0000000000600480
AUTHOR
Davide Bergna
showing 11 related works from this author
Production of ethyl lactate by activated carbon-supported Sn and Zn oxide catalysts utilizing lignocellulosic side streams
2021
Abstract In this study, activated carbon-supported Sn and Zn oxide catalysts were prepared from hydrolysis lignin and used for the conversion of model solutions of trioses, hexoses, and lignocellulosic biomass hydrolysates to ethyl lactate. Both catalysts, SnO2@AC and ZnO@AC, were able to produce ethyl lactate in high yields. SnO2@AC was a more active and selective catalyst in triose (dihydroxyacetone) conversion, providing 99% yield to ethyl lactate. ZnO@AC, by contrast, was more selective in glucose and hydrolysate conversion, with a yield of 60% and 85%, respectively. The ethyl lactate yields were significantly higher than those from the optimized model solution experiments when using Zn…
Use of Fe and Al containing electrocoagulation sludge as an adsorbent and a catalyst in water treatment
2023
In this study, three different electrocoagulation (EC) sludges were studied as an adsorbent (removal of humic acids) and as a catalyst [catalytic wet peroxide oxidation (CWPO) of bisphenol A (BPA)]. The sludges originated from electrocoagulation process in which aluminum (Al) and iron (Fe) electrodes were used for the treatment of mining industry wastewater. All the materials were used as dried sludge and calcined material. The stability of these materials was studied in neutral and alkaline conditions with analysis of the leached iron content in solution. Based on the EC sludge characterization with X-ray fluorescence (XRF), X-ray diffractometer (XRD), and diffuse-reflectance infrared Four…
Activated Carbon from Renewable Sources: Thermochemical Conversion and Activation of Biomass and Carbon Residues from Biomass Gasification
2017
Activated carbon is one of the most widely applied adsorbent. As a porous carbon, it is used for the purification of both gaseous and liquid emissions. Activated carbon is prepared from fossil resources, such as coal, or from biomass through (hydro)thermal processing followed by chemical and/or physical activation. Further, some biomass thermal treatment processes, such as biomass gasification, produce carbon residues that can be modified to activated carbon with physical or chemical activation methods. The desired properties of activated carbon, i.e. high specific surface area and porosity, high carbon content and excellent sorption capacity, can be modified and optimized during thermochem…
Carbons from second generation biomass as sustainable supports for catalytic systems
2018
Abstract In this study activated carbons were produced from the wood of three different wood species (pine, birch, spruce). The resulting activated carbons were characterized in bulk for ash content, carbon content (elemental analyses), specific surface area, and pore size distribution, and at the surface by measuring the autogenerated pH and studying their structure by XPS. All the samples presented high surface areas and appeared to be mesoporous materials (mesopores >80%). The carbons were then used as support for AuPt nanoparticles and tested in the liquid phase oxidation of glycerol (GLY) and in the hydrogenation of levulinic acid (LA), two important chemicals from cellulose-based biom…
Effects of Briquetting and High Pyrolysis Temperature on Hydrolysis Lignin Char Properties and Reactivity in CO-CO2-N2 Conditions
2021
Carbonaceous reductants for pyrometallurgical applications are usually obtained from fossil-based sources. The most important properties of the reductants greatly depend on the application and the feeding of the reductant into the process. However, the mechanical strength, calorific value, fixed carbon content, and reactivity of the reductant are the properties that usually define the applicability of the reductant for different processes. The reactivity of the biochars is usually high in comparison to metallurgical coke, which may restrict the applicability of the biochar in reduction processes. One cause of the higher reactivity is the higher surface area of the biochars, which can be sup…
Activated carbon from hydrolysis lignin: Effect of activation method on carbon properties
2022
This study presents the effects of different activation methods to produce activated carbon from the hydrolysis lignin. Pretreatment of the feedstock with common mineral acids (HCL, HNO3, and H3PO4), different steam rates for physical activation, and different chemical activating agents (ZnCl2, Na2CO3, and KOH) for chemical activation were investigated. The pretreated biomass was carbonized and activated in one-stage process and the surface characteristics, such as total pore volume, pore size distribution and specific surface area, were investigated. The results showed that the activated carbon surface properties were not greatly affected by acid pretreatment. Brunauer-Emmett-Teller (BET) …
Preparation and Characterization of Pulp and Paper Mill Sludge-Activated Biochars Using Alkaline Activation : A Box–Behnken Design Approach
2022
This study utilized pulp and paper mill sludge as a carbon source to produce activated biochar adsorbents. The response surface methodology (RSM) application for predicting and optimizing the activated biochar preparation conditions was investigated. Biochars were prepared based on a Box–Behnken design (BBD) approach with three independent factors (i.e., pyrolysis temperature, holding time, and KOH:biomass ratio), and the responses evaluated were specific surface area (SSA), micropore area (Smicro), and mesopore area (Smeso). According to the RSM and BBD analysis, a pyrolysis temperature of 800 °C for 3 h of holding and an impregnation ratio of 1:1 (biomass:KOH) are the optimum conditions f…
Comparison of the Properties of Activated Carbons Produced in One-Stage and Two-Stage Processes
2018
Activated carbons (ACs) can be produced from biomass in a thermal process either in a direct carbonization-activation process or by first carbonizing the biomass and later activating the bio-chars 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 one-stage and two-stage processes are considered. Activated carbons were produced by physical activation of two types of starting materials: bio chars 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 …
Zinc Adsorption by Activated Carbon Prepared from Lignocellulosic Waste Biomass
2019
Sawdust was used as a precursor for the production of biomass-based activated carbon. Carbonization and activation are single-stage processes, and steam was used as a physical activation agent at 800 °
Carbons from second generation biomass as sustainable supports for catalytic systems
2018
In this study activated carbons were produced from the wood of three different wood species (pine, birch, spruce). The resulting activated carbons were characterized in bulk for ash content, carbon content (elemental analyses), specific surface area, and pore size distribution, and at the surface by measuring the autogenerated pH and studying their structure by XPS. All the samples presented high surface areas and appeared to be mesoporous materials (mesopores >80%). The carbons were then used as support for AuPt nanoparticles and tested in the liquid phase oxidation of glycerol (GLY) and in the hydrogenation of levulinic acid (LA), two important chemicals from cellulose-based biomass. The …
Activated Carbon Production from Peat Using ZnCl2 : Characterization and Applications
2017
The process for producing activated carbon from peat was optimized. The peat was impregnated with different ratios of ZnCl2, and the impregnated biomass was activated at different temperatures. The specific surface area, pore size distribution, total carbon content, and yield of the activated carbon were investigated. The best results for the specific surface area and mesoporosity of the activated peat were obtained by using a high impregnation ratio (2) and high activation temperature (1073 K). Highly porous activated carbon was produced that had a specific surface area of approximately 1000 m2/g and total pore volume that was higher than 0.5 cm3/g for most samples. The activated carbon ha…