Abstract

Currently, sewage sludge is considered as a biomass, according to the Polish act on renewable energy sources from 20th of February 2015 and its novel version from 19th of July 2019. Possibility to utilize sewage sludge in gasification process is an additional advantage of the negative CO2 emissions power plant (nCO2PP). The work presents results of thermodynamic, ecological, and economical analysis using a zero-dimensional mathematical models of a negative CO2 emission novel structure power plant. Parameters of thermodynamic cycles such as output power, efficiency, combustion gas composition, exhaust temperature, avoided emission of carbon dioxide, as well Specific Primary Energy Consumption for Carbone Avoided (SPECCA), Discounted cash-flows, NPV, IRR etc., will be taken into account. Precise thermodynamic models are particularly important for Carbon Capture and Storage (CCS) and CCU (Carbon Capture and Utilization) energy system, where quite new devices mutually cooperate and their thermodynamic parameters affect those devices. Proposed negative CO2 emission novel power plant includes wet combustion chamber, spray-ejector condenser, gas-steam turbine, sewage sludge gasifier, separator of CO2, to determine the effect of cycle into environment. First of all, the possibility of a negative CO2 emission power plant and the positive environmental impact of the proposed solution has been demonstrated. Secondly, the technical-economic analysis made for presented feasibility study showed the high profitability of the installation which allows to: 1) gasification and vitrification of the sludge, 2) energy generation and 3) CO2 capture. All these activities are the basis of revenues or avoided costs. According to the performed analysis, the real return period for assumed commercial scale installation is 4 years. Internal rate of return is also high (IRR=24.11%). The main conclusion is that the investment in the analysed installation is profitable.

Citations

Authors (9)