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Ethanol-to-Olefins (ETO) Front-End Unit

Screening model for an ethanol drying + vaporisation + catalytic dehydration unit producing light olefins for downstream jet-fuel synthesis, including mass balance, utility demands, plot space, and scaled CAPEX/OPEX with levelized cost.

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alexi

I do low-carbon energy stuff for 10 years & build things I wish existed.

Inputs

Selects default energy intensity, catalyst productivity proxy (WHSV), and CAPEX reference for screening.

Overall mass yield of light olefins per ethanol feed (wt% of ethanol in). Must be below the stoichiometric maximum for dehydration.

Average annual utilisation of the ETO unit. Used to compute load hours and part-load utility penalty.

min 10 · max 100 · step 1 · %

Wet ethanol feed to the ETO front-end unit on an as-received mass basis (screening approximation).

min 0.1 · max 200 · step 0.1 · t/h

Light olefins product flow

Main product stream to downstream upgrading

…t/h

Annual ethanol need (for olefins conversion)

Ethanol actually consumed to form olefins (excludes offgas/unconverted)

…t/year

Annual olefins production

Main annual output basis for levelized cost

…t/year

Results

Reaction water produced

Water formed by dehydration chemistry (separated downstream)

…t/h

Offgas / other products (mass balance remainder)

Represents unconverted ethanol + side products + losses (lumped)

…t/h

Electricity demand (average at design throughput)

Includes drying, pumps, compression/conditioning (lumped)

…MW

Annual electricity consumption

Scaled by capacity factor (load hours)

…MWh/year

Heat demand (average at design throughput)

Primarily vaporisation + reactor duty (lumped)

…MWth

Annual heat consumption

Scaled by capacity factor (load hours)

…MWhth/year

Number of parallel trains

Based on a maximum practical train throughput

…count

Plot space requirement

Includes integration and access margin

…m2

Equipment purchase cost (EPC, purchase only)

Excludes installation, indirects, and owner’s costs

…EUR

Total installed CAPEX (TIC)

Scaled with capacity; technology-dependent reference point

…EUR

Fixed O&M cost

Labor + maintenance + overhead (fraction of installed CAPEX)

…EUR/year

Annualized catalyst replacement cost

Straight-line annualization over replacement interval

…EUR/year

Levelized Cost Indicators

Levelized cost of olefins (energy basis, LHV)

Uses a representative olefins LHV to express EUR/MWh-LHV

…EUR/MWh

Levelized cost of olefins (gate cost)

Levelized cost per tonne of olefins produced

…EUR/t

Amortization period used in the capital recovery factor.

years

min 5 · max 40 · step 1 · years

Optional: include ethanol feedstock cost in total annual cost. Set to 0 for a tolling/processing-only view.

EUR/t

Used in CRF for annualizing CAPEX.

ratio

Grid or contracted electricity price used to value annual electricity consumption.

EUR/MWh

Price for steam/thermal energy (e.g., natural gas boiler, waste heat credit, or steam import).

EUR/MWhth

About

Calculator context

Introduction

This calculator provides a pre-feasibility (screening-stage) model for an Ethanol-to-Olefins (ETO) front-end conversion asset covering ethanol drying, vaporisation, catalytic dehydration, water separation, olefin conditioning, and transfer to downstream processing (e.g., oligomerization/hydrogenation for ATJ / e-kerosene). It is a global, generic estimator intended for early concept comparison, using mass-balance stoichiometry, simple equipment sizing heuristics, and standard cost-scaling methods consistent with IEA/IRENA/NREL-style techno-economic modelling.

Methodology

The model is built on an hourly design basis with annualization using capacity factor. Core steps:

  • Operating time

    • load_hours = hours_per_year * capacity_factor * 0.01
    • Part-load penalty for utilities: load_penalty = clamp(1 + penalty_coeff*(1 - capacity_factor*0.01), 1, max_penalty)

  • Mass balance (overall ETO lumped yield)

    • Olefins production: olefins_tph = ethanol_inlet_capacity_tph * (ethanol_to_olefins_yield_pct*0.01)
    • Stoichiometric water from dehydration (consistent with ethanol → olefin + H2O): reaction_water_tph = olefins_tph * water_per_olefin_mass_ratio
    • Ethanol consumed to form olefins: ethanol_consumed_for_olefins_tph = olefins_tph * ethanol_per_olefin_mass_ratio
    • “Offgas/other” is the remaining mass to close the balance: offgas_tph = ethanol_inlet_capacity_tph - ethanol_consumed_for_olefins_tph

  • Utilities (energy intensity with part-load penalty)

    • effective_consumption = specific_consumption * load_penalty (electricity basis)
    • electricity_power_kw = ethanol_inlet_capacity_tph * effective_consumption; annual energy from electricity_power_kw * load_hours
    • Heat demand uses the same structure with a technology-specific heat intensity constant.

