Zeolite 13X molecular sieve 13X
Na2O . Al2O3 . m SiO2 . n H2O (m ≤ 2.35)
Also known as BASF 13X Molecular Sieve, BASF 13X
Zeolite 13X is a synthetic sodium aluminosilicate with the faujasite (FAU) framework and a nominal 10 Å pore size.
Evidence level
2 of 5
Lab-measured
- 0Predicted only. No one has made it, or no measurement exists.
- 1Calculated. Only calculated or predicted values from sources.
- 2Lab-measured. Measured properties with their conditions stated.
- 3Space-relevant tests. Measured in conditions relevant to space, such as vacuum or atomic oxygen.
- 4Ground-qualified. Qualified for an application on the ground.
- 5Flown or field-proven. Flight or field results exist.
Water capacity
> 26.5 % wt
Pore size
10 Å
Recipe, share of the weight
- Na2O not statedSodium oxide
- Al2O3 not statedAluminium oxide
- SiO2 not statedSilicon dioxide
- H2O not statedWater
Best for
Residual drying of gas streams where low dust in a packed bed matters (NASA's stated selection criterion).
Weakest at
Little numeric data in text: NASA's adsorption and dust results are in plots, and the BASF data sheet gives typical values only. CO2 performance fell after cyclic humid exposure in NASA's tests.
Risk at a glance
- People None found. Nontoxic per BASF; no GHS hazard found
- If it fails Moderate. Dust release in a packed bed
- Corrosion Moderate. NASA's cyclic tests show 13X sorbents below their dry capacity, and the paper says 13X recovers most capacity at 204 °C.
Why it exists
Zeolite 13X is a synthetic sodium aluminosilicate sold as a molecular sieve. A molecular sieve is a material with pores of uniform size comparable to individual molecules (Wikipedia, Molecular sieve). A zeolite is a microporous crystalline aluminosilicate used as a commercial adsorbent (Wikipedia, Zeolite). The BASF 13X grade has a nominal pore size of 10 Å (1.0 nm). NASA's paper names 13X as the residual desiccant layer in the ISS Carbon Dioxide Removal Assembly, and it judged 13X the primary residual desiccant among the candidates it tested.
Where it's used
ISS carbon dioxide removal
NASA describes 13X zeolite as the residual desiccant layer of the ISS Carbon Dioxide Removal Assembly. The grade flown there is Grace MS 544 (Grade 544 13X in NASA's paper), not the BASF product in the data sheet.
Gas drying and oxygen enrichment
BASF lists drying of gases and liquids, removal of mercaptans, and non-cryogenic oxygen enrichment from air by pressure or vacuum swing adsorption as applications of its 13X grade.
Thermal energy storage
BASF says the product can be used as regenerative thermochemical energy storage for the generation of cold or heat.
Recipe
Na2O . Al2O3 . m SiO2 . n H2O (m ≤ 2.35)
Zeolite 13X is a sodium aluminosilicate with the general composition Na2O . Al2O3 . m SiO2 . n H2O, where m is at most 2.35 (BASF data sheet). Its framework is faujasite (FAU), built from sodalite cages (Wikipedia, Faujasite). The data sheet does not fix the water content n, and the synthesis route is not stated in our sources.
| Ingredient | Share of the weight | What it does |
|---|---|---|
| Sodium oxide Na2O | not stated | Sodium is the cation in the framework. The name 'Na-X' in Wikipedia's molecular sieve table marks the sodium form of the X-type zeolite. |
| Aluminium oxide Al2O3 | not stated | Alumina part of the framework, as printed in the chemical formula. |
| Silicon dioxide SiO2 | not stated | Silica part of the framework; the printed formula gives m SiO2 with m at most 2.35. |
| Water H2O | not stated | Water of hydration, printed as n H2O; the amount is not fixed in the data sheet. |
Weight shares are as printed in the sources.
What it can do
Water capacity
> 26.5 % wt
measured
The data sheet gives a minimum water adsorption of 26.5 % wt at 55 % relative humidity and 20 °C for the activated sample.
Pore size
10 Å
measured
The nominal pore size is 10 Å (1.0 nm), per the BASF data sheet.
Bead strength
Crush strength is at least 25 N per bead for the 1.6 to 2.5 mm beads and at least 50 N per bead for the 2.5 to 5.0 mm beads.
Regeneration
BASF recommends regenerating with purge gas at 200 °C to 300 °C, and not above 450 °C.
How it compares
In NASA's standalone residual-desiccant tests, 13X zeolite was by a large order the best option for capturing water below detectable limits for the longest time. 4A zeolite came next at about half that effectiveness, and 3A zeolite broke through early despite a similar final capacity. In NASA's CO2 screening, every X-type zeolite under consideration gave higher CO2 capacity than RK-38, a 5A zeolite used in CDRA, after 204 °C activation. The paper says APGIII and VSA-10 have exceptional adsorption capacity but weaker pellet integrity, so NASA selected a 13X grade for its low dusting instead.
