Technological pathway exploration for simultaneous water conservation and carbon reduction for the titanium dioxide manufacturing plant in China

Abstract

With the increasing global concerns on climate change and water scarcity, titanium dioxide manufacturing plants (TDMP) are facing the challenge of simultaneous water conservation and carbon reduction (SWCCR) in water networks with controllable comprehensive water-use costs. Such complex multi-objective optimization problems are usually studied in steel and petrochemical industries or in the macro region, but very few studies have been devoted to TDMP in the past decade. This paper proposes a novel multi-scale and multi-objective optimization model for the water-carbon-economy nexus specific to TDMP, accompanied by an effective solution methodology. The model was designed to explore the interaction between water conservation and carbon reduction under the condition of keeping controllable comprehensive water-use costs and to find the optimal technological pathway for industrial practice. Then a typical TDMP adopting the sulfuric acid technology was selected as the case study. The findings reveal that the plant can achieve SWCCR by integrating different technological measures to formulate the optimal technological pathway. When the plant put equal weight on water conservation and carbon reduction, the water consumption and carbon emissions were reduced by 8.48% and 21.11% respectively, with a 3.06% increase in comprehensive water-use cost per ton of product (813.55 RMB). Additionally, long-term projections of the optimal technological pathway toward the Carbon Neutrality goal were explored, highlighting the progressive augmentation of reclaimed water utilization. This study pioneers in filling the research gap on SWCCR in water networks with controllable comprehensive water-use costs for TDMP and offers valuable insights, thereby facilitating a greener and low-carbon transformation.