Ismail Zeitoun
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300 K / Ambient

Ismail Zeitoun

Independent cryogenic, hydrogen, and CO2 engineering.

Safety audits, performance optimization, and feasibility studies for operators who need the analysis right, not upsold.

Cutaway drawing: vacuum-jacketed pipe feeding a radial-inflow turboexpanderEngineering section view. A vacuum-jacketed cryogenic pipe is cut open to show its outer jacket, multilayer insulation, vacuum annulus, and inner process line. The pipe feeds the volute of a radial-inflow turboexpander through a bayonet joint and inlet flange. The volute scroll, 17-vane nozzle ring, 13-blade impeller, shaft, and axial discharge are labeled. A glowing line traces the process flow path through the machine.VACUUM JACKETPUMP-OUT PORTMLI BLANKETVACUUM ANNULUSPROCESS LINESPACERBAYONET JOINTVOLUTENOZZLE RING / 17 VANESIMPELLER / RADIAL INFLOWDISCHARGESHAFTINLET FLANGEFIG. 01 / TURBOEXPANDER, RADIAL INFLOWVACUUM-JACKETED FEED / SECTION VIEW / NTS

You work with the engineer doing the work.

Independent of equipment vendors and EPCs. NDA-friendly.

Scope and price are fixed in writing before anything starts.

ASPEN HYSYS / ASPEN PLUS / REFPROP

Follow the cold

300 K → 4 K

Book a discovery call
Cryogenic storage tank cross-sectionSection view of a vertical double-wall cryogenic storage tank. The outer shell encloses a perlite and vacuum annulus around the inner vessel. Liquid LNG at 111 kelvin sits below a vapor space. A relief valve stack and fill line enter the top head; a withdrawal line with an isolation valve leaves the bottom. The tank stands on a support skirt.INNER VESSELLNG @ 111 KOUTER SHELLPERLITE + VACUUMRELIEF VALVEFILL LINEVAPOR SPACESUPPORT SKIRTWITHDRAWAL

02 / 111 K / LNG

Feasibility studies

Independent go or no-go before you commit to FEED. Industrial facilities with emissions targets, companies pursuing 45Q tax credits, CCU startups needing independent validation.

  • 01Source characterization
  • 02Technology screening (amine, membrane, adsorption, cryogenic)
  • 03Equipment sizing
  • 04CAPEX and OPEX estimation
  • 05Economic model (IRR, payback, $/ton abatement)

TOOLS: Aspen HYSYS and Aspen Plus where the screened technology requires it

Deliverable: Feasibility report with go/no-go recommendation and a defined next-phase scope.

$20,000fixed scope / 3 to 4 weeks

Download the service detail sheet (PDF)
Vacuum-jacketed pipe cross-sectionLongitudinal section of a vacuum-jacketed cryogenic pipe, drawn on a gentle diagonal descending left to right. From outside in: outer jacket, then the high-vacuum annulus, then the multilayer insulation blanket wrapped directly on the inner process line carrying liquid nitrogen at 77 kelvin. Spacers center the inner line. A bayonet joint with a flanged closure connects two spool pieces at mid-run, and a pump-out port on the jacket serves the vacuum space.OUTER JACKETMLI / MULTILAYER INSULATIONVACUUM ANNULUSINNER LINE / LN2 @ 77 KPUMP-OUT PORTBAYONET JOINTSPACER

03 / 77 K / LN2

Safety audits

Closes code gaps before a regulator, an insurer, or an incident does. Independent code-compliance and risk review of hydrogen systems or facilities.

  • 01Pressure relief sizing
  • 02Emergency shutoff systems
  • 03Ventilation and gas detection
  • 04Piping integrity
  • 05Operating procedures

BASIS: NFPA 2, IFC Chapter 58, DOE Hydrogen Safety Guidelines, OSHA PSM where applicable

Deliverable: Written report, findings ranked by risk severity, gaps against code, prioritized recommendation list.

Best fit: Facilities without recent independent review, post-incident reviews, pre-regulatory audit prep, hydrogen fueling operations, electrolyzer-integrated facilities.

