Ex-situ Catalytic Fast Pyrolysis Research Articles

Ex-situ catalytic fast pyrolysis of waste polycarbonate for aromatic hydrocarbons: Utilizing HZSM-5/modified HZSM-5

Catalytic pyrolysis has been proven as a highly efficient process for transforming waste polycarbonate (PC) into valuable aromatic hydrocarbons, especially benzene, toluene, ethylbenzene, and xylene (BTEX). In the present work, the ex-situ catalytic fast pyrolysis of PC on metal- or alkali-modified HZSM-5 was investigated using the double micro-fixed bed system. Experimental results indicate that the rapid pyrolysis of PC may follow a homolytic chain scission mechanism, resulting in pyrolysis products dominated by phenols. Metal- or alkali-modified HZSM-5 significantly enhances the cleavage of C-OH bonds in phenols, improving the yield of aromatics. The yield of aromatics in the liquid product is 91 %, 72 %, and 77 % when loaded with nickel (Ni), iron (Fe), and cobalt (Co), respectively, all of which are higher than unmodified HZSM-5 with the yield of 43 %. Among them, the Ni/HZSM-5 has significantly enhanced the yield of BTEX reaching 81.64 %. When using alkali-modified HZSM-5 with a larger pore volume and higher specific surface area, the yield of aromatics can be increased to 60 %. Furthermore, the dual modification of alkali treatment and Ni loading on HZSM-5 simultaneously enhanced catalytic activity and resistance to coke formation. The yield of BTEX reaches 94.47 %. The BTEX formation mechanism can be explained by direct deoxygenation (DDO) of the pyrolytic volatiles of PC and the “phenol pool” mechanisms of primary products on the catalyst surface. This study enriches the understanding of catalytic pyrolysis of PC and provides a theoretical foundation for the harmless treatment of PC.

One-pot synthesis of Fe modified lignin biochar for ex-situ catalytic fast pyrolysis of enzymatic hydrolysis lignin to promote the generation of aromatic hydrocarbons

The utilization of waste lignin to produce bio-oil rich in aromatics aromatic hydrocarbons is promising and attractive for a wide range of applications. Fe-modified lignin biochar (xFe/ALC) prepared using a one-step method was utilized as catalysts to investigate their impact on product distribution, aromatic hydrocarbon generation, and pathways during ex-situ catalytic fast pyrolysis of enzymatic hydrolysis lignin. The results revealed that the addition of Fe enhanced the production of gas products such as H2, while decreasing bio-oil yield. The lowest bio-oil yield, at 12.10 wt%, was observed at a Fe loading of 25 wt%, however the relative content of aromatic hydrocarbons reached a maximum value of 16.24 area%. Compared to the pyrolysis of lignin alone, their contents increased by 2.46 times, with the content of monocyclic aromatic hydrocarbons (toluene, ethylbenzene, styrene, xylene) increasing by 1.5–3.8 times. Spent 25Fe/ALC had good stability on the production of aromatic hydrocarbons. Compared with non-catalytic pyrolysis of lignin, the aromatic hydrocarbons content for spent 25Fe/ALC after four cycles increased by 26.70%.

Ex-situ catalytic fast pyrolysis of wood chips over lamellar MFI zeolite supported nickel catalyst

Lamellar MFI zeolite and lamellar MFI zeolite supported nickel were synthesized and examined for ex-situ catalytic upgrading of the vapors (without using any fluidized gases such as N2 and H2) resulted from fast pyrolysis of wood chips in comparison to its commercial MFI zeolite and its supported nickel counterparts. Pyrolysis tests were carried out using a catalytic augur reactor at atmospheric pressure, while pyrolysis unit was operating at 450 °C and upgrading unit at 420 °C, respectively. The introduction of nickel with a high dispersion over the zeolitic supports caused a significant increase in the products of aromatic compounds. Moreover, the addition of nickel to zeolite supports changed their acidity and decreased the total number of acid sites and the ratio of Brønsted to Lewis acid sites as determined by pyridine-FTIR spectroscopy. The use of lamellar zeolite catalysts increased the efficiency of catalytic cracking of pyrolysis vapors and their modification with nickel helped tuning the Lewis acidity to further increase catalytic cracking which resulted in a higher yield of the low molecular weight aromatics present in the bio-oil.

