Methylamines (MMA, DMA, TMA) from methanol and ammonia

Methanol and ammonia react over amorphous silica-alumina at 350-440 C to an equilibrium mix of mono-, di- and trimethylamine; ammonia, TMA, surplus MMA and methanol are recycled, and a five-column train (ammonia, TMA extractive distillation with water, dehydration, MMA/DMA, methanol recovery) gives 8 t/h of anhydrous amines (concept design, gate-to-gate LCI).

Calculation maturity: BalancedEvidence outdatedDesign maturity: Concept (research)Not independently reviewedNitrogen organicsReport a problem with this process
Research outputNot engineering advice and not an approved design: do not use it for construction, operation or safety decisions. What this means

Concept design covering issues #171 (methylamine) and #166 (dimethylamine) as one co-production plant. Methanol (methanol-1) and ammonia (ammonia-1) are boundary feeds. The converter is modelled as an ideal-gas chemical equilibrium (no kinetics); separations are sharp splits; duties are concept estimates. Preliminary gate-to-gate LCI with unmapped background datasets. See DESIGN.md.

Capacity
8 t/h anhydrous methylamines (2.0 MMA + 4.4 DMA + 1.6 TMA), ASSUMED
Operation
8,000 h/a
Engineering gates
Concept and feasibility (no results yet)
Design basis and assumptions (7)
  • Converter: adiabatic fixed bed of amorphous silica-alumina, inlet 625 K / 2200 kPa(a), outlet 713 K / 2000 kPa(a); window 350-450 C and 150-350 psig from US 3,387,032 A and US 4,283,254 A (D-004).
  • Converter outlet at the ideal-gas equilibrium of the three methylations at the outlet temperature, ATcT/CRC/Poling data; a model basis, not kinetics (D-005). Checked against the published equilibrium at 400 C, N/C 2.0 (US 4,485,261 A): TMA under-predicted (0.37 vs 0.43 among the amines on a weight basis, D-005). The source does not state the basis of its equilibrium ratios; weight is ASSUMED from its weight-basis prior-art ratios (on a mole basis the miss would be about 16 points, D-005).
  • Converter feed N/C ratio 2.0 (mol N / mol methyl carbon), ASSUMED inside the ranges of US 7,435,855 B2 and US 4,485,261 A (D-004).
  • All ammonia and the TMA recycle return as the ammonia column distillate; MMA beyond the product rate and unconverted methanol are recycled (D-007).
  • Columns are sharp splits; reflux ratios, pressures, extraction water ratio 1 kg/kg and a minimum boil-up of 0.1 kmol/kmol bottoms are ASSUMED (D-008).
  • No by-products (dimethyl ether, higher amines, CO/H2 from decomposition, coke), no inert purge and no caustic dosing modelled (D-005, D-008).
  • Duties are concept estimates (ideal gas + heats of vaporisation, no mixing enthalpy), +/-30 % at best; no heat integration beyond the feed/effluent exchanger (D-006, D-009).

From process/design-basis.yaml.

Engineering model

Loading the drawing…
Drawing of the process (preview)Open the engineering model

The interactive model (drawings, streams, 3D) is made for larger screens.

Snapshot of c3ab348, cheme-as-code 1.6.0.

What goes in and out

In

  • MethanolFeedstockfeed:MEOH: methanol (e.g. methanol-1), 2.48 kg/kg DMA (unallocated; MMA and TMA are co-products)
  • AmmoniaFeedstockfeed:NH3F: liquid ammonia (e.g. ammonia-1), 0.732 kg/kg DMA (unallocated)

Out

Utilities: Steam (MP steam 1500 kPa(a): feed vaporiser, C-101 and C-103 reboilers), Steam (LP steam 450 kPa(a): C-102, C-104, C-105 reboilers), Electricity (Feed and recycle pumps (ASSUMED electric drives)), Cooling water (25/35 C (ASSUMED))

Show in the process graph

Reactions

IdAs writtenReactionOther processes
DMA_SYNCH3OH + MMA ⇌ DMA + H2OCH4O+CH5NC2H7N+H2O
MMA_SYNCH3OH + NH3 ⇌ MMA + H2OCH4O+NH3CH5N+H2O
TMA_SYNCH3OH + DMA ⇌ TMA + H2OCH4O+C2H7NC3H9N+H2O

