Pt/HZSM-5 and HZSM-5 | 400–500 | Canola Oil | Pt/HZSM-5 increased isomerization and hydrogenation, increased gas yields, increased C4 iso/n-hydrocarbon ratio, and lowered organic liquid product (OLP) yield. Steam decreased the OLP yield. | [100] |
Pretreatment with Na2CO3 | 300–450 | Chlorella algae | Na2CO3 lowered the initial degradation temperature. Catalyst also increased gas yield and decreased liquid yield. Resulting bio-oil had higher heating value, more aromatics, and lower acidity. | [101] |
ZnCl2 impregnated in biomass | 250–500 | Corn cob, fir wood, bagasse, and rice husk | Enhanced charring and dehydration and promoted production of furfural (FF) and acetic acid (AA). Corn cob gave most FF (8%) at 340 °C with 15% ZnCl2 and a yield of 4% AA compared to a non-catalytic yield of FF 0.49%. | [102] |
MgO at 5%, 10%, 15%, and 20% of raw material | 550 | Cotton seed | Increasing the amount of catalyst decreased the oil yield and increased the gas and char yields. MgO increased the oil quality by reducing oxygen levels from 9.56% to 4.90% and converting almost all of the long chain alkanes and alkenes to lower molecular weight hydrocarbons in the diesel range. | [103] |
Boric Oxide mixed with biomass | 400 | Empty palm oil fruit bunch and oil palm fronds | Promoted deoxygenation, eliminated 50%–80% of the hydroxyl and methoxy groups, increased both water and char yields, and decreased gas yields. | [104] |
Al/MCM-41, Al/MCM-48, HZSM-5, Meso-MFI, Pt/ HZSM-5 (0.5%), Pt/Meso-MFI (0.5%) | 450 | Miscanthus | Al/MCM-41, Al/MCM-48, and Meso-MFI produced more phenolics and reduced more oxygenates than HZSM-5. HZSM-5 and Meso-MFI produced aromatics due to their acidic sites. Meso-MFI zeolite, which has both mesopores and high acidity, performed the best overall. Pt enhanced deoxygenation and aromatization in both cases. | [105] |
Meso-MFI and Pt/Meso-MFI (0.5%, ion exchanged) | 500 | Waste rice husk | Meso-MFI reduced oxygenates by 38%. Pt/Meso-MFI reduced oxygenates by 49%. Both converted heavy phenols to light phenols and aromatics. | [106] |
Pt/Hbeta, Pt/SiO2, Hbeta | 400 | Anisole | Pt/Hbeta catalyzed both methyl transfer and hydrodeoxygenation at significantly higher rates than the monofunctional catalysts. Formed benzene, toluene, and xylenes with lower hydrogen consumption and a significant reduction in carbon losses. The rate of deactivation and coke deposition were moderately reduced. | [107] |
Ga/HZSM-5 | 400–550 | Benzaldehyde | Ga/HZSM-5 catalyzed decarbonylation, producing benzene and CO in the absence of H2. In the presence of H2, it catalyzed toluene production. Addition of water increased benzene and reduced toluene. | [108] |
Zn/HZSM-5 (0.5 and 1.5%) | 300–500 | Furfural | 1.5% Zn/H-ZSM-5 produced slightly more aromatics (~5%) than 0.5% Zn/HZSM-5. Zn/HZSM-5 catalysts yielded more aromatics and olefins and less furan and coke than HZSM-5. | [109] |
Ce/HZSM-5 | 600 | Glucose | Increased oxygenated compounds and CO while reducing coke. | [110] |
Hybrid Pt/HZSM-5 (mixture) and Pt/HZSM-5 | 350–450 | Pyrolysis gasoline | Hybrid Pt/HZSM-5 catalyst showed lower metal-support interaction but a higher catalytic activity. Pt/HZSM-5 increased C2+n-alkanes and decreased methane and hydrogen requirements. | [111] |
Pd/HY, Pt/HY, Ir/HY, Ni/HY | 350–450 | Pyrolysis gasoline | Ir/HY showed better metal dispersion, acidity, hydrogen adsorption, and metal surface exposure than Pt/HY or Pd/HY. Ni/HY catalyzed less hydrogenation than the other three. Hydrogen pressure helped stabilize the catalysts. | [112] |