The same measurements for each material, so you can compare them. Each row names the key condition under the value; the full conditions and methods are in the numbered notes under Technical details. Other materials are shown beside it; each was measured under its own conditions, so open its page before comparing closely. Compare every grade in the family.
| Measurement | 13X | Al2O3 | BaTiO3 | BeO | CaTiO3 | RCF | CeO2 | CoO and Co3O4 | CuO, Cu2O | HfO2 | Fe2O3, Fe3O4 | LSM | PZT | MgO | NiO | Nb2O5 | Al2Si4O10(OH)2 | Ln2O3 | SiO | MgO-SiO2 | SnO2, ITO | TiO2 | WO3 | V2O5 | Y2O3 | ZnO | Mg-PSZ, ATZ, ZTA | YSZ |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Capacity and energy | ||||||||||||||||||||||||||||
| Water adsorption capacity | > 26.5 % wt5 | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Physical and electrical | ||||||||||||||||||||||||||||
| Bulk density, compacted, small gradeManufacturer typical-properties table | 655 to 700 g/L | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | 2.2 g/cm³ | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Bulk density, compacted, large gradeManufacturer typical-properties table | 655 to 700 g/L | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | 2.2 g/cm³ | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Temperature behavior | ||||||||||||||||||||||||||||
| Regeneration purge gas temperature, recommended range | 200 to 300 °C6 | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Regeneration temperature, not to exceed | < 450 °C7 | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Other measurements | ||||||||||||||||||||||||||||
| Pore size, nominalManufacturer typical-properties table | 10 Å | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Bead size, small gradeManufacturer typical-properties table | 1.6 to 2.5 mm | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Bead size, large gradeManufacturer typical-properties table | 2.5 to 5 mm | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Attrition, small grade | < 0.2 % wt1 | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Attrition, large grade | < 0.2 % wt2 | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Crush strength, small grade | > 25 N/bead3 | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Crush strength, large grade | > 50 N/bead4 | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Moisture content as deliveredManufacturer typical-properties table | < 1 % wt | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
Why choose it, and why not
Good for
- Drying gas streams to very low water levels: NASA chose a 13X grade for residual drying in the ISS desiccant beds.
- Low dust in a packed bed: NASA judged the 13X grades to carry the least overall dusting risk among the candidates it compared.
Watch out for
- CO2 capacity falls after cyclic humid exposure: NASA's cyclic tests show the 13X zeolites below their dry isotherm values.
- Dust is the main failure mode NASA screened for, and thermal-expansion mismatch in the pellet is a theorised cause.
- No flight, vacuum or radiation data for the BASF grade were found in our sources.
NASA treats 13X as the primary residual desiccant for ISS-style CO2 removal beds. The BASF data sheet gives typical manufacturing values only, so confirm the grade and its test data before design.
Technical details
For scientists and researchers. Everything above comes from the record below: every number with its method, its conditions and its source.
Other names and standards
The same grade under other systems, as datasheets and standards print them. Each code was checked against the page it comes from.
| System | Codes |
|---|---|
| Trade name | BASF 13X Molecular Sieve, BASF 13X |
Notes
The method, full conditions and any caveat for the numbered rows above.
| # | Measurement | Method | Conditions | Caveat |
|---|---|---|---|---|
| 1 | Attrition, small grade | Manufacturer typical-properties table, printed as Max 0.2 | grade beads 1.6 to 2.5 mmtest not described in the data sheet | — |
| 2 | Attrition, large grade | Manufacturer typical-properties table, printed as Max 0.2 | grade beads 2.5 to 5.0 mmtest not described in the data sheet | — |
| 3 | Crush strength, small grade | Manufacturer typical-properties table, printed as Min 25 | grade beads 1.6 to 2.5 mmtest not described in the data sheet | — |
| 4 | Crush strength, large grade | Manufacturer typical-properties table, printed as Min 50 | grade beads 2.5 to 5.0 mmtest not described in the data sheet | — |
| 5 | Water adsorption capacity | Manufacturer typical-properties table, printed as Min 26.5 | relative humidity 55 %temperature 20 °Csample activated, as the data sheet footnote states | — |
| 6 | Regeneration purge gas temperature, recommended range | Manufacturer recommendation printed in the regeneration paragraph | purpose warms the bed to this level during regenerationnote recommended operating range, not a measured limit | — |
| 7 | Regeneration temperature, not to exceed | Manufacturer recommendation printed in the regeneration paragraph, 'not exceeding 450 °C' | purpose upper limit for the purge gas during regeneration | — |
Corrosion and compatibility
What happens when it meets other materials and environments.
