O. Badr

An integrated approach to municipal solid waste management

A theoretical model has been developed for the management of municipal solid waste streams (MSW), taking into account their rates and compositions, as well as their adverse environmental impacts. The model identifies the optimal combination of technologies for the handling, treatment and disposal of MSW in a better economic and more environmentally sustainable way.

Municipal solid waste: a prediction methodology for the generation rate and composition in the European Union countries and the United States of America

Abstract The economically-viable and environmentally-acceptable disposal of municipal solid waste (MSW) is a major concern in many industrialised countries. The main problem facing policy makers in the waste management sector is how to predict the amount and the composition of MSW that is likely to be generated in the near future in order to devise the most appropriate treatment/disposal strategy. Published data on MSW arisings in European countries during the period 1980–1993 and those for the USA between 1960 and 1993 have been correlated with the corresponding figures for the gross domestic product (GDP) and population. The typical composition of MSW has been expressed in terms of the fraction of the total consumer expenditure on goods and products resulting in the generation of MSW, i.e. related total consumer expenditure (RTCE). A model linking RTCE to GDP has been developed and utilised to estimate the amounts of the individual fractions in the total MSW generated. The correlations permit highly-accurate predictions of the total amount of MSW arisings to be obtained both for European countries and the USA. Deviations between the predicted and measured values are, however, much lower in the case of the USA, because the corresponding model is based on data for a single country. Good matches between the predicted and measured figures for the individual fractions of the MSW also ensue. However, the model for predicting the individual fractions in the MSW for the European countries is based solely on information available for the UK.

Biomass resources for energy in North-Eastern Brazil

Due to the high dependency on hydroelectric power generation, Brazil faced a power shortage in 2001. In order to remedy the situation and avoid more severe power crises in the future, the Brazilian Government launched incentive programmes to encourage thermal and renewable power generation. The Programme of Incentives to Alternative Sources (PROINFA) is mainly devoted to the utilisation of biomass. The success of PROINFA depends on the availability of reliable studies for assessing existing biomass resources and the viability of their utilisation for power generation. In this study, energy potentials of the main biomass resources in the north-eastern region of Brazil have been assessed. The economy of the north-eastern region of Brazil is heavily dependent on its sugar industry. Biomass available from sugarcane cultivation and processing represents an annual regional energy resource of 40.5 TWh at an average cost of US

Rankine-cycle systems for harnessing power from low-grade energy sources

0.005/kWh. Bamboo, cultivated as a dedicated energy crop, has the second largest annual energy potential of 30.8 TWh at an average cost of US

Multi-vane expanders as prime movers for low-grade energy organic Rankine-cycle engines

0.009/kWh. Municipal solid waste, generated in the region, has an annual energy potential of about 16.7 TWh.

Economic and Environmental Evaluations of Waste Treatment and Disposal Technologies for Municipal Solid Waste

Rankine-cycle systems, each employing a single organic compound as the working medium, are the most commonly used units for converting low-temperature heat into mechanical work. The performances of these systems have been analysed and simulated. The composed interactive computer programs (in BASIC) for predicting the properties of the candidate organic fluids, and for evaluating the behaviour of the simple and regenerative Rankine-cycle units, are listed. The accuracies of the estimated values of the thermodynamic properties have been assessed. Samples of the performance characteristics predicted, employing the routine developed, are given. The programs should help facilitate (i) choosing the most appropriate working fluid from amongst those considered, as well as (ii) predicting the optimal design and operating conditions of a proposed system for a particular application.

Environmental impacts of atmospheric nitrous oxide

The behaviour of the prime mover in a low-grade energy Rankine-cycle engine is one of the most important factors affecting the overall system performance. A survey of published data concerning various types of expander in use in Rankine engines and an analysis based on the concept of similarity shows that, for the low power outputs, positive-displacement expanders have potential advantages when compared with turbines. However, the multi-vane expander (i.e. the MVE) offers considerable promise as the most appropriate prime mover for organic Rankine-cycle engines utilizing solar energy or waste heat as energy inputs, especially in the developing countries. The features and characteristics of the appropriate MVEs are discussed, together with the operational problems remaining to be solved.

Assessing the viability of using rape methyl ester (RME) as an alternative to mineral diesel fuel for powering road vehicles in the UK

MSW management can be defined as the discipline associated with the control of generation, storage, collection, transfer, processing and disposal of MSW, in a way which is governed by the best principles of public health, economics, engineering, aesthetics and other environmental considerations. The disposal of MSW has been the focus of environmental policy for several industrialised countries since the mid-1970s, when attempts were made to identify and categorise, in a systematic way, the waste fractions involved. This categorisation provided the policy makers with the necessary information, to determine the most appropriate option for dealing with the waste in a more economic and environmentally-sustainable way. This paper reviews the main economic costs and the environmental impacts of the widely-accepted waste treatment and disposal methods. Examples of successful waste-management schemes are presented and prospective future trends are assessed.

Rotary Wankel engines as expansion devices in steam Rankine-cycle engines

Nitrous oxide (N2O) is an important trace gas in the atmosphere. Changes in the atmospheric concentration of N2O have evoked considerable concern because of its role in (i) regulating stratospheric ozone levels, (ii) contributing to the atmospheric greenhouse phenomenon and (iii) participating in the acid-rain formation process. The global concentration of N2O in the atmosphere has been rising since the start of the Industrial Revolution, before which it was almost constant at about 285 ± 5 ppbv (billion = 109). In 1990, the concentration reached about 310 ppbv and is now rising at a rate of 0·5-1·1 ppbv (i.e. 0·2-0·3%) per year. In this paper, the environmental impacts of the increasing atmospheric concentration of N2O are discussed.

Multi-vane expanders: Vane dynamics and friction losses

Rape methyl ester (RME) is a suitable substitute for mineral diesel in existing compression-ignition engines. Its use as an alternative transport fuel will result in decreased emissions of atmospheric pollutants (particularly SO2, hydrocarbons and smoke) from this source. However, to encourage such a trend in the UK, the Government needs to adopt the European Unions recommendation of a reduction of excise duties on biofuels to 10% of the rate applied to lead-free petrol to ensure its economic short-term competitiveness in the UK market. Such a subsidy will not be required by the year 2004. The available resource base for rape-seed oil in the UK limits the production of RME, so it could satisfy only up to 4% of demand on fuel by road vehicles powered by diesel engines in the UK. This suggests that it should be used preferentially in urban areas and waterways where its environmental benefits would be maximised.