Constantinos S. Psomopoulos

Waste-to-energy: A review of the status and benefits in USA

The USA has significant experience in the field of municipal solid waste management. The hierarchy of methodologies for dealing with municipal solid wastes consists of recycling and composting, combustion with energy recovery (commonly called waste-to-energy) and landfilling. This paper focuses on waste-to-energy and especially its current status and benefits, with regard to GHG, dioxin and mercury emissions, energy production and land saving, on the basis of experience of operating facilities in USA.

Use of waste derived fuels in cement industry: a review.

Purpose – Cement production has advanced greatly in the last few decades. The traditional fuels used in traditional kilns include coal, oil, petroleum coke, and natural gas. Energy costs and environmental concerns have encouraged cement companies worldwide to evaluate to what extent conventional fuels can be replaced by waste materials, such as waste oils, mixtures of non-recycled plastics and paper, used tires, biomass wastes, and even wastewater sludge. The paper aims to discuss these issues. Design/methodology/approach – The work is based on literature review. Findings – The clinker firing process is well suited for various alternative fuels (AF); the goal is to optimize process control and alternative fuel consumption while maintaining clinker product quality. The potential is enormous since the global cement industry produces about 3.5 billion tons that consume nearly 350 million tons of coal-equivalent fossil and AF. This study has shown that several cement plants have replaced part of the fossil fu...

WTE plants installed in European cities: a review of success stories

Purpose – Waste is a resource. Generating energy from waste instead of sending it to landfill avoids methane gas which equals 25 times CO2 in mass. In combination with the energy efficiency thresholds set in Waste Framework Directive, this could prevent up to a further 45 million tons of CO2 eq. per year. The purpose of this paper is to present the waste-to-energy (WTE) plants installed in ten European cities which have been selected among the most sustainable cities or among the best cities to live in. Design/methodology/approach – The work is based on literature review and a combination of several statistical data and reports that include the required data. Findings – The European Directives, along with the general thinking that wastes are resources and the effort to reduce the environmental impact in urban environment from waste management, were the driving forces. The most sustainable cities in EU considered that their sustainability is based also in energy recovery from wastes. All of them are using WTE facilities to treat a significant part of their waste in order to produce energy in the form of heat and electricity. And they do it in a very successful and environmental friendly way, as they mainly utilize the waste fractions that cannot be recycled or reused, and they do not landfill these resources. This approach is proving that the sustainable waste management cannot be achieved without WTE facilities, since a fraction of wastes consists of non-recyclable and non-reusable materials, which present significant heating value that cannot be neglected as an energy source. Originality/value – This paper presents the WTE plants installed in ten European cities which have been selected among the most sustainable cities or among the best cities to live in. This work aims to present the strong and successful relation between WTE and sustainability in the modern complex urban environment.

The Combustion of As-received and Pre-processed (RDF/SRF) Municipal Solid Wastes as Fuel for the Power Sector

This article examines the electricity generation potential from the mass burn application of as-derived and pre-processed municipal solid wastes in Greece, based on the experience gained in Europe and the USA under the Greek National Plan for Waste Management. The results showed that it is feasible to use the latter in existing power plants that are properly equipped for handling volatile metal and dioxin emissions. Athens, Thessaloniki, Thessaly, and Western Greece require regional Waste-to-Energy facilities for as-derived and pre-processed wastes. Implementation of such a plan will reduce fossil fuel consumption and greenhouse gas emissions.

Detection of transient signals based on the tricepstrum

Abstract In this paper, the problem of detecting transient signals of unknown waveforms and arrival times embedded in white Gaussian noise is addressed. The use of the cepstrum coefficients of the fourth order correlations of the transient signal for forming a detection statistic is demonstrated. It is considered both a batch and adaptive approach for the detection of the signal which is assumed to satisfy a linear constant coefficient difference equation. The adaptive approach is a least squares realization based on Q–R decomposition of the fourth order statistics matrix involved in the computation of the cepstrum coefficients. Their performance is compared in terms of probability of detection and probability of false alarm with the conventional energy detector by means of Monte-Carlo simulations and improved performance is demonstrated. It is shown that the adaptive approach allows for detection of short length transients which are of unknown arrival times using a single data record even before the whole amount of data becomes available. The Q–R decomposition offers good numerical properties when fourth order statistics are involved and in contrast to the energy detector the proposed receiver has false alarm rate independent of the noise if it is of zero mean and independent, identically, distributed (i.i.d).