scholarly journals Thermal Activation of Digested Sewage Sludges for Carbon Dioxide Removal from Biogas

Fuels ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 30-46
Author(s):  
Mirko Tinnirello ◽  
Davide Papurello ◽  
Massimo Santarelli ◽  
Sonia Fiorilli
Keyword(s):  
Adsorption Capacity ◽  
Dwell Time ◽  
Activated Carbons ◽  
Co2 Concentration ◽  
Physical Activation ◽  
Maximum Adsorption Capacity ◽  
Activation Process ◽  
Co2 Removal ◽  
Sewage Sludges ◽  
Activating Agent

Anaerobically digested sewage sludges were used as feedstock in the production of activated carbons through physical activation. These char samples were experimentally tested as adsorbents for the removal of CO2 from a simulated biogas mixture. The CO2 concentration level allowed in biomethane was fixed from the European Standards EN 16723-1 and EN 16723-2. The char yield and the subsequent adsorption capacity values were studied, considering the operating parameters of the process. A physical activation process was considered with the following parameters: the temperature, the dwell time, the activating agent, the heating rate, the flow rate, and the method. Among the adsorption tests, the activating temperature and the agent employed affected the CO2 removal. The maximum adsorption capacity was achieved with nitrogen as an activating agent at 600 °C, with 2 h of dwell time (102.5 mg/g).

scholarly journals H2S Removal with Sorbent Obtained from Sewage Sludges

Processes ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 130
Author(s):  
Davide Papurello ◽  
Andrea Lanzini ◽  
Maurizio Bressan ◽  
Massimo Santarelli
Keyword(s):  
Adsorption Capacity ◽  
Flow Rate ◽  
Dwell Time ◽  
Chemical Activation ◽  
Future Research ◽  
Sewage Sludges ◽  
H2s Removal ◽  
Bed Height ◽  
Activating Agent

Biochar obtained from sewage sludges are adopted for biogas cleaning. Sewage sludges are treated considering temperature, dwell time, activating agent, heating, and flow rate. The best performances achieved are registered considering the char produced at 400 °C using CO2 as an activating agent with a dwell time of 2 h. The adsorption capacity for the biogas cleaning CH4/CO2/H2S (20 ppm(v)) increased from 1.3 mg/g to 5.9 mg/g with the bed height. Future research with chemical activation processes will be made to improve the adsorption capacity achieved to produce cheaper sorbents than commercial ones.

Activated Carbon Prepared from Date Pits for the Retention of NO2 at Low Temperature

2014 ◽  
Vol 12 (2) ◽  
pp. 717-726 ◽  
Author(s):  
Zohra Belala ◽  
Meriem Belhachemi ◽  
Mejdi Jeguirim
Keyword(s):  
Activated Carbon ◽  
Low Temperature ◽  
Adsorption Capacity ◽  
Activated Carbons ◽  
Textural Properties ◽  
Operating Conditions ◽  
Physical Activation ◽  
Maximum Adsorption Capacity ◽  
Increasing Temperature ◽  
Date Pits

Abstract Activated carbons were prepared from date pits by physical activation with CO2 and the textural properties were investigated by BET and D-R methods with N2 and CO2 adsorption isotherms. The interaction of the NO2 with activated carbon was examined at ambient temperature and the effect of operating conditions such as temperature and inlet gas compositions was also examined. It was observed that the development of porosity with increasing time of activation favours the adsorption capacity of NO2. The maximum adsorption capacity reached was about 107 mg/g, which is higher than several activated carbon prepared from classical lignocellulosic biomass. However, a slight decrease of NO2 adsorption capacity was observed with increasing temperature. The addition of oxygen into the inlet gas gave rise to an increase in amount adsorbed of NO2.

scholarly journals Dysprosium Removal from Water Using Active Carbons Obtained from Spent Coffee Ground

2019 ◽  
Author(s):  
Lorena Alcaraz ◽  
María Esther Escudero ◽  
Francisco J. Alguacil ◽  
Irene Llorente ◽  
Ana Urbieta ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Activated Carbons ◽  
Chemical Study ◽  
Bet Surface Area ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Microporous Material ◽  
Physico Chemical ◽  
Spent Coffee Ground ◽  
Coffee Ground

