Activated carbon – produced according to EU envi­ron­mental stan­dards

With the precisely controll­able and clean PYREG carbo­ni­sa­tion tech­no­logy, activated carbons with a surface area of up to 1000 m2/g can be produced on an indus­trial scale. The high-quality special coal is obtained in an energy-effi­cient, single-stage and envi­ron­ment­ally friendly produc­tion process. Gentle steam activa­tion ensures the largest possible surface area, while fully auto­matic opera­tion ensures maximum effi­ci­ency. Depen­ding on the requi­re­ments placed on the activated carbon, regio­nally rene­wable raw mate­rials such as nut shells or hard­wood can also be used for produc­tion.

Learn more about activated carbon

The fine black powder plays an extre­mely important role in water treat­ment. Activated carbon is very porous and like a sponge, has count­less pores that are only a few nano­me­tres in size. Pores are divided into micro-, meso- and macro­pores and toge­ther create a huge surface to which liquid or gaseous subs­tances can adhere. The inner surface of 2 grams of activated carbon corre­sponds appro­xi­mately to the surface of a foot­ball field (source: CHEMIE.DE/lexikon/aktivkohle [German]). With parti­cu­larly high-quality activated carbon, this inner surface can be up to 2000 square metres per gram.
If a liquid or gas flows through the activated carbon, pollutant mole­cules (espe­ci­ally non-polar ones) are bound to the surface. The adsorp­tion process can be either physical or chemical. In the case of physical adhe­sions of a subs­tance, the bonding occurs through mole­cular surface forces (van-der-Waals forces). In the case of chemical accu­mu­la­tions, the pollutant and the biochar undergo a chemical reac­tion at the surface and the bond is usually stronger (source: QUICKER/WEBER, Biokohle, 2016 [German]). In the case of indus­trial adsorb­ents, the density and thermal conduc­tivity of the activated carbon is decisive in addi­tion to the surface area and pore volume (source: QUICKER/WEBER, Biokohle, 2016 [German]). The so-called ‘activa­tion’ process leads to an expan­sion and enlar­ge­ment of the pore struc­ture and thus also of the inner surface.
The global demand for activated carbon is around 2 million metric tons per year. A quarter of the activated carbon produced and distri­buted world­wide is used in water and waste­water treat­ment (Source: ELEMENTE 2/2016 [German]). With rising tendency. The fine-grained char­coal is also used as an adsor­bent (adhe­sion of a liquid or gaseous subs­tance to the surface of a solid) in the chemical, medical, venti­la­tion and air-condi­tio­ning indus­tries. Activated carbon is mainly produced outside Europe from hard coal, lignite or coconut fibres. Activated carbon imports to Germany have been rising for years. Whereas in 2006 around 30,000 tonnes of activated carbon were brought to Germany, by 2017 this figure had risen to more than 70,000 tonnes (source: DIE ZEIT, Wie aktiv kann Kohle sein (How Active Can Coal Be), 2018; ESSER-SCHMIT­MANN/ SCHMITZ, Verglei­chende Ökobi­lanzen für Adsor­ben­tien zur Abgas­rei­ni­gung (Compa­ra­tive Life Cycle Assess­ments of Adsorb­ents for Exhaust Gas Puri­fi­ca­tion).
Carbon from biogenic subs­tances can be activated in two ways: In physical activa­tion, the biomass is first carbo­nised and then activated by the addi­tion of steam or carbon dioxide. In chemical activa­tion, the biomass is treated with a chemical subs­tance (e.g. NaOH, H3PO4 or KOH) and then carbo­nised (source: QUICKER/WEBER, Biokohle, 2016 [German]). Chemical activa­tion is a one-step process and usually takes place at lower pyro­lysis tempe­ra­tures as compared to physical activa­tion.
In all produc­tion processes, the raw mate­rial (lignite, hard coal, anthr­acite, peat, wood, olive stones or nut shells) is dried, charred and activated through the supply of energy – an extre­mely energy- and resource-inten­sive process (source: ESSER-SCHMIT­MANN/ SCHMITZ, Verglei­chende Ökobi­lanzen für Adsor­ben­tien zur Abgas­rei­ni­gung (Compa­ra­tive Life Cycle Assess­ments of Adsorb­ents for Exhaust Gas Puri­fi­ca­tion)). Due to cost pres­sure and high envi­ron­mental stan­dards, there are hardly any activated carbon produ­cers left in Europe (Source: ESSER-SCHMIT­MANN/ SCHMITZ, Compa­ra­tive Life Cycle Assess­ments for Adsorb­ents for Exhaust Gas Puri­fi­ca­tion). The envi­ron­mental pollu­tion caused by the emis­sion of carbon monoxide, vola­tile hydro­car­bons and soot parti­cles, among others, is thus mainly caused in coun­tries where European envi­ron­mental stan­dards do not apply (USA, Australia, China, Phil­ip­pines, Sri Lanka; source: ITHAKA JOURNAL, Aktiv­kohlen – eine saubere Sache (Activated Carbon – A Clean Thing), 2018).
The ability of activated carbon as a water and particle filter has its price. Depen­ding on the market situa­tion, one ton of activated carbon costs between 1,500 and 2,000 euros (source: GELSEN­WASSER, Gewäs­ser­schutz & Koope­ra­tionen [German]). Here, too, the trend is increa­sing due to rising demand (for example, to the intro­duc­tion of the 4th treat­ment stage in sewage treat­ment plants).