| Environment | Concern | What happens |
|---|---|---|
| Humid air and water vapour in a cyclic desiccant or CO2 bed | moderate | NASA's cyclic tests show 13X sorbents below their dry capacity, and the paper says 13X recovers most capacity at 204 °C.1 |
| Thermal cycling of pelletized zeolite in a packed bed | low | NASA lists thermal-expansion mismatch in the pellet as a theorised cause of dusting, and judges the 13X grades to carry the least dusting risk.2 |
| Hydrothermal conditions during regeneration | not rated | The data sheet asks users to avoid hydrothermal conditions during regeneration, and gives no test figure for them.3 |
| # | Environment | Details | Test conditions |
|---|---|---|---|
| 1 | Humid air and water vapour in a cyclic desiccant or CO2 bed | NASA's paper reports that the three 13X zeolites in its screening settled at a reduced performance level in cyclic testing, compared with the dry isotherm values or with a 350 °C activation cycle. In a simulated cycle the paper says "13X zeolites can recover 90-95% of full CO2 removal capacity from a worst-case water exposure event" at a regeneration temperature of 204 °C. | cycling simulated 4-BMS cycles with humid air exposureregeneration 204 °C for the simulated recovery case, 350 °C for the full activation case |
| 2 | Thermal cycling of pelletized zeolite in a packed bed | NASA lists differing thermal-expansion coefficients between zeolite crystals and the binder as a theorised cause of pellet cracking, dusting and flaking. The paper also names bed-wide crushing from thermal expansion and contraction as a possible cause. The authors judged Grade 544 13X and BASF 13X to carry the least overall risk of dusting among the candidates they compared. | test hydrothermal stability test stand, thermal cycling of packed bedsgrades 13X grades named in the paper |
| 3 | Hydrothermal conditions during regeneration | BASF says the appearance of so-called hydrothermal conditions during regeneration should be avoided as far as possible. The data sheet does not quantify the loss of capacity or strength under these conditions. | regeneration purge gas warms the bed to 200 °C to 300 °C, not exceeding 450 °C |
Risks and side effects
Hazards to people, what happens when a cell overheats, and how the material is handled and stored.
For people
BASF calls the product nontoxic, but its own disclaimer asks users not to assume that toxicity data are given. The PubChem record used covers sodium aluminosilicate, a related substance, not the BASF grade.
- The powder
- BASF states the product is nontoxic. PubChem's record for sodium aluminosilicate reports no GHS hazard criteria for 97.4% (559 of 574) of company reports.
- Dust
- NASA ranks dust as the main selection risk for these beds. The data sheet gives no dust-handling guidance.
If the bed overheats
The sources we opened contain no runaway or fire test for 13X. Hydrothermal conditions during regeneration are the one warning BASF gives.
- Regeneration
- BASF advises avoiding hydrothermal conditions during regeneration as far as possible, and recommends 200 °C to 300 °C with a purge gas, not exceeding 450 °C.
Handling and storage
- Packaging
- The product ships in 216 L (135 kg) airtight steel drums, or in polypropylene-lined big bags of 650 or 800 kg net.
- Thermal cycling
- NASA lists thermal-expansion mismatch between zeolite crystals and binder as a theorised cause of pellet dusting.
Test details
The original wording and numbers from the sources, for readers who want them.
Failure risks
| Failure | Trigger and consequence |
|---|---|
| Dust release in a packed bedmoderate severity | Crushing loads, thermal cycling and particle collisions in the voids of a packed bed (causes NASA lists)NASA states that dust can impair moving parts and seals, damage pumps and compressors, and clog filters, which raises pressure drop and can force a system shutdown. The paper reports no dusting problems for the flown Grade 544 13X on the ISS. |
| Lower CO2 capacity after cyclic humid exposuremoderate severity | Repeated cycles with humid air, and regeneration below the full-activation temperatureIn NASA's cyclic tests the three 13X zeolites settled at a reduced CO2 performance level compared with dry isotherm values. The paper's simulated recovery figure depends on regeneration at 204 °C. |
Handling and storage
- BASF packs the product in 216 L (135 kg) airtight steel drums, or in polypropylene-lined big bags of 650 or 800 kg net.
Mitigations
- Regenerate with purge gas at 200 °C to 300 °C and do not exceed 450 °C, as BASF recommends.
- NASA selected a 13X grade after screening candidates on crush strength, attrition and hydrothermal stability, with minimised dusting as the main criterion.
Supply and geography
How common the raw materials are and where they come from.
Zeolites (natural), the mined analogue; synthetic 13X is not covered by the USGS data
USGS gives 1,300,000 t of world natural zeolite mine production in 2025e. No producer data for synthetic 13X was found in any source we opened.
- Top producers (2025)
- Slovakia 21.5%, Georgia 18.5%, Korea, Republic of 12.3%, China 11.5%
- Recycling
- USGS: zeolites used for desiccation, gas absorbance, wastewater treatment and water purification may be reused after reprocessing of the spent zeolites.
Alumina (aluminium oxide), an aluminium raw material; the 13X synthesis route is not stated in our sources
- Top producers (2025)
- China, Australia, Brazil
Documents
Datasheets, safety data sheets, papers and standards you can open.
Full record
The complete spore, as stored. Free to reuse under CC-BY-4.0. Images keep the licence shown with each one.