Product regulation and catalyst deactivation during ex-situ catalytic fast pyrolysis of biomass over Nickel-Molybdenum bimetallic modified micro-mesoporous zeolites and clays

Ni-Mo bimetallic modified micro-mesoporous zeolite catalysts were prepared and employed in the process of ex-situ catalytic fast pyrolysis (CFP) of poplar to produce liquid fuel. Clay catalysts were incorporated to further improve the products quality. The mass yield of monocyclic aromatic hydrocarbons (MAHs) increased under the catalysis of composite catalysts AZM and NiMo/AZM. HAP&Zeolite dual catalyst system reduced coke yield of NiMo/AZM to 5.01 wt%. Through real-time monitoring of gas products, the catalytic performance of zeolites began to decrease after the ratio of biomass and catalyst was more than 1. A series of characterization results futher demonstrated that AZM and NiMo/AZM possessed more stable catalytic ability and higher catalytic activity during the whole CFP process. N2 adsorption–desorption measurement and Raman characterization illustrated the formation and structure of coke, catalyst deactivation and the protective mechanism of mesopores on micropores.

Optimising ex-situ catalytic fast pyrolysis of pine wood at pilot scale: Impacts on the energy content, chemical composition and stability of the liquid fuel product

A central composite design was used to optimise the yield and higher heating value (HHV) of the liquid fuel produced through ex-situ catalytic fast pyrolysis of pine wood. The variables were the temperature and loading of H-ZSM-5 zeolite catalyst. GC/MS, 1H NMR and stability tests were undertaken to compare the fuel properties of organic phases with similar HHVs, generated from catalytic treatments at low (≤ 370 °C) and high (≥ 470 °C) temperatures. When targeting an HHV of 32 MJ/kg, higher yields were obtained at low temperature and high catalyst loading, despite higher coke yield. Treatment at low temperature preserved more alkyl groups and made the fuel less aromatic (−13 % of aromatic hydrogen and lower content of Crich hydrocarbons). Undesirable catalytic cracking of alkyl groups at higher temperature was evidenced by a 60 % increase in the production of hydrocarbon gases. Despite a higher oxygen content, the fuel produced at low temperature was also found to be more stable.

Enhancing liquid hydrocarbon production from invasive plant via ex-situ catalytic fast pyrolysis coupled with electron-beam irradiation cracking

Ex-situ catalytic fast pyrolysis of alligator weed (invasive plant) coupled with electron-beam irradiation (EBI) cracking is carried out in this investigation. Experimental results show that EBI possesses the advantage to crack and decompose heavy components in primary oil vapors into smaller oxygenates. Oil fraction and coke yields decrease gradually with increasing EBI dose rate, and water and gas yields show an opposite trend. It is demonstrated that EBI dose rate of 250 mGy/s favors the hydrocarbon production most. On the other hand, the augmentation of ZSM-5 catalyst proportion gives rise to a better catalytic conversion performance, resulting in the decrease in oil fraction yield and increase in water and gas yields. In addition, the carbon yields of hydrocarbons and oxygen-containing aromatic compounds in bio-oil increase significantly, whereas the carbon yield of oxygen-containing aliphatic compounds reduces at the studied catalyst-to-biomass mass ratio range.

Study on the reaction mechanism of nitrogenous compounds in zeolite-catalyzed pyrolysis of blue-green algae

The ex-situ catalytic fast pyrolysis (CFP) of blue-green algae (BGA) and its nitrogenous model compounds over HZSM-5 was conducted in a microfluidized bed reactor (MFBR) combined with a U-shape fixed bed reactor (U-FBR). A single photoionization mass spectrometer (SPI-MS) was used for on-line studying the dynamics of volatiles formation with the biomass-to-catalyst ratio (BCR). In the CFP of BGA, six different groups of products were differentiated by statistical analysis of SPI mass spectra, which were obtained with the cumulative BCRs. The relative concentration of each group has its own evolution with catalyst deactivation, indicating the different formation pathways of six groups. In combination with results from the CFP of six model compounds, the reaction pathways of nitrogenous compounds in the CFP of BGA over HZSM-5 were proposed. The benzyl nitrile could be fully converted to hydrocarbons while this is hard to achieve N-cyclic compounds (particularly the pyridines). Besides, most of nitrogenous compounds could be interconvertible in the CFP process. Transmethylation is the favorite way for catalytic conversion. In addition, the CFP of BGA and its N-cyclic compounds would lead to the fast coking of HZSM-5, especially the hard coke.

Catalytic fast pyrolysis of steam-exploded biomass for long-chain ethers precursors

A novel valorization pathway for steam-exploded corn stalk conversion to long-chain ethers was proposed in the work. The procedure enabled the transformation of multifunctional components in catalytic fast pyrolysis (CFP) vapors using Fe-Ce mixed oxides into carbonyl compounds (ketones, aldehydes and furans with carbonyl group) suitable for preparing long-chain oxygenated fuels in a fluidized-bed/fixed-bed consolidation reactor. A series of Fe-Ce bimetallic oxides were explored and the results indicated that the catalyst with 0.3 of molar ratio of Fe to Ce (Fe/Ce(0.3)) showed highly active in converting levoglucosan and acetic acid into linear and cyclic ketones. Moreover, the conversion rate of acetic acid and levoglucosan in pyrolytic vapors was close to 100% and 90.07%, respectively. The carbon yield of carbonyl compounds (28.91%) in ex-situ CFP was achieved under optimal conditions. The continuous operation showed that Fe/Ce(0.3) remained highly active and there was little coke and carboxylates on the catalyst surface after 200 min.

