Techno-economics feasibility of supercritical CO2 ambrette seed extraction for optimised parameters obtained using RSM

Abstract

Seeds of a native aromatic plant of India, Abelmoschus moschatus (Ambrette), Malvaceae family, were considered for extraction and techno-economic evaluation in this study considering the commercial importance of unique volatile oil in the seed coat. Supercritical fluid extraction (SFE) using CO2 as the extraction fluid was performed at different process parameters. Impact on overall yield, absolute yield, wax yield, and characteristic component was determined using the response surface methodology tool to understand the interaction of independent variables and optimise the process parameters. Maximisation of desired extract (minimum wax content and maximum content of farnesyl acetate) was found at optimum process conditions of 36.01 °C, 75 min, 109.38 bar and 3.236 ml/min flow of CO2. Experimental readings at the predicted conditions were in good agreement with the predicted responses giving an overall yield of 5.50 %, with 96.15 % absolute and 5.578 % of farnesyl acetate in the composition. The techno-economic feasibility study at these parameters revealed that the manufacturing cost would be USD 392.5 per kg for a processing capacity of about 26.12 tons of raw material per year. The associated raw material and utility costs are the major contributing factors to the manufacturing cost. Profitability indices of net present value (NPV), internal rate of returns (IRR), pay-back time and return on investment (ROI) indicate that implementation of a supercritical fluid extraction plant is economically viable with a production of about 1430 kg of ambrette seed oil per year.