Development of sustainable resource recovery approach from agro-industrial wastes by revealing the economic added value potential

Abstract

The physicochemical sludge generated from treatment of effluents from marble processing facilities should be managed properly due to their adverse effects on the environment. These sludges can be evaluated as catalyst in pyrolysis since they consist of some inorganics such as CaCO3 and Al or Fe salts which come from marble structure and coagulation–flocculation treatment of the effluent, respectively. Therefore, in this study, an approach for sustainable resource recovery from agro-industrial wastes (olive pomace) was developed by offering a solution to the two different waste types via pyrolysis and by revealing economic value-added potential of the process. Olive pomace-marble sludge catalyst mixtures were pyrolyzed in a laboratory-scale fixed bed batch pyrolysis system by using four catalyst dosages (10, 20, 30 and 50%) and three pyrolysis temperatures (300, 500 and 700 °C) at 5 °C/min heating rate. Pyrolysis oils and gases were analyzed with GCMS-FID and FTIR for evaluating the potential of economically valuable organic compounds. Organic compounds having extensive usage areas, such as feedstock for surfactants production, emollient, flavoring and softening, and high economic value in the market, such as 1-Pentadecanol, 2-Pentadecanone and Octane, were identified especially in catalytic pyrolysis liquid products. For instance, the potential profit that can be obtained from the conversion of olive pomace to ‘2-pentadecanone’ compound found in catalytic pyrolysis oil produced in this study is around 2.46 × 1013 USD for 2021/22 years at ideal conditions. Consequently, the presented approach contributes to sustainable circular economy via converting wastes into economic value instead of conventional waste disposal methods. Graphical abstract: (Figure presented.). © The Author(s) under exclusive licence to Iranian Society of Environmentalists (IRSEN) and Science and Research Branch, Islamic Azad University 2024.