Characterization of waste bio-oil as an alternate source of renewable fuel for marine engines

Abstract

Several physical and chemical properties of waste fish oils (FOs) and used cooking oils (UCOs) were of acceptable levels for utilization as renewable fuels in marine engines. However, the relatively high acid number of FOs and its increase with ageing might lead to increased risk of corrosion. The physical properties density, dynamic viscosity and kinematic viscosity, as well as water content were measured using different standard methods. Similarly, the acid number, the content of unsaturated fatty acids and the ash content were measured with standard methods. The chemical composition of fatty acids and monoglycerideswere measured with gas chromatography-flame ionization detector and Fouriertransform infrared spectroscopy. The sulphur and phosphorus content were measured using inductively coupled plasma-optical emission spectroscopy.Finally, the thermal properties were measured with thermogravimetric analysis while the heat content was measured with an adiabatic oxygen-bomb calorimeter.The results suggested that these locally produced waste stream-based bio-oils have potential as carbon dioxide neutral fuels. Several properties could be correlated with the fatty acid content of the oils. The results suggested that for waste derived bio-oils the earlier history (storage, thermal treatments before waste classification, ageing), all affect their suitability as fuels in marine engines.

Factors Affecting the Corrosive Behavior of Used Cooking Oils and a Non-Edible Fish Oil That Are in Contact with Ferrous Metals

“…Compositional analysis of the COref was also performed using GC-FID and GC-MS. The result indicated that the sample mainly composed of aliphatic hydrocarbons predominantly composed of linear saturated hydrocarbons up to C30 with the largest compounds in the C14 to the C26 range [16]. Detailed oil composition results can be found in Tables S1 and S2.…”

“…High water content and acidity in bio-oils can substantially increase the risk of corrosion during the storage and the use of the oils [21][22][23]. Moreover, the presence of water in a bio-oil decreases the heating value of the oil [16]. The measured physicochemical properties of the bio-oils are summarized in Table 1.…”

“…According to the oil delivered to these laboratory tests, UCO1/18, UCO2/18, and UCO3/18 have been successfully tested for marine engines without the requirement for any modification of engine components. In contrast, the AN of the fish oil (FO1/18) was above the limit of 15 mg KOH/g oil set by the engine manufacturer, hence testing was not permitted [16]. The content of free fatty acids in the tested oils can have a profound effect on increasing the acid number of the oils.…”

“…Despite the corrosive behavior of bio-oils and the mechanisms for the observed corrosion that might be very complex to understand, the corrosion itself can be measured using different techniques. In our previous work [16], the physicochemical, as well as thermal properties of fish oils and used cooking oils, were investigated to determine their applicability as alternative fuels for marine engines. The objective of this work, which is a continuation from our previous publication [16], was to experimentally examine the corrosive properties of crude bio-oils (used cooking oils and non-edible fish oil) that are in contact with ferrous metals.…”

Metal Rod Surfaces after Exposure to Used Cooking Oils

“…In our previous works, the chemical, physical, and thermal properties and the effect of storage time on the corrosivity of bio-oils were investigated [13,26,27]. The corrosiveness of different bio-oils during storage and usage are some of the concerns yet to be investigated for addressing compatibility issues.…”