Application of Life Cycle Assessment (LCA) to reactions between carbonates and cyclic ketones for the synthesis of diesters

Nowadays chemistry plays a crucial role in everyday life, being the basis of products and services useful to achieve a fulfilling lifestyle. However, the excessive consumption of resources can lead to devastating consequences for the delicate balance within Earth’s ecosystems. A growing awareness of these issues brought 1990s to the developments of green chemistry, with the aim of safeguarding both human and environmental well-being. In this context, the Life Cycle Assessment (LCA) methodology comes into play, a technique that allows for the analysis of the environmental impacts associated with a process or the production of a good. In this thesis, this methodology was used to study the impacts associated with the production of 1 kg of dimethyl adipate, a monomer widely used in the textile industry, comparing bio-based (corncob) and fossil-based (benzene) feedstocks. The study involved modelling the fossil-based process starting from adipic acid followed by esterification made with methanol. On the other hand, for the bio-based route, the process was developed starting from corncob, which is transformed into furfural via acid hydrolysis and subsequently reduced to cyclopentanone. From this point, the work utilizes a laboratory scale process, after scaled up to the kilogram level. The results showed that the bio-based route was, in most cases, more impactful. This is particularly evident in the climate change impact category, which registered 1.45E+01 kg CO2eq for the renewable path, compared to 9.58E+00 kg CO2eq for the fossil-based route. These impacts are for the majority ascribable to heat usage, especially during the final distillation step. This critical point was then addressed through a sensitivity analysis where it was alternatively supplied using syngas and biogas, which led to some improvements, though still not enough to outperform the fossil route. These findings were further confirmed by a following Monte Carlo statistical analysis.