Acrylic Acid Removal Using Membrane Contactors during Acrylate Downstream Processing: A Techno-economic Assessment

In the acrylate industry, the conventional acrylic acid (AA) removal process uses a water washing tower that features a large water consumption of approximately 10 m(3)/kg of AA and by consequence entails an energy-intensive distillation step in the downstream processing (DSP). In light of waste prevention, we propose and report on the experimental evidence of a proof-of-concept alternative process using TiO2 ceramic membrane contactors to extract AA from the acrylate DSP. Experimental results allow us to estimate the overall mass transfer coefficient of the proposed membrane system, being 0.003 m(3)/m(2)h, which is crucial for the design of membrane contactors. Having established its design, we perform a technoeconomic analysis (TEA) for the acrylate production process using membrane contactors for AA removal. The acrylate production cost is estimated with a focus on DSP with the membrane contactors. The results are benchmarked with the conventional process using a water washing tower for AA removal. 2-Ethylhexyl acrylate (2-EHA) is taken as the model product with a yield of 20,000 t/year. We find that for the membrane contactors to be cost-competitive with the water washing tower, the overall mass transfer coefficient of AA needs to increase to 0.005 m(3)/m(2)h while keeping the other parameters constant.