Notes
Technical notes
14 articles on selection, specification and bed design. Every figure in them resolves to a published number or a named standard, and where our own data falls short, they say so.
Selection
9 min read
Granular, Pellet or Sphere: Choosing an Activated Carbon Form
A pellet bed runs about 1 in. w.c. per foot against about 2 for granular. Spheres buy something else: SURSORB Ultra is ball pan hardness min 99, ash max 0.5 %.
Read →9 min read
Ammonia Removal: Why Virgin Activated Carbon Barely Works
Virgin carbon holds 0.25-2 mg NH3/g; acid-impregnated or oxidised carbon holds 19-35 mg/g. A hundredfold gap that surface area does not explain or predict.
Read →Specification
10 min read
CTC Activity vs Iodine Number: What Each One Actually Measures
CTC activity is a mass-gain percentage; iodine number is mg/g from solution. Across SURSORB PAC-900 to PAC-1250, CTC rises 50 % while iodine rises 32 %.
Read →13 min read
How to Read an Activated Carbon Datasheet: Min, Max, Typical
ASTM E29 shows how a 1.8 % result passes one conformance method and fails the other. Here is what min, max and typical actually commit a carbon supplier to.
Read →10 min read
H₂S Capacity on Activated Carbon: Why Figures Don't Compare
Same carbon: 3.91 mg H₂S/g anoxic, 84.87 mg/g with 0.1 % oxygen — 22× from one variable. The seven conditions a capacity figure must state to mean anything.
Read →10 min read
What an Activated Carbon Certificate of Analysis Must Contain
ICH Q7 requires eight elements on a certificate of analysis, including the numerical result for every test. A COA that only says conforms is not a COA.
Read →System design
10 min read
Mercury Removal from Natural Gas with Sulfur-Impregnated Carbon
Cryogenic sections need gas below 0.01 µg Hg/Nm³. Sulfur carbon gets there by chemisorption to HgS — and capacity tracks surface area, not sulfur loading.
Read →11 min read
EBCT and Bed Sizing: Empty Bed Contact Time for Carbon Beds
US EPA sizes working capacity at about 50 % of equilibrium capacity, and says go lower. Here is how EBCT, velocity and the mass transfer zone really set a bed.
Read →10 min read
When to Regenerate Activated Carbon and When to Replace It
Acid-impregnated ammonia carbon gave 19.650 mg NH₃/g new and about 2.4 mg/g after one regeneration — 12 %. The binding mechanism decides, not the budget.
Read →Respiratory & CBRN
11 min read
What EN 14387 Actually Tests: ABEK Classes and Breakthrough
EN 14387:2004+A1:2008 was superseded in 2021. A B1 filter must pass three gases — 20 min on chlorine, 40 on hydrogen sulphide, 25 on HCN, all at 0.1 vol %.
Read →9 min read
ASZM-TEDA and the Chromium Question in NBC Filter Carbon
The US DoD left chromium carbon in 1992 after ~50 years. The current specification is MIL-DTL-32101B (2017), B w/AMD2 accepted 2020 — not the 2002 base.
Read →Biogas & RNG
Case study
Written, not published
One more is written and is not published, because the figures inside it are not yet verified — it is waiting on logistics data from the factory. Publishing early would undercut the standard the rest of these set.
Selection
Activated Carbon Lead Time, Port and Landed Cost Explained
Coconut shell carbon ships in 25 kg PP bags, 500 kg jumbo bags or bulk container. Here is the whole enquiry-to-delivery chain a US buyer should price first.