Recent Strategy of Biodiesel Production from Waste Cooking Oil and Process Influencing Parameters: A Review

Table 2

Recent research on waste cooking oil and operating parameters.

Oil types	Type of alcohol	Process method	Parameters						Catalyst type	References
			T°C	C (catalyst percentage)		M (alcohol to oil ratio and wt%)	Speed (rpm)	Time
				A (acid catalyst)%	B (base catalyst)%
Palm oil	Ethanol	Acid-catalyzed transesterification	90°C	0.5, 1.0, 1.5, and 2.25 wt%	—	25, 50, and 100%	—	—	HCL, H2SO4	Al-Widyan and Al-Shyoukh (2002) [39]
Waste frying oil	Methanol	Alkali-catalyzed transesterification	65°C	—	5.3% of the KOH/MeOH solution	5.3% of the KOH/MeOH solution	—	90 min	KOH	Cvengroš and Cvengrošová (2004) [40]
Waste frying oil	Methanol	Base-catalyzed transesterification	65°C	—	Between 0.2% and 1.0%	3.6–5.4	—	1 h	NaOH	Felizardo et al. (2006) [41]
Waste cooking-oil collected from restaurant		Two-step catalyzed process	95°C & 65°C	0, 1, 2, 3, and 4 wt%	1%	3, 5, 7, 8, and 10 : 1, and 6 : 1	—	0.25 h, 0.5, 1, 2, 3 h, and 4 h	Ferric sulfate, KOH	Wang et al. (2007) [42]
Sunflower oil	Methanol	Base-catalyzed transesterification	25°C & 65°C	—	0.5 and 1.0%	3 : 1, 6 : 1, and 9 : 1	—	1–3 h	KOH, NaOH	Refaat et al. (2008) [43]
Canola oil	Ethanol	Base-catalyzed transesterification	60°C	—	0.2, 0.4, 0.6, 0.8, 1.0, and 1.2%	—	—	25 min	NaOH	Refaat et al. (2008) [44]
Sunflower oil		Base-catalyzed transesterification	40°C	—	0.5–2.0%	1 : 4.1 : 3, 3 : 1, 4 : 1, 6 : 1	350 rpm	3 h	KOH, NaOH	Hossain and Boyce (2009) [15]
Soybean oil	Methanolethanol, butanol		50°C–65°C	—	0.5%	1 : 4, 1 : 3, 1 : 2, 1 : 1	—	2 h and 6 h	NaOH	Hossain et al. (2010) [45]
Canola oil	Methanolethanol, butanol	Base-catalyzed transesterification		—	0.5%	1 : 4, 1 : 3, 1 : 2, 1 : 1	250 rpm	2 h and 6 h	NaOH	Hossain et al. (2010) [46]
Palm oil	Methanol	Heterogeneous transesterification	90°C–150°C	2–4	—	20 : 1, 30 : 1, 40 : 1		120, 180, and 240 min	ZrO2	Wan Omar and Saidina Amin (2011) [47]
Palm oil	Methanol	Esterification	50°C–65°C	1–4%	—	1 : 6, 1 : 1-0, 1 : 15	700 rpm	15–90 min	Ion-exchange resin catalysts	Gan et al. (2012) [48]