Cost-effectiveness and economic growth potential evaluation of olive pomace gasification process to sustainable fuel: Comparison study of different gasifying agent

Abstract

This research addresses the growing global demand for sustainable and renewable energy solutions, focusing on biomass gasification (BG) as a promising avenue. Olive pomace is explored as a primary feedstock, assessing its potential as a plentiful and renewable energy source. The study aims to bridge existing gaps in the literature, particularly in the simultaneous and comparative examination of CO2, steam, and air as traditional gasifying agents. Utilizing Aspen Plus, a validated simulation tool, the research models the gasification process (GP) while considering key parameters such as gasifying agent, feed composition, and temperature. Through meticulous simulation and validation against experimental data, the goal is to develop a robust model tailored for gasification. A thorough sensitivity analysis evaluates critical parameters' impact on exergy efficiency, levelized cost of hydrogen (LCOH), and molar flow of hydrogen (H2). Parameters include temperature variations (600°C to 1000°C), equivalence ratio (ER) for the air agent (0.15–0.3), C/CO2 ratio for the CO2 agent (1–2.5), and SBR for the steam agent (0.5–2). The aim is to provide a nuanced understanding of these parameters and their influence on system performance, offering valuable insights for process optimization. The response surface methodology is employed to optimize critical parameters for distinct gasification agents, aiming to identify the most economically efficient agent. The study's findings are crucial for enhancing BG efficiency and developing sustainable energy systems. An economic evaluation underscores the cost-effectiveness of the GP, emphasizing its potential for economic growth in the renewable energy sector and long-term savings. In the concluding phase, optimization of the GP aimed at minimizing LCOH and maximizing molar flow of H2 and exergy efficiency was conducted. Upon scrutinizing the optimization results, a compelling conclusion arose: The steam agent emerged as the most suitable, with 48% exergy efficiency, 1.77 €/kg LCOH, and an optimal temperature of 884°C. Notably, steam showcased remarkable exergy efficiency, even when subjected to lower temperatures, positioning it as a superior choice.