Each reaction's page has the conversion, heat of reaction, catalyst and sources this process states, next to those of other processes with the same reaction. All reactions

Life cycle assessment

Footprint not publishedThe process changed since the LCA was last run; its values return once it is run again. Method, functional unit and inventory are below.
Method and data
Goal
Preliminary gate-to-gate life cycle inventory of anhydrous dimethylamine co-produced with monomethylamine and trimethylamine from methanol and ammonia (amorphous silica-alumina, equilibrium converter with recycle, five-column separation) at concept stage, per kg of DMA: raw materials, utilities by level, co-products and wastewater from the balanced flowsheet. The backgrounds are gaps to be linked later; no impact result is claimed (D-014).
Functional unit
1 kg Anhydrous dimethylamine (1 kg dimethylamine)
Boundary
cradle-to-gate
Allocation
mass
Characterisation
Factors kept with the process · GWP100
Data quality
No factors
Result
partial screening carbon footprint · 7 data gaps

Inventory per 1 kg Anhydrous dimethylamine (10 flows)

FlowPhaseDirectionQuantityUnitProvenance
Methanol (boundary feed; made by methanol-1)operationinput1.365kggiven
Liquid ammonia (boundary feed; made by ammonia-1)operationinput0.4025kggiven
Electric poweroperationinput0.00325kWhassumed
MP steam 1500 kPa(a)operationinput3.472kWhassumed
LP steam 450 kPa(a)operationinput1.005kWhassumed
Anhydrous monomethylamine to storageoperationoutput0.4545kgcalculated
Anhydrous dimethylamine to storageoperationoutput1kgassumed
Anhydrous trimethylamine to storageoperationoutput0.3636kgassumed
Process wastewater to biological treatmentoperationoutput0.7675kgcalculated
Cooling water returnoperationoutput4.782kWhassumed

Computed by ChemE-as-Code from lca/README.md, lca/dataset.yaml, lca/factors.yaml, lca/gaps.csv, lca/inventory.csv, lca/lca.yaml, lca/mappings.yaml, lca/results.csv, lca/results.md.

In the open LCI database (cheme-as-code-atlas-preview-c3ab348) as Methylamine (monomethylamine), Anhydrous monomethylamine to storage Preliminary; Anhydrous dimethylamine to storage Preliminary; Anhydrous trimethylamine to storage Preliminary.

Download it for Brightway, openLCA and other tools.

In the LCI database: system model, datasets and KPIs against the benchmarks

In the LCI database

Status
Preliminary 1 unmapped exchange. Some exchanges have no background mapping yet: they are exported unlinked and count no burden, so the inventory is incomplete.
System model
attributional, cut-off (methodology 1.1.0)
Allocation
mass (deviation, from study) · product:DMAP 55 %, product:MMAP 25 %, product:TMAP 20 %
Allocation findings
none
Change report
Not available: this build has no change report against an earlier release.
Dataset pages
Anhydrous dimethylamine to storage Preliminary · Methylamine (monomethylamine), Anhydrous monomethylamine to storage Preliminary · Anhydrous trimethylamine to storage Preliminary

KPI benchmark positions: not available (no benchmarked KPI for this process's datasets).

Maturity and review

Design maturity Concept (claimed): An idea or first flowsheet; numbers are rough. Main products and feeds are listed under chemistry with their chemicals registry entries (issue #251).

Calculation maturity, from the checked evidenceBalancedsupports the design maturity Screening

The checked evidence supports the level Balanced: A balanced conceptual flowsheet: the process rules pass, every mass and component balance closes within its tolerance, and every reactor and separator rests on sourced data.

Outdated evidenceprocess/flowsheet.yaml, process/materials.yaml, process/simulation.yaml changed after the report was written (2026-10-28 15:32 UTC). The levels below are the report's and may no longer hold until cheme maturity --write runs again.
The four levels: 2 of 4 achieved (Sourced ✓, Balanced ✓, Predictive ✕, Engineering ✕)

  1. Sourced

    Achieved

    A sourced process description: the flowsheet and design basis are valid, and every feed is given with a source.

