Table 1. State-of-the-Art of Bio-Based Aromatics from Vegetable Oils.
| feedstock | reactor, catalyst and reaction conditions | aromatics maximum productiona | ref | |
|---|---|---|---|---|
| Continuous Setups | ||||
| 1 | Peanut oil soap stock | Fixed bed reactor (catalytic), continuous, H-ZSM-5 catalyst: 15 g, feed: WHSV of 5.4 h–1, T: 450–550 °C, TOS: 30 min | BTEXb: ca. 33 vol % (at 500 °C). | Hilten et al., (2011)34 |
| 2 | Palm fatty acid distillate | Fixed bed reactor (catalytic), continuous, H-ZSM-5 and Ga, and Zn modifided H-ZSM-5 catalyst, feed: WHSV of 5 h–1, T: 500 °C, TOS: 3 h | BTEXb: ca. 65 wt % (over 5% Zn/H-ZSM-5 at 500 °C). | Tamiyakul et al., (2016)35 |
| 3 | Vegetable oils (3 types) | FCC plant (internal circulated riser-regenerator, in situ catalytic), continuous, E-Ultima FCC equilibrium catalyst, feed: 2.6 L h–1, T: 550 °C, operation time: >6 h | Aromatics yield: 26.8 wt % (for rapeseed oil), 24.5 wt % (for soybean oil) and 22 wt % (for palm oil) | Bielansky et al., (2011)36 |
| 4 | Camelina (sativa) seed oil | Fixed bed reactor (ex situ catalytic), continuous, Zn modified ZSM-5 catalyst: 25 g, feed: WHSV of 0.6 h–1, T: 500 °C, TOS: 12 h | BTXb yield: ca. 6.2 wt % (over 20%Zn/ZSM-5) | Zhao et al., (2015)37 |
| 5 | Soybean oil | Fixed bed reactor (catalytic), continuous, La–Fe modified Si-MCM-41 catalysts: 5 g, feed: 30 g with a WHSV of 6.69 h–1, T: 460 °C | Aromatics: ca. 25 wt % (over Si-MCM-41) | Zheng et al., (2019)38 |
| 6 | Canola oil | Fixed bed reactor (catalytic), continuous, H-ZSM-5, SiO2, Al2O3 CaO and MgO catalysts: 2 g, feed: 5.1 g h–1 and 24.2 g h–1, T: 400 and 500 °C | BTXb yield: 22.5 wt % (over H-ZSM-5 at 500 °C) | Idem, et al., (1997)39 |
| 7 | Rapeseed oil | Fixed bed reactor (catalytic), continuous, Ga and Zn modified ZSM-5 catalysts: 0.25 g, feed: WHSV of 7.6 h–1, T: 550 °C, TOS: 3 h | Aromatics: ca. 43 wt % of the overall product distribution (over Ga/ZSM-5) | Ramos et al., (2016)40 |
| 8 | Rubber seed oil | Fixed bed reactor (ex situ catalytic), continuous, alkali treated ZSM-5 catalysts: 4 g, feed: WHSV of 1.37–6.85 h–1, T: 400–700 °C, TOS: 15 min | BTXb selectivity: 78 A.% (at 550 °C and WHSV of 5.48 h–1). Three cycles of reaction-regeneration | Wang et al., (2017)41 |
| 9 | Oleic acid | Fixed bed reactor (ex situ catalytic), continuous, Al2O3, ZrO2, AC, H-ZSM-5, HUSY, MCM-41 and Hβ catalysts: 1.2 g, feed: 0.25 mL h–1, T: 500 °C, TOS: 30 min | Aromatics content: 65.2% (over H-ZSM-5)c | Zheng et al., (2020)28 |
| 10 | Oleic acid | Microriser reactor, continuous, a commercial equilibrium catalyst, catalyst:feed = 4 (wt:wt), T: 480–585 °C | Aromatics concentration: ca. 30 wt % in C5–C11 fraction | Dupain et al., (2007)27 |