Effect of low-temperature hydrothermal treatment of HZSM-5 extrudates on the production of deeply-deoxygenated bio-oil via ex-situ catalytic fast pyrolysis of biomass

Catalytic fast pyrolysis (CFP) of biomass has high potential for producing deoxygenated bio-oil in one single process. HZSM-5 is a widely used catalyst for this purpose and various parameters have already been extensively investigated on this catalytic material. Limited studies were performed on the effect of low-temperature hydrothermal treatment of the catalyst with none being applied in ex-situ CFP in a lab-scale pyrolysis unit. The current paper therefore reports the investigation of HZSM-5 characteristics and activities when hydrothermally treated by steam at 550 °C for 5 h. The treatment modified the catalyst in a positive way that can increase 30% of the non-aqueous catalytic bio-oil yield. A maximum organic liquid yield of 11.4 wt% was achieved with 6.7 wt% being heavy fraction and 4.7 wt% being light fraction. These heavy and light bio-oils had very low oxygen contents of 4.3 and 1.6 wt%, respectively. This is equivalent to 93% oxygen removal compared to its corresponding non-catalytic bio-oil. Based on the elemental, FTIR, and GC/MS analyses, the hydrothermal treatment slightly increased the bio-oil oxygen content. Characterization of the catalysts reveal irreversible catalyst deactivation by dealumination. The severity of the deactivation increased continuously with higher amount of biomass being fed to the process. However, the catalyst deoxygenation ability was still acceptable for producing partially-deoxygenated bio-oil even after applying the biomass-to-catalyst ratio of 20.5.

Deactivation and regeneration of solid acid and base catalyst bodies used in cascade for bio-oil synthesis and upgrading

The modes of deactivation -and the extent to which their properties can be restored- of two catalyst bodies used in cascade for bio-oil synthesis have been studied. These catalysts include a solid acid granulate (namely ZrO2/desilicated zeolite ZSM-5/attapulgite clay) employed in ex-situ catalytic fast pyrolysis of biomass, and a base extrudate (K-exchanged zeolite USY/attapulgite clay) for the subsequent bio-oil upgrading. Post-mortem analyses of both catalyst bodies with Raman spectroscopy and confocal fluorescence microscopy revealed the presence of highly poly-aromatic coke distributed in an egg-shell manner. Deactivation due to coke adsorption onto acid sites affected the zeolite ZSM-5-based catalyst, while for the base catalyst it is structural integrity loss, resulting from KOH-mediated zeolite framework collapse, the main deactivating factor. A hydrothermal regeneration process reversed the detrimental effects of coke in the acid catalyst, largely recovering catalyst acidity (∼80%) and textural properties (∼90%), but worsened the structural damage suffered by the base catalyst.

Ex‐situ catalytic fast pyrolysis of low‐rank coal over HZSM ‐5 and modified Mg/ HZSM ‐5 catalysts

Catalytic effects in fast pyrolysis of low-rank coal and coal tar conversion were investigated in a two-stage fixed-bed reactor over HZSM-5 zeolite and Mg/HZSM-5. Mg/HZSM-5 caused the lower total tar yield and the higher non-condensable gas yield but the fraction of light tar (boiling point below 360°C) increased to allow a slightly higher total yield of light tar. It also exhibited good catalytic activity and increased the species of light tar than HZSM-5 zeolite. The light tar fraction was increased from 45 to 74.6 wt% than without catalyst (66%) at the pyrolysis temperature of 600°C. Ex-situ catalytic fast pyrolysis over Mg/HZSM-5 also lowered the contents of element N and S in the resulting coal tars by 29% and 15% respectively. The corresponding increase in the content of element H and molar ratio of H to C of the resulting coal tars was reported as 17% and 13% respectively. The addition of Mg into HZSM-5 increased the ability of the catalyst for inhibiting coke deposition.