    Every required criterion of this level and of the levels below passes. What Sourced requires

    Criteria and evidence (3 of 3 pass)

  2. Balanced

    Achieved

    A balanced conceptual flowsheet: the process rules pass, every mass and component balance closes within its tolerance, and every reactor and separator rests on sourced data.

    Every required criterion of this level and of the levels below passes. What Balanced requires

    Criteria and evidence (4 of 5 pass)
    • Passno error in the process rules (units, ports, reactions, reactors)

      process/flowsheet.yaml · cheme.maturity-balanced-process-rules

    • Passevery block and step balance evaluable in every case (mass and components or elements)

      process/flowsheet.yaml · cheme.maturity-balanced-balances-evaluable

    • Passevery balance closes within the flowsheet's explicit tolerance

      process/flowsheet.yaml · cheme.maturity-balanced-balances-closed

    • Passevery reactor and separator rests on a sourced model or sourced specified values

      process/flowsheet.yaml · cheme.maturity-balanced-model-basis

    • Missingenergy balances of the blocks and steps (stream enthalpies against energy streams) (reported, not required)

      no balance evaluable: stream enthalpies or duties missing

      To resolve: cheme process props --fill writes the enthalpies

      process/flowsheet.yaml · cheme.maturity-balanced-energy-closure

  3. Predictive

    Not yet achieved

    A converged predictive simulation, current with its inputs, with every reactor and separator predicted by a model, the property methods inside their benchmarked ranges and the energy balance closed.

    10 required criteria fail or are missing: process/simulation.yaml translates into a simulator model for every case, a run record for every case, every run record is current: simulated from the inputs as they are (fingerprints) and 7 more. What Predictive requires

    Criteria and evidence (4 of 14 pass)
    • Failprocess/simulation.yaml translates into a simulator model for every case

      refused for case design: P101 (class ProcessStep) maps to no unit operation

      To resolve: run cheme process simulate --check

      process/flowsheet.yaml:150 · cheme.maturity-predictive-simulation-spec

    • Missinga run record for every case

      no run recorded in process/simulation-run.json

      To resolve: run cheme process simulate --fill (it records the run)

      process/simulation-run.json · cheme.maturity-predictive-run-record

    • Missingevery run record is current: simulated from the inputs as they are (fingerprints)

      no run recorded in process/simulation-run.json

      To resolve: run cheme process simulate --fill (it records the run)

      process/simulation-run.json · cheme.maturity-predictive-current

    • Missingevery recorded run converged without errors

      no run recorded in process/simulation-run.json

      To resolve: run cheme process simulate --fill (it records the run)

      process/simulation-run.json · cheme.maturity-predictive-converged

    • Missingsimulator, simulator version, property package and core version recorded

      no run recorded in process/simulation-run.json

      To resolve: run cheme process simulate --fill (it records the run)

      process/simulation-run.json · cheme.maturity-predictive-solver

    • Passevery step simulated: none excluded and left at specified values

      process/simulation.yaml · cheme.maturity-predictive-coverage

    • Passphysical validity: the balances of the simulated flowsheet close within tolerance

      process/flowsheet.yaml · cheme.maturity-predictive-balances

    • Passevery reactor and separator predicted by a model: specified splits, conversions and stream values cap the level at balanced

      process/simulation.yaml · cheme.maturity-predictive-model-basis

    • Missingthe property package is supported and recommended by a recorded method selection (or a recorded substitution)

      no method_selection recorded for property package 'Peng-Robinson (PR)'

