A heat recovery rate of the thermochemical waste-heat recuperation systems based on experimental prediction

The concept of the thermochemical waste-heat recuperation system by steam methane reforming is considered. The heat recovery rate of the recuperation system can be considered as the main criterion of its efficiency. The methodology of determination of the recovery rate of the thermochemical recuperation system is developed. The recovered heat in such systems is a sum of the recovered heat in a steam generator and a reformer. The experimental investigation was performed from 500 to 1000 degrees C and for various steam-to-methane ratio from 1 to 3. The total recovered heat and the recovered heat in the steam generator and the reformer are calculated. In the temperature range below 700 degrees C the total recovered heat increases significantly due to the sharp increase in the enthalpy of steam methane reforming reaction. In the temperature range above 700 degrees C, the increase in the total recovered heat is carried out mainly due to the preheating of the synthesis gas since the reaction enthalpy reaches maximum value. The heat recovery rate of the thermochemical recuperation system is determined. It is established that the maximum recovery rate is for 700 degrees C and H2O:CH4 = 2. At temperature of 700 degrees C, the thermochemical recuperation system is capable of recovering more than 85% heat of exhaust gases. (C) 2020 Elsevier Ltd. All rights reserved.