Binding mechanism in bio-briquette prepared with wheat straw and lignite by mechanical thermal expression process

ABSTRACT

In this study, bio-briquette was prepared with lignite and wheat straw by mechanical thermal expression (MTE) process and analyzed using an optical microscope (OM), scanning electron microscope (SEM) and Fourier transform infrared (FTIR) spectroscopy. Under the combined action of thermal and mechanical energy, the binding mechanism between lignite and biomass in bio-briquette was discussed. Results showed that the compressive strength of bio-briquette increased with the increase of pressure and temperature, which positively affected the bonding of material particles. Lignite particles were wrapped into the network formed by interconnected fibers of different lengths. During the MTE process, the liquid bridges were built among the biomass undergoing glass transition, water, and partially melted lignite, which became solid bridges after briquette formation, enhancing the compressive strength of bio-briquette.

KEYWORDS:

• Lignite
• bio-briquette
• binding mechanism
• MTE

Disclosure Statement

No potential conflict of interest was reported by the author(s).

Author Contributions

Lei Xiao: Conceptualization, Writing – Original Draft, Data curation. Yunjiao Wang: Writing – Original Draft. Rui Wang: Data curation. Xiujuan Feng: Supervision, Reviewing. Jinghua Yao: Supervision, Data Processing, Reviewing and Editing.

Availability of Data and Material

Data can be available from the corresponding author upon request.

Ethical Approval

This article does not contain any studies with human participants or animals.

Additional information

Funding

This work was supported by the Fundamental Research Funds for the Central Universities, China [2019XKQYMS60].