  • Costing and finance (standard chemical scaling; see e.g., Peters & Timmerhaus approach used in many NREL/IEA TEAs)

    • CRF = (r*(1+r)^n)/((1+r)^n-1)
    • specific_capex_scaled = clamp(capex_ref * (capacity/capacity_ref)^scale_exp, min, max)
    • annualized_capex = capex_total * CRF; total_annual_cost sums annualized CAPEX, fixed O&M, utilities, and catalyst replacement
    • Levelized cost reported as EUR/t olefins and EUR/MWh-LHV olefins.

Applications

  • Project developer (screening): compare dehydration technology options (alumina vs zeolite) for a target ethanol throughput and estimate utility loads and unit count.
  • Techno-economic analyst (concept selection): generate first-pass CAPEX/OPEX breakdown and levelized processing cost for integration into an ATJ / e-kerosene value chain model.
  • Site/integration engineer (layout): estimate plot space and parallel-train count to check brownfield fit and tie-in complexity assumptions.

Model

106 variables — inputs, calculations and outputs, with their dependencies.

106 variables shown of 106
VariableValueUnitDepends on
10t/h—
95%—
1——
55%—
70EUR/MWh—
25EUR/MWhth—
0EUR/t—
0.08ratio—
20years—
VariableFormulaUnitDepends on
if(((<=0)+(<0)+(>100)+(<1)+(>3)+(<0)+(>)+(<0)+(<0)+(<0)+(<0)+(>1)+(<=0))>0,1,0)bool
t/h
*0.01—
**0.01h/year
clamp(+*(-*0.01),,)—
if(==1,,if(==2,,))kWh/t
*kWh/t
if(==1,,if(==2,,))kWhth/t
*kWhth/t
*0.01—
*t/h
*t/year
*t/year
*t/year
*t/year
*kW
*kWth
*t/h
*t/h
/max(max(,),)t/h
if(==1,,if(==2,,))t/h/m3
/max(,)m3
*kg
+*(/max(,))^m2
if(==1,,if(==2,,))EUR/(t/h)
*(/max(,))^(-1)EUR/(t/h)
clamp(,,)EUR/(t/h)
*(/max(,))^—
clamp(,,)—
*EUR
*EUR/year
*EUR/year
*EUR/year
(*(1+)^)/max(((1+)^-1),)—
*EUR/year
**/max(,)MWh/year
VariableFormulaUnitDepends on
*t/h
*t/h
-t/h
t/year
*t/year
/max(,)MW
*/max(,)MWh/year
/max(,)MWth
*/max(,)MWhth/year
ceil(/max(,))count
**m2
*EUR
/max(,)EUR
*EUR/year
/max(,)EUR/year
+++++EUR/year
/max(,)EUR/t
/max(,)EUR/MWh

Assumptions

43 assumptions used in the calculations

  • Prevents divide-by-zero and non-finite results during scaling and annualization.

    Market range Not applicable

    0.000001
    Numerical stability constant for division guards in the DSL.

  • Standard conversion from capacity factor to annual operating hours.

    Market range 8760 h/year

    8760h/year
    Calendar-year hours.

  • Avoids inline numeric literals in DSL expressions.

    Market range Not applicable

    1
    Model constant.

  • Represents reduced efficiency at low utilisation (start/stop, fixed losses). Used for screening only.

    0.25
    Generic part-load penalty coefficient for balance-of-plant utilities.

  • Prevents unrealistically large penalties at low utilisation for early-stage models.

    1.3
    Screening cap on part-load penalty multiplier.

  • Constrains user input to physically plausible mass yield for dehydration-dominated pathways.

    Market range Up to ~60.9%

    60.87%
    Stoichiometric mass yield ceiling from ethanol dehydration to ethylene (28/46).

  • Used to infer ethanol consumed to form olefins to close the mass balance and estimate offgas remainder.

    Market range 1.64 (stoichiometric for dehydration basis)

    1.642857t_ethanol/t_olefins
    Stoichiometric inverse of maximum mass yield: 46/28.

  • Allows explicit reporting of reaction water for separation and downstream water handling.

    Market range 0.64 (stoichiometric)

    0.642857t_water/t_olefins
    Dehydration water formed per olefin mass: 18/28.

  • Provides optional linkage to the e-fuels scaffold by estimating upstream CO2 demand embodied in ethanol throughput (outside ETO unit scope).

    Market range 1.91 (stoichiometric)

    1.913043t_CO2/t_ethanol
    Implied upstream requirement if ethanol is produced via CO2 hydrogenation: 2CO2 + 6H2 → C2H5OH + 3H2O (88/46).

  • Supports e-fuels context by estimating upstream green H2 embodied in ethanol throughput (outside ETO unit scope).

    Market range 0.26 (stoichiometric)

    0.26087t_H2/t_ethanol
    Implied upstream requirement for CO2-to-ethanol: 6H2 (12/46).

  • Converts kW to MW and kWh to MWh.

    Market range 1000

    1000kW/MW
    Unit conversion.

