2.3. Economic evaluation
To determine the economic viability of the biorefinery concept, the economic indicators net present value (NPV), internal rate of return (IRR) and the amortization duration (AD) were calculated using a discounted cash flow model. The NPV represents the surplus yielded by an investment at the beginning of the time period in regard to the discount rate. Respectively, the IRR allows a comparison with the discount rate, indicating whether an interest return on the invested capital is achieved with at least the discount rate. The AD determines the recovery period for the invested capital.