Daniele Guglielmi

Comparison of alternative flue gas dry treatment technologies in waste-to-energy processes.

Acid gases such as HCl and SO2 are harmful both for human health and ecosystem integrity, hence their removal is a key step of the flue gas treatment of Waste-to-Energy (WtE) plants. Methods based on the injection of dry sorbents are among the Best Available Techniques for acid gas removal. In particular, systems based on double reaction and filtration stages represent nowadays an effective technology for emission control. The aim of the present study is the simulation of a reference two-stage (2S) dry treatment system performance and its comparison to three benchmarking alternatives based on single stage sodium bicarbonate injection. A modelling procedure was applied in order to identify the optimal operating configuration of the 2S system for different reference waste compositions, and to determine the total annual cost of operation. Taking into account both operating and capital costs, the 2S system appears the most cost-effective solution for medium to high chlorine content wastes. A Monte Carlo sensitivity analysis was carried out to assess the robustness of the results.

Simulation of a Two-stage Dry Process for the Removal of Acid Gases in a Mswi

Power generation from municipal solid wastes is an attractive technology in the area of renewable energy utilization. Because of the restrictive pollutant emission limits dictated by European Union Directives, it is very important to optimize the flue gas cleaning system to reduce the environmental impact caused by incineration, also taking into account economic aspect. In the present study a simplified conversion model for the assessment of removal efficiency of acid gases from flue gas was developed. The model is based on the ratio between the rate of solid reactants and the rate of incoming acid gases with respect to the stoichiometric ratio. The model was implemented with the Aspen Hysys code to simulate a two-stage flue gas cleaning system. Simulations were based on design data of an existing RDF incineration plant and can be easily adjusted to fit other design data. The optimal feed rate of reactants for a fixed removal efficiency was estimated through the proposed model.

Identification of critical safety barriers in biogas facilities

Abstract Biogas production is growing worldwide. At European level, biogas is among the renewable energy sources whose exploitation is progressing more. Important investments are planned in biogas upgrading facilities for the production of biomethane. The relevant increase in biogas production raises emerging risk issues associated to biogas facilities. In order to systematically explore the hazards related to biogas production and upgrading, a specific methodology (DyPASI - Dynamic Procedure for Hazard Identification) was applied. Despite the great variety of existing plants and components, it was possible to identify reference critical events and cause-consequence chains. The results were used to identify a set of safety barriers for accident prevention and mitigation in biogas production and upgrading facilities.