Show the full YAML
spore: profile
id: zeolite-13x
spore_version: 0.2
family: oxide-ceramics
name: Zeolite 13X molecular sieve
abbreviation: 13X
role: CO2 and water sorbent (residual desiccant)
category: ceramics
type: oxides
summary: |
Zeolite 13X is a synthetic sodium aluminosilicate with the faujasite (FAU) framework and a nominal 10 Å pore size. The BASF product data sheet for its 13X grade gives beads of 1.6 to 5.0 mm, a compacted bulk density of 655 to 700 g/L and a minimum water adsorption of 26.5 % wt at 55 % relative humidity. NASA reports 13X as the residual desiccant layer of the ISS Carbon Dioxide Removal Assembly, but the grade flown there is Grace MS 544 (Grade 544 13X in NASA's paper), not the BASF product.
best_for: Residual drying of gas streams where low dust in a packed bed matters (NASA's stated selection criterion).
weakest_at: 'Little numeric data in text: NASA''s adsorption and dust results are in plots, and the BASF data sheet gives typical values only. CO2 performance fell after cyclic humid exposure in NASA''s tests.'
identity:
formula: Na2O . Al2O3 . m SiO2 . n H2O (m ≤ 2.35)
source: basf-13x
where: Product Data Sheet, Chemical Formula row
designations:
- system: Trade name
code: BASF 13X Molecular Sieve
source: basf-13x
where: Title block, first line
- system: Trade name
code: BASF 13X
source: nasa-ices2017
where: Table 2, Molecular Sieve rows, Sorbent Name column
tags:
environments:
- low-earth-orbit
stresses:
- thermal-cycling
- dust-abrasion
applications:
- habitats-and-suits
- thermal-control
properties:
- benchmark: pore_size
label: Pore size, nominal
value: 10
unit: Å
scope: material
conditions:
printed: 10 Å (1.0 nm)
product: BASF 13X Molecular Sieve, as delivered
method: Manufacturer typical-properties table
status: ground
source: basf-13x
where: Product Data Sheet, Typical Properties table, Pore Size row
- benchmark: bead_size
label: Bead size, small grade
value: 1.6
value_high: 2.5
bound: range
unit: mm
scope: material
conditions:
grade: beads 1.6 to 2.5 mm nominal, mesh range 8 x 12 as printed
method: Manufacturer typical-properties table
status: ground
source: basf-13x
where: Typical Properties table, Beads size range row, first column
- benchmark: bead_size
label: Bead size, large grade
value: 2.5
value_high: 5
bound: range
unit: mm
scope: material
conditions:
grade: beads 2.5 to 5.0 mm nominal, mesh range 4x8 as printed
method: Manufacturer typical-properties table
status: ground
source: basf-13x
where: Typical Properties table, Beads size range row, second column
- benchmark: bulk_density
label: Bulk density, compacted, small grade
value: 655
value_high: 700
bound: range
unit: g/L
scope: material
conditions:
state: compacted
grade: beads 1.6 to 2.5 mm
method: Manufacturer typical-properties table
status: ground
source: basf-13x
where: Typical Properties table, Bulk Density, compacted row, first column
- benchmark: bulk_density
label: Bulk density, compacted, large grade
value: 655
value_high: 700
bound: range
unit: g/L
scope: material
conditions:
state: compacted
grade: beads 2.5 to 5.0 mm
method: Manufacturer typical-properties table
status: ground
source: basf-13x
where: Typical Properties table, Bulk Density, compacted row, second column
- benchmark: attrition
label: Attrition, small grade
value: 0.2
bound: upper
unit: '% wt'
scope: material
conditions:
grade: beads 1.6 to 2.5 mm
test: not described in the data sheet
method: Manufacturer typical-properties table, printed as Max 0.2
status: ground
source: basf-13x
where: Typical Properties table, Attrition row, first column
- benchmark: attrition
label: Attrition, large grade
value: 0.2
bound: upper
unit: '% wt'
scope: material
conditions:
grade: beads 2.5 to 5.0 mm
test: not described in the data sheet
method: Manufacturer typical-properties table, printed as Max 0.2
status: ground
source: basf-13x
where: Typical Properties table, Attrition row, second column
- benchmark: crush_strength
label: Crush strength, small grade
value: 25
bound: lower
unit: N/bead
scope: material
conditions:
grade: beads 1.6 to 2.5 mm
test: not described in the data sheet
method: Manufacturer typical-properties table, printed as Min 25
status: ground
source: basf-13x
where: Typical Properties table, Crush Strength row, first column
- benchmark: crush_strength
label: Crush strength, large grade
value: 50
bound: lower
unit: N/bead
scope: material
conditions:
grade: beads 2.5 to 5.0 mm
test: not described in the data sheet
method: Manufacturer typical-properties table, printed as Min 50
status: ground
source: basf-13x
where: Typical Properties table, Crush Strength row, second column
- benchmark: moisture_content_as_delivered
label: Moisture content as delivered
value: 1
bound: upper
unit: '% wt'
scope: material
conditions:
state: as delivered
grade: both bead sizes, printed as Max 1.0
method: Manufacturer typical-properties table
status: ground
source: basf-13x
where: Typical Properties table, Moisture Content row
- benchmark: water_adsorption_capacity
label: Water adsorption capacity
value: 26.5
bound: lower
unit: '% wt'
scope: material
conditions:
relative_humidity: 55 %
temperature: 20 °C
sample: activated, as the data sheet footnote states
method: Manufacturer typical-properties table, printed as Min 26.5
status: ground
source: basf-13x
where: Typical Properties table, Water Adsorption Capacity row, and the footnote marked with an asterisk
- benchmark: regeneration_temperature
label: Regeneration purge gas temperature, recommended range
value: 200
value_high: 300
bound: range
unit: °C
scope: material
conditions:
purpose: warms the bed to this level during regeneration
note: recommended operating range, not a measured limit
method: Manufacturer recommendation printed in the regeneration paragraph
status: ground
source: basf-13x
where: Regeneration paragraph, page 1
- benchmark: max_regeneration_temperature
label: Regeneration temperature, not to exceed
value: 450
bound: upper
unit: °C
scope: material
conditions:
purpose: upper limit for the purge gas during regeneration
method: Manufacturer recommendation printed in the regeneration paragraph, 'not exceeding 450 °C'
status: ground
source: basf-13x
where: Regeneration paragraph, page 1
corrosion:
- environment: Humid air and water vapour in a cyclic desiccant or CO2 bed
headline: NASA's cyclic tests show 13X sorbents below their dry capacity, and the paper says 13X recovers most capacity at 204 °C.
