Impact of the reverse water-gas shift operating conditions on the Power-to-Liquid process efficiency. (February 2021)

• Record Type: Journal Article
• Authors: Adelung, Sandra; Maier, Simon; Dietrich, Ralph-Uwe
• Is Part Of: Sustainable energy technologies and assessments. Volume 43(2021)
• Publication Date: 2021-02
• Subjects: Synthetic fuels -- Alternative fuels -- rWGS -- Syngas -- Syncrude; Renewable energy sources -- Periodicals; Energy development -- Technological innovations -- Periodicals; Electric power production -- Periodicals; Energy storage -- Periodicals; 333.79
• DOI: 10.1016/j.seta.2020.100897
• Languages: English
• ISSNs: 2213-1388

Abstract

Graphical abstract: Highlights: Aspen Plus® model of a Fischer-Tropsch based Power-to-Liquid process. Influence of different reverse water-gas shift operating conditions on: ∘ Power-to-Liquid efficiency, ∘ Carbon and hydrogen efficiency. Heat integration possibilities and sensitivity studies. Abstract: Fischer-Tropsch based fuels from renewable electricity and carbon dioxide provide one possibility to defossilise the transport sector, especially where long distances and high loads require fuels with high energy density. In this work, a stationary Power-to-Liquid (PtL) process model is set up in Aspen Plus®. The process involves CO2 absorption, water electrolysis, CO2 activation by reverse water-gas shift reaction (rWGS), an oxyfuel burner, Fischer-Tropsch synthesis, product separation and hydrocracking. The influence of the rWGS operating conditions (pressure and temperature) on the overall process performance in terms of PtL-efficiency and hydrogen/carbon efficiency is investigated. The operating conditions are varied between 550 and 950 °C and 1–25 bar. The temperature and pressure dependent methane formation in the rWGS is found to have major influence on the efficiencies. For the base case, a maximum Power-to-Liquid efficiency of η PtL = 38.7 % is obtained at 5 bar and 825 °C, while a maximum hydrogen efficiency of η H = 28 % results at 1 bar and 725 °C. The carbon efficiency is found to be constant ( η C = 88 %). Sensitivity studies show that the optimum operating conditions are not affected significantly by variation of the investigated process variables.