Computer-aided process design for waste minimization

Problems related to process design with environmental considerations have been studied in this dissertation. A new heuristic design methodology has been formulated with the objective of minimizing the adverse environmental impact of chemical processes. This hierarchical methodology starts with the definition and analysis of a process flowsheet followed by quantification of the process environmental loads. The quantification of environmental loads is an essential aspect of this methodology, because it serves as the comparative measure for environmental performance. If the calculated environmental loads do not satisfy the environmental constraints (e.g., regulatory limits), waste minimization is investigated in the following order: Pollution prevention; process modifications aiming at pollution prevention are identified, prioritized, and evaluated. Pollution control; pollution control flowsheets are synthesized, analyzed, and evaluated based on the environmental loads. The main focus of this research has been the partial implementation of this methodology on the computer to assist in the synthesis, analysis, and evaluation of pollution control flowsheets. Two separate programs have been developed: WasteMin Expert, a knowledge-based system which provides an organized framework for assisting the designer in the synthesis of pollution control flowsheets. It is an interactive rule-based expert system, which follows the task decomposition paradigm to accomplish the flowsheet synthesis task. The output of WasteMin Expert provides a conceptual flowsheet in the form of an ordered list of key unit operations for pollution control. This list serves as a good starting point for the creation of detailed designs using a process simulator. EnviroCAD, a simulator developed for the analysis and evaluation of pollution control processes. EnviroCAD includes a variety of unit operation models used for waste treatment and disposal. EnviroCAD accounts for environmental loads on the basis of individual pollutants as well as aggregate environmental properties. Tracking the fate of individual pollutants facilitates retrofitting efforts to achieve the environmental objectives. The methodology has been demonstrated in several examples, including the design of a wastewater treatment facility. The results of this case study are in good agreement with field data

The Effect of Different Types of Diet on Greenhouse Gas Emissions in Greece

Diet modifications are explored for the mitigation of greenhouse gases emissions worldwide. The current paper aims at estimating the carbon footprint of the diet of the Greek consumers in 2011. Based on food items consumption data, equivalent CO2 emission factors, the total carbon footprint associated with the per capita Greek diet patterns is calculated. Data for this task are retrieved from readily available resources of existent literature. The per capita carbon footprint resulting from the consumption of food items in Greece in 2011 for the reference scenario is calculated to be 1,827.4 kg CO2/y. In addition, alternative diet scenarios are proposed, their carbon footprint is calculated and suggestions are made for possible sustainable dietary changes. The results indicate that transition to a lacto-ovo-vegetarian diet constitutes a very drastic change towards mitigating greenhouse gases. However its acceptance by the public is very questionable. Thus, the second alternative scenario, which anticipates the substitution of beef by mainly pork and chicken, becomes more relevant. These results could serve as a yardstick for policy interventions aiming at reducing GHG emissions via diet modifications in Greece

FOOD WASTE PREVENTION AS A TOOL FOR CLIMATE CHANGE MITIGATION: A CASE STUDY FROM GREECE

Abstract Since the publication of the findings that consumers in the UK throw away 31% of the food that they buy, food waste is becoming an increasingly significant global issue. Food waste is generated throughout the entire life cycle of food. Since significant resources are required for food production, manufacturing, transportation, storage, retailing and preparation, food waste is a waste of valuable resources with obvious economic and environmental implications. To make matters environmentally worse, food waste typically ends up in landfills and, due to its high biodegradability, contributes to the global greenhouse gases generation. Thus, food waste prevention, among its other positive contributions, can also act as a tool for the mitigation of man-made climate change. The aim of this paper is the estimation of the GHG emissions associated with food waste generation in Greece. The scope of the research included both the emissions upstream of the waste management and those associated with the management of food waste. The results indicate that emissions of 5,609.2 Gg of CO 2 eq. are associated with food waste in Greece. In order to reduce the burden on global warming resulting from food waste, emphasis should be placed on the prevention of food waste generated throughout the life cycle of food stuff. Keywords: greenhouse gases, food waste, prevention 2 Introduction There is evidence that the most environmentally damaging form of human consumption is eatin

WASTE PREVENTION SCENARIOS USING A WEB-BASED TOOL FOR LOCAL AUTHORITIES

Abstract Waste prevention is the highest ranked priority in the European Waste Framework Directive. The aim of this paper is to present the design, development and main features of a web-based tool that enables local authorities to select and implement optimum waste prevention programmes for their local conditions and to prepare their Waste Prevention Plans. The aforementioned tool, namely the WASP-Tool, is implemented as a knowledge-based decision support system which extracts characteristics and features of the waste prevention strategy models and applies multi-criteria evaluation techniques in order to facilitate decision making. It has been developed in Greek and reflects Greek and Cypriot data, context and waste prevention potential, to facilitate its use by local authorities and local administration

Food Waste Prevention: Reduction, Reuse, and Recycling

Food loss and waste (FLW) is a global concern that has adverse environmental, social, and economic impacts [...

Sustainable cities through alternative urban farming: the case of floriculture

Floriculture is an intensive type of agriculture with an income per unit area much higher than any other branch of agriculture. Urban floriculture can be a more sustainable and socially acceptable alternative to urban food production as the latter is exposed to high levels of urban generated contaminants. Urban floriculture may also decrease the carbon footprint associated with transportation of fresh cut flowers and provide better quality seasonal product. In this article, we investigate the concept of urban floriculture as an innovative approach for mitigating the negative impacts of global floriculture supply chains