Abstract
| Original language | English |
|---|---|
| Pages (from-to) | 1054-1061 |
| Journal | ACS Sustainable Chemistry & Engineering |
| Volume | 5 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 2016 |
| MoE publication type | A1 Journal article-refereed |
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Keywords
- sulfate lignin
- cationic
- complex
- wheat straw
- impregnation
- dissolution
Cite this
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Calcium chelation of lignin from pulping spent liquor for water resistant slow-release urea fertilizer systems. / Sipponen, Mika (Corresponding Author); Rojas, Orlando; Pihlajaniemi, Ville; Lintinen, Kalle; Österberg, Monika.
In: ACS Sustainable Chemistry & Engineering, Vol. 5, No. 1, 2016, p. 1054-1061.Research output: Contribution to journal › Article › Scientific › peer-review
TY - JOUR
T1 - Calcium chelation of lignin from pulping spent liquor for water resistant slow-release urea fertilizer systems
AU - Sipponen, Mika
AU - Rojas, Orlando
AU - Pihlajaniemi, Ville
AU - Lintinen, Kalle
AU - Österberg, Monika
PY - 2016
Y1 - 2016
N2 - Slow-release fertilizers represent a possible large-scale application for plant polymers. Here we show a facile way to stabilize urea in fertilizer systems by lignin. Chelation of kraft black liquor with calcium acetate at pH 13 precipitated lignin as a calcium complex (Ca-lignin), which offered beneficial effects if compared to those from lignin obtained by precipitation at low pH (Acid-lignin). The reduced affinity of water to Ca-lignin was exploited in the formulation of slowrelease fertilizers comprising wheat straw sections impregnated with Ca-lignin in molten urea. Compared to the case of Acid-lignin, immersion in water was slowed down more extensively by Ca-lignin. After 24 h incubation at low moisture conditions, the highest proportion of urea retained in the Ca-lignin/straw fertilizer system was 58%. The water resistance of Ca-lignin was explained by a lower aqueous solubility that differed from the typical pH-dependent solubility of Acid-lignin. Electron microscopy, infrared spectroscopy, and accessible surface areas suggested that Ca-lignin consisted of less densely packed molecules organized as calcium-chelated chains. Overall, the controlled water-solubility of lignin precipitated by metal cations is greatly beneficial in fertilizer systems and can open new opportunities in material development (permeable films and others).
AB - Slow-release fertilizers represent a possible large-scale application for plant polymers. Here we show a facile way to stabilize urea in fertilizer systems by lignin. Chelation of kraft black liquor with calcium acetate at pH 13 precipitated lignin as a calcium complex (Ca-lignin), which offered beneficial effects if compared to those from lignin obtained by precipitation at low pH (Acid-lignin). The reduced affinity of water to Ca-lignin was exploited in the formulation of slowrelease fertilizers comprising wheat straw sections impregnated with Ca-lignin in molten urea. Compared to the case of Acid-lignin, immersion in water was slowed down more extensively by Ca-lignin. After 24 h incubation at low moisture conditions, the highest proportion of urea retained in the Ca-lignin/straw fertilizer system was 58%. The water resistance of Ca-lignin was explained by a lower aqueous solubility that differed from the typical pH-dependent solubility of Acid-lignin. Electron microscopy, infrared spectroscopy, and accessible surface areas suggested that Ca-lignin consisted of less densely packed molecules organized as calcium-chelated chains. Overall, the controlled water-solubility of lignin precipitated by metal cations is greatly beneficial in fertilizer systems and can open new opportunities in material development (permeable films and others).
KW - sulfate lignin
KW - cationic
KW - complex
KW - wheat straw
KW - impregnation
KW - dissolution
U2 - 10.1021/acssuschemeng.6b02348
DO - 10.1021/acssuschemeng.6b02348
M3 - Article
VL - 5
SP - 1054
EP - 1061
JO - ACS Sustainable Chemistry & Engineering
JF - ACS Sustainable Chemistry & Engineering
SN - 2168-0485
IS - 1
ER -