Pelleted activated carbon

Pelleted Activated Carbon - extruded and cylindrical shaped with diameters from 0.8 to 5 mm. These are mainly used for gas phase applications because of their low pressure drop, high mechanical strength and low dust content. 

The way activated carbon is used is normally determined by the form of activated carbon. With granular and pelleted activated carbon, in most cases the carbon is installed in a fixed bed with the liquid or gas passing through the bed. The compounds to be removed are retained on the activated carbon. The carbon is used until exhaustion. It can then be ... 

If a powder does not have all the required qualities, one can add lubricants to aid the sliding and positioning of the microgranules. Such lubricants can be liquid (water, mineral oil) or solid (tale, graphite, stearic acid, and various stearates). Binders are also added to increase the post-compression adhesion, as for example starch is added for pelletizing active carbon. An increase in the adhesive forces title to chemical bonds resulting from contact between the granules can also be... 

In the majority of cases, for the purification of gases, granular or pelletized activated carbon with a particle size of 0.8-4 mm are used. In order to obtain a high quality product the impregnation must be carried out in an appropriate way. The deposition of additives usually affects the specific surface area and pore size distribution of the resulted carbons. Depending... 

For most situations with a small enclosed vapor degreaser, a dmm holding 200 to 500 pounds of pelletized activated carbon should suffice well. Treatment of air emissions from lip vents on an open-top vapor degreaser... 

Duan H, Koe L C C, Yan R and Chen X, Biological treatment of HjS using pellet activated carbon as a carrier of microorganisms in a biofilter . Water Research, 2006,40,... 

The subject area of activated carbon was by now a significant technology in several industries where the applications of carbons, prepared by thermal (as well as chemical activation) were of fundamental importance. This handbook provided a chapter (summary) of aspects which must be considered in discussions of the use of activated carbon. The chapter contains an Introduction, Production Methods, Precursors, Physical (Thermal) Activation, Chemical Activation, Combined Activations, Carbon Molecular Sieves, Activated Carbon Fibers and Cloths, Pelletized Activated Carbons, Washed, Treated and Impregnated Activated Carbon, as well as a section covering industrial production and applications. As such, this chapter is a substantial reference document and will remain so for some considerable time (Rodriguez-Reinoso, 2002). 

Activated carbon is an amorphous solid with a large internal surface area/pore strucmre that adsorbs molecules from both the liquid and gas phase [11]. It has been manufactured from a number of raw materials mcluding wood, coconut shell, and coal [11,12]. Specific processes have been developed to produce activated carbon in powdered, granular, and specially shaped (pellet) forms. The key to development of activated carbon products has been the selection of the manufacturing process, raw material, and an understanding of the basic adsorption process to tailor the product to a specific adsorption application. 

Gas phase applications of activated carbon fall into the main categories of separation, gas storage, and catalysis. These applications account for about 20% of the total use of activated carbon, with the majority using either granular or pellet type. Table 3 shows the major gas phase applications, again along with 1987 consumption levels. 

Once the heel has been established in the carbon bed, the adsorption of the fuel vapor is characterized by the adsorption of the dominant light hydrocarbons composing the majority of the hydrocarbon stream. Thus it is common in the study of evaporative emission adsorption to assume that the fuel vapor behaves as if it were a single light aliphatic hydrocarbon component. The predominant light hydrocarbon found in evaporative emission streams is n-butane [20,33]. Representative isotherms for the adsorption of n-butane on activated carbon pellets, at two different temperatures, are shown in Fig. 8. The pressure range covered in the Fig. 8, zero to 101 kPa, is representative of the partial pressures encountered in vehicle fuel vapor systems, which operate in the ambient pressure range. 

The current requirements have led to the development of pellet shaped activated carbon products specifically for automotive applications. These pellets are typically generated as chemically activated, wood-based carbons. 

Complex mycelium pellets of Trametes versicolor with activated carbon powder were investigated for decolorization of Acid Violet 7 [49]. The complex pellets showed the best dye removal. The dye was almost completely removed in 6 h. For complex pellets, maximum decolorization rate (Vmax mg/L h) and half velocity concentration (Ks mg/L) was calculated 130.5 and 345.0 in batch system, respectively. 

The decolorization of mono-azo textile dye Astrazon Red dye by free pellets and immobilized on activated carbon of Funalia trogii ATCC200800 was studied [52], The decolorization efficiency of the immobilized pellets after 10 days of operation was found higher (88%) compared with the results of a similar experiment with free... 

Zhang FM, Yu J (2000) Decolourisation of acid violet 7 with complex pellets of white rot fungus and activated carbon. Bioprocess Eng 23 295-301... 

For application in flow reactors the nanocarbons need to be immobilized to ensure ideal flow conditions and to prevent material discharge. Similar to activated carbon, the material can be pelletized or extruded into millimeter-sized mechanically stable and abrasion-resistant particles. Such a material based on CNTs or CNFs is already commercially available [17]. Adversely, besides a substantial loss of macroporosity, the use of an (organic) binder is often required. This material inevitably leaves an amorphous carbon overlayer on the outer nanocarbon surface after calcination, which can block the intended nanocarbon surface properties from being fully exploited. Here, the more elegant strategy is the growth of nanocarbon structures on a mechanically stable porous support such as carbon felt [15] or directly within the channels of a microreactor [14,18] (Fig. 15.3(a),(b)), which could find application in the continuous production of fine chemicals. Pre-shaped bodies and surfaces can be... 

The sorbitol solution produced from hydrogenation is purified in two steps [4]. The first involves passing the solution through an ion-exchange resin bed to remove gluconate and other ions. In the second step, the solution is treated with activated carbon to remove trace organic impurities. The commercial 70% sorbitol solution is obtained by evaporation of the water under vacuum. The solid is prepared by dehydration until a water-free melt is obtained which is cooled and seeded. The crystals are removed continuously from the surface (melt crystallization). The solid is sold as flakes, granules, pellet, and powder forms in a variety of particle size distributions. 

Due to this technology s stage of development, no cost information is available regarding product cost. Cost information regarding production cost, however, has been developed. The cost of producing BAC is 39% less than producing conventional activated carbon 227.00 per ton for BioBinder pellets compared with 375.00 per ton for activated carbon pellets made from wood char and wood tar in 1996 dollars (D137421, p. 2). 

In the third variation a mixture of moisturized green coffee beans and activated carbon is filled into the extractor, and the activated carbon pellets used are just big enough to fit between the beans. For 3 kg of coffee beans, 1 kg of activated carbon is needed. At 220 bar and 90°C the caffeine in the supercritical CO2 diffuses directly out of the beans into the activated carbon. A CO2 circulation is not necessary. The required degree of decaffeination is reached after 6 to 8 hours. After extraction, the beans and activated carbon are separated by a vibrating sieve. 

Catalyst-supporting materials are used to immobilize catalysts and to eliminate separation processes. The reasons to use a catalyst support include (1) to increase the surface area of the catalyst so the reactant can contact the active species easily due to a higher per unit mass of active ingredients (2) to stabilize the catalyst against agglomeration and coalescence (fuse or unite), usually referred to as a thermal stabilization (3) to decrease the density of the catalyst and (4) to eliminate the separation of catalysts from products. Catalyst-supporting materials are frequently porous, which means that most of the active catalysts are located inside the physical boundary of the catalyst particles. These materials include granular, powder, colloidal, coprecipitated, extruded, pelleted, and spherical materials. Three solids widely used as catalyst supports are activated carbon, silica gel, and alumina ... 

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