An Environmentally Friendly Technology for Biomass Production Hydorchar from Renewable Resources

2013 ◽  
Vol 726-731 ◽  
pp. 634-637 ◽  
Author(s):  
Yan Qiu Lei ◽  
Hai Quan Su

A green and sustainable route for preparation of hydrochars from cornstalk by hydrothermal carbonization (200°C) was described. The morphology of the hydrochars changed with reaction time increased, the surface of the materials contained a large number of functional groups, showed higher adsorption capacity for Cr (VI) than activated carbon and the removal rates of Cr (VI) were 67% and 29% respectively (pH=1, 20°C).

2013 ◽  
Vol 726-731 ◽  
pp. 1687-1690
Author(s):  
Jing Zhang ◽  
Jian Song Liu ◽  
Chun Liu ◽  
Jing Liang Yang ◽  
Lei Zhang

The structure and surface chemical properties of activated carbon after nitric acid modification and their influences on adsorption and catalytic ozonation of acid red 3R were investigated. The results showed that both specific surface area and micropore volume of activated carbon decreased, but mesopore volume increased after nitric acid modification. The adsorption capacity and catalytic ozonation performance of modified activated carbon were influenced due to the increased surface acidic functional groups. The adsorption capacity of modified activated carbon was enhanced under acidic condition due to dispersion interaction between increased surface acidic functional groups and acid red 3R. The increase in surface acidic functional groups of activated carbon was also considered to be responsible for improvement of the catalytic ozonation of acid red 3R under alkaline condition, because of their participation in the ozone decomposition and OH generation.


2018 ◽  
Vol 54 (4B) ◽  
pp. 19
Author(s):  
Hoa Thai Ma

Activated carbon (AC) has been proven to be an effective adsorbent for the removal of a variety of pollutants. AC is extensively used for adsorption because its high surface area is well-developed internal micro porosity. The objective of this study is to determine the optimal condition of the surface modification process of activated carbon from rice husk (ACRH) using HNO3. That increase the functional group, and improve affinity towards certain contaminants of ACRH for increasing the adsorption capacity of Ni2+ and Cd2+. Two factors were taken into account as: the concentration of HNO3 (1, 3, and 5 M), reaction time (1, 2, 3, 4 and 5 hours). The results showed that the optimal condition of the surface modification process was derived at the equilibrium concentration of HNO3 = 3 M and the equilibrium reaction time = 4 hour. Interestingly, in comparison with the control sample (ACRH not modified), the adsorption capacity of Ni2+ and Cd2+ increased from 10.0 to 17.2 mg/g and 10.4 to 29.6 mg/g, respectively. This adsorption capacity of modified ACRH shows the increase significantly.


Author(s):  
Hind Yaacoubi ◽  
Zuo Songlin

Abstract The objective of this research is to study the retention of two acidic anthraquinone dyes by Coconut-shell-based activated carbon. Ultimately, this work allows the valorization of this new material as an adsorbent. The effect of ammonia modification on the adsorption capacity of activated carbon towards remazol brilliant blue R19 (RB19) and acid blue 25 (AB25), has been studied. Coconut-shell-based activated carbon material was modified under ammonia flow at 900 and 1000 °C. The adsorption rates and isotherms of RB19 and AB25 on the resultant materials were then tested. The results show that ammonia modification remarkably increases the adsorption capacities of the activated carbons to RB19 and AB25, by a factor of 2–3 after treatment at 1000 °C (From 0.22 mmol g−1 and 1.04 mmol g−1 to 0.76 mmol g−1 and 2.19 mmol g−1 on AC and AC-O-N-1000, respectively). The increased adsorption capacity is attributed to the introduction of basic nitrogen-containing functional groups and enhanced pore development by ammonia modification. The collected experimental kinetic and isotherm data are well compatible with the intraparticle diffusion kinetic model and the Langmuir isotherm model. According to these results, the adsorption affinity is homogeneous in terms of surface functional groups and the surface bears a finite number of identical adsorption sites.


