Hydrogen iodide, anhydrous

Activity Anhydrous hydrogen iodide by gas-phase catalytic synthesis from hydrogen and iodine, GLO: the inventory of 1 kilogram of its reference product, attributional, cut-off.

Calculation maturity: not assessed Design maturity: Concept (research)Not independently reviewedhydrogen-iodide-1:hydrogen-iodide-catalytic-gas-phase:product:hydrogen-iodidePreliminaryReport a problem with this dataset

Research outputAn inventory from a research design at the design maturity its process states, not verified plant data: check its calculation maturity and review status before use. Background activities are referenced by name only; no background data is included. All caveats

What it is

Tier 0 screening estimate per 1 t of anhydrous hydrogen iodide, gate-to-gate. Stoichiometry H2 + I2 -> 2 HI at the iodine conversion of a continuous 100-hour patent run (platinum on alumina, 350 degC), the unconverted feed lost by the Hischier et al. (2005) rule, electricity and heat from core's Tier 0 defaults. The energy defaults are Gendorf 2000 site averages (ASSUMED, older than the 10-year limit for secondary data); valid_until follows the reference year and does not endorse them.

Reference product: 1 kilogram of Hydrogen iodide, anhydrous
Chemical: hydrogen-iodide
CAS: 10034-85-2
Code: hydrogen-iodide-1:hydrogen-iodide-catalytic-gas-phase:product:hydrogen-iodide
Dataset: hydrogen-iodide-catalytic-gas-phase version 0.1.0 · UUID 3adaf26d-f4f9-582f-a8e0-f8a7010ab9e6
Activity UUID: not available (the library assigns none; use the code)
Database: cheme-as-code-atlas-preview-a3c52e4 (version preview-a3c52e4)
Process: Anhydrous hydrogen iodide by gas-phase catalytic synthesis from hydrogen and iodine
Geography: GLO · background inputs with a site rule link at the user's site location (default DE)
Time period: 2008 · valid until 2013
Technology: continuous gas-phase reaction of hydrogen with iodine vapour over a supported metal catalyst (platinum or nickel on alumina in the sources), about 300 to 350 degC near atmospheric pressure; the hydrazine, hydrogen sulfide, red phosphorus and aqueous (hydriodic acid) routes are not modelled · level current
Boundary: gate-to-gate: iodine melting and vaporisation, mixing with hydrogen, catalytic reactor, removal of unreacted iodine, condensation and purification of HI; power and heat from outside
Classification: ISIC Rev.4 2011 (taxonomy/families.yaml (ISIC Rev.4) of the process's families)
System model: attributional, cut-off (docs/system-model.md, methodology 1.1.0)
Allocation: mass, 100 % of the dataset to this product (rule single-output, from default)
one product: nothing to allocate
Rights: CC-BY-4.0

Exchanges per 1 kilogram of Hydrogen iodide, anhydrous

As exported: allocated and scaled to the reference product. Provenance: 3 calculated, 4 assumed. Pedigree scores (1 best, 5 worst): reliability, completeness, temporal correlation, geographical correlation, further technological correlation.

Preliminary1 exchange is not yet linked to a background dataset. It counts no burden, so the inventory is incomplete: do not read a result from it as complete.