      To resolve: record method_selection.facts (thermodynamic-model-selection) so the package is checked against the recommendation

      process/simulation.yaml:7 · cheme.maturity-predictive-property-package

    • Missingthe property methods are used inside their declared regimes

      no run recorded in process/simulation-run.json

      To resolve: run cheme process simulate --fill (the regime is checked on its streams)

      process/simulation.yaml · cheme.maturity-predictive-property-regime

    • Passevery stream with calculated properties lies inside the benchmarked claim of the process's property package

      no stream has calculated properties

      process/flowsheet.yaml · cheme.maturity-predictive-stream-properties

    • Missingthe simulated plant's enthalpy flows close with its heat and work within tolerance

      no run recorded

      To resolve: run cheme process simulate --fill (it records the energy audit)

      process/simulation-run.json · cheme.maturity-predictive-energy-closure

    • Missingno exchanger temperature cross or approach below its minimum, every utility level can serve its duty

      no run recorded

      To resolve: run cheme process simulate --fill (it records the energy audit)

      process/simulation-run.json · cheme.maturity-predictive-exchangers

    • Missingthe simulated reaction heat agrees with the formation enthalpies declared in process/materials.yaml

      no energy audit recorded

      To resolve: run cheme process simulate --fill (it records the energy audit)

      process/simulation-run.json · cheme.maturity-predictive-formation-data

  4. Engineering

    Not yet achieved

    A preliminary/basic engineering package (equipment list, datasheets, P&IDs, process links) on top of the levels below. Not detailed engineering, and not a review.

    2 required criteria fail or are missing: a valid, final datasheet for every equipment item, P&IDs without errors. What Engineering requires

    Criteria and evidence (2 of 5 pass)
    • Passan equipment list

      equipment/equipment-list.yaml · cheme.maturity-engineering-equipment-list

    • Faila valid, final datasheet for every equipment item

      no datasheet in equipment/datasheets/ for V-101, P-101, E-101, E-102, R-101, E-103, C-101, C-102, C-103, C-104 and 1 more

      To resolve: cheme datasheets fill, then complete them

      equipment/datasheets/ · cheme.maturity-engineering-datasheets

    • MissingP&IDs without errors

      To resolve: draft the P&IDs (cheme sheet new)

      pid/ · cheme.maturity-engineering-pid

    • Passevery flowsheet link resolves against the lists and the sheets

      process/flowsheet.yaml · cheme.maturity-engineering-process-links

    • Unsupporteddatasheet duties and sizes cross-checked against the current simulation (reported, not required)

      not cross-checked by this command

      equipment/datasheets/ · cheme.maturity-engineering-consistency

Artifact completeness

Which deliverables exist. They never raise a calculation maturity level: a drawing from unchecked numbers is still unchecked.

  • Drawings: 2 of 2 declared sheets drawn
  • Design basis: present
  • Equipment list: present
  • Datasheets: none
  • Line list: present
  • Instrument list: present
  • Layout: none
  • Cost estimate: present
  • LCA files: 5 files
  • Simulation run record: none

Independent review

Not independently reviewed

No independent engineering review yet. Automated checks passing is not a review.

Set by people only. Reaching a calculation maturity level or passing automated checks is not an independent review or an approval.

Assumptions, limitations and checked cases
Operating caseBalances closeSimulated
design (default)
Design case: net 2.0 t/h MMA, 4.4 t/h DMA, 1.6 t/h TMA (D-002), converter feed N/C 2.0, outlet 713 K (D-004)
yesno

The levels hold for these cases only; the criteria name the property and model ranges they were checked against.

