A subscription to JoVE is required to view this content. Sign in or start your free trial.
A protocol for the emission precursor depletion from low quality biomass by low temperature microwave assisted hydrothermal carbonization treatment is presented. This protocol includes the microwave parameters and the analysis of the biocoal product and process water.
Biomass is a sustainable fuel, as its CO2 emissions are reintegrated in biomass growth. However, the inorganic precursors in the biomass cause a negative environmental impact and slag formation. The selected short rotation coppice (SRC) willow wood has a high ash content ( = 1.96%) and, therefore, a high content of emission and slag precursors. Therefore, the reduction of minerals from SRC willow wood by low temperature microwave assisted hydrothermal carbonization (MAHC) at 150 °C, 170 °C, and 185 °C is investigated. An advantage of MAHC over conventional reactors is an even temperature conductance in the reaction medium, as microwaves penetrate the whole reactor volume. This allows a better temperature control and a faster cooldown. Therefore, a succession of depolymerization, transformation and repolymerization reactions can be analyzed effectively. In this study, the analysis of the mass loss, ash content and composition, heating values and molar O/C and H/C ratios of the treated and untreated SCR willow wood showed that the mineral content of the MAHC coal was reduced and the heating value increased. The process water showed a decreasing pH and contained furfural and 5-methylfurfural. A process temperature of 170 °C showed the best combination of energy input and ash component reduction. The MAHC allows a better understanding of the hydrothermal carbonization process, while a large-scale industrial application is unlikely because of the high investment costs.
The application of microwaves for hydrothermal carbonization (MAHC) was used for the thermochemical transformation of biomass model compounds like fructose, glucose1,2 or cellulose3, and for organic substrates, preferably waste material4,5,6,7,8,9,10. The utilization of microwaves is advantageous as it allows an even heating of the treated biomass
1. Preparation of sample material
2. Microwave assisted hydrothermal carbonizati.......
The results of the elemental analysis revealed differences between the O/C-H/C ratio of the willow wood and the MAHC biocoals (Figure 1). The raw material shows higher O/C-H/C ratios and a higher variation of the values. The MAHC treatment reduced the value variation due to homogenization in the microwave reactor. The precision of the microwave reactor allowed the differentiation of three stages of degradation. The H/C ratio was reduced at 150 °C and the.......
The MAHC allows the differentiation of the steps of the chemical degradation by applying different intensities of thermal treatment. Therefore, it is possible to assess the interactions between the mass loss, O/C-H/C ratio, heating value, ash component reduction, pH increase of the process water and accumulation of furans in the process water. The advantage of the MAHC method over the conventional HTC reactor method is based on the thermal conduction via microwaves that penetrate the whole reactor volume and conduct the .......
The authors like to thank Christoph Warth, Michael Russ, Carola Lepski, Julian Tejada and Dr. Rainer Kirchhof for their technical support. The study was funded by the BMBF (Project BiCoLim-Bio-Combustibles Limpios) under the grant number 01DN16036.
....Name | Company | Catalog Number | Comments |
5MS non-polar cloumn | Thermo Fisher Scientific,Waltham, USA | TraceGOLD SQC | GCMS |
9µm polyvinylalcohol particle column | Methrom AG, Filderstadt, Germany | Metrosep A Supp 4 -250/4.0 | Ion chromatography |
argon | Westfalen AG, Münster, Germany | UN 1006 | ICP-OES |
calorimeter | IKA-Werke GmbH & Co.KG, Stauffen, Germany | C6000 | higher and lower heating value |
centrifuge | Andreas Hettich GmbH & Co.KG, Germany | Rotofix 32 A | |
centrifuge mill | Retsch Technology GmbH, Haan, Germany | ZM 200 | |
ceramic dishes | Carl Roth GmbH&Co.KG, Karlsruhe, Germany | XX83.1 | Ash content |
cutting mill | Fritsch GmbH, Markt Einersheim, Germany | pulverisette 19 | |
D(+) Glucose | Carl Roth GmbH&Co.KG, Karlsruhe, Germany | X997.1 | higher and lower heating value |
elemental analyzer | elementar Analysesysteme GmbH, Langenselbold, Germany | varioMACRO cube | elemental analysis |
exicator | DWK Life Sciences GmbH, Wertheim, Germany | DURAN DN300 | Ash content |
GC-MS system | Thermo Fisher Scientific,Waltham, USA | Trace 1300 | GCMS |
hydrochloric acid | Carl Roth GmbH&Co.KG, Karlsruhe, Germany | HN53.3 | ICP-OES |
ICP OES | Spectro Analytical Instruments GmbH, Kleve, Germany | Spectro Blue-EOP- TI | ICP-OES |
Ion chromatograph | Methrom GmbH&Co.KG, Filderstadt, Germany | 833 Basic IC plus | Ion chromatography |
kiln dryer | Schellinger KG, Weingarten, Germany | ||
kiln dryer | Schellinger KG, Weingarten, Germany | Ash content | |
mesh filter paper | Carl Roth GmbH&Co.KG, Karlsruhe, Germany | L874.1 | ICP-OES |
microwave oven | Anton Paar GmbH, Graz, Austria | Multiwave Go | |
muffel furnance | Carbolite Gero GmbH &Co.KG, Neuhausen, Germany | AAF 1100 | Ash content |
nitric acid | Carl Roth GmbH&Co.KG, Karlsruhe, Germany | 4989.1 | ICP-OES |
oxygen | Westfalen AG, Münster, Germany | UN 1072 | higher and lower heating value |
pH-meter | ylem Analytics Germany Sales GmbH & Co. KG, Weilheim,Germany | pH 3310 | pH |
sample bag | IKA-Werke GmbH & Co.KG, Stauffen, Germany | C12a | higher and lower heating value |
Standard Laboratory Vessels and Instruments | |||
standard samples | Bernd Kraft GmbH, Duisburg, Germany | ICP-OES | |
sulfonamite | elementar Analysesysteme GmbH, Langenselbold, Germany | SLBS4782 | elemental analysis |
teflon reaction vessels | Anton Paar, Austria | HVT50 | |
teflon reaction vessels | Anton Paar, Austria | HVT50 | ICP-OES |
tin foil | elementar Analysesysteme GmbH, Langenselbold, Germany | S12.01-0032 | elemental analysis |
tungstenVIoxide | elementar Analysesysteme GmbH, Langenselbold, Germany | 11.02-0024 | elemental analysis |
twice deionized water | Carl Roth GmbH&Co.KG, Karlsruhe, Germany | ||
twice deionized water | Carl Roth GmbH&Co.KG, Karlsruhe, Germany | higher and lower heating value | |
twice deionized water | Carl Roth GmbH&Co.KG, Karlsruhe, Germany | ICP-OES |
This article has been published
Video Coming Soon
ABOUT JoVE
Copyright © 2024 MyJoVE Corporation. All rights reserved