This paper describes the physico-chemical study of the adsorption of dysprosium (Dy3+) in aqueous solution onto two types of activated carbons synthesized from spent coffee ground. KOH activated carbon is a microporous material with a specific BET surface area of 2330 m2·g-1 and pores with a diameter of 3.2 nm. Carbon activated with water vapor and N2 is a solid mesoporous, with pores of 5.7 nm in diameter and a specific surface of 982 m2·g-1. A significant dependence of the adsorption capacity on the solution pH was found, while it does not depend significantly neither on the dysprosium concentration nor on the temperature. A maximum adsorption capacity of 31.26 mg·g-1 and 33.52 mg·g-1 for the chemically and physically activated carbons, respectively, were found. In both cases, the results obtained from adsorption isotherms and kinetic study were better fit to a Langmuir model and a pseudo-second-order kinetics. In addition, thermodynamic results indicate that dysprosium adsorption onto both activated carbons is an exothermic, spontaneous and favorable process.

scholarly journals Synthesis and Characterisation of Pyridinium-Based Ionic Liquid as Activating Agent in Rubber Seed Shell Activated Carbon Production for CO2 Capture

2021 ◽  
Vol 82 (1) ◽  
pp. 85-95
Author(s):  
Nawwarah Mokti ◽  
Azry Borhan ◽  
Siti Nur Azella Zaine ◽  
Hayyiratul Fatimah Mohd Zaid
Keyword(s):  
Ionic Liquid ◽  
Activated Carbon ◽  
Adsorption Capacity ◽  
Co2 Capture ◽  
Low Cost ◽  
Chemical Activation ◽  
Green Technology ◽  
Activation Process ◽  
Rubber Seed ◽  
Activating Agent

The use of an activating agent in chemical activation of activated carbon (AC) production is very important as it will help to open the pore structure of AC as adsorbents and could enhance its performance for adsorption capacity. In this study, a pyridinium-based ionic liquid (IL), 1-butylpyridinium bis(trifluoromethylsulfonyl) imide, [C4Py][Tf2N] has been synthesized by using anion exchange reaction and was characterized using few analyses such as 1H-NMR, 13C-NMR and FTIR. Low-cost AC was synthesized by chemical activation process in which rubber seed shell (RSS) and ionic liquid [C4Py][Tf2N] were employed as the precursor and activating agent, respectively. AC has been prepared with different IL concentration (1% and 10%) at 500°C and 800°C for 2 hours. Sample AC2 shows the highest SBET and VT which are 392.8927 m2/g and 0.2059 cm3/g respectively. The surface morphology of synthesized AC can be clearly seen through FESEM analysis. A high concentration of IL in sample AC10 contributed to blockage of pores by the IL. On the other hand, the performance of synthesized AC for CO2 adsorption capacity also studied by using static volumetric technique at 1 bar and 25°C. Sample AC2 contributed the highest CO2 uptakes which is 50.783 cm3/g. This current work shows that the use of low concentration IL as an activating agent has the potential to produce porous AC, which offers low-cost, green technology as well as promising application towards CO2 capture.

scholarly journals Characterization and comparison of walnut shells-based activated carbons and their adsorptive properties

2020 ◽  
Vol 38 (9-10) ◽  
pp. 450-463
Author(s):  
Xiya Li ◽  
Jieqiong Qiu ◽  
Yiqi Hu ◽  
Xiaoyuan Ren ◽  
Lu He ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Activated Carbons ◽  
Low Cost ◽  
Total Pore Volume ◽  
Textural Properties ◽  
Hydrothermal Carbonization ◽  
Bet Surface Area ◽  
Activation Process ◽  
Walnut Shells ◽  
Adsorption Desorption

