TY  - JOUR
A1  - Reza, M. Toufiq
A1  - Rottler, Erwin
A1  - Tölle, Rainer
A1  - Werner, Maja
A1  - Ramm, Patrice
A1  - Mumme, Jan
T1  - Production, characterization, and biogas application of magnetic hydrochar from cellulose
JF  - Bioresource technology : biomass, bioenergy, biowastes, conversion technologies, biotransformation, production technologies
N2  - Hydrothermal carbonization (HTC) produces carbon-rich nano-micro size particles. In this study, magnetic hydrochar (MHC) was prepared from model compound cellulose by simply adding ferrites during HTC. The effects of ferrites on HTC were evaluated by characterizing solid MHC and corresponding process liquid. Additionally, magnetic stability of MHC was tested by magnetic susceptibility method. Finally, MHC was used as support media for anaerobic films in anaerobic digestion (AD). Ash-free mass yield was around 50% less in MHC than hydrochar produced without ferrites at any certain HTC reaction condition, where organic part of MHC is mainly carbon. In fact, amorphous hydrochar was growing on the surface of inorganic ferrites. MHC maintained magnetic susceptibility regardless of reaction time at reaction temperature 250 degrees C. Pronounced inhibitory effects of magnetic hydrochar occurred during start-up of AD but diminished with prolong AD times. Visible biofilms were observed on the MHC by laser scanning microscope after AD. (C) 2015 Elsevier Ltd. All rights reserved.
KW  - Cellulose
KW  - Hydrothermal carbonization
KW  - Magnetic hydrochar
KW  - Magnetic susceptibility
KW  - Anaerobic digestion
Y1  - 2015
U6  - https://doi.org/10.1016/j.biortech.2015.03.044
SN  - 0960-8524
SN  - 1873-2976
VL  - 186
SP  - 34
EP  - 43
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Thuenemann, Andreas F.
A1  - Klobes, Peter
A1  - Wieland, Christoph
A1  - Bruzzano, Stefano
T1  - On the nanostructure of micrometer-sized cellulose beads
JF  - Analytical & bioanalytical chemistry
N2  - The analysis of the porosity of materials is an important and challenging field in analytical chemistry. The gas adsorption and mercury intrusion methods are the most established techniques for quantification of specific surface areas, but unfortunately, dry materials are mandatory for their applicability. All porous materials that contain water and other solvents in their functional state must be dried before analysis. In this process, care has to be taken since the removal of solvent bears the risk of an incalculable alteration of the pore structure, especially for soft materials. In the present paper, we report on the use of small-angle X-ray scattering (SAXS) as an alternative analysis method for the investigation of the micro and mesopores within cellulose beads in their native, i.e., water-swollen state; in this context, they represent a typical soft material. We show that even gentle removal of the bound water reduces the specific surface area dramatically from 161 to 109 m(2) g(-1) in cellulose bead sample type MT50 and from 417 to 220 m(2) g(-1) in MT100. Simulation of the SAXS curves with a bimodal pore size distribution model reveals that the smallest pores with radii up to 10 nm are greatly affected by drying, whereas pores with sizes in the range of 10 to 70 nm are barely affected. The SAXS results were compared with Brunauer-Emmett-Teller results from nitrogen sorption measurements and with mercury intrusion experiments.
KW  - Small-angle X-ray scattering
KW  - Cellulose
KW  - Mesopores
KW  - Micropores
KW  - Porosimetry
Y1  - 2011
U6  - https://doi.org/10.1007/s00216-011-5176-z
SN  - 1618-2642
VL  - 401
IS  - 4
SP  - 1101
EP  - 1108
PB  - Springer
CY  - Heidelberg
ER  -