$15,000fixed scope / 2 to 3 weeks

Download the service detail sheet (PDF)
Centrifugal compressor cross-section, horizontal shaftAxial section of a centrifugal compressor for hydrogen gas service. Gas enters the axial inlet at left, turns through the overhung impeller, passes the vaned diffuser, and collects in the volute. The discharge nozzle leaves the bottom of the volute pointing down. The horizontal shaft runs right from the impeller through a dry gas seal, then a bearing, to the drive coupling.INLET / H2 GASIMPELLERVANED DIFFUSERDISCHARGEVOLUTESHAFT SEALBEARINGSHAFTCENTRIFUGAL COMPRESSOR / H2 GAS
Cryogenic pump cross-section, vertical shaftAxial section of a vertical cryogenic pump for liquid hydrogen at 20 kelvin. Liquid enters the suction at top, passes the inducer that protects the impeller from cavitation, and turns radially through the impeller into the volute. The discharge line runs down the left side. The integral drive motor sits below the pump end on the same vertical shaft, with bearings above and below the rotor.SUCTIONINDUCERMOTORDISCHARGEIMPELLERVOLUTEBEARINGSHAFTCRYO PUMP / LH2 @ 20 K

04 / 20 K / LH2

Performance optimization

Quantifies and recovers losses on systems already in service. Engineering changes typically pay back inside 12 to 18 months.

  • 01Boil-off loss analysis
  • 02Heat leak assessment
  • 03Insulation performance (vacuum jacket, MLI, perlite)
  • 04Heat exchanger effectiveness
  • 05Pump and compressor performance
  • 06Procedure review

TOOLS: Aspen HYSYS, REFPROP, performance curve analysis

Deliverable: Optimization report with specific engineering changes, projected savings, phased implementation path.

Best fit: Facilities with unexplained losses, aging systems, capacity bottlenecks, post-expansion performance issues at LNG, industrial gas, and pharma cryo storage.

$25,000fixed scope / 3 to 4 weeks

Download the service detail sheet (PDF)

05 / 4 K / LHe / Terminus

Five fixed-scope services. Price and timeline in writing before any work begins.

  • 01

    Initial Technical Screen

    Low-friction first engagement before committing to a full audit, optimization, or feasibility study. One-week review of a specific issue, system, P&ID, or operating concern.

    $3,5001 week

    • Review of one specific issue, system, P&ID, or operating concern
    • Scope and deliverable agreed in writing before work begins
    • Written findings with a clear recommendation
    • Fee credits 100% toward a larger fixed-scope engagement on conversion within 60 days

    Deliverable: Written findings on the specific issue reviewed, with a recommendation and, where it fits, the defined scope for a larger engagement.

    Best fit: Operators who want a concrete read on a specific concern before committing to a full engagement.

  • 02

    Hydrogen Safety Audit

    Closes code gaps before a regulator, an insurer, or an incident does. Independent code-compliance and risk review of hydrogen systems or facilities.

    $15,0002 to 3 weeks

    Service detail sheet (PDF)
    • Pressure relief sizing
    • Emergency shutoff systems
    • Ventilation and gas detection
    • Piping integrity
    • Operating procedures

    BASIS: NFPA 2, IFC Chapter 58, DOE Hydrogen Safety Guidelines, OSHA PSM where applicable

    Deliverable: Written report, findings ranked by risk severity, gaps against code, prioritized recommendation list.

    Best fit: Facilities without recent independent review, post-incident reviews, pre-regulatory audit prep, hydrogen fueling operations, electrolyzer-integrated facilities.

  • 03

    Cryogenic System Optimization

    Quantifies and recovers losses on systems already in service. Engineering changes typically pay back inside 12 to 18 months.

    $25,0003 to 4 weeks

    Service detail sheet (PDF)
    • Boil-off loss analysis
    • Heat leak assessment
    • Insulation performance (vacuum jacket, MLI, perlite)
    • Heat exchanger effectiveness
    • Pump and compressor performance
    • Procedure review

    BASIS: Aspen HYSYS, REFPROP, performance curve analysis

    Deliverable: Optimization report with specific engineering changes, projected savings, phased implementation path.

    Best fit: Facilities with unexplained losses, aging systems, capacity bottlenecks, post-expansion performance issues at LNG, industrial gas, and pharma cryo storage.

  • 04

    Aerospace Cryogenic Ground Systems

    Reduces ground system schedule risk on test campaigns and launch windows.

    $25,000 to $40,000scoped to the campaign / 3 to 5 weeks

    • LOX and LH2 storage and transfer system design
    • Vacuum-jacketed piping
    • Vent stack and flare design
    • Chilldown analysis
    • Process safety review of fueling sequences

    Deliverable: System review report with safety findings, performance recommendations, design or procedural changes.

