公开(公告)号：US20240174516A1

公开(公告)日：2024-05-30

申请号：US18520882

申请日：2023-11-28

Applicant: EXXONMOBIL TECHNOLOGY AND ENGINEERING COMPANY

Inventor： Everett J. O'NEAL ,  David C. DANKWORTH ,  Sarah E. FEICHT

IPC: C01B3/04

CPC classification number: C01B3/047 ,  C01B2203/1058 ,  C01B2203/1076 ,  C01B2203/1205

Abstract: Systems and methods are provided for performing ammonia cracking as the endothermic reaction step of a reaction cycle in a cyclic reaction environment, such as a reverse flow reaction environment. In such aspects, heat for the endothermic reaction can be provided by direct heating during a regeneration step. Optionally, the fuel for the regeneration step can correspond to additional ammonia and/or can include hydrogen generated during the ammonia cracking reaction step. Optionally, a selective catalytic reduction (SCR) zone can be included as part of the reactor, to reduce or minimize the amount of nitrogen oxides in the regeneration effluent from the reactor.

公开(公告)号：US20230391617A1

公开(公告)日：2023-12-07

申请号：US18248888

申请日：2020-10-16

Applicant: EXXONMOBIL TECHNOLOGY AND ENGINEERING COMPANY

Inventor： Ramesh GUPTA ,  Amrit JALAN ,  Hugo S. CARAM ,  David C. DANKWORTH

IPC: C01B3/28

CPC classification number: C01B3/28 ,  C01B2203/0833 ,  C01B2203/1614 ,  C01B2203/0272

Abstract: Systems and methods are provided for conversion of methane and/or other hydrocarbons to hydrogen by pyrolysis while reducing or minimizing production of carbon oxides. The heating of the pyrolysis environment can be performed at least in part by using electrical heating within a first stage to heat the coke particles to a desired pyrolysis temperature. This electrical heating can be performed in a hydrogen-rich environment in order to reduce, minimize, or eliminate formation of coke on the surfaces of the electrical heater. The heated coke particles can then be transferred to a second stage for contact with a methane-containing feed, such as a natural gas feed. Depending on the configuration, pyrolysis of methane can potentially occur in both the first stage and second stage. In some aspects, the hydrogen-rich environment in the first stage is formed by passing the partially converted effluent from the second stage into the first stage. In such aspects, the partially converted effluent from the second stage can have an H2 content of 60 vol % or more, or 70 vol % or more, or 80 vol % or more, such as up to 99 vol % or possibly still higher.