Ex-situ catalytic upgrading of pyrolysis vapors using mixed metal oxides

Ex-situ catalytic fast pyrolysis (CFP) was employed to produce bio-oils from beech wood. The effect of Nb-based mixed oxides (with second metal oxide = W, Al or Mn) in upgrading the pyrolysis vapors was compared to an H-ZSM-5 catalyst and to non-catalyzed pyrolysis. The catalysts acidic properties were assessed by NH3-TPD and FTIR of adsorbed pyridine. The bio-oils obtained were characterized by Karl-Fischer titration, GPC, CHNS analyses, 13C-NMR, GC–MS, GCxGC–MS. In spite their very different acidic properties, the NbxMnyOz catalyst (with essentially Lewis acid sites) exhibited similar performances as H-ZSM-5 (that presents a high density of Brønsted sites), in terms of liquid phase selectivity and reduction of oxygen content in the bio-oils produced. These observations were accompanied by a reduction of compounds such as acids, aldehydes, ketones, ethers and sugars that contribute to the detrimental properties of bio-oils. Finally, the results suggest that the Lewis acid sites of NbxMnyOz are converted into Brønsted sites in the presence of water vapor produced by pyrolysis of wood, whereas the strongest Brønsted sites of H-ZSM-5 have a limited impact on the upgrading process due to their limited accessibility for most components of pyrolysis vapors.

Boosting the selectivity of aromatic hydrocarbons via ex-situ catalytic fast pyrolysis of cellulose over Pt–Sn–Ce/γ-Al2O3 catalyst

Pt–Sn–Ce/γ-Al2O3 catalysts were synthesized by the impregnation method and used to produce aromatic hydrocarbons (AHs)-rich bio-oil via catalytic fast pyrolysis of cellulose. The upgraded products were on-line analyzed by pyrolysis-comprehensive two-dimensional gas chromatography/mass spectrometry (Py-GC × GC/MS). It was found that Pt–Sn–Ce/γ-Al2O3 catalysts were effective for improving the relative content of AHs in bio-oil. Especially, Pt–Sn–Ce/γ-Al2O3 contributed the highest AHs content (85.82%), which was 3 times than that of γ-Al2O3, and increased 85.44% compared with non-catalytic. In addition, Pt–Sn–Ce/γ-Al2O3 and Pt–Sn/γ-Al2O3 can generate the highest monocyclic aromatic hydrocarbons (MAHs) with the relative content of 60.24% and 51.92%, respectively. Pt–Sn–Ce/γ-Al2O3 catalyst can be reused five times with stable catalytic activity to produce AHs-rich bio-oil.

Catalytic upcycling paper sludge for the recovery of minerals and production of renewable high-grade biofuels and bio-based chemicals

Paper sludge is a solid waste by-product abundantly produced in the paper industry and contains fine minerals and lignocellulosic biomass. In this contribution, the ex-situ catalytic fast pyrolysis of paper sludge with a high mineral content of ca. 71 wt% is reported for the first time and demonstrated in a pilot-scale unit (feeding rate of 11.3 kg h−1) using a granular Na2CO3/γ-Al2O3 catalyst (loading of 650 g) to produce a high-grade bio-oil at a fast pyrolysis temperature of 475 ± 5 °C (pre-screened using a pyroprobe) and a catalytic upgrading temperature of 500 °C. Besides, > 99 wt% minerals in the paper sludge could be recovered, including paper fillers such as CaCO3 (major) and talc. The bio-oil obtained at a carbon yield of 21 C.% has a low oxygen content of 3.2 wt%, a low total acidity number of 5.2 mg KOH g−1, low H2O content of 0.7 wt%, and a high higher heating value of 40.9 MJ kg−1. It consists of value-added bio-based chemicals such as paraffins, olefins, and low molecular weight aromatics. The results demonstrate that the use of paper sludge to recover minerals and to obtain fuels and chemicals using ex-situ catalytic pyrolysis is technically feasible at a pilot plant scale, which will be of importance for the development of future bio-based economy.

Effects of steam to enhance the production of light olefins from ex-situ catalytic fast pyrolysis of biomass

This study aims to report on the feasibility of enhancing light olefins production from ex-situ catalytic fast pyrolysis (CFP) of biomass by co-feeding with steam and determine the role of steam. Effects of steam on catalyst and pyrolysis/catalysis reactions in ex-situ CFP were investigated using a two-stage fluidized-bed/fixed-bed reactor. Carbon yield of olefins + monocyclic aromatic hydrocarbons (MAHs) increased by 23.80% after proper steam dealumination of HZSM-5 framework, which suggests that HZSM-5 can be activated at the initial exposure to steam. For activated HZSM-5, olefins carbon yield increased by 35.65% and olefins to MAHs (O/M) ratio boosted from 0.83 to 1.60 as steam concentration in carrier gas increased from 0% to 40%, while the total carbon yield of olefins and MAHs still kept at the same level. Steam enhanced olefins production by: (1) promoting the formation of light compounds in bio-oil, which are the main precursors of hydrocarbons, during pyrolysis; (2) inhibiting aromatization reