Synthesis and performance of a novel bio-oil-based dispersant as coal water slurry. (1st April 2023)

• Record Type: Journal Article
• Authors: Qi, You; Zhang, Luming; Zhang, Shiyuan; Cao, Qiufeng; Guo, Fengjie; Wang, Zhaohui; Cao, Qing
• Is Part Of: Fuel. Volume 337(2023)
• Publication Date: 2023-04-01
• Subjects: Bio-oil -- Pyrolysis of biomass -- Coal water slurry -- Dispersant -- Synthesis; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2022.126883
• Languages: English
• ISSNs: 0016-2361

Abstract

Graphical abstract: Highlights: A dispersant BOBD derived from bio-oil has been synthesized for CWS. The route of synthesized BOBD is simple and environmentally friendly. The maximum coal contents of CWS with BOBD may reach about 72 wt%. BOBD shows an excellent dispersibility comparing to SL and PSS in CWS. BOBD has the lowest surface tension of 47.71 mN/m −1 relative to SL and PSS. The contact angle of BOBD on the coal surface decrease by 24% comparing to SL and PSS. Abstract: With pyrolytic bio-oil as raw material, an efficient bio-oil-based dispersant (BOBD) applied to coal water slurry (CWS) has been synthesized successfully by grafting polymerization of the organic fractions from the bio-oil and acrylic acid (AA) in the mild condition. As a comparison, two commercial dispersants, namely poly (styrene sulfonic acid) sodium (PSS) and sodium lignosulfonate (SL) were employed. The structures and properties of the synthesized BOBD were characterized by using FTIR, 1 H NMR, GC/MS, GPC, zeta potential, contact angle, and surface tension. The results showed the molecular weight of the BOBD was concentrated at 832 g/mol and 1954 g/mol. The surface tension and contact angle of BOBD aqueous solution were 47.71 mN/m −1 and 60.8° respectively. The zeta potential of the suspension prepared from BOBD-water-coal was −67.1 mV. Using BOBD as a dispersant, the apparent viscosity of CWS loading 66 wt% coal dropped to 288 mPa·s at 0.3 wt% BOBD, and the maximum coal content reached 72 wt%. BOBD exhibited better viscosity reduction and stability enhancement capabilities than PSS and SL. The excellent dispersion performance of BOBD was due to the large electrostatic repulsion and steric hindrance derived from the grafted acrylic polymer, which effectively dispersed the coal particles uniformly. The rheological behavior of CWS with BOBD belonged to pseudoplastic fluid. The synthesized BOBD not only had an excellent dispersion performance but also could overcome the shortcomings of secondary pollution caused by PSS and SL containing element sulfur as dispersants in combustion. In addition, the synthetic route possessed simple, environmentally friendly and sustainable characteristics. The research opened up a new way for the utilization of bio-oil.