Pre-feasibility analysis of the production of mucic acid from orange peel waste under the biorefinery concept

The orange peel waste is essentially an important residue in many countries, representing more a problem than one opportunity. Most of this residue processing is related to low added value products and it includes the generation of other residues. Among new alternatives to valorize this residue during last years a high added value product is the mucic acid. This work addresses the pre-feasibility analysis of the mucic acid production using galacturonic acid from pectin using Orange Peel Waste (OPW) as feedstock through the biorefinery concept. The proposed biorefinery comprises the pectin extraction using citric acid, mucic acid production from the liquid fraction of the pectin hydrolysis, and biogas production using the remaining solid. The experiments for pectin extraction and biogas production were carried out to determine the yields to be used in the process simulation. The material and energy balances of the biorefinery were obtained through the Aspen Plus V9.0 tool. These results were used in the energy, economic, and environmental evaluation. A preliminary environmental evaluation for the process was done with Waste Reduction Algorithm (WAR) software. The experimental pectin hydrolysis and biogas production yields were 0.15 ± 0.77 g/g of OPW, and 0.256 Nm³/kg of OPW, respectively. The technical assessment of the biorefinery shows a good performance. Besides, the economic analysis of the proposed biorefinery exhibited feasibility at a processing scale of 140 kg/h. An economic sensitivity analysis was done varying the raw materials costs. From this, the low influence of the raw materials costs in the economic feasibility of the process was elucidated at different scales. Finally, the environmental analysis exposed that the environmental impact of the exit streams is lower than the impact of feeding streams.