Uncovering and Filtering Industrial Symbiosis Networks for Carbon Dioxide Utilization in Trinidad and Tobago

The emission source profile of the small island developing State of Trinidad and Tobago (T&T) is unique amongst high national CO₂ emitters per unit of GDP. To consider appropriate options for sustainably reusing CO₂ in an industrial symbiosis network (ISN), a simple enterprise input-output model of CO₂ exchanges between representative plants in a petrochemical cluster at the Point Lisas Industrial Estate in T&T was created. Then multi-objective optimization (MOO) was performed, so that both CO₂ emissions and levelized transportation costs would be enhanced. Initial benchmarking uncovered the potential to reuse 17% of the process CO₂ emissions in chemical manufacturing on the representative petrochemical network. Next, the effect of adding a CO₂-reusing propylene carbonate plant to the ISN was examined. To determine how to add the propylene carbonate plant, MOO was reapplied to an updated network model, to filter all the possible ISNs. These MOO results suggest the addition of a CO₂-reusing plant would increase the mass of CO₂ reused in the ISN by 6.3%. Thus, eco-connectance, which is a measure of the level of IS, would be increased by 35%. The proposed changes could improve multiple Sustainable Development Goal (SDG) indicators concomitant with SDGs 8, 9, 12 and questionably 13.