| dc.description.abstract | Recent decades have witnessed groundbreaking advancements in the field of carbon dioxide (CO2) utilization and conversion, primarily due to the commitment put forth by the top global economies to address climate change. Dry reforming of methane (DRM) is one of the many pathways that enable CO2 utilization to produce precursors for chemical and fuel production; however, due to several process limitations, DRM technology has yet to be commercialized. The major advantage of this technology is that it catalytically converts two greenhouse gases (CO2 and methane [CH4]) into a mixture of carbon monoxide and hydrogen, which is known as synthesis gas or syngas. Syngas is an essential precursor in the production of value-added chemicals, hydrocarbons, and alternative fuels.
In the present work, an innovative advancement in the DRM field—carbon generation technology (CARGEN™)—is developed. The CARGEN™ technology addresses some of the major challenges facing the commercialization of DRM technology while bringing compelling economic advantages over benchmark methane reforming processes (i.e., steam reforming, partial oxidation, and autothermal reforming). CARGEN™ technology is built on a system of two integrated reactors in series, which are meant to segregate two opposing reactions occurring in the DRM: (a) carbon formation at low temperatures (at 400-600C, via Boudouard and methane decomposition reactions) and (b) syngas formation at high temperatures (at ≥ 750C). This unique feature of CARGEN™ entails exceptional flexibility that overcomes all the DRM challenges. A detailed energy assessment via thermodynamic analysis has demonstrated that CARGEN™ enables at least 65% CO2 conversion while consuming 50% of the typical energy required in an equivalent-capacity DRM process. Additionally, in contrast to DRM, CARGEN™ presents the flexibility to produce syngas that meets downstream process requirements. Another study involving a lifecycle assessment of the process indicates that CARGEN™ enables at least a 40% reduction in both CO2 emissions and operational costs, compared to benchmark commercial technologies such as autothermal reforming and partial oxidation. The unique, transformational benefit of the CARGEN™ process, which was discovered during the experimental proofing stage, is its ability to produce a high-quality form of carbon material: specifically, multiwalled carbon nanotubes. Moreover, dedicated reproducibility tests utilizing state-of-the-art reactor systems at microgram, milligram, and multigram scales have revealed reproducibility and consistency in the quality of the multiwalled carbon nanotubes, which were tested and validated employing scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, and the Raman analysis. | en |
