Natural gas based cogeneration system proposal to a textile industry: a financial assessment

This work presents a techno-economic evaluation of the implementation of a cogeneration system in the textile sector. The study was based on energy analysis for the survey of energy data, energy audit in the industrial plant, and also, an analysis of technical and economic feasibility, based on the parameters of net present value (NPV), internal rate of return (IRR), and time of return on investment (payback). The study was based on the use of single-effect absorption chillers, with the pair lithium bromide-water (LiBr/H2O) as the working fluid. Scenario studies were created to verify the feasibility of cogeneration in terms of the current system configuration. The sensitivity analysis of the scenarios studied depending on the exchange rate from Brazilian Real to US Dollar, the natural gas tariff, the investment of time, and interest rate financing allowed to find a hypothetical scenario for natural gas rates between 0.05 and 0.14US$/m(3) and an interest rate set at 3% per year, where the proposal for full cogeneration (production of electricity and heat) was quite favorable, even for the high investments of the proposed cogeneration plant.