Study on Synergistic Viscosity Reduction Mechanism and Product Characteristics of Co-Aquathermolysis of Corn Stalk and Furfural Extraction Oil

TL;DR

This study explores using corn stalks and a catalyst to improve the properties of furfural extraction oil through a co-aquathermolysis process.

Contribution

The study introduces a co-aquathermolysis method with corn stalk and a Ni/Mo catalyst to effectively reduce the viscosity and aromatic content of furfural extraction oil.

Findings

A viscosity reduction rate of 19.96% was achieved under optimized co-aquathermolysis conditions.

The aromatic ring index decreased from 3.049 to 2.593, and the H/C ratio increased to 1.568.

Corn stalk promotes long-chain scission and inhibits aromatic condensation, reducing aromatic carbon fraction.

Abstract

Furfural extraction oil (FEO) is rich in polycyclic aromatic hydrocarbons (PAHs) and is hard to convert under mild conditions. To address this upgrade challenge, this study proposed a co-aquathermolysis process with corn stalk and a Ni/Mo hydrofining catalyst. Key parameters, including reaction temperature, time, catalyst dosage, and corn stalk dosage, were systematically evaluated for their impact on upgrade performance. Under optimized conditions (oil-to-water mass ratio 2:1, 280 °C, 18 h, 8 wt% catalyst, 8 wt% corn stalk), a viscosity reduction rate of 19.96% was achieved, significantly exceeding the 12.69% rate obtained without corn stalk. Meanwhile, the average molecular weight decreased from 430.0 to 353.3 g·mol−1 and the aromatic ring index declined from 3.049 to 2.593. The H/C ratio increased to 1.568, and the sulfur content decreased to 0.09210%. 1H NMR analysis revealed that corn stalk promotes long-chain scission and inhibits aromatic condensation, leading to a reduced aromatic carbon fraction. A detailed hydrocarbon composition analysis corroborated the conversion of tricyclic and tetracyclic aromatic hydrocarbons to monocyclic and bicyclic aromatic hydrocarbons. These findings offer valuable insights for the modification of FEO via aquathermolysis and establish biomass utilization as a practical strategy for FEO upgrades.

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