Analytical approach for energy retrofit of waste gas-to-energy units

Abstract

• Energy demand of waste gas-to-energy (WGtE) units can be significantly reduced by performing the Energy Retrofit (ER). • A new tailor-made analytical method for the ER of the WGtE units is proposed. • The suggested procedure does not require the use of any simulation and optimization tools. • Supporting graphical tool, called the Heat Recovery Shifting Diagram, promotes the useŕs interactivity. • The accuracy of the proposed method is verified by comparing its results to the non-linear simulation of two case studies. Thermal oxidation represents an efficient and reliable technology for processing industrial waste gases containing combustible pollutants, for example, Volatile Organic Compounds. Thermal oxidation units (or waste gas-to-energy units) enable the heat utilization of the waste gases, which thus become a promising energy source. This is, however, very energy-intensive process requiring a huge amount of primary fuel, which is dependent on the heat recovery efficiency. This paper presents a straightforward and fairly accurate graphic-numerical method for the Energy Retrofit of waste gas-to-energy units, which doesńt require any advanced computational approach. There are provided tailor-made formulas for estimation of maximum reachable fuel savings and tools for the design of specific technological modifications, which results in the increase of the heat recovery efficiency, energy demand reduction, operational costs savings and environmental pollution mitigation, while the unit́s operational safety is also considered. The method is further applied to the Energy Retrofit of a standard industrial unit and a modern compact unit for thermal processing of waste gases. Finally, the developed method́s accuracy was successfully verified by the comparison with non-linear simulation of both studied industrial units.