| 11 | Palm-oil-based fatty acids residue | Fixed bed reactor (in situ catalytic), continuous, H-ZSM-5, MCM-41, and their composites: 1 g, feed: WHSV of 2.5 h–1, T: 450 °C | BTXb yield: ca. 23.6 wt % (over MCM-41-H-ZSM-5 (20/80 wt %) composite) | Ooi et al., (2005)20 |
| 12 | Canola oil and its methyl ester | Fixed bed reactor (in situ catalytic), continuous, H-ZSM-5(50)d, feed: WHSV of 2 h–1, T: 450 °C | BTXb yield: ca. 25.8 wt % from canola oil, and 28.4 wt % from canola oil methyl ester | Bayat et al., (2015)21 |
| 13 | Sunflower seed and meat oils | Fixed bed reactor (in situ catalytic), continuous, H-ZSM-5(30)d catalyst: 25 g, feed: LHSV of 2.5–3 h–1, T: 450–550 °C | BTX (peak area% <1%) was not observed in the main products, though hydrocarbon content was high (e.g., 63 peak area% at 500 °C) | Zhao et al., (2015)42 and (2016)43 |
| Batch Setups | ||||
| 14 | Waste cooking oil | CDS Pyroprobe 5200 (ex situ catalytic), batch, alkali treated ZSM-5 catalyst: ca. 4 mg, feed: ca. 1 mg, T: 600 °C | BTXNEb selectivity: 58.6 A.% | Wang et al., (2017)44 |
| 15 | Vegetable oils (3 types) | A 4-ml batch reactor, H-ZSM-5, feed: 150 mg, water: 0.1 g mL–1, catalyst: 150 mg, T: 400 °C, P: 200 bar, reaction time: 180 min | BTXb yield: ca. 2.9 wt % from algal oil, 28.0 wt % from coconut oil, and 48 wt % from peanut oil | Mo et al., (2017)22 |
| 16 | Palmitic acid | A 4-ml batch reactor, Zeolites Y, β, and H-ZSM-5 with different SiO2/Al2O3 ratio, feed: 150 mg, water: 0.15 g mL–1, catalyst: 150 mg, T: 400 °C, P: 240 bar, reaction time: 180 min | BTXb yield: ca. 43.9 C.% (over H-ZSM-5 (23)d) | Mo et al., (2014)30 and (2015)31 |
| 17 | C18 fatty acids (3 types) | A 4 mL batch reactor, H-ZSM-5(30)d, feed: 150 mg, water: 0.15 g mL–1, catalyst: 150 mg, T: 400 °C, P: 240 bar, reaction time: 180 min | BTXb yield: ca. 12.5 C.% from linoleic acid, 23.1 C.% from oleic acid, and 30.8 C.% from stearic acid | Mo et al., (2015)31 |
| 18 | Soybean oil | A 500 mL batch reactor, H-ZSM-5(23)d, feed:catalyst: 4.5, T: 432 °C, reaction time: 12.5 min | BTEXb yield: ca. 7.6 wt % | Fegade et al., (2015)45 |
| 19 | Soybean oil | A 500 mL batch reactor, H-ZSM-5(50)d, feed: 200 mL, catalyst: 38 g, T: 430 °C, reaction time: 60 min | Aromatics: ca. 21 wt % | Kadrmas et al., (2015)46 |
| 20 | Oleic acid | A microreactor (Quatra C-GC-MS), batch, H-ZSM-5(23)d catalyst: ca. 5–25 mg, feed: ca. 1 mg, T: 400 °C | BTXb yield: ca. 5 wt % (catalyst:oleic acid = 20). | Benson et al., (2008)29 |
a
wt %: on weight basis, C.%: on carbon basis, A.%: on GC peak area basis, and vol %: on volume basis.
b
Abbreviated aromatics include benzene (B), toluene (T), xylene (X), naphthalene (N), and ethylbenzene (E).
c
Not clear whether this is for the total liquid phase or organic phase only.
d
SiO2/Al2O3 molar ratio.