effect: NASA's paper reports that the three 13X zeolites in its screening settled at a reduced performance level in cyclic testing, compared with the dry isotherm values or with a 350 °C activation cycle. In a simulated cycle the paper says "13X zeolites can recover 90-95% of full CO2 removal capacity from a worst-case water exposure event" at a regeneration temperature of 204 °C.
rating: moderate
conditions:
cycling: simulated 4-BMS cycles with humid air exposure
regeneration: 204 °C for the simulated recovery case, 350 °C for the full activation case
source: nasa-ices2017
where: Results, section C (CO2 sorbent selection), text beside Figures 13 to 15, and Conclusions
- environment: Thermal cycling of pelletized zeolite in a packed bed
headline: NASA lists thermal-expansion mismatch in the pellet as a theorised cause of dusting, and judges the 13X grades to carry the least dusting risk.
effect: NASA lists differing thermal-expansion coefficients between zeolite crystals and the binder as a theorised cause of pellet cracking, dusting and flaking. The paper also names bed-wide crushing from thermal expansion and contraction as a possible cause. The authors judged Grade 544 13X and BASF 13X to carry the least overall risk of dusting among the candidates they compared.
rating: low
conditions:
test: hydrothermal stability test stand, thermal cycling of packed beds
grades: 13X grades named in the paper
source: nasa-ices2017
where: Section III.A, Hydrothermal Stability Test text, and Sorbent Structural Property Summary
- environment: Hydrothermal conditions during regeneration
headline: The data sheet asks users to avoid hydrothermal conditions during regeneration, and gives no test figure for them.
effect: BASF says the appearance of so-called hydrothermal conditions during regeneration should be avoided as far as possible. The data sheet does not quantify the loss of capacity or strength under these conditions.
rating: unknown
conditions:
regeneration: purge gas warms the bed to 200 °C to 300 °C, not exceeding 450 °C
source: basf-13x
where: Regeneration paragraph, page 1
risks:
hazards:
- text: BASF states that BASF 13X Molecular Sieve is nontoxic. The same data sheet warns that users should not assume that toxicity data and safety measures are indicated, or that other measures may not be required.
ghs: []
source: basf-13x
where: Regeneration paragraph (nontoxic statement) and the disclaimer on the last page
- text: PubChem's record for sodium aluminosilicate (CID 72941443), a related substance and not the BASF 13X grade, reports that it does not meet GHS hazard criteria for 97.4% (559 of 574) of company reports. Only 2.6% of companies provided GHS information.
ghs: []
source: pubchem-sodium-aluminosilicate
where: Safety and Hazards, GHS Classification (CID 72941443)
failure_risks:
- mode: Dust release in a packed bed
trigger: Crushing loads, thermal cycling and particle collisions in the voids of a packed bed (causes NASA lists)
consequence: NASA states that dust can impair moving parts and seals, damage pumps and compressors, and clog filters, which raises pressure drop and can force a system shutdown. The paper reports no dusting problems for the flown Grade 544 13X on the ISS.
severity: moderate
source: nasa-ices2017
where: Introduction (dust paragraph), and Conclusions
- mode: Lower CO2 capacity after cyclic humid exposure
trigger: Repeated cycles with humid air, and regeneration below the full-activation temperature
consequence: In NASA's cyclic tests the three 13X zeolites settled at a reduced CO2 performance level compared with dry isotherm values. The paper's simulated recovery figure depends on regeneration at 204 °C.
severity: moderate
source: nasa-ices2017
where: Results, section C (CO2 sorbent selection)
handling:
- text: BASF packs the product in 216 L (135 kg) airtight steel drums, or in polypropylene-lined big bags of 650 or 800 kg net.