  • Captures balance-of-plant electric loads at pre-feasibility level.

    25kWh/t_ethanol
    Screening utility intensity for alumina-based dehydration front-end (drying + compression + auxiliaries lumped).

  • Assumes slightly higher compression/conditioning needs and tighter controls.

    30kWh/t_ethanol
    Screening utility intensity for zeolite-based dehydration option.

  • Intermediate between alumina and zeolite cases.

    28kWh/t_ethanol
    Screening utility intensity for mixed/advanced catalyst system.

  • Represents net heat import after basic heat integration at concept level.

    220kWhth/t_ethanol
    Screening thermal demand (drying/vaporisation/reactor duty lumped) for alumina case.

  • Assumes improved conversion/selectivity and somewhat better heat integration potential.

    200kWhth/t_ethanol
    Screening thermal demand for zeolite case.

  • Intermediate between alumina and zeolite cases.

    210kWhth/t_ethanol
    Screening thermal demand for mixed/advanced system.

  • Enforces parallel trains for large capacities to reflect equipment/operability constraints at screening stage.

    25t/h
    Heuristic maximum single-train throughput for modularization.

  • Provides order-of-magnitude plot footprint for layout screening.

    1200m2
    Base plot area per train (includes typical access and spacing).

  • Captures non-linear footprint growth with throughput (larger vessels, more auxiliaries).

    600m2
    Capacity-dependent footprint coefficient.

  • Normalizes the power-law plot scaling to a reasonable mid-size train.

    10t/h
    Reference capacity for plot scaling.

  • Similar to cost exponents; reflects economies of scale but not linear.

    0.6
    Footprint scaling exponent.

  • Accounts for pipe-racks, access ways, firefighting clearance, and tie-ins at concept stage.

    1.25
    Integration/access margin multiplier.

  • Defines the anchor point for power-law scaling of specific CAPEX and O&M fractions.

    10t/h
    Reference capacity point for CAPEX and O&M scaling.

  • Represents lumped installed cost for drying/vaporisation/reactor/separation/conditioning for early comparisons.

    550000EUR/(t/h)
    Installed CAPEX reference specific cost for alumina ETO front-end (screening).

  • Higher cost case reflecting catalyst system complexity and/or tighter separations.

    650000EUR/(t/h)
    Installed CAPEX reference specific cost for zeolite option (screening).

  • Intermediate CAPEX between alumina and zeolite options.

    600000EUR/(t/h)
    Installed CAPEX reference specific cost for mixed/advanced case (screening).

  • Represents typical chemical process scale economies (cost grows sub-linearly with capacity).

    0.65
    Economy-of-scale exponent for installed CAPEX.

  • Prevents unrealistically low specific costs at large scale in a screening model.

    200000EUR/(t/h)
    Lower clamp on specific installed CAPEX.

  • Prevents unrealistically high specific costs at very small scale in a screening model.

    1400000EUR/(t/h)
    Upper clamp on specific installed CAPEX.

  • Converts purchased equipment cost to total installed cost including piping, E&I, civil, and indirects at screening level.

    2.2
    Installed-to-purchase factor for conceptual CAPEX.

  • Represents labor/maintenance/overhead for continuous chemical process units at concept stage.

    0.045ratio
    Reference fixed O&M fraction of installed CAPEX.

  • Allows slightly lower O&M fraction at larger scale while keeping within clamps.

    -0.05
    Mild scale economy exponent for fixed O&M fraction.

  • Prevents unrealistic staffing/maintenance underestimation at scale.

    0.025ratio
    Lower clamp for fixed O&M fraction.

  • Avoids unrealistic O&M inflation at small scale in screening models.

    0.08ratio
    Upper clamp for fixed O&M fraction.

  • Used only to estimate catalyst inventory for replacement cost and rough reactor sizing metrics.

    2.2t/h/m3_cat
    Screening catalyst productivity proxy (WHSV-like) for sizing catalyst volume.

  • Assumes higher activity/productivity than alumina for sizing purposes.

    3t/h/m3_cat
    Screening catalyst productivity proxy for zeolite case.

  • Intermediate productivity assumption.

    2.6t/h/m3_cat
    Screening catalyst productivity proxy for mixed/advanced case.

  • Converts catalyst volume to mass for replacement cost estimation.

    650kg/m3
    Typical bulk density for shaped catalyst pellets/particles.

  • Order-of-magnitude annualized replacement cost; not intended for procurement accuracy.

    18EUR/kg
    Screening catalyst cost for dehydration catalyst inventory replacement.

  • Represents periodic replacement due to deactivation/coking at industrial operation.

    2years
    Screening catalyst replacement interval.

  • Enables expressing levelized cost on an energy basis for fuel-chain comparisons.

    46.8MJ/kg
    Representative LHV for light olefins mixture (ethylene/propylene range).

  • Converts MJ to MWh for LHV-based normalization.

    Market range 3600

    3600MJ/MWh
    Energy unit conversion.