Issue 11, 2021

Biological calcium carbonate with a unique organic–inorganic composite structure to enhance biochar stability

Abstract

Biochar stability is a key factor affecting the efficiency of soil carbon sequestration. Mineral calcium carbonate (M-CaCO3) can enhance the stability of biochar, and the mechanism has been extensively studied; however, similar studies on biological calcium carbonate (Bio-CaCO3), another natural form of calcium carbonate, are lacking. In this work, Bio-CaCO3 was used as an additive to explore the mechanism by which it enhances the stability of biochar. The results showed that Bio-CaCO3 improved the stability of biochar at pyrolysis temperatures ranging from 250 to 700 °C, and the enhancement effects increased upon increasing the pyrolysis temperature. The enhancement effects of M-CaCO3 were better at lower temperatures (250 and 400 °C) while Bio-CaCO3 was better at higher temperatures (550 and 700 °C). Mechanistic studies showed that the enhanced stability of Bio-CaCO3 at 250 °C was due to the fact that the inorganic component in Bio-CaCO3 promoted the deoxidation of the carbon matrix and the aromatization of aliphatic carbon at 400 °C. The reasons for the increased stability using Bio-CaCO3 at high temperatures included two mechanisms. One is that the inorganic components in Bio-CaCO3 promoted the aromatization of the carbon matrix. The other is that the unique organic nitrogen-containing functional groups in Bio-CaCO3 underwent dimerization and cyclization with the organic carbon components in biomass to form a more stable pyridinic-N structure. This work provides novel ideas for enhancing biochar stability using Bio-CaCO3.

Graphical abstract: Biological calcium carbonate with a unique organic–inorganic composite structure to enhance biochar stability

Article information

Article type
Paper
Submitted
22 Jun 2021
Accepted
06 Sep 2021
First published
06 Sep 2021

Environ. Sci.: Processes Impacts, 2021,23, 1747-1758

Biological calcium carbonate with a unique organic–inorganic composite structure to enhance biochar stability

J. Zhang, C. Wu, W. Hou, Q. Zhao, X. Liang, S. Lin, H. Li and Y. Xie, Environ. Sci.: Processes Impacts, 2021, 23, 1747 DOI: 10.1039/D1EM00247C

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements