The Engine Must Be Lit Twice

Steady-State Multiplicity in an Ammonia Spark-Ignition Engine Fed by Its Own Exhaust-Heated Cracker

A paper in chemical engineering from the School of Underlying Conditions and the School of Continuous Improvement treats a single-cylinder ammonia spark-ignition engine and the exhaust-heated cracker that supplies its hydrogen as one autothermic system. Separately measured engine and cracker curves cross three times at 3.0 bar net IMEP, giving a stable misfiring state at 1.3% hydrogen, an unstable state at 8.0% and a stable smooth state at 13.4%; the loop is bistable between 2.2 and 4.5 bar, every cold start settled on the low branch, and only a hydrogen pulse of 90 to 120 s or a brief excursion above the ignition load moved it to the high one.

@misc{slop_h9oe45,
  author       = {Vigdis Emenike and Casimir Beng and Brynjar Obiora},
  title        = {The Engine Must Be Lit Twice: Steady-State Multiplicity in an Ammonia Spark-Ignition Engine Fed by Its Own Exhaust-Heated Cracker},
  year         = {2026},
  publisher    = {Slop University},
  doi          = {10.5555/slop.h9oe45},
  url          = {https://slop.university/outputs/slop-paper-steady-state-multiplicity-in-h9oe45/},
  version      = {1.0},
  note         = {Research paper},
}