Refinery Process Engineer Jobs in Tennessee (NOW HIRING)

Location: Franklin, TN (On-Site)
Type: Full-Time
Seniority: Mid to Senior Level / Technical Contributor

Enexor is a venture-backed, early-stage climate tech company just outside of Nashville, TN, developing distributed systems that turn organic and plastic waste into clean energy and high-purity CO. We are reimagining how the world addresses emissions, waste, and energy access-one modular system at a time.

We're not just solving problems. We're redefining what's possible at the intersection of engineering, energy, and sustainability.

We're hiring a Process Engineer with a strong mechanical foundation to help design and deploy our next-generation waste-to-energy and carbon capture systems.

This is not a modeling-only role. You'll work end-to-end-translating high-level process concepts to concrete designs by developing P&IDs, performing mass and energy balances, modeling processes, selecting hardware, guiding physical builds, and gaining insights from testing. By diving into technical challenges to turn concepts into reality,  your work will sit at the core of how our systems perform in the real world.

This role is perfect for process design engineers with a systems background and strong mechanical intuition who want to own full process-mechanical design and get hands-on in fabrication, instrumentation, and deployment.

• Design & Simulate Separation Processes: Build and validate cyclic adsorption (TSA/PSA) flowsheets in process modeling software (including custom isotherm and kinetic models); analyze breakthrough curves, cycle efficiency, and heat integration.
• Perform Mass & Energy Balances: Develop detailed mass-energy balances for energy systems and carbon capture processes.
• Translate Models into Hardware: Generate PFDs and P&IDs from your process simulations; size pressure vessels, adsorption beds, heat exchangers, pumps/blowers, and piping networks based on process conditions.
• 3D CAD Layout & Mechanical Detailing: Create or review CAD assemblies and AutoCAD schematics to ensure the process equipment fits skid dimensions and meets requirements.
• Support Fabrication, Commissioning, & Testing: Work with the shop and controls teams to oversee fabrication, instrumentation, and loop checks; participate in testing development and data review.
• Data Analysis & Model Refinement: Use testing results to update simulation parameters and re-optimize cycle timings or hardware specs.
• Cross-Functional Collaboration: Partner daily with chemical, mechanical, and controls engineers plus technicians, aligning on control strategies, safety interlocks, and operational procedures.
• Continuous Improvement: Identify design-to-cost opportunities and reliability enhancements; propose material, cycle, or control refinements to boost capture rate and reduce parasitic loads.

Requirements

• Education: B.S. or M.S. in Chemical Engineering or Mechanical Engineering with significant process modeling experience.
• Process Modeling: 3-8 years designing and simulating adsorption or gas-separation processes-expertise in Aspen Plus (including custom isotherms & dynamic cycles), gPROMS, or equivalent.
• Transport & Thermodynamics: Deep understanding of mass-transfer, reaction kinetics, heat-transfer, and property estimation methods.
• Experimental Validation: Proven ability to validate simulation and modeling results through lab-scale or pilot-scale experimentation-designing tests, analyzing data, and refining models accordingly.
• Mechanical Aptitude: Hands-on experience sizing pressure vessels, piping networks, heat exchangers, pumps, and blowers; experienced in SolidWorks/Inventor and AutoCAD.
• Field & Commissioning Experience: Familiarity with pilot-scale builds, instrumentation calibration, loop checks, and on-site troubleshooting.

Bonus Points For:

• Hands-on experience with cyclic adsorption systems (TSA/PSA) using Aspen Adsorption or equivalent.
• Designing modular or containerized process skids for rapid deployment.
• Control-system co-simulation (DCS/PLC loop tuning, model-based control strategies).
• CFD or multiphase-flow modeling to support detailed mechanical design.
• Scaling processes from pilot to demonstration or commercial units.
• Familiarity with gas-analysis instrumentation.

Benefits

• Mission with urgency: Your designs will help clean up emissions and generate real impact.
• Hands-on everything: If you're not satisfied just modeling, you want to see your ideas come to life through building, testing, and owning full systems.
• Flat org, fast feedback: Make decisions, iterate quickly, and learn fast.
• Equity upside: Be part of a venture-backed team building breakthrough clean tech systems.

• Competitive salary + equity opportunity in a fast-growing climate tech company.
• 401(k) plan and health insurance stipend (QSEHRA).
• Paid vacation and holidays.

Send your resume and a brief note to careers@enexor.com. Highlight your experience with process-mechanical systems, gas treatment, or thermal integration.