    Best fit: Rocket manufacturers, launch site operators, aerospace test facilities.

  • 05

    CO2 Feasibility Study

    Independent go or no-go before you commit to FEED.

    $20,0003 to 4 weeks

    Service detail sheet (PDF)
    • Source characterization
    • Technology screening (amine, membrane, adsorption, cryogenic)
    • Equipment sizing
    • CAPEX and OPEX estimation
    • Economic model (IRR, payback, $/ton abatement)

    BASIS: Aspen HYSYS and Aspen Plus where the screened technology requires it

    Deliverable: Feasibility report with go/no-go recommendation and a defined next-phase scope.

    Best fit: Industrial facilities with emissions targets, companies pursuing 45Q tax credits, CCU startups needing independent validation.

Advisory and ongoing project support, $175/hr.

All fixed-scope engagements exclude PE-stamped drawings, field installation, procurement, construction management, and regulatory submission unless separately scoped.

Credentials

EIT, California Board of Professional Engineers. B.S. Chemical Engineering, UC Davis. US Citizen.

Design background: cryogenic pump and skid systems under ASME and API standards, turboexpander and skid design, hydrogen electrolyzer integration and CO2 purification.

Read by the industry

Technical post on LN2 joint heat leak and iceball formation, published May 2026. 157,200+ impressions and 114,000+ unique members reached. Top viewer companies: Nikkiso Clean Energy, Airgas, Air Liquide.

Current engagements

  • Fortune 500 pharmaceutical operator, cryogenic storage
  • Industrial cryogenic facility
  • Consumer products manufacturer

Client names held confidential. References on request after NDA.

Process

How it works

Most reviews begin remotely using drawings, operating data, and interviews. Site visits added when field verification is required.

01

Discovery call, 30 minutes

Send a PFD, P&ID, or a specific operating concern. One call confirms whether it fits a fixed-scope review.

02

NDA and fixed-scope written proposal

NDA first, then document review. The proposal states price, timeline, and deliverable in writing before any work begins.

03

Analysis, written report, final review call

Technical review and analysis, a written report, and a final call to walk findings and recommendations.

Questions

FAQ

How long does an engagement take?

Initial Technical Screen: 1 week. Hydrogen Safety Audit: 2 to 3 weeks. Cryogenic System Optimization: 3 to 4 weeks. Aerospace Cryogenic Ground Systems: 3 to 5 weeks. CO2 Feasibility Study: 3 to 4 weeks. The clock starts at kickoff, after the NDA and document handoff, not at first contact.

Are revisions included?

One review pass on the report is included: you read it, we walk it on the final call, and I incorporate corrections and clarifications. Further revision rounds or scope additions are quoted separately before any work continues.

What inputs do you need from us?

PFDs, P&IDs, equipment datasheets, operating procedures, historical operating data, incident reports, utility data, and site constraints. Not every engagement needs all of them; the proposal lists exactly what the scope requires.

How is our data handled?

NDA-friendly, and most clients start there. Client information, drawings, operating data, and project details are treated as confidential. Drawings can be sent after the NDA is in place.

Are the reports PE-stamped?

Reports and analysis from this practice are independent engineering work products for the client's internal evaluation and decision-making. They are not PE-stamped drawings and are not a substitute for professional engineering judgement. Findings are to be verified by a qualified engineer before use in final design, construction, or regulatory submission. All fixed-scope engagements exclude PE-stamped drawings, field installation, procurement, construction management, and regulatory submission unless separately scoped. PE-stamped drawings and AHJ submission are coordinated with a licensed PE where required. Work is provided as is. Liability is limited to fees paid.

06 / Contact

Book a consultation.

A 30-minute discovery call confirms whether the system fits a fixed-scope review. NDA first, then a written proposal with price, timeline, and deliverable.

Book the call
i@ismailzeitoun.com
+1 (949) 529-8419

Or describe the system in writing

You get a reply within one business day, and a fixed-scope written proposal follows the discovery call.

No drawings needed yet. PFDs, P&IDs, and operating data can be sent after an NDA is in place.

Independent engineering analysis. Not PE-stamped. Verify with a qualified engineer before final design. Provided as is; liability limited to fees paid.