Conceptual Design Method for Energy Retrofit of Waste Gas to Energy Units
Many industrial waste gasses, especially from chemical and petrochemical processes, contain combustible substances enabling their utilization as a promising energy source. Thermal oxidation represents a suitable and proven technology, which is, however, very energy intensive in terms of external fuel demand dependent on exhaust heat recovery efficiency. This paper presents a systematic method developed for the Energy Retrofit of industrial units for thermal oxidation of waste gases (waste gas-to-energy units) in order to improve the units´ waste heat recovery and thus to reduce the external energy demand. This results in the reduction of operational costs and emissions and improves waste gas energy utilization. The method procedure is further applied to Energy Retrofit of a specific waste gas‑to‑energy unit, where the fuel saving of over 30% was achieved by the proposed conceptual modifications with a payback period of only 5.5 months. Finally, the developed method accuracy was successfully verified by comparison with results of non-linear simulation.