Hydrothermal carbonization of industrial mixed sludge from a pulp and paper mill

Abstract

Please cite this article as: Mäkelä, M., Benavente, V., Fullana, A., Hydrothermal carbonization of industrial mixed sludge from a pulp and paper mill, Bioresource Technology (2015), doi: http://dx.doi.org/10.1016/j.biortech. 2015.10.062 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. AbstractMixed sludge from a pulp and paper mill was hydrothermally carbonized at 180-260 °C for 0.5-5 h with the use of HCl or NaOH for determining the effect of acid and base additions during sludge carbonization. Based on the results carbonization was mainly governed by dehydration, depolymerization and decarboxylation of sludge components.Additive type had a statistically significant effect on hydrochar carbon content and carbon and energy yield, of which especially energy yield increased through the use of HCl. The theoretical energy efficiencies of carbonization increased with decreasing reaction temperature, retention time and the use of HCl and suggested that the energy requirement could be covered by the energy content of attained hydrochar. The BOD 5 /COD -ratios of analyzed liquid samples indicated that the dissolved organic components could be treated by conventional biological methods.

Hydrothermal carbonization of food waste for nutrient recovery and reuse

“…As a result of these reactions, value-added solid, liquid and gas products are generated. The properties of these products largely depend on the starting feedstock and operating conditions (e.g., Falco et al, 2011;Girotto et al, 2015;Hoekman et al, 2013;Li et al, 2015;Lu et al, 2013;Lu, 2014;Mäkelä et al, 2016;Nizamuddin et al, 2016). Several recent reviews have detailed different aspects of carbonization, including reaction mechanisms (Funke and Ziegler, 2010b;Kruse et al, 2013;Libra et al, 2011), effect of process parameters (Hoekman et al, 2011;Nizamuddin et al, 2017), recovery of valuable liquid and solid products (Reza et al, 2014), and material synthesis for various material and/or environmental applications (Libra et al, 2011;Titirici et al, 2012).…”

Hydrothermal Carbonization: Modeling, Final Properties Design and Applications: A Review

“…Figure S1, supplied as supplementary material and taken from reference [25] shows the strong interaction of variables during HTC of tomato waste. Makela et al [28] used response-surface contour plots to show the effect of HCl or NaOH on the HTC of sludge from a pulp and paper mill. The result show that the pattern solid yield as a function of temperature and time is not affected by the addition of acid or base.…”

Hyperspectral Imaging to Determine the Properties and Homogeneity of Renewable Carbon Materials

“…It should be noted that the wavelength accuracy of hyperspectral cameras is generally not as high as that of spectrometers, and the literature on wavelength assignments within the NIR region still remains very incomplete. Previous results on mixed sludge chars have shown that hydrothermal treatment did not lead to significant changes in solid‐state NMR spectra until a temperature of 260 °C was used . Based on the data, aliphatic carbon signals largely disappeared at higher temperatures, but the shifts for acetyl methyl groups of cellulose suggested that some alkyl carbon was still present in the chars.…”