2013 ◽  
Vol 663 ◽  
pp. 807-812
Author(s):  
Guo Yang ◽  
Yan Jie ◽  
Hu Yang ◽  
Chen Hong Zhang

To investigate the influence of N-containing surface functional groups on adsorption capacity of AC, the activated carbon (AC) was modified with ammonia gas at 650 °C. Surface functional groups were quantitatively analyzing by Boehm titration. The effect of temperature on adsorption capacity suggested higher temperature is favourable. The influence of pH indicated the adsorption was favorable in acidic solution. The adsorption isotherms were fitted by Langmuir model and Freundlich model. Moreover, kinetic studies showed the adsorption of phenol onto adsorbents was followed by pseudo-second-order kinetic model. The adsorption capacity of ammoniated AC for p-chlorophenol was greatly improved.


2018 ◽  
Vol 13 (1) ◽  
pp. 153-159
Author(s):  
Sahira Joshi

 This paper presents the comparative study on the adsorption capacity of activated carbons prepared from Lapsi (Choerospondias axillaris) seed stone and Betel (Areca catechu) nut. Activated carbons (ACs) were prepared from Lapsi seed stone (LSS) and Betel Nut (BN) by chemical activation with H3PO4 (in the ratio of 1:1 by weight) at 400°C. The pore structure of activated carbons was determined by iodine number and methylene blue number. Surface morphology of ACs was studied by scanning electron microscopy (SEM). Surface functional groups were analyzed by Fourier Transform Infra Red Spectroscopy (FTIR). As indicated by TGA analysis, the appropriate temperature required for carbonization was 400 ºC. Betel nut AC showed high iodine number and methylene number of 888 mg/gm and 369 mg/gm respectively. SEM micrographs of Betel nut AC show the presence of well developed pores on its surface. FTIR result indicated that both ACs contain −OH, >C=O groups as oxygen containing surface functional groups. Based on the result, the AC prepared from betel nut by activation with H3PO4 is comparable with commercial activated carbon and could be used as potential adsorbent for removal of pollutants from water and waste water.Journal of the Institute of Engineering, 2017, 13(1): 153-159


2020 ◽  
Author(s):  
Cristian Cavedon ◽  
Eric T. Sletten ◽  
Amiera Madani ◽  
Olaf Niemeyer ◽  
Peter H. Seeberger ◽  
...  

Protecting groups are key in the synthesis of complex molecules such as carbohydrates to distinguish functional groups of similar reactivity. The harsh conditions required to cleave stable benzyl ether protective groups are not compatible with many other protective and functional groups. The mild, visible light-mediated debenzylation disclosed here renders benzyl ethers orthogonal protective groups. Key to success is the use of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as stoichiometric or catalytic photooxidant such that benzyl ethers can be cleaved in the presence of azides, alkenes, and alkynes. The reaction time for this transformation can be reduced from hours to minutes in continuous flow. <br>


2020 ◽  
Vol 5 (3) ◽  
pp. 221
Author(s):  
Muhammad Azam ◽  
Muhammad Anas ◽  
Erniwati Erniwati

This study aims to determine the effect of variation of activation temperature of activated carbon from sugar palm bunches of chemically activatied with the activation agent of potassium silicate (K2SiO3) on the adsorption capacity of iodine and methylene blue. Activated carbon from bunches of sugar palmacquired in four steps: preparationsteps, carbonizationstepsusing the pyrolysis reactor with temperature of 300 oC - 400 oC for 8 hours and chemical activation using of potassium silicate (K2SiO3) activator in weight ratio of 2: 1 and physical activation using the electric furnace for 30 minutes with temperature variation of600 oC, 650 oC, 700 oC, 750 oC and 800 oC. The iodine and methyleneblue adsorption testedby Titrimetric method and Spectrophotometry methodrespectively. The results of the adsorption of iodine and methylene blue activated carbon from sugar palm bunches increased from 240.55 mg/g and 63.14 mg/g at a temperature of 600 oC to achieve the highest adsorption capacity of 325.80 mg/g and 73.59 mg/g at temperature of 700 oC and decreased by 257.54 mg/g and 52.03 mg/g at a temperature of 800 oCrespectively.However, it does not meet to Indonesia standard (Standard Nasional Indonesia/SNI), which is 750 mg/g and 120 mg/g respectively.


2017 ◽  
Vol 28 (Suppl. 1) ◽  
pp. 227-240 ◽  
Author(s):  
Nur 'Izzati A. Ghani ◽  
◽  
Nur Yusra Mt Yusuf ◽  
Wan Nor Roslam Wan Isahak ◽  
Mohd Shahbuddin Masdar ◽  
...  

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