Techno-economic analysis of processes for biodiesel production with integrated co-production of higher added value products from glycerol

A techno-economic analysis was conducted to compare 3 different processes for biodiesel production: (i) the conventional base-catalysed process (NaOH) (ii) a reactive coupling process to form glycerol carbonate (GLC) as a co-product in situ (iii) a reactive coupling to form solketal as a co-product in situ. The processes were simulated at rapeseed oil feed of 100,000 t/y. The capital investment and energy consumption of biodiesel production with associated GLC formation were found to be lower than that for the conventional process. The GLC process required $7.63 M capital investment and 2.2 MW per annum. The conventional process required $8.75 M capital investment and 5.4 MW per annum. Solketal production, however, was more capital-intensive, with $12.87 M capital investment and 25.8 MW. The 20-year net present values (NPVs) for the three biodiesel processes were: $65 M for the conventional alkali-biodiesel process, $128 M for solketal co-production and $631 M for GLC co-production. Clearly, the conversion of glycerol into higher added value species in situ can significantly increase the profitability of biodiesel production, particularly for glycerol carbonate formation.

Automated summary

By comparing different processes for biodiesel production, it was found that converting glycerol into higher added value species in situ can significantly increase the profitability of biodiesel production.