Abstract
This work presents studies on the preparation of porous carbon materials from waste biomass in the form of orange peels, coffee grounds, and sunflower seed husks. The preparation of activated carbons from these three waste materials involved activation with KOH followed by carbonization at 800 °C in an N2 atmosphere. This way of obtaining the activated carbons is very simple and requires the application of only two reactants. Thus, this method is cheap, and it does not generate much chemical waste. The obtained activated carbons were characterized by XRD, SEM, XPS, and XRF methods. Moreover, the textural properties, acidity, and catalytic activity of these materials were descried. During catalytic tests carried out in the alpha-pinene isomerization process (the use of the activated carbons thus obtained in the process of alpha-pinene isomerization has not been described so far), the most active were activated carbons obtained from coffee grounds and orange peels. Generally, the catalytic activity of the obtained materials depended on the pore size, and the most active activated carbons had more pores with sizes of 0.7–1.0 and 1.1–1.4 nm. Moreover, the presence of potassium and chlorine ions in the pores may also be of key importance for the alpha-pinene isomerization process. On the other hand, the acidity of the surface of the tested active carbons did not affect their catalytic activity. The most favorable conditions for carrying out the alpha-pinene isomerization process were the same for the three tested activated carbons: temperature 160 °C, amount of the catalyst 5 wt.%, and reaction time 3 h. Kinetic studies were also carried out for the three tested catalysts. These studies showed that the isomerization over activated carbons from orange peels, coffee grounds, and sunflower seed husks is a first-order reaction.
Highlights
The synthesis of activated carbons from biomass has become an interesting way to obtain useful carbonaceous materials from raw materials that are a waste byproduct of the food industry
The obtained carbonaceous materials were characterized by a well-developed specific surface area ranging from 1366 m2/g to 1566 m2/g, a total pore volume ranging from 0.584 cm3/g to 0.694 cm3/g, and microporous structure ranging from 0.477 cm3/g to 0.54 cm3/g
Activated carbons obtained from waste biomass turned out to be active catalysts for the alpha-pinene isomerization process
Summary
The synthesis of activated carbons from biomass has become an interesting way to obtain useful carbonaceous materials from raw materials that are a waste byproduct of the food industry. Materials of natural origin are often used as precursors in the synthesis of carbonaceous materials [4] For this purpose are used, e.g., corn cobs [5], nutshells [6], pomegranate peels [7], coconut shells [8], coir pith [9], brazilian nutshell [10], palm fruits shells [11], oil palm fruits shells [12], olive stones [13], jackfruit shell waste and jackfruit peels [14], rice husk [15], banana peels [16], apple pulp [17], cotton stalk [18], and egg white biomass [19]. There are reports describing biological precursors used in the production of carbonaceous materials [20]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