Design basis assumptions (7)
  • Converter: adiabatic fixed bed of amorphous silica-alumina, inlet 625 K / 2200 kPa(a), outlet 713 K / 2000 kPa(a); window 350-450 C and 150-350 psig from US 3,387,032 A and US 4,283,254 A (D-004).
  • Converter outlet at the ideal-gas equilibrium of the three methylations at the outlet temperature, ATcT/CRC/Poling data; a model basis, not kinetics (D-005). Checked against the published equilibrium at 400 C, N/C 2.0 (US 4,485,261 A): TMA under-predicted (0.37 vs 0.43 among the amines on a weight basis, D-005). The source does not state the basis of its equilibrium ratios; weight is ASSUMED from its weight-basis prior-art ratios (on a mole basis the miss would be about 16 points, D-005).
  • Converter feed N/C ratio 2.0 (mol N / mol methyl carbon), ASSUMED inside the ranges of US 7,435,855 B2 and US 4,485,261 A (D-004).
  • All ammonia and the TMA recycle return as the ammonia column distillate; MMA beyond the product rate and unconverted methanol are recycled (D-007).
  • Columns are sharp splits; reflux ratios, pressures, extraction water ratio 1 kg/kg and a minimum boil-up of 0.1 kmol/kmol bottoms are ASSUMED (D-008).
  • No by-products (dimethyl ether, higher amines, CO/H2 from decomposition, coke), no inert purge and no caustic dosing modelled (D-005, D-008).
  • Duties are concept estimates (ideal gas + heats of vaporisation, no mixing enthalpy), +/-30 % at best; no heat integration beyond the feed/effluent exchanger (D-006, D-009).
Values marked as assumed (96)
  • process/flowsheet.yaml: 96
Limitations (11)
  • R101: equilibrium limit: no kinetics, the approach is not predicted
  • R101: in the simulation, K comes from DWSIM's own formation data
  • engineering.consistency: not cross-checked by this command
  • engineering: mechanical design to a code (wall thickness, nozzle loads) is not checked
  • engineering: materials and corrosion selection is not checked
  • engineering: relief and blowdown sizing is not checked
  • engineering: control and dynamic behaviour is not checked
  • simulation-route: no electrolytes: the worker exposes no electrolyte property package
  • simulation-route: no pseudocomponents: every compound must be in DWSIM's database (by CAS number or the name in simulation.yaml); no assay characterisation
  • simulation-route: no solid phase: simulation.yaml has no solid compounds or solid-phase input, and none is tested
  • simulation-route: binary interaction parameters: DWSIM's own database (not inspected by cheme-as-code) unless simulation.yaml interaction_parameters set them (equation-of-state packages only)
Where the evidence comes from
Report
Maturity report (JSON) · checks/maturity.json in the repository (the parts that may be published)
Checked
2026-10-28 15:32 UTC
ChemE-as-Code
0.8.0
Inputs at
fdea259
Input fingerprints
8 files

"Outdated" compares these files only: core does not fingerprint drawings, datasheets and the other engineering files.

  • equipment/equipment-list.yaml 4c293dbc4697
  • plant.yaml 688200e38e42
  • process/catalysts.yaml 47d20a9a7339
  • process/design-basis.yaml 3027ad0744b5
  • process/flowsheet.yaml 4312e11cd10echanged since
  • process/materials.yaml a759ffa7733achanged since
  • process/reactions.yaml 35282c5633c6
  • process/simulation.yaml 8712eec55495changed since
Design basis
process/design-basis.yaml
Method
How ChemE-as-Code checks the levels (requirement by requirement)

Open items

0 open items · 0 closed

New action itemNew engineering holdNew technical queryNew design changeAll issues

Sources

Engineering project
Methylamines (MMA, DMA, TMA) · cheme-as-code>=0.8
Library version
c3ab348 (process last changed in c3ab348)
Drawings rendered by
cheme 1.6.0 (pyDEXPI 2.1.0)
Data
Catalog record (JSON) · CC-BY-4.0
Files
View the files on GitHub · change history and authors

References

How to cite

For the data, cite the Process Atlas paper; for the platform that builds and checks it, the ChemE-as-Code paper.

Schweidtmann, A. M. & Weber, J. M. (2026, in preparation). Process Atlas: an open, git-native, reproducible library and life cycle inventory of chemical processes (working title).

For this process: "Methylamines (MMA, DMA, TMA) from methanol and ammonia", ChemE-as-Code process library, version c3ab348.

BibTeX
@unpublished{schweidtmann_process_atlas,
  author = {Schweidtmann, Artur M. and Weber, Jana M.},
  title = {{Process Atlas: an open, git-native, reproducible library and life cycle inventory of chemical processes (working title)}},
  year = {2026},
  url = {https://atlas.cheme-as-code.org},
  note = {in preparation}
}

Schweidtmann, A. M. (2026, in preparation). ChemE-as-Code: An Open-Source Platform for AI-Accelerated Chemical Process Engineering (working title).

BibTeX
@unpublished{schweidtmann_cheme_as_code,
  author = {Schweidtmann, Artur M.},
  title = {{ChemE-as-Code: An Open-Source Platform for AI-Accelerated Chemical Process Engineering (working title)}},
  year = {2026},
  url = {https://cheme-as-code.org},
  note = {in preparation}
}