Albert W. Chan

Life cycle assessment of bio-ethanol derived from cellulose.

Objective, Scope, BackgroundA comprehensive Life Cycle Assessment was conducted on bio-ethanol produced using a new process that converts cellulosic biomass by enzymatic hydrolysis. Options for sourcing the feedstock either from agricultural and wood waste, or, if the demand for bio-ethanol is sufficient, from cultivation are examined. The main focus of the analysis was to determine its potential for reducing greenhouse gas emissions in a 10% blend of this bio-ethanol with gasoline (E10) as a transportation fuel.MethodsSimaPro 4.0 was used as the analysis tool, which allowed a range of other environmental impacts also to be examined to assess the overall relative performance to gasoline alone. All impacts were assigned to the fuel because of uncertainties in markets for the by-products. This LCA therefore represents a worst case scenario.Results, ConclusionIt is shown that E10 gives an improved environmental performance in some impact categories, including greenhouse gas emissions, but has inferior performances in others. Whether the potential benefits of the bio-ethanol blend to reduce greenhouse gas emissions will be realized is shown to be particularly sensitive to the source of energy used to produce the process steam required to break down the cellulose to produce sugars and to distil the final product. One key area where improvements in environmental performance might be derived is in enzyme production.Recommendations and OutlookThe LCA profile helps to highlight those areas where positive and negative environmental impacts can be expected. Technological innovation can be directed accordingly to preserve the benefits while minimizing the negative impacts as development progresses to commercial scales.

The Role of Systems Modeling for Sustainable Development Policy Analysis: the Case of Bio-Ethanol

A dynamic systems modeling technique has been developed to assess technologies according to the criterion of sustainability. In a case study, the potential contribution of bio-ethanol toward achieving Canadas commitment to the Kyoto targets for greenhouse gas reductions is analyzed. The analysis concludes that, although bio-ethanol may help reduce greenhouse gas emissions, the technology by itself is insufficient to meet the Kyoto target. Applying the systems modeling approach to analyze sustainability helps highlight those policy issues that warrant more in-depth study. Although the systems model may not provide definitive answers, it raises relevant questions about physical constraints that might be encountered and estimates the extent to which sustainability targets may be met under various scenarios.

ExTool: an interactive object-oriented expert system toolkit for distributed decision-making

The objective of this project has been to develop a flexible, generic (which can be easily adapted to various application domains), and interactive decision support toolkit (called ExTool) with a friendly user interface and distributed decision-making capabilities. A hybrid methodology has been adopted in which features from Artificial Intelligence have been incorporated into an object-oriented environment (in this case Smalltalk-80), taking advantage of the benefits offered by both paradigms.<<ETX>>

Operational tactics at a Nortel Networks plant: cycle time and inventory issues

Increased competition through globalisation, coupled with increasing complexity and uncertainty in the marketplace, is challenging companies to deploy various operational tactics. Three widely used manufacturing cycle time and inventory reduction tactics are evaluated at a Nortel Networks plant, namely, setup reduction, non-value added time reduction and lot size adjustment. A computer simulation with actual data from company operations was used to study and evaluate the different tactics for an assembly line. We illustrate the possibility of achieving up to 88% reduction in cycle time and up to 19% savings in inventory costs. The impact of reduced cycle time on selected raw material component groups is also evaluated. Field implementation of the study is discussed with respect to industrial and pedagogical applications.

Reduction of cycle time in manufacturing using simulation

A shop floor model of a large electronics manufacturer was developed to study the reduction of manufacturing cycle time. The model followed the manufacture of electronic systems from printed circuit board preparation, through board assembly and test, to final system assembly and system testing.

Simulating a Manufacturing Enterprise Using Integrated Process Models

Abstract A two-level process model of a large electronics manufacturer has been developed to allow the study of the management and operational issues that have an enterprise wide impact. An order fulfillment (business process) submodel considers the end-to-end processes from order entry to delivery to the customer. A shop floor (production process) submodel captures the flow of infonnation and materials on the shop floor. The integrated model is being used to reduce total product cycle time while allowing the development of department specific solutions as well as the resolution of corporate wide constraints.

High Level Process Modelling: A Key Feature of Any BPR Project

A wide range of software tools are available for use in BPR programmes. This paper debates some of the issues involved in using enterprise modelling tools. Additionally, a specific enterprise modelling tool, and its use in two case studies, is described.

OPERATIONS STUDY OF AN INTERMEDIATE CAPACITY TRANSIT SYSTEM ON A HYBRID COMPUTER

A combined discrete-continuous model of an intermediate capacity transit system has been developed to be run on a hybrid computer for the purpose of studying the operation of the system.

Sustainability Assessment Using Dynamic Systems Modelling

A dynamic systems modelling approach is examined for its suitability for assessing sustainable performance in technological innovation. A computer model of the energy needs in the Canadian road transportation sector was developed to study the sustainable performance of bio-ethanol. It considers the potential increase in the consumption of energy as the economy expands in the next 25 years, taking into account demographic trends, consumer choices, and technological advances. While the primary environmental measure tracked is focused on greenhouse gas emissions with respect to the Kyoto target, it also includes considerations for land use and farming practices, and distinguishes between fossil and bio-carbon emissions. As well, it allows for different sources of biomass, including crop byproducts and dedicated crops. Various scenarios for bio-ethanol to penetrate the consumer market were set up to investigate a range of future evolution paths.

Process modelling for intelligent manufacturing systems

In order to succeed in the current global market environment, manufacturing enterprises must implement world-class manufacturing techniques and eliminate inefficient practices from their organisations. The incorporation of intelligence in manufacturing systems, from improving strategic planning decisions to streamlining shop floor operations, will play an important role in redesigning processes by manufacturing companies. Process modelling allows current practices to be documented, analysed and re-engineered for better performance. An integrated process modelling system with rule-based inferencing capabilities can be a valuable tool to help companies meet the competitive challenge.<<ETX>>