High-temperature pH measuring during hot-water extraction of hemicelluloses from wood

A1 Originalartikel i en vetenskaplig tidskrift (referentgranskad)


Interna författare/redaktörer


Publikationens författare: Jens Krogell, Kari Eränen, Kim Granholm, Andrey Pranovich, Stefan Willför
Förläggare: ELSEVIER SCIENCE BV
Publiceringsår: 2014
Tidskrift: Industrial Crops and Products
Tidskriftsakronym: IND CROP PROD
Volym: 61
Artikelns första sida, sidnummer: 9
Artikelns sista sida, sidnummer: 15
Antal sidor: 7
ISSN: 0926-6690
eISSN: 1872-633X


Abstrakt

A high-temperature pH measuring system was developed, calibrated, and validated for measuring pH during hot-water extraction of hemicelluloses from wood. The aim was to measure in-line pH during extraction in order to control the extraction pH. An yttria-stabilized Zr/ZrO2 electrode was used for measuring the potential. Phthalate and phosphate buffers were used to calibrate the system at 160, 170, and 180 degrees C. Also, different buffer concentrations were tested for stability. Tap water and different salt solutions were tested to investigate the system response to pure water and water solutions. Calibration curves were acquired from the calibration results and Nernst equation was used to calculate the in-line pH during wood extractions. The setup showed stable and reliable potential readings during both calibration tests and wood extractions. The in-line pH was found to be 0.35 pH units higher than when measured at room temperature with a conventional pH meter.


Nyckelord

Hemicelluloses, High-temperature pH, Hot-water extraction, pH calibration, Spruce wood

Senast uppdaterad 2019-15-10 vid 03:26