Sustainable and economic analysis of marine macroalgae based chemicals production - Process design and optimization

CASONI, ANDRÉS I.; RAMOS, FERNANDO D.; ESTRADA, VANINA; DIAZ, M. SOLEDAD

JOURNAL OF CLEANER PRODUCTION

ELSEVIER SCI LTD

Año: 2020 vol. 276

0959-6526

This work proposes a Mixed Integer Nonlinear Programming (MINLP) model to determine the optimaldesign of macroalgae based chemicals production plants. The superstructure considers two brownmarine macroalgae species (Macrocystis pyrifera and Lessonia vadosa) that are used to produce sorbitolfor further transformation. Two additional alternatives are included: corn starch as the traditionalfeedstock to obtain the corresponding sugars and directly buying sorbitol from market. Sorbitol istransformed into isosorbide, a platform molecule, which can be converted into a drug for heart disease(isosorbide dinitrate), a flame retardant, a biopolymer and a biosolvent (dimethyl isosorbide). TheRenewable Process Synthesis Index Metric (RePSIM) is used as objective function to address sustainability. Alternatively, Net Present Value (NPV) is also considered to obtain a detailed economic analysis. Interms of sustainability, the production of isosorbide dinitrate is the optimal pathway, albeit it shows anegative RePSIM of 4.30 million USD/yr. On the other hand, the production of dimethyl isosorbide is theoptimal configuration taking into account the economic objective function. Its NPV is 44.31 million USDwith a production cost of 6.97 USD/kg. It is worth mentioning that the social and environmental aspect ofthe dimethyl isosorbide production process is positive. In this sense, this chemical can be obtained frommarine macroalgae biomass in a profitable way with a process that is socially and environmentallybeneficial.