the last three decades of resource use and the economic, social and environmental implications. We also discuss scenarios of future resource use patterns based on a stocks and flows model of the Australian economy. We argue that current extractive economic patterns have contributed to the recent economic boom in Australia but will eventually lead to negative social and environmental outcomes. While there is currently little evidence of political support for changing the economic focus on export-oriented agriculture and mining industries, there is significant potential for improvements in socio-technological systems, and room for more sustainable household consumption.natural resources, resource use patterns and dynamics, physical accounting, resource productivity, social and environmental impacts of resource use, Australia

Energy Efficient Policies, Scheduling, and Design for Sustainable Manufacturing Systems

Climate mitigation, more stringent regulations, rising energy costs, and sustainable manufacturing are pushing researchers to focus on energy efficiency, energy flexibility, and implementation of renewable energy sources in manufacturing systems. This thesis aims to analyze the main works proposed regarding these hot topics, and to fill the gaps in the literature. First, a detailed literature review is proposed. Works regarding energy efficiency in different manufacturing levels, in the assembly line, energy saving policies, and the implementation of renewable energy sources are analyzed. Then, trying to fill the gaps in the literature, different topics are analyzed more in depth. In the single machine context, a mathematical model aiming to align the manufacturing power required to a renewable energy supply in order to obtain the maximum profit is developed. The model is applied to a single work center powered by the electric grid and by a photovoltaic system; afterwards, energy storage is also added to the power system. Analyzing the job shop context, switch off policies implementing workload approach and scheduling considering variable speed of the machines and power constraints are proposed. The direct and indirect workloads of the machines are considered to support the switch on/off decisions. A simulation model is developed to test the proposed policies compared to others presented in the literature. Regarding the job shop scheduling, a fixed and variable power constraints are considered, assuming the minimization of the makespan as the objective function. Studying the factory level, a mathematical model to design a flow line considering the possibility of using switch-off policies is developed. The design model for production lines includes a targeted imbalance among the workstations to allow for defined idle time. Finally, the main findings, results, and the future directions and challenges are presented