Hydrothermal Carbonization Of Biomass Research Articles

A novel porous carbon derived from hydrothermal carbon for efficient adsorption of tetracycline

Increasing attention is being paid to hydrothermal carbonization (HTC) of waste biomass, due to energy shortages, environmental crises and developing customer demands. However, most research has been dedicated to the production of bio-oil, with few studies focusing on the application of hydrothermal carbon (hydrochar), a solid residue from HTC of biomass. In this study, a novel porous carbon (PC) was prepared from hydrochar, via pyrolysis at different temperatures (300–700°C), the characteristics of PC as well as tetracycline (TC) adsorption behavior were investigated. The hydrochar and PC samples showed a remarkable range of surface properties, as characterized by Boehm titration, the Fourier transform infrared spectra and nuclear magnetic resonance spectra. The changes in characteristics suggested that the PC samples produced at high activation temperature (500–700°C) were well carbonized and exhibited a high surface area (>270m2/g). Linear relationships were obtained between Freundlich adsorptive capacity (KF) and elemental atomic ratios, surface area and pore volume. The high adsorption capacity of PC samples can be attributed to its low polarity and high aromaticity, surface area and pore volume. The molecular variations among the hydrochar and PC samples translated into differences in their ability to adsorb TC.

Influence of reaction time and temperature on product formation and characteristics associated with the hydrothermal carbonization of cellulose

Studies have demonstrated that hydrothermal carbonization of biomass and waste streams results in the formation of beneficial materials/resources with minimal greenhouse gas production. Data necessary to understand how critical process conditions influence carbonization mechanisms, product formation, and associated environmental implications are currently lacking. The purpose of this work is to hydrothermally carbonize cellulose at different temperatures and to systematically sample over a 96-h period to determine how changes in reaction temperature influence product evolution. Understanding cellulose carbonization will provide insight to carbonization of cellulosic biomass and waste materials. Results from batch experiments indicate that the majority of cellulose conversion occurs between the first 0.5-4h, and faster conversion occurs at higher temperatures. Data collected over time suggest cellulose solubilization occurs prior to conversion. The composition of solids recovered after 96h is similar at all temperatures, consisting primarily of sp(2) carbons (furanic and aromatic groups) and alkyl groups.

Sodium salt effect on hydrothermal carbonization of biomass: a catalyst for carbon-based nanostructured materials for lithium-ion battery applications

The salt effect of NaxA (A = SO42−, Cl−, NO3−, etc.) on the hydrothermal carbonization of biomass is reported. It is a new catalyst and recyclable template to more simply and effectively prepare carbon-based materials, such as porous carbon-coated anode materials (e.g., Fe3O4@porous-C) in lithium-ion battery applications with enhanced performance.

Hydrothermal Carbonization of Waste Biomass for Energy Generation

In this study, hydrothermal carbonization was used to upgrade waste biomass at temperatures ranging from 150 to 375 oC and a residence time of 30 minutes. The kinetics of hydrothermal carbonization was investigated and fuel properties of produced hydrochars were evaluated. The kinetic study indicated that hydrothermal carbonization of biomass followed first-order reaction rate with the apparent activation energy of 67.41 and 179.54 kJ/mol for coconut fiber and 59.18 and 173.70 kJ/mol for eucalyptus leaves within the temperature ranges of 150-300 oC and 300-375 oC, respectively. Hydrothermal carbonization narrowed the differences in fuel properties among different biomass feedstocks. The fuel qualities of hydrochars were significantly improved: increased ignition temperatures and elevated combustion temperature regions compared to raw biomass feedstock. The present study showed that hydrothermal carbonization was a promising conversion process for the production of the hydrochars which had increased fuel qualities compared to raw biomass.

Climate Friendly Coal from Hydrothermal Carbonization of Biomass

AbstractEs wird das Verfahren der Hydrothermalen Karbonisierung (HTC) von biogenen Reststoffen und die Umsetzung in einer kontinuierlich laufenden, industriellen Anlage beschrieben. Die Vorteile des Verfahrens zur Verwertung der Biomasse und die Energiebilanz werden erläutert. Die Produkteigenschaften werden exemplarisch für HTC‐Kohle aus Klärschlamm aufgezeigt. Es wird dargelegt, dass das Verfahren eine gute Energieeffizienz aufweist und für die energetische Verwertung unterschiedlicher Eingangsstoffe gut geeignet ist.

Hydrothermal carbonization of biomass as a route for the sequestration of CO2: Chemical and structural properties of the carbonized products

Abstract A highly functionalized carbonaceous material (hydrochar) was obtained by means of the hydrothermal carbonization (250 °C) of two representative types of biomass, i.e. eucalyptus sawdust and barley straw. This product has a brown colour; it contains around 50–60% of the carbon originally present in the biomass and it is composed of particles that retain the cellular appearance of the raw material. These particles are covered by microspheres (1–10 μm) which were probably formed as a consequence of the transformation of the cellulose fraction. From a chemical point of view, the hydrochar products have a high degree of aromatization and they contain a large amount of oxygen-containing groups (i.e. carbonyl, carboxylic, hydroxyl, quinone, ester, etc) as was confirmed by Raman, IR and XPS spectroscopic techniques. The presence of these oxygen functionalities on the surface of the hydrochar particles explains their high water affinity (hydrophilic properties). On the basis of the highly condensed chemical nature of the hydrochar products, we postulated that this material has a recalcitrant nature that could lead to a significant increase in carbon turnover time in relation to the biomass. This suggests an important route for the sequestration of CO 2 present in the atmosphere.

Hydrothermal carbonization of biomass: A summary and discussion of chemical mechanisms for process engineering

AbstractHydrothermal carbonization can be defined as combined dehydration and decarboxy lation of a fuel to raise its carbon content with the aim of achieving a higher calorific value. It is realized by applying elevated temperatures (180–220°C) to biomass in a suspension with water under saturated pressure for several hours. With this conversion process, a lignite‐like, easy to handle fuel with well‐defined properties can be created from biomass residues, even with high moisture content. Thus it may contribute to a wider application of biomass for energetic purposes. Although hydrothermal carbonization has been known for nearly a century, it has received little attention in current biomass conversion research. This review summarizes knowledge about the chemical nature of this process from a process design point of view. Reaction mechanisms of hydrolysis, dehydration, decarboxylation, aromatization, and condensation polymerization are discussed and evaluated to describe important operational parameters qualitatively. The results are used to derive fundamental process design improvements. Copyright © 2010 Society of Chemical Industry and John Wiley & Sons, Ltd

Functional carbonaceous materials from hydrothermal carbonization of biomass: an effective chemical process

Recently, much attention has been attracted to the use of biomass to produce functional carbonaceous materials from the viewpoint of economic, environmental and societal issues. Among different techniques, the hydrothermal carbonization (HTC) process, a traditional but recently revived method, presents superior characteristics that make it a promising route of wide potential application. This perspective gives an overview of the latest advances in the HTC process of functional carbonaceous materials from biomass. First, we discuss the preparation of carbonaceous materials synthesized by the use of either highly directed or catalyst/template-assisted methods, from crude plant materials and carbohydrates respectively. These carbonaceous materials not only have special morphologies, such as nanospheres, nanocables, nanofibers, submicrocables, submicrotubes and porous structures, but also contain rich functional groups which can greatly improve hydrophilicity and chemical reactivity. Further, a general look is cast on the applications of this kind of carbonaceous materials in environmental, catalytic and electrical areas. Recent advances have demonstrated that the HTC process from biomass can provide promising methods for the rational design of a rich family of carbonaceous and hybrid functional carbon materials with important applications.