Preliminary techno-economic assessment and uncertainty analysis of scaled-up integrated process for bioactive extracts production from Senna alata (L.) leaves

Abstract

This work reported the effects of heat-assisted extraction (HAE) temperature (35–55 °C), solid: liquid (1:20–1:50 g/mL) and time (100–200 min) on the total phenolic content (TPC, GAE/g), bioactive extracts yield (EYs, %) and antioxidant activity (AA, AAE/g) of Senna alata leaves (SALs) using the Box-Behnken experimental design. Multi-objective HAE process optimization was also carried out. The large scale (1000 L extractor capacity) HAE integrated process was thereafter designed using the global optimum data and techno-economically analyzed. Profitability sensitivity and uncertainty analyzes were conducted on the large scale integrated process to determine the associated risk. The extraction temperature, solid: liquid and time had significant effects on TPC, EYs and AA. The extraction conditions at 54.97 °C, 41.59 g/mL and 100 min gave an optimum TPC, EYs and AA of 84.3897 mg GAE/g, 21.3607% and 6.61696 µM AAE/g, respectively. The phenolic profiling showed that SALs extracts were rich in betulinic, gallic, chlorogenic, caffeic and ferulic acids. The large scale integrated plant possessed net present value (NPV), internal rate of return (IIR), return on investment (ROI) and payback time (PBT) of 193.511 US$, 7.11%, 13.97%, and 7.16 y, respectively. The certainty of obtaining base case NPV and ROI were 55.88 and 60.96%. Out of technical and cost variables selected for sensitivity analysis, extracts recovery contributed the most (26.6 and 27.9% in NPV and ROI, respectively) while the extraction temperature and SALs purchase cost did not contribute significantly to the variance in NPV and ROI.