The production of low-cost biologically activated carbons (BACs) is urgent need of environmental protection and ecological sustainability. Hence, walnut shells were treated by traditional pyrolysis, direct KOH impregnation and combined activation composed of hydrothermal carbonization and two-step H3PO4- and pyrolysis-activation process to obtain porous carbon with high adsorption capacity. It was found that the best adsorption capacity for iodine and organic dye methylene blue (MB) can be obtained using the KOH impregnation at impregnation ratio of 1:1 or combined activation comprising of 2 h H3PO4 activation and 1 h pyrolysis activation at 1000°C. The produced KOH, H3PO4/pyrolysis activated BACs at the optimum conditions are superior to that of commercial ACs, 9.4 and 1.3 times for MB removal, 4 and 4.5 times for iodine number respectively. Characterization results demonstrated their porous structure with very good textural properties such as high BET surface area (1689.1 m2/g, 1545.3 m2/g) and high total pore volume (0.94 cm3/g, 0.96 cm3/g). The N2 adsorption-desorption isotherm of H3PO4/pyrolysis activated hydrochar suggested the co-existence of micro and meso-pores. Moreover, they are more effective for the removal of Fe(III) and Cr(VI) from aqueous solution than the commercial AC, suggesting a promising application in the field of water treatment.

scholarly journals Dysprosium Removal from Water Using Active Carbons Obtained from Spent Coffee Ground

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1372 ◽  
Author(s):  
Lorena Alcaraz ◽  
María Esther Escudero ◽  
Francisco José Alguacil ◽  
Irene Llorente ◽  
Ana Urbieta ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Potassium Hydroxide ◽  
Activated Carbons ◽  
Bet Surface Area ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Microporous Material ◽  
Spent Coffee Ground ◽  
Coffee Ground ◽  
Pseudo Second Order

This paper describes the physicochemical study of the adsorption of dysprosium (Dy3+) in aqueous solution onto two types of activated carbons synthesized from spent coffee ground. Potassium hydroxide (KOH)-activated carbon is a microporous material with a specific Brunauer–Emmett–Teller (BET) surface area of 2330 m2·g−1 and pores with a diameter of 3.2 nm. Carbon activated with water vapor and N2 is a solid mesoporous, with pores of 5.7 nm in diameter and a specific surface of 982 m2·g−1. A significant dependence of the adsorption capacity on the solution pH was found, but it does not significantly depend on the dysprosium concentration nor on the temperature. A maximum adsorption capacity of 31.26 mg·g−1 and 33.52 mg·g−1 for the chemically and physically activated carbons, respectively, were found. In both cases, the results obtained from adsorption isotherms and kinetic study were better a fit to the Langmuir model and pseudo-second-order kinetics. In addition, thermodynamic results indicate that dysprosium adsorption onto both activated carbons is an exothermic, spontaneous, and favorable process.

scholarly journals ADSORPSI ZAT WARNA METILEN BIRU DENGAN KARBON AKTIF DARI KULIT DURIAN MENGGUNAKAN KOH DAN NaOH SEBAGAI AKTIVATOR

2017 ◽  
Vol 6 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Farida Hanum ◽  
Rikardo Jgst Gultom ◽  
Maradona Simanjuntak
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Contact Time ◽  
Wavelength Region ◽  
Second Order ◽  
Carbon Surface ◽  
Maximum Adsorption Capacity ◽  
Activation Process ◽  
Maximum Surface

Durian is a kind of tropical fruits which can grow well in Indonesia. Durian is containing 60-75% shell. Durian shell could be a potential alternative to activated carbon because it contains 57.42% carbon. The aim of this research is to know the effect of contact time and  stirring speed to activated carbon adsorption capacity from durian shell with KOH and NaOH as activators. FTIR (Fourier Transform Infra Red) analysis showed the activation process effects on  absorption intensity  wavelength region and resulted in formation of C = C aromatic tape, so that the nature of the charcoal becomes more polar compared with the initial condition. Analysis using spectrophotometer UV-Vis to determine  absorbance and  final concentration of each variation of contact time and stirring speed. The results showed that the maximum adsorption capacity obtained by activation of KOH and NaOH on stirring speed of 150 rpm and a contact time of 90 minutes is equal to 3.92 mg / g and 3.8 mg / g respectively. The maximum surface area obtained by activation of KOH and NaOH during the stirring speed 130 rpm and a contact time of 120 minutes is equal to 1785.263 m2 / g and 1730.332 m2 / g respectively. The maximum surface area obtained from this research has met the standards of commercial activated carbon surface area was between 800-1800 m2/ g. Modeling pseudo second order presents a more representative adsorption data, a second order equation is based on the assumption that adsorption step is chemosorption.

