Effects of Pyrolysis Bio-Oils on Fuel Atomisation—A Review

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.

Review on Aging of Bio-Oil from Biomass Pyrolysis and Strategy to Slowing Aging

“…Aging leads to an increase in viscosity, which significantly influences bio-oil handling (including mixing operation, pumping, injection and atomization). The high viscosity of aged bio-oil may cause its poor atomization, low-efficiency combustion, and higher pressure drop . In addition, the higher viscosity causes a higher pressure drop.…”

“…The high viscosity of aged bio-oil may cause its poor atomization, low-efficiency combustion, and higher pressure drop. 156 In addition, the higher viscosity causes a higher pressure drop. The high water content could lower the heating value of bio-oil that causes ignition delay.…”

Co-Pyrolysis of PCB with Cotton Stalk: Product Characterisation

“…Furthermore, to use this oil as a fuel in industrial burners, furnaces, and boilers, it's fuel characteristics, like thermal stability, calori c value, viscosity, and acidity need to be monitored. Hydrodeoxygenation (HDO) reaction can also be used to increase the fuel property by removing oxygen (Panchasara & Ashwath, 2021;Xu et al, 2011). Although, some attempts have been made to address this issue, it is still very expensive since external hydrogen is needed in the engine and a metal oxide catalyst is added in the process.…”

“…Many research has demonstrated that co-pyrolysis improved the properties of oil generated, as well as increased oil yield. Secondly, biomass has a higher H/C molar ratio than PCBs, thus this high hydrogen content can act as a hydrogen donor to PCBs during co-pyrolysis (Panchasara & Ashwath, 2021). Further, water is one of the most signi cant components in biomass, and it can function as a reactive agent, stimulating further cracking of PCB tar and raising pyrolysis oil yields.…”

Spray curtains as devices for surface spraying during the SARS-CoV-2 pandemic

“…The atomization of liquids is used in many areas, including combustion and firefighting ( Gai et al, 2021 ; Panchasara and Ashwath, 2021 ). The most important parameters that determine the suitability of a given atomizer, and also the effectiveness of the atomization process, include the distribution of droplet sizes and the equivalent diameters of the droplets, among which the Sauter mean diameter is the most popular ( Ochowiak et al, 2021 ; Juslin et al, 1995 ; Wan et al, 1995 ).…”