Sustainable food processing systems - Path to a zero discharge: reduction of water, waste and energy

Abstract

Since food processing systems consume extensive amounts of water and energy, the food industry has the incentive to reduce water and energy with the goal of developing a zero discharge process that utilizes substantially less water and energy, and generates no waste. The objective of this study is to evaluate water/energy consumption and to propose alternatives that reduce water and energy in the processing of three food products; 1) edible bean, 2) dairy products, and 3) corn masa. Three main approaches were; 1) plant-scale audit data collection to determine energy consumption, 2) laboratory scale experiments to assess product quality changes with a reduction in water and energy usage, and 3) computer-aided simulation to design systems for reduced water and energy consumption and wastewater generation. The results suggest that a zero discharge process is feasible by reducing water and energy. Modifications to the edible bean process reduced water input up to 55% and wastewater generation was decreased up to 91%. In dairy plant, the optimal heat recovery option could economically decrease the boiler fuel requirement by 50 times, and reduce the operating cost to 2.7% of the present cost. The water reuse process in redesigned corn masa process could reduce 90% of wastewater and 55% of water usage compared to the traditional process. The amount of energy required for heating was saved by 70% in the water reuse process. When scaling-up to plant-scale, reusing water could reduce water consumption by 95% and reduce energy requirement by about 80%.