Abstract
Bio-oils produced by biomass pyrolysis are substantially different from those produced by petroleum-based fuels and biodiesel. However, they could serve as valuable alternatives to fossil fuels to achieve carbon neutral future. The literature review indicates that the current use of bio-oils in gas turbines and compression-ignition (diesel) engines is limited due to problems associated with atomisation and combustion. The review also identifies the progress made in pyrolysis bio-oil spray combustion via standardisation of fuel properties, optimising atomisation and combustion, and understanding long-term reliability of engines. The key strategies that need to be adapted to efficiently atomise and combust bio-oils include, efficient atomisation techniques such as twin fluid atomisation, pressure atomisation and more advanced and novel effervescent atomisation, fuel and air preheating, flame stabilization using swrilers, and filtering the solid content from the pyrolysis oils. Once these strategies are implemented, bio-oils can enhance combustion efficiency and reduce greenhouse gas (GHG) emission. Overall, this study clearly indicates that pyrolysis bio-oils have the ability to substitute fossil fuels, but fuel injection problems need to be tackled in order to insure proper atomisation and combustion of the fuel.
Highlights
Today, global energy supply and demand rely heavily on more conventional and nonrenewable resources such as oil, gas and coal
Studies have shown that Sauter mean diameter (SMD) is known to be dominant in controlling fuel injection, the role of shear forces at the injector exit in the near field have an effect on flame instabilities and emissions
Use of an effective atomisation strategy makes the combustion of 100% pyrolysis oils in combustors possible and helps in reducing harmful emissions while maintaining comparable combustion efficiency as those of fossil fuels
Summary
Global energy supply and demand rely heavily on more conventional and nonrenewable resources such as oil, gas and coal. Compared to other renewable liquid fuels, pyrolysis bio-oils are derived from biomass and other sources of waste (approximately 10% of the world’s energy resources) [6]. The interaction between cellulose, lignin and Energies 2021, 14, 794 hemicellulose as well as the inorganic chemicals present in the plant tissues will result in numerous other chemicals such as furans and acetic acid Some of these products can be converted into biofuels via distillation and hydrotreatment, or they can be used in the synthesis of industrial chemicals and biopolymers [22]. Due to the shorter time of residence and the smaller volume of these engine applications, relatively higher combustion efficiency with lower emissions is important This is where the fuel injection and atomisation quality are more important especially when using pyrolysis oils in smaller combustor applications which require faster rates of fuel/air mixing and combustion. The paper discusses the use, status and production of biomass pyrolysis fuels and potential R&D on pyrolysis fuels
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