source: basf-13x
where: Packaging
mitigations:
- text: Regenerate with purge gas at 200 °C to 300 °C and do not exceed 450 °C, as BASF recommends.
source: basf-13x
where: Regeneration paragraph, page 1
- text: NASA selected a 13X grade after screening candidates on crush strength, attrition and hydrothermal stability, with minimised dusting as the main criterion.
source: nasa-ices2017
where: Introduction, and Sorbent Structural Property Summary
uses:
- application: habitats-and-suits
device: Residual desiccant layer in the ISS Carbon Dioxide Removal Assembly (CDRA)
example: NASA's paper says the desiccant beds contain layers of silica gels and 13X zeolite, and the grade flown on the ISS is Grace MS 544 (Grade 544 13X).
source: nasa-ices2017
where: Section I (Introduction), CDRA paragraph; Table 2
- application: habitats-and-suits
device: Pressure or vacuum swing adsorption plant for non-cryogenic oxygen enrichment from air
example: BASF lists non-cryogenic oxygen enrichment from air using pressure (vacuum) swing adsorption (PSA/VPSA) as a field of application for BASF 13X.
source: basf-13x
where: Product applications, first page
- application: thermal-control
device: Regenerative thermochemical energy storage for cold or heat
example: BASF says BASF 13X can be used as regenerative thermo-chemical energy storage for the generation of cold or heat, possibly with sun energy or exhaust heat.
source: basf-13x
where: Product applications, first page
supply:
- subject: Zeolites (natural), the mined analogue; synthetic 13X is not covered by the USGS data
abundance: USGS gives 1,300,000 t of world natural zeolite mine production in 2025e. No producer data for synthetic 13X was found in any source we opened.
producers:
- country: Slovakia
share_percent: 21.5
year: 2025
- country: Georgia
share_percent: 18.5
year: 2025
- country: Korea, Republic of
share_percent: 12.3
year: 2025
- country: China
share_percent: 11.5
year: 2025
critical_lists: []
recycling: 'USGS: zeolites used for desiccation, gas absorbance, wastewater treatment and water purification may be reused after reprocessing of the spent zeolites.'
substitutes: []
source: usgs-zeolites-2026
where: World Mine Production and Reserves table, 2025e column (shares calculated by Space Mushroom against the 1,300,000 t world total); Recycling
- subject: Alumina (aluminium oxide), an aluminium raw material; the 13X synthesis route is not stated in our sources
producers:
- country: China
year: 2025
- country: Australia
year: 2025
- country: Brazil
year: 2025
critical_lists: []
substitutes: []
source: usgs-bauxite-alumina-2026
where: 'Alumina production table, 2025e column: China 93,000 t, Australia 17,000 t, Brazil 11,000 t. The table total was not read reliably, so no shares are given.'
documents:
- title: BASF 13X Molecular Sieve product data sheet (BASF-9391 rev 02/2024)
type: datasheet
url: https://download.basf.com/p1/8a8082048fa5910c018fc44de15565ae/en/13X_Molecular_Sieve_Datasheet_Technical_Data_Sheet_English.pdf
year: 2024
- title: Investigation of Desiccants and CO2 Sorbents for Exploration Systems 2016-2017 (ICES-2017-188)
type: report
url: https://ntrs.nasa.gov/api/citations/20170008962/downloads/20170008962.pdf
year: 2017
- title: 'PubChem: Sodium aluminosilicate (CID 72941443), GHS classification'
type: database
url: https://pubchem.ncbi.nlm.nih.gov/compound/72941443
year: 2026
- title: 'USGS Mineral Commodity Summaries 2026: Zeolites (Natural)'
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-zeolites.pdf
year: 2026
- title: 'USGS Mineral Commodity Summaries 2026: Bauxite and Alumina'
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-bauxite-alumina.pdf
year: 2026
gaps:
- 'No attrition, crush-strength, humidity-cycling or hydrothermal-stability numbers for the BASF grade were recorded: NASA''s values are printed in figures, not in the text we could read.'
- No flight, vacuum, radiation or thermal-vacuum result for the BASF grade was found. NASA's ISS flight heritage refers to Grace MS 544 (Grade 544 13X), a different product.
- No CAS number for zeolite 13X was confirmed in a source we opened; PubChem returned no record for the name 'zeolite 13X'.
- No SDS or PubChem hazard record for 13X itself was found. The PubChem record used is for sodium aluminosilicate (CID 72941443), a related substance; the BASF data sheet gives only a 'nontoxic' statement.
- 'The 13X synthesis route is not stated in any source we opened. Wikipedia describes the 4A route: aqueous sodium silicate and sodium aluminate combined at 80 °C and then activated at 400 °C.'
- Producer shares for synthetic 13X were not found. The USGS zeolite data cover natural zeolites only, and the alumina table total was not read reliably, so no alumina shares are given.
- Wikipedia's molecular sieve table gives 13X figures, but the column headings were not readable in the text we extracted, so none of those numbers were recorded.
- CO2 capacity values for the BASF grade at 25 °C or 50 °C were not found in text; NASA's isotherm results are in figures.
