Thermal analysis of activated carbon obtained from residue after supercritical extraction of hops

Abstract

Activated carbons have been obtained by physical activation of residue left after supercritical extraction of hops. The effect of pyrolysis temperature on the physicochemical properties of the adsorbents prepared was tested. The carbonaceous materials were characterised by low-temperature nitrogen sorption, determination of pH and the number of surface oxygen groups. The thermal properties of the chars and activated carbons were identified by thermogravimetric analysis and differential thermogravimetry. The products of thermochemical treatment of the starting hops were carbonaceous adsorbents of specific surface area ranging from 2 to 416 m 2 g-1 , showing definitely basic character of the surface and moderate thermal stability as evidenced by a considerable mass loss at about 300-400°C. The results obtained in our study have proved that residue left after supercritical extraction of hops (or similar plant materials) can be cheap, easily accessible and promising precursor for activated carbons. The results have also shown that future research should be aimed at the optimum choice of the temperature of carbonation and activation in order to significantly improve the textural parameters of the activated carbons as well as their thermal stability.

Shape engineered three dimensional α-Fe2 O3 -activated carbon nano composite as enhanced electrochemical supercapacitor electrode material

“…The weight loss at 250°C may be mainly due to the loss of coordinated water molecules from the Plain Fe 2 O 3. In the case of SDAC800, this weight loss can be attributed to the decomposition of organic structure . Whereas in the case Fe 2 O 3 ‐AC, the weight loss at this temperature can be attributed to the presence of Fe which might be preventing the breakdown of organic structure.…”

“…In the case of SDAC800, this weight loss can be attributed to the decomposition of organic structure. 35 Whereas in the case Fe 2 O 3 -AC, the weight loss at this temperature can be attributed to the presence of Fe which might be preventing the breakdown of organic structure. The weight loss at around 550°C in plain Fe 2 O 3 can be attributed to the loss of hydroxyl groups.…”

Structural-Property Relationship in Activated Carbon Synthesized from Rice Straw for Electronic Application

“…As indicated by EDX and XPS results, carbon is the most preponderant element in all samples (more than 80%), and C-C bonding opening for ACs is the most thermally stable fragment. Typically their degradation occurs at higher temperature (more than 950ºK) [53,54]. For this reason, we present thermal analysis only on the temperature range corresponding to the loss of all other elements except carbon.…”

Adsorption Properties of Activated Tire Pyrolysis Chars for Phenol and Chlorophenols

“…The obtained TG curves give information on the amount of each type of functional group on the carbon surface [16]. Previously, this method was successfully used for pyrolyzed and then CO 2 -activated residues left after supercritical extraction of hops [17]. Fig.…”