Maleic anhydride from bio-based 1-butanol and furfural: a life cycle assessment at the pilot scale

The necessity to feed the chemical industry with bio-based platform chemicals encourages the usage of a life cycle perspective in order to evaluate potentialities and drawbacks, before launching them at the industrial scale. In this study, we proposed a life cycle assessment of two bio-based routes for the production of maleic anhydride (1000 kg as the functional unit, FU): from butanol (bio-ButOH MA) and furfural (bio-Furf MA). In both cases, dedicated biomasses were used to feed the pilot plants, since it represents a more realistic scenario. The study considers two levels of analysis. The first one takes into account the simplest situation, in which no energy recovery is considered within the system boundaries. In the second assessment level it is assumed that 100% of the heat released by the reaction is recovered to feed the plant and co-produce steam (available for other commodities). In both scenarios, the production of MA from bio-Furf results in being more competitive. Models were evaluated in terms of carbon footprint (IPCC), cumulative energy demand (CED) and following a multi-impact approach (ReCiPe method). The life cycle impact assessment phase confirms the scores achieved from the application of the E-factor (green metric). In fact, the higher selectivity of the catalytic system used to convert bio-Furf into MA implies a lower amount of raw materials per FU with consequent minor potential impacts on the several impact categories considered. Results, also confirmed by Monte Carlo analysis, could be used to attain future improvements and support the design or the retrofit of innovative industrial plants able to enhance the whole efficiency.