(10%) Pd/C, (30%) Pd/C, Pd(OH)2/C, Pd(OAc)2, Pd-PEPPSI-iPr and Pd/Lindlar with Nafion SAC-13 used in every run. | 300 | Various lignin types and lignin model compounds | Various phenols such as guaiacol, pyrocatechol, and resorcinol were formed from lignin. Model compounds were hydrodeoxygenated, demethylated, and demethoxylated. Percentage yields were better than many other HDO techniques. Activity of catalysts was in the following order; Pd(OAc)2 < Pd-PEPPSI-IPr < Pd(OH)2/C < 10% Pd/C < Pd-Lindlar. | [113] |
Ni/HZSM-5 (1%) | 450 | Bio-oil from Pinus insignis with 60% methanol | 90% conversion of the bio-oil in the feed with a selectivity for aromatics of 0.4 (benzene, toluene, xylenes (BTX) selectivity of 0.25). Rapid coke deposition was observed. | [114] |
Ni/Al2O3, Ni/CeO2, and Ni/Al2O3-CeO2 with varying percentages of nickel. | 800 | Cellulose | Initial degradation at lower temp. All reduced tar. 30% Ni/CeO2 catalyst yielded least amount of tar and least CO. 30% Ni/Al2O3 produced maximum amount of H2 (43.5 vol % at 800 °C, 15 min residence time). | [115] |
Ga/HZSM-5 | 600 | Furan with pinewood sawdust | Depending on preparation, Ga/HZSM-5 increased the rate of aromatics production. Ga seemed to increase the rate of decarbonylation and olefin aromatization, whereas HZSM-5 catalyzed other reactions such as oligomerization. 41% of the energy in the wood was converted into usable products. | [116] |
NiCl2, HZSM-5, Ni/ZSM-5 | 700 | Kraft Lignin | HZSM-5 almost completely decomposed the aliphatic C-O bonds and carbonyl groups and eliminated 80% of the methoxy groups. It showed more deoxygenation than Ni/ZSM-5. NiCl2 reduced liquid yield while increasing the molecular weight and increasing the gas yield. It produced more aromatic carbons and less aliphatic carbons. | [117] |
Al/MCM-41, Cu-Al/MCM-41, Fe-Al/MCM-41, Zn-Al/MCM-41 | 500 | Lignocel from beech wood and Miscanthus | Lignocel yielded more hydrocarbons and Miscanthus more phenols. All catalysts produced more phenols. A low Si/Al ratio increased product yields and improved final composition. Fe and Cu containing catalysts produced the most phenols. The presence of Al/MCM-41 reduced oxygenated compounds. Cu/MCM-41 promoted the largest increase of H2 in the gas yield. | [118] |
31 catalysts mixed with biomass. Included ZnO, CuO, Fe2O3. | 500 | Pine sawdust | A significant decrease in non-volatile fraction and slight decrease in bio-oil yield were obtained with ZnO (reduced the proportion of heavy fraction in the bio-oil with a limited decrease in its yield), CuO (exhibited the highest yields in semi-volatile compounds), Fe2O3, and mixed oxide catalysts containing Cu and Co. | [119] |
HFer-20, Fe/HFer-20, HY-12, Fe/HY-12, HBeta-25, Fe/HBeta-25 | 400–450 | Pine wood | Iron modified zeolites increased coke and methyl substituted phenols, decreased methoxy substituted phenols, and didn't affect the CO to CO2 ratio. Beta zeolite was the most active in deoxygenation. All zeolites increased levoglucosan. | [120] |
K2CO3 or Ca(OH)2 mixed with biomass | 700 | Pine wood | K2CO3 was more active producing no saccharides, aldehydes, or alcohols and substantially reducing the formation of acids, furans, and guaiacols. The yields of alkanes and phenols were increased. Ca(OH)2 reduced char, increased liquid, and increased alcohols, opposing the results from K2CO3. | [121] |
MgO, CaO, TiO2, Fe2O3, NiO, and ZnO | 600 | Poplar Wood | ZnO showed no activity. CaO reduced heavy products including phenols and anhydrosugars and increased formation of cyclopentanones, hydrocarbons, and light products including acetaldehyde, 2-butanone, and methanol. CaO also reduced acids. Other catalysts were not as effective. Fe2O3 produced PAHs. | [13] |
Ni/C mixed with biomass | 350 | Pubescens | Produced bio-oil with high content of phenols but low contents of acetic acid, furfural, and water. | [122] |