- RK-38 (a 5A zeolite CO2 sorbent in CDRA, Table 2 of NASA's paper) is used only as a comparison point here; its dust history is not a property of 13X.
- Property names not in spores/property-canon.yaml (pore_size, bead_size, bulk_density, attrition, crush_strength, moisture_content_as_delivered, water_adsorption_capacity, regeneration_temperature, max_regeneration_temperature) were used as short snake_case names.
sources:
basf-13x:
title: BASF 13X Molecular Sieve, Product Data Sheet (BASF-9391 rev 02/2024)
id: BASF-9391 rev 02/2024
url: https://download.basf.com/p1/8a8082048fa5910c018fc44de15565ae/en/13X_Molecular_Sieve_Datasheet_Technical_Data_Sheet_English.pdf
year: 2024
kind: datasheet
license: manufacturer data sheet, linked not reproduced
nasa-ices2017:
title: Investigation of Desiccants and CO2 Sorbents for Exploration Systems 2016-2017
id: ICES-2017-188, 47th International Conference on Environmental Systems; NTRS 20170008962
url: https://ntrs.nasa.gov/api/citations/20170008962/downloads/20170008962.pdf
year: 2017
kind: report
license: public domain (NASA)
usgs-zeolites-2026:
title: Mineral Commodity Summaries 2026, Zeolites (Natural)
id: USGS MCS 2026, February 2026
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-zeolites.pdf
year: 2026
kind: report
license: public domain (USGS)
usgs-bauxite-alumina-2026:
title: Mineral Commodity Summaries 2026, Bauxite and Alumina
id: USGS MCS 2026, February 2026
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-bauxite-alumina.pdf
year: 2026
kind: report
license: public domain (USGS)
pubchem-sodium-aluminosilicate:
title: PubChem compound record, Sodium aluminosilicate (CID 72941443)
id: CID 72941443
url: https://pubchem.ncbi.nlm.nih.gov/compound/72941443
year: 2026
kind: database
license: public domain (NCBI)
wiki-molecular-sieve:
title: Molecular sieve, Wikipedia
id: en.wikipedia.org/wiki/Molecular_sieve
url: https://en.wikipedia.org/wiki/Molecular_sieve
kind: web
license: CC BY-SA 4.0 (Wikipedia text)
wiki-zeolite:
title: Zeolite, Wikipedia
id: en.wikipedia.org/wiki/Zeolite
url: https://en.wikipedia.org/wiki/Zeolite
kind: web
license: CC BY-SA 4.0 (Wikipedia text)
wiki-faujasite:
title: Faujasite, Wikipedia
id: en.wikipedia.org/wiki/Faujasite
url: https://en.wikipedia.org/wiki/Faujasite
kind: web
license: CC BY-SA 4.0 (Wikipedia text)
license: CC-BY-4.0
updated: '2026-11-01'
review:
status: draft
method: assistant
checked_values: 13
unreachable: 0
caveats: 2
note: Written by an AI assistant on 2026-11-01 from the BASF datasheet, the NASA ICES-2017 paper, two USGS chapters, the PubChem record for a related substance and three Wikipedia pages. Values are the datasheet's typical values, not NASA test results.
story:
why: Zeolite 13X is a synthetic sodium aluminosilicate sold as a molecular sieve. A molecular sieve is a material with pores of uniform size comparable to individual molecules (Wikipedia, Molecular sieve). A zeolite is a microporous crystalline aluminosilicate used as a commercial adsorbent (Wikipedia, Zeolite). The BASF 13X grade has a nominal pore size of 10 Å (1.0 nm). NASA's paper names 13X as the residual desiccant layer in the ISS Carbon Dioxide Removal Assembly, and it judged 13X the primary residual desiccant among the candidates it tested.
uses:
- where: ISS carbon dioxide removal
line: NASA describes 13X zeolite as the residual desiccant layer of the ISS Carbon Dioxide Removal Assembly. The grade flown there is Grace MS 544 (Grade 544 13X in NASA's paper), not the BASF product in the data sheet.
- where: Gas drying and oxygen enrichment
line: BASF lists drying of gases and liquids, removal of mercaptans, and non-cryogenic oxygen enrichment from air by pressure or vacuum swing adsorption as applications of its 13X grade.
- where: Thermal energy storage
line: BASF says the product can be used as regenerative thermochemical energy storage for the generation of cold or heat.
can_do:
- label: Water capacity
benchmark: water_adsorption_capacity
line: The data sheet gives a minimum water adsorption of 26.5 % wt at 55 % relative humidity and 20 °C for the activated sample.
- label: Pore size
benchmark: pore_size
line: The nominal pore size is 10 Å (1.0 nm), per the BASF data sheet.
- label: Bead strength
line: Crush strength is at least 25 N per bead for the 1.6 to 2.5 mm beads and at least 50 N per bead for the 2.5 to 5.0 mm beads.
- label: Regeneration
line: BASF recommends regenerating with purge gas at 200 °C to 300 °C, and not above 450 °C.
compare: In NASA's standalone residual-desiccant tests, 13X zeolite was by a large order the best option for capturing water below detectable limits for the longest time. 4A zeolite came next at about half that effectiveness, and 3A zeolite broke through early despite a similar final capacity. In NASA's CO2 screening, every X-type zeolite under consideration gave higher CO2 capacity than RK-38, a 5A zeolite used in CDRA, after 204 °C activation. The paper says APGIII and VSA-10 have exceptional adsorption capacity but weaker pellet integrity, so NASA selected a 13X grade for its low dusting instead.
compare_rows:
- label: Water adsorption capacity
benchmark: water_adsorption_capacity
- label: Crush strength
benchmark: crush_strength
- label: Bulk density
benchmark: bulk_density
handling:
- The data sheet calls the product nontoxic, but also says users should not assume that toxicity data and safety measures are indicated.
- 'Store and ship it in its airtight packaging: 216 L (135 kg) steel drums or 650 or 800 kg big bags.'
- Regenerate with purge gas at 200 °C to 300 °C, and do not exceed 450 °C.
- Avoid hydrothermal conditions during regeneration as far as possible, as BASF advises.
good_for:
- 'Drying gas streams to very low water levels: NASA chose a 13X grade for residual drying in the ISS desiccant beds.'
- 'Low dust in a packed bed: NASA judged the 13X grades to carry the least overall dusting risk among the candidates it compared.'
watch_out:
- 'CO2 capacity falls after cyclic humid exposure: NASA''s cyclic tests show the 13X zeolites below their dry isotherm values.'
- Dust is the main failure mode NASA screened for, and thermal-expansion mismatch in the pellet is a theorised cause.
- No flight, vacuum or radiation data for the BASF grade were found in our sources.
verdict: NASA treats 13X as the primary residual desiccant for ISS-style CO2 removal beds. The BASF data sheet gives typical manufacturing values only, so confirm the grade and its test data before design.
recipe:
line: Zeolite 13X is a sodium aluminosilicate with the general composition Na2O . Al2O3 . m SiO2 . n H2O, where m is at most 2.35 (BASF data sheet). Its framework is faujasite (FAU), built from sodalite cages (Wikipedia, Faujasite). The data sheet does not fix the water content n, and the synthesis route is not stated in our sources.
parts:
- name: Sodium oxide
symbol: Na2O
role: Sodium is the cation in the framework. The name 'Na-X' in Wikipedia's molecular sieve table marks the sodium form of the X-type zeolite.
- name: Aluminium oxide
symbol: Al2O3
role: Alumina part of the framework, as printed in the chemical formula.
- name: Silicon dioxide
symbol: SiO2
role: Silica part of the framework; the printed formula gives m SiO2 with m at most 2.35.
- name: Water
symbol: H2O
role: Water of hydration, printed as n H2O; the amount is not fixed in the data sheet.
risk_groups:
- title: For people
level: 0
verdict: Nontoxic per BASF; no GHS hazard found
lead: BASF calls the product nontoxic, but its own disclaimer asks users not to assume that toxicity data are given. The PubChem record used covers sodium aluminosilicate, a related substance, not the BASF grade.
points:
- label: The powder
line: BASF states the product is nontoxic. PubChem's record for sodium aluminosilicate reports no GHS hazard criteria for 97.4% (559 of 574) of company reports.
- label: Dust
line: NASA ranks dust as the main selection risk for these beds. The data sheet gives no dust-handling guidance.
- title: If the bed overheats
lead: The sources we opened contain no runaway or fire test for 13X. Hydrothermal conditions during regeneration are the one warning BASF gives.
points:
- label: Regeneration
line: BASF advises avoiding hydrothermal conditions during regeneration as far as possible, and recommends 200 °C to 300 °C with a purge gas, not exceeding 450 °C.
- title: Handling and storage
points:
- label: Packaging
line: The product ships in 216 L (135 kg) airtight steel drums, or in polypropylene-lined big bags of 650 or 800 kg net.
- label: Thermal cycling
line: NASA lists thermal-expansion mismatch between zeolite crystals and binder as a theorised cause of pellet dusting.
References
Every number above carries a reference number. Click one to see the source and where in it the value comes from.
| # | Source | Type | Year | Used for |
|---|---|---|---|---|
| BASF 13X Molecular Sieve, Product Data Sheet (BASF-9391 rev 02/2024) | datasheet | 2024 | 20 values | |
| Investigation of Desiccants and CO2 Sorbents for Exploration Systems 2016-2017 | report | 2017 | 6 values | |
| Mineral Commodity Summaries 2026, Zeolites (Natural) | report | 2026 | 1 value | |
| Mineral Commodity Summaries 2026, Bauxite and Alumina | report | 2026 | 1 value | |
| PubChem compound record, Sodium aluminosilicate (CID 72941443) | database | 2026 | 1 value | |
| Molecular sieve, Wikipedia | web | 0 values | ||
| Zeolite, Wikipedia | web | 0 values | ||
| Faujasite, Wikipedia | web | 0 values |
Updated