Input	Amount	Unit	Provenance	Pedigree	Linked to
Hydrogen feed:hydrogen stoichiometry H2 + I2 -> 2 HI at the sourced efficiency y (US 8 268 284 B2, Example 1)	0.00805	kilogram	calculated	4 4 5 4 4	Atlas (pinned): Hydrogen by natural-gas steam methane reforming with PSA (100 000 Nm3/h, steam export) (Hydrogen product 99.9 mol% to battery limit, GLO) compatible: grade the input names hydrogen only; hydrogen (Hydrogen product 99.9 mol% to battery limit) is taken; unit kilogram; system model cutoff (one database); allocation exergy (deviation); boundary plant gate (pinned): no distribution or losses; the consumer's dataset counts its delivery
Iodine feed:iodine stoichiometry H2 + I2 -> 2 HI at the sourced efficiency y (US 8 268 284 B2, Example 1); compare the stoichiometric 992.1 kg/t: the difference is the once-through iodine loss	1.013	kilogram	calculated	4 4 5 4 4	Atlas (pinned): Iodine from natural iodide brine by chlorine oxidation, air blowing-out and SO2 absorption (1000 t/a) (Iodine flakes (99.8 wt% I2) to packing, GLO) compatible: grade the input names iodine only; iodine (Iodine flakes (99.8 wt% I2) to packing) is taken; unit kilogram; system model cutoff (one database); allocation mass (single-output); boundary plant gate (pinned): no distribution or losses; the consumer's dataset counts its delivery
Electricity feed:electricity cheme tier-defaults 1.0.0: electricity [ASSUMED]: 1.2 MJ (0.333 kWh) per kg of product, attributed to the Gendorf (2000) site average that the ecoinvent v2-era chemicals proxies used. ASSUMED, not read in either source: Hischier et al. 2005 (p. 61) names the Gendorf (2000) average as the default but prints no value, and the number could not be confirmed in an open copy of Althaus et al. 2007 (ecoinvent report No. 8). Dated: newer ecoinvent proxies rest on later Gendorf reports, so this value may be low for a present-day process electricity	0.3333	kilowatt hour	assumed	4 5 5 4 5	market for electricity, medium voltage (electricity, medium voltage, DE, site location) in your background (default ecoinvent-3.11-cutoff)
Heat from fossil fuel (iodine melting, vaporisation, preheating, distillation) feed:heat cheme tier-defaults 1.0.0: heat [ASSUMED]: 2.0 MJ (0.556 kWh) of heat per kg of product, generated from fossil fuel (the carrier is a heat flow, not a fuel input), attributed to the Gendorf (2000) site average that the ecoinvent v2-era chemicals proxies used. ASSUMED, not read in either source (see electricity); dated, and possibly low against newer ecoinvent proxies heat	0.5556	kilowatt hour	assumed	4 5 5 4 5	Atlas: heat from natural gas, industrial furnace, per kWh (Atlas unit proxy) (heat from natural gas, by energy, GLO)
Iodine, unconverted, to wastewater treatment output:iodine-loss cheme tier-defaults 1.0.0: loss-water: Hischier et al. 2005, section 2.3: the water emissions are the difference between the input materials and the air emissions (here: the unconverted iodine less its air share). Routed to wastewater treatment (a technosphere output) as the library's cut-off model puts treatment without recovery in the producer's system; in practice the iodine is recovered (US 11 554 956 B2), see system_boundary	0.01925	kilogram	assumed	4 5 5 5 4	unlinked unlinked, no technosphere mapping: no mapping (no chemical slug or factor id); add it to lci/mappings.yaml technosphere or to the process's lca/mappings.yaml exchanges

Elementary flows

Flow	Direction	Compartment	Amount	Unit	Provenance	Pedigree
Hydrogen no biosphere3 UUID: linked by name and compartment	emission	air	1.69e-4	kilogram	calculated	4 4 5 4 4
Iodine 446d8fe4-fde6-4640-bc23-f04a663bbc04	emission	air	0.002027	kilogram	assumed	4 5 5 5 4

Where these numbers come from: each exchange names its source above; the dataset is processes/hydrogen-iodide-1/lca/datasets/hydrogen-iodide-catalytic-gas-phase.yaml in library version a3c52e4.

Used by

No other activity of this database links to it.

How good it is

Review: Not reviewed: no LCI review record yet
Data quality: not available
Mass and carbon closure: Not available: a hand-written dataset: no lca/manifest.json records its balance
Change report: Not available: this build has no change report against an earlier release.

KPI benchmark positions

KPI	Value	Reference range	Position
HI made per iodine fed, as a fraction of the stoichiometric HI	– kg/kg	0.895 to 0.958 kg/kg Yang, T. et al. (Honeywell International) US 11 554 956 B2 (2023), Integrated process and catalysts for manufacturing hydrogen iodide from hydrogen and iodine (other)	not evaluated
Electricity per t of hydrogen iodide No open source with an electricity figure for HI production found (2026-11-05). Read: US 8 268 284 B2 and US 11 554 956 B2 (process descriptions and examples, no utility data). Not read: Ullmann's chapter Iodine and Iodine Compounds (doi:10.1002/14356007.a14_381.pub2, licensed). No EU BREF was checked for HI. The dataset's value is core's Tier 0 default, ASSUMED.	– kWh/t	not available	not evaluated
Heat per t of hydrogen iodide No open source with a heat figure for HI production found (2026-11-05); the same sources were read as for electricity and give operating temperatures (iodine melted at about 120 degC, vaporised at 150 to 170 degC, reactor at 300 to 350 degC) but no duty. The dataset's value is core's Tier 0 default, ASSUMED.	– kWh/t	not available	not evaluated

How to use it

Downloads

cheme-as-code-atlas-preview-a3c52e4.xlsx · bw2io ExcelImporter workbook (bw2io 0.9 Excel layout) · the whole database
code hydrogen-iodide-1:hydrogen-iodide-catalytic-gas-phase:product:hydrogen-iodide
cheme-as-code-atlas-preview-a3c52e4-olca-jsonld.zip · openLCA JSON-LD (olca-schema) (2) · the whole database
process 3adaf26d-f4f9-582f-a8e0-f8a7010ab9e6 (processes/3adaf26d-f4f9-582f-a8e0-f8a7010ab9e6.json)
cheme-as-code-atlas-preview-a3c52e4-multifunctional.json · Brightway 2.5 multifunctional database (JSON, for the multifunctional package) (cheme-as-code/lci-multifunctional/v1) · the whole database
code hydrogen-iodide-1:hydrogen-iodide-catalytic-gas-phase:product:hydrogen-iodide
cheme_as_code_lci-0.1.0-py3-none-any.whl · the installer

A file with this activity alone is not available: each file above is the whole database, and the line under it says how to find this activity there.

import bw2data as bd
from cheme_as_code_lci import install

bd.projects.set_current("my-project")   # holds your licensed background + biosphere3
install("cheme-as-code-atlas-preview-a3c52e4.xlsx", background="ecoinvent-3.11-cutoff", location="DE")
activity = bd.get_activity(("cheme-as-code-atlas-preview-a3c52e4", "hydrogen-iodide-1:hydrogen-iodide-catalytic-gas-phase:product:hydrogen-iodide"))

While any exchange of the database has no mapping, install() writes nothing and only lists the unlinked exchanges. So the last line finds no activity until the gaps are mapped: the download section gives the ways to use the database now.

How to cite

Hydrogen iodide, anhydrous, from Anhydrous hydrogen iodide by gas-phase catalytic synthesis from hydrogen and iodine (dataset hydrogen-iodide-catalytic-gas-phase 0.1.0), ChemE-as-Code Process Atlas LCI database preview-a3c52e4, activity hydrogen-iodide-1:hydrogen-iodide-catalytic-gas-phase:product:hydrogen-iodide. Cite the Process Atlas paper (in preparation, 2026), by Artur M. Schweidtmann and Jana M. Weber, and the ChemE-as-Code Process Atlas LCI database version preview-a3c52e4.

DOI: none yet (the Process Atlas paper is in preparation)

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).

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). ChemE-as-Code: An Open-Source Platform for Agentic AI in Chemical Engineering. arXiv:2611.07947. https://doi.org/10.48550/arXiv.2611.07947

BibTeX

@misc{schweidtmann_cheme_as_code,
  author = {Schweidtmann, Artur M.},
  title = {{ChemE-as-Code: An Open-Source Platform for Agentic AI in Chemical Engineering}},
  year = {2026},
  eprint = {2611.07947},
  archivePrefix = {arXiv},
  doi = {10.48550/arXiv.2611.07947},
  url = {https://arxiv.org/abs/2611.07947}
}