scholarly journals Comparison of the Properties of Activated Carbons Produced in a One-stage And a Two-Stage Process

2018 ◽  
Author(s):  
Davide Bergna ◽  
Toni Varila ◽  
Henrik Romar ◽  
Ulla Lassi
Keyword(s):  
Activated Carbons ◽  
Total Carbon ◽  
Physical Activation ◽  
Activation Process ◽  
Two Stage ◽  
Total Carbon Content ◽  
One Stage ◽  
Pore Size Distributions ◽  
Significant Difference ◽  
Stage Process

Activated carbons (ACs) can be produced from biomass in a thermal process either in a direct carbonization-activation process or first by carbonizing the biomass and later on activating the biochars into activated carbons. The properties of the ACs are dependent on the type of process used for production. In this study, the properties of activated carbons produced in a one-stage and a two-stage process are considered. Activated carbons were produced by physical activation of two types of starting materials, biochars produced from spruce and birch chips in a commercial carbonization plant and from the corresponding raw chips. The activated carbons produced were characterized regarding specific surfaces, pore volumes and pore size distributions. The unactivated biochars had some degree of surface area and some porosity. According to the results obtained, two slightly different types of activated carbons are produced depending if a one-stage or a two-stage carbonization and activation process is used. The ACs produced in the one-stage process had higher specific surface areas compared to the ones produced in a two-stage process. In addition, total pore volumes were higher in one-stage process but development of micropores is greater compared to two-stage process. There was no significant difference in total carbon content between one-stage and two-stage process.

scholarly journals Activated Carbon Produced by Pyrolysis of Waste Wood and Straw for Potential Wastewater Adsorption

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2047 ◽  
Author(s):  
Katarzyna Januszewicz ◽  
Paweł Kazimierski ◽  
Maciej Klein ◽  
Dariusz Kardaś ◽  
Justyna Łuczak
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Physical Activation ◽  
Activation Process ◽  
Waste Wood ◽  
Carbon Production

Pyrolysis of straw pellets and wood strips was performed in a fixed bed reactor. The chars, solid products of thermal degradation, were used as potential materials for activated carbon production. Chemical and physical activation processes were used to compare properties of the products. The chemical activation agent KOH was chosen and the physical activation was conducted with steam and carbon dioxide as oxidising gases. The effect of the activation process on the surface area, pore volume, structure and composition of the biochar was examined. The samples with the highest surface area (1349.6 and 1194.4 m2/g for straw and wood activated carbons, respectively) were obtained when the chemical activation with KOH solution was applied. The sample with the highest surface area was used as an adsorbent for model wastewater contamination removal.

scholarly journals Surface Interactions during the Removal of Emerging Contaminants by Hydrochar-Based Adsorbents

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2264 ◽  
Author(s):  
Silvia Román ◽  
Joâo Manuel Valente Nabais ◽  
Beatriz Ledesma ◽  
Carlos Laginhas ◽  
Maria-Magdalena Titirici
Keyword(s):  
Nicotinic Acid ◽  
Adsorption Capacity ◽  
Emerging Contaminants ◽  
Activated Carbons ◽  
Surface Acidity ◽  
Maximum Adsorption Capacity ◽  
Adsorption Mechanisms ◽  
Olive Stone ◽  
Steric Factors ◽  
Negative Ionization

The aim of this work was to test activated carbons derived from hydrochars produced from sunflower stem, olive stone and walnut shells, as adsorbents for emerging contaminants in aqueous solution, namely fluoxetine and nicotinic acid. The adsorption capacity was determined by the chemical nature of the adsorbents, namely the presence of specific functional groups and their positive or negative ionization in aqueous solutions and also by steric factors. The activated carbons produced by air showed a higher adsorption capacity of fluoxetine, whilst the samples produced by carbon dioxide activation were more useful to remove nicotinic acid. In general, surface acidity was advantageous for fluoxetine adsorption and detrimental for nicotinic acid removal. The adsorption mechanisms involved in each case were discussed and related to the adsorbents characteristics. The maximum adsorption capacity, Q0, given by the Langmuir model was 44.1 and 91.9 mg g−1 for fluoxetine and nicotinic acid adsorption, respectively.

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