One-step catalytic pyrolysis of pre-treated rice straw to biofuel over waste-extracted Ni–H₃PW₁₂O₄₀ activated nano-catalyst

ABSTRACT

Alternative, renewable and carbon-neutral fuels are an urgent requirement. Pyrolysis has received the most attention in the conversion of biomass into fuel. The main disadvantages of chemical and physical properties of pyrolysis crude bio-oil include its high oxygen content and acidity. Catalytic fast pyrolysis can overcome this problem. Rice straw is an abundant biomass residual that can be of environmental negative impact and is not of proper use. Therefore, this research work introduces the use of this residual in the production of fuel sources by one-step catalytic pyrolysis with the reusability of the employed catalyst. A waste extraction catalyst modified with acidic and nickel sites has been prepared and was utilised for the proposed target in this study. The removal of silica, lignin and minerals by treatment of the rice straw with KOH and then HNO₃ in a green terminated process improved the catalytic biomass conversion from 83% to 96% at a catalyst dose of 5%, at 250°C. The pre-treatment of the rice straw enables the reusability of the catalyst in direct catalytic pyrolysis where the employed catalyst exhibits good stability in four consecutive runs. The used KOH and HNO₃ were neutralised by mixing to produce KNO₃ as a valuable fertiliser.

KEYWORDS:

• Biomass residuals
• catalytic pyrolysis
• waste-to-energy
• acidic catalysts

Authors contribution

The authors contributed to the study's conception and design. Material preparation, data collection, and analysis were performed by the co-authors interdependently. The first draft of the manuscript was written by Dr. Nasser H. Shalaby; all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Consent to participate

All authors are aware and agree for the research publication as stated in the Cover Letter.

Disclosure statement

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

Data transparency

All data and materials, as well as software applications and custom code, support their published claims and comply with field standards.

Ethical approval

There is no contradiction with ethical standards.

Additional information

Funding

The research was supported and completed by the co-authors.