Role OverviewWe're looking for an R&D Process Engineer to bring process engineering rigor to Arbor's fast-paced R&D programs-turning ambitious test plans into operating reality on first-of-a-kind hardware. Our current center of gravity is a high-pressure gasification program operating at conditions never before attempted at any scale, on an aggressive path to commercial operation. You'll own the process side of test stand design, problem-solve at the P&ID and control-scheme level to bring test plans to life, and lead troubleshooting on a challenging fouling-, plugging-, and erosion-prone service. You'll partner closely with senior systems team engineers, gasification engineers, and test engineers, and bring the same rigor to other R&D programs across Arbor as priorities evolve. This is hands-on, high-stakes engineering work on first-of-a-kind technology at the frontier of carbon-negative baseload power.
This is an onsite opportunity in our El Segundo, CA office.
Responsibilities- Own the process engineering deliverables for R&D test stand design-design basis, process flow diagrams, heat and material balances, equipment and line sizing, and supporting calculations that take a new test rig from concept to ready-to-run.
- Apply that rigor first to the gasification program's hardest subsystems-high-pressure oxygen and CO2 control, refractory-lined reactor zones, and syngas analysis, cooling and cleanup.
- Develop and maintain steady-state and dynamic process models to predict performance, explore design space, and inform test planning across active R&D programs.
- Translate test campaign objectives, set by gasification and test engineers, into P&IDs, control narratives, instrument specifications, and safe operating envelopes-bringing rigorous process design to ambitious experimental plans.
- Reduce, analyze, and interpret test data-closing mass and energy balances, reconciling instrumentation, and turning campaign results into design decisions and next-test recommendations on the parts of the system you know best.
- Lead root-cause investigations on fouling, plugging, erosion, instability, and other off-design behavior in a challenging high-temperature, high-pressure service; drive corrective actions through to verified resolution.
- Develop operating procedures, run sheets, and startup/shutdown sequences, and participate in process hazard analyses (PHA/HAZOP) as the test program evolves.
Requirements- Bachelor's Degree in Mechanical, Chemical, Aerospace, or related Engineering field.
- 5+ years of hands-on process engineering experience, with meaningful time spent in an R&D, pilot plant, or test stand context.
- Demonstrated experience troubleshooting fouling, plugging, erosion, instability, or off-design behavior on real hardware-able to walk through specific events, diagnostic approaches, and outcomes.
- Comfort with commercial process simulation tools (Aspen HYSYS, Symmetry, or equivalent), including both steady-state and dynamic simulation.
- Strong fundamentals in chemical engineering and a broad appreciation of adjacent disciplines (mechanical, instrumentation, controls, materials).
- Willingness and ability to travel to Arbor's test site in San Bernardino, CA (approximately 20-40%, weighted toward active campaign windows).
- Highly self-driven, with the ability to identify technical mysteries and pursue them to root cause when operating with loose guidance.
- Strong ownership mentality and curious, inventive mindset comfortable driving rigorous problem-solving in a small, fast-paced startup environment.
Preferred Qualifications- Direct experience with gasification, oxy-combustion, slag-forming combustion, FCC, coker, hydrocracking, refractory-lined reactors, ash- or solids-handling, or other high-temperature, high-pressure, fouling-prone systems.
- Hands-on operating experience in a pilot plant, test stand, hardware startup, national lab pilot program, or aerospace test cell environment.
- Programming or scripting proficiency for data reduction and custom analysis (Excel, Python, MATLAB, or similar).
- Experience with supercritical CO₂, high-pressure (100+ bar) systems, or power generation.
- Familiarity with PHA/HAZOP leadership, LOPA, and pressure relief design.
- Background in startup, R&D, or first-of-a-kind hardware development environments.
Compensation & Benefits- Pre-IPO stock options
- Medical, dental, and vision insurance (Arbor covers 90% for employees)
- Basic life insurance fully covered
- Health savings account (HSA) with matching
- Flexible savings account (FSA)
- Unlimited PTO
- 12+ company holidays, including Earth Day!
- 401(k)
- Commuter benefits
- Annual learning and development stipend
- And more!
Base Pay: $140,000 - $155,000 USD/year. The salary is subject to the applicant's skills, qualifications, experience, and geographic location.
