DECEMBER 20239Fig.3. At the moment, on-going work is focused on improving and optimizing catalyst performance (Fig. 4.) as well as the process steps to be employed in an industrial application. Technology Background: Synthesis Gas Technology In the field of synthesis gas technology (such as Fischer-Tropsch), carbon monoxide (CO) and hydrogen are the typical feed stocks. Carbon capture and utilization (CCU) is an expansion of synthesis gas technology with the key difference being the carbon-containing feedstock is now CO2 rather than CO. Chiyoda has many years of experience in the field of synthesis gas, which is the basis from which they can develop CCU-based technologies, including both the catalyst and the process.But is CCU really green?Based on our calculations, while considering scope 1 and 2, provided that the hydrogen is green (i.e., made from water electrolysis and powered by renewable energy), the carbon intensity of the technology is negative. Namely the amount of CO2 fixed in para-xylene is much larger than that being emitted. Therefore, one can say that CCU-based para-xylene is indeed green.Additionally, there are opinions that say that the CO2 emission when the CCU product will be burnt (for example when waste processed at an incinerator) should be considered. In this regard, let us compare the both cases with and without CCU as shown in figure 5. It is clear from this simplified diagram that the total CO2 emission with CCU is lower than the one without CCU. Therefore, we can confidently say that CCU contributes to a net CO2 emission reduction.Fig. 5 CO2 emissions with & without CCUFig. 2 Pilot Plant Fig. 3 Product para-xylene Fig. 4 CatalystHydrogen supply for CCUHydrogen may often be construed as a carbon-free energy carrier. While this is true, we can also draw your attention to the fact that hydrogen is a feedstock for CCU-based processes.As a matter of course, the supply of the feedstock is a key element to the success of this technology. In this regard, we can say there are three potential issues regarding the supply of hydrogen, namely: Quantity, Reliability, and Cost.Firstly, when the CCU para-xylene technology is eventually scaled up to an industrial capacity, the major limiting factor will be the availability of hydrogen. Because the technology can off-take tens of thousands tones/year of hydrogen, securing such a quantity will not be easy. Secondly, if hydrogen will be produced on site by water electrolysis using renewable power, the inevitable intermittency of renewable power becomes yet another issue. Since CCU plants would be of a chemical process nature, the plant should be operated continuously. Therefore, battery back-up and/or hydrogen storage as buffers become imminently desirable and, in fact, necessary as a practical matter and economical solution.Thirdly, we must mention that the cost driver for CCU-based para-xylene is embedded in the cost of hydrogen. Hence, achieving a competitive and affordable cost for hydrogen is key to realizing suitable project economics. It should be obvious then that the above issues are common for most CCU-based projects. In this regard, it will be appreciated to hear the voices of those who have potential solutions for any and all of the above. We sincerely look forward to hearing from you! This innovative project brings together key players from academia, industry and government, whose collective aim is to someday, bring this concept to commercial realityTadashi Ito
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