Design of an integrated system that combines the steam gasification of plastic waste and a solid oxide fuel cell for sustainable power generation

As part of sustainable development efforts, this study presents an innovative integrated system that combines the steam gasification of plastic waste with solid oxide fuel cells (SOFCs) to produce electricity. The proposed system is designed using Aspen Plus v10 (R) with two primary units. The first, a steam gasification system to produce H2 from the steam gasification of plastic waste. The second is a H2 driven SOFC system that generates electricity and is developed using Python. The study evaluates the combined system output in terms of power, current and voltage based on variation of temperature, steam/feed ratio (0.5-2), and CaO/feed ratio (0-1.5) of the gasifier. The study observes a decrease in the voltage (0.864 to 0.859 V) and power (0.852 to 0.845 W) with increasing gasification temperature (923-1173 K). Conversely, a rise in the steam/feed ratio inversely impacts the SOFC output, which is attributed to a decline in the H2 flowrate. Optimal conditions are met at gasifier temperature of 973 K, steam/feed ratio of 1.5, and CaO/feed ratio of 1. Moreover, using H2 flow rates to assess SOFC performance reveal increasing activation and ohmic losses (0.04 to 0.09 V and 0 to 0.28 V) with a temperature increase (973-1473 K), while concentration losses decreased (0-0.10 V). Nernst voltage and SOFC output voltage also decreased (1.1 to 0.52 V and 1.1 to 0.78 V) as SOFC temperature increases. Power output increased (0.0 to 1.57 W) with temperature, and the current-voltage relationship demonstrated reduced voltage (1.1 to 0.53 V) as the current is increased (0.0 to 2.8 A). This study provides an in-depth exploration into the development, modelling, and performance of both units, emphasizing their synergistic potential in the realm of sustainable electricity generation.