Multiobjective Optimization and Implementation of a Biorefinery Production Scheme for Sustainable Extraction of Pectin from Quince Biowaste

The objective of this study was to optimize the pectin extraction from industrial quince biowaste using citric acid as a hydrolytic agent and assisting the process with ultrasound technology. For this, the process was modeled using the Box–Behnken design (BBD) to find the factors’ optimum values and their interactions. The quince pectin extraction was carried out by adding to the biowaste a citric acid solution at different pH values (2.0, 2.5, and 3.0) in mass volume ratios of 1/25, 1/20, and 1/15 g/mL and immersing it in an ultrasound bath for 30, 45, and 60 min at controlled temperatures of 70, 80, and 90 °C. Pectin yield, process cost, and CO₂ emission were calculated under different conditions according to the BBD model, and a polynomial function was adjusted for each dependent variable. A multiobjective optimization technique known as “Genetic algorithms” was used to find the proper extraction conditions that would maximize the pectin yield and minimize the process cost. The optimal extraction conditions obtained were as follows: pH = 2.12, mvr = 0.04 g/mL, time = 48.98 min, and temperature = 85.20 °C, with response variables of pectin yield = 12.78%, cost = 1.501 USD/kg of pectin, and calculated CO₂ emission = 0.565 kg of CO₂/kg of pectin.