SELECTING THE APPROPRIATE GAS TREATMENT TECHNOLOGY FOR JAZAN INTEGRATED GASIFICATION COMBINED CYCLE(IGCC)PROJECT

摘要

Saudi Aramco is executing a mega-project,which includes building a world-scale Integrated Gasification Combined Cycle Complex(IGCC)adjacent to a new 400,000 BPSD grassroots refinery in the Jazan Economic City(JEC)near Jazan,in Saudi Arabia.The primary feedstock to the IGCC would be the vacuum residue(VR)produced in the refinery,plus imported high sulfur fuel oil(HSFO).The design feed capacity of the IGCC is expected to be about 110 MBD of VR or HSFO and would export 2.4 GW of net power to the grid.Selecting a feasible gas treatment technology for this project went through extensive evaluation and analysis.The selected design would not only meet the targeted gas specifications,but would also be capable of mitigating the identified impacts of the contaminants,such as metal carbonyls,to comply with environmental and reliability requirements associated with the gas turbines in the power generation block.Different design options were evaluated during the Front-End Engineering Design(FEED)of the project before adopting the final design,which included using methanol-based technology for treating the syngas.The base case design for treating the syngas included hydrolysis beds,followed by MDEA-based Acid Gas Removal(AGR)units,which was adequate to achieve the required total sulfur specification in the treated gas.The subsequently identified need to control the nickel and iron carbonyls,before feeding the syngas to the gas turbines,led to additional design considerations to mitigate negative impacts,as a result of having high levels of these contaminants.The evaluated design options included activated carbon beds to adsorb the metal carbonyls after the MDEA-based AGR,but was excluded because it would not reduce the metal content to the targeted levels.Other options included methanol wash after the AGR,and switching to a physical solvent for AGR.This paper summarizes the efforts undertaken by Saudi Aramco to select the final configuration and technology to mitigate design challenges associated with syngas metal impurities.The paper provides details about the potential impacts of the metal impurities and the evaluated design alternatives,before selecting the final configuration that met all of the design objectives.