Table 3 Categorisation and physical properties of tested adsorbent media
From: Adsorbent media for the sustainable removal of organic air pollutants from museum display cases
Adsorbent category | Adsorbent media | Supplier/distributor | Compositiona | Physical characteristicsa | Manufacturer remarks/application recommendations |
|---|---|---|---|---|---|
Pure charcoal | PC1 | A | Pure activated carbon, non-impregnated coconut shells, extra-fine pores | Dimensions: chips: 2.4–4.8 mm Apparent density: 450 ± 25 g/l Internal surface area: ~ 1100 m2/g Iodine number: > 1050 mg/g Moisture (as packed): max 10 w/w% Ash content: max 5% | Adsorption of non-polar organic compounds (e.g. biocides), small amounts of acidic gases and substances; good adsorption of small pollutant concentrations due to narrow pores |
PC2 | B | Virgin grade, activated charcoal with high inner surface, non-impregnated | Relative moisture content: max 2% Surface area: 1100–1200 m2/g Moisture content: max 5% Ash content: max 2.5–3% | Designed to remove high molecular weight pollutants by means of adsorption; gases shall adhere to the surface of the media pellet during the adsorptive process | |
PC3 | C | Granular activated carbon; coconut shell steam-activated carbon, non-impregnated | Granular size: > 3.35 mm (max 8%), < 1.7 mm (max 5%) | ||
Impregnated charcoal | IC1 | A | Granulated peat-carbon, impregnated with NaOH, base material: mineral coal | Dimensions: extruded cylinders: diameter ~ 4 mm Apparent density: 500 ± 5 g/l Iodine number: 900 mg/g Moisture (as packed): max 10 w/w% | Adsorption of acidic gases due to alkaline impregnation; chemical application, pollutants are firmly bonded on the charcoal; gases will not be liberated again in long-term application; avoid direct contact with sensitive surfaces due to alkaline impregnation |
IC2 | A | Granulated peat-carbon, impregnated with KOH | Dimensions: extruded cylinders: diameter ~ 3 mm, 5 mm length Apparent density: 500 g/l Moisture (as packed): max 18 w/w% | Avoid direct contact with sensitive surfaces due to alkaline impregnation | |
IC3 | B | Spherical, porous pellets; formed from a combination of activated alumina and other binders, impregnated with potassium permanganate (KMnO4); impregnant is uniformly distributed throughout the pellet volume | Moisture content: max. 35% Density: 800 kg/m3 Nominal diameter: 3.175 mm (1.8’’) Content KMnO4: min 4% Filter capacity: H2S: min 8% (mass fraction) SO2: min 4% (mass fraction) NOx: min 2.8% (mass fraction) | Primary adsorption of hydrogen sulphide (H2S) and sulphur dioxide (SO2); optimum adsorption, absorption and oxidation of a wide variety of gaseous contaminants; desorption not possible; Recommended airflow: 42.5–169.920 m3/h Recommended air velocity: 18–150 m/min | |
IC4 | B | Spherical, porous pellets, impregnated; impregnant is uniformly distributed throughout the pellet volume; impregnant not specified | Manufactured specifically for the control of ammonia and amines | ||
IC5 | B | Equal mix (by volume) of impregnated (IC3) and pure charcoal (PC2, 50/50); spherical, porous pellets, impregnated with KMnO4 | Moisture content: max. 35% Density: 800 kg/m3 Nominal diameter: 3.175 mm (1.8’’) Content KMnO4: min 4% Breaking strength: 35–70% Abrasion: max 4.5% Filter efficiency: 99.5% | Optimum adsorption, absorption and oxidation of a wide range of contaminants; for the control of hydrocarbons with a high surface area available for adsorption Recommended airflow: 42.5–169.920 m3/h Recommended air velocity: 18–150 m/min Temperature range: − 20–51 °C Relative humidity: 10–95% | |
IC6 | B | Generally spherical, porous pellets, formed from a combination of powdered activated alumina and other binders, impregnated with potassium permanganate (KMnO4); the impregnant is uniformly distributed throughout the pellet volume | Moisture content: max. 35% Density: 800 ± 5 kg/m3 Nominal diameter: 3.175 mm (1.8’’) Content KMnO4: min 8% Breaking strength: 35–70% Abrasion: max 4.5% Filter efficiency: 99.5% | Removes sulphur oxides and other odorous pollutants from makeup air, emissions from office furnishings and human bioeffluents; removes H2S, NOx, SO2, HCHO, and low-molecular aldehydes/organic acids; optimum adsorption, absorption and oxidation of a wide variety of gaseous contaminants | |
IC7 | B | Generally spherical, porous pellets, formed from a combination of powdered activated alumina and other binders, impregnated with sodium permanganate (NaMnO4); the impregnant is uniformly distributed throughout the pellet volume | Moisture content: max. 35% Density: 800 kg/m3 Nominal diameter: 3.175 mm (1.8’’) Content KMnO4: min 12% Breaking strength: 35–70% Abrasion: max 4.5% Filter efficiency: 99.5% Filter capacity: H2S: min 14% (mass fraction) SO2: min 7% (mass fraction) NOx: min 4.9% (mass fraction) HCHO: min 4% (mass fraction) | Filtration of H2S, NOx, SO2, HCHO, high molecular aldehydes/organic acids; higher working capacity for broad-spectrum oxidation of contaminants; contains more permanganate as active ingredient for increased removal capacity; neutralization of target substances by chemisorption Recommended airflow: 42.5–169.920 m3/h Recommended air velocity: 18–150 m/min Temperature range: − 20–51 °C Relative humidity: 10–95% | |
IC8 | C | Granular impregnated activated carbon; coconut shell, specially impregnated for chemisorption of formaldehyde | Surface area: 1150 m2/g Apparent density: 620 kg/m2 Moisture content: max 15% | ||
Charcoal cloth | CC1 | C | Activated carbon adsorptive filter media; polyester non-woven on both sides | Basis weight: 310 g/m2 Thickness AFM: 0.9 mm Thickness AFM: 2000 l/m2s Content of activated carbon: 200 g/m2 | |
CC2 | C | Synthetic composite carbon filter media | Basis weight: 119 g/m2 Stiffness, MD: 1000 mgs | Patented gradient density, durable synthetic construction, pleatable, high efficiency, low resistance | |
CC3 | C | Non-woven carbon filter media | Nominal thickness: 6 mm Product weight: 290 gsm Carbon weight: 95 gsm Carbon content: 33% | ||
CC4 | C | Three-layer composite beaded carbon media, 2*100% PES with activated carbon layer | Weight: 295 (g/m2) ± 15% Width: 152 ± 4 cm Thickness: 0.75 ± 0.15 mm Adsorption surface: 165.000 m2/m2 Iodine adsorption: 175,000 mg/m2 | ||
CC5 | C | Activated carbon felt; fibre structure, low pressure drop, low ash content | Weight: 120 g/m2 Butane uptake: 25% Length × width: 50 × 1.15 BET surface area: > 1200 m2/g Thickness: 2–3 mm | ||
CC6 | C | Activated carbon-coated foam; reticulated polyurethane foam which is coated with activated granular carbon | Weight: 4300 g/m2 Thickness: 30 mm Activated-carbon content: 2600 g/m2 | ||
CC7 | C | Open-cell polyurethane foam which is coated with activated granular carbon | Weight: ≥ 2000 g/m2 Thickness: 11 ± 0.5 mm Activated-carbon content: ≥ 1300 g/m2 | ||
CC8 | C | Activated carbon cloth | Highly microporous, knitted structure, excellent kinetics, physically robust; maximum utilisation of available surface area; very good drape and good stretch; very fast adsorption of target contaminants; virtually zero shedding of carbon particulates | ||
CC9 | A | Woven, bonded on one side to a white non-woven | Activated carbon content: 120 g/m2 Internal surface area: 900–1100 m2/g Width: 108 cm Thickness: 0.5 mm | Can oxidize metal at direct contact; possible application for decontamination purposes; interleaf a neutral fabric between the carbon cloth and the object | |
CC10 | A | Woven, bonded on one side to a white non-woven; alkaline impregnated | Internal surface area: 1000–1200 m2/g Width: 100 cm Thickness: 0.5 mm | Alkaline impregnation for tenfold higher adsorption capacity for H2S, NOx and other acid gases; avoid contact with delicate surfaces | |
Zeolites | Z1 | D | Synthetic ZSM (zeolite socony mobil) zeolite; pentasile structure; adsorption of molecules with a diameter of max. 5.6 Å | White, microporous, organophilic, inorganic zeolite powder, large adsorption capacity for odours and flavours and other organic compounds; high adsorption capacity is maintained even after incorporating into a polymer matrix; usually used for VOC adsorption of molecules to about 5.6 Å | |
Z2 | D | Synthetic US-Y zeolite (ultra-stable zeolite Y) | Generally used for VOC adsorption of molecules to about 7.6 Å | ||
Z3 | D | Hydrophobic adsorption media; synthetic HPZ zeolite (high-performance zeolite); high silica/alumina-ratio zeolite product; cubic crystal structure with straight 10-membered ring channels of 5.3*5.6 Å; the channels are connected by sinusoidal channels of 5.1*5.5 Å | Removal of VOCs according to molecular size and polarity; catalytic reaction | ||
Z4 | D | Synthetic zeolite, pentasile structure without Al (pure silica); straight channels with a diameter of 5.1*5.6 Å, connected by 5.4*5.6 Å channels | |||
Z5 | D | Synthetic zeolite, tetragonal structure with 12-membered ring channels (7.6*6.4 Å), connected by 10-membered channels of 5.5*5.6 Å | Pores are composed of 12 tetrahedron; large pore zeolite | ||
Z6 | D | Synthetic zeolite, sodium form of the type X crystal, large pore opening; adsorption of molecules with a kinetic diameter of < 9 Å (0.9 nm) and exclusion of those larger | Highest theoretical capacity of the common adsorbents, very good mass-transfer rates; removal of CO2 and moisture from air, mercaptans, H2S | ||
Z7 | D | Natural zeolite, micro porous structure, silica/alumina tetrahedrons | |||
Molecular sieves | MS1 | D | Molecular sieve, powder, pore opening 3 Å | ||
MS2 | D | Molecular sieve, powder, pore opening 4 Å | |||
MS3 | D | Molecular sieve, powder, pore opening 5 Å | |||
Silica gels | SG1 | A | Silica gel, 97% SiO2, 3% Al2O3, free of chlorides | ||
SG2 | A | Silica gel, 90% SiO2, lithium chloride (LiCl) | No off-gassing; adsorption of small amount of VOCs; degradation by acid contaminants with time (not fixed, can be released again) | ||
Miscellaneous | CF | A | Foam; copper particles embedded on polymeric matrix | Reduce contaminants attacking metals, such as SO2, H2S and others | |
PS | A | 100% cotton fabric embedded with fine silver particles (pure, colloidal silver) | Absorbs tarnish producing gases | ||
AC1 | A | Cardboard embedded with synthetic zeolites; 100% cotton fibres, free of pulp wood and lignin, alkaline binder, alkaline lamination (water-based, solvent-free); colour: white | Acid-free, durable, absorbs and neutralizes pollutants | ||
AC2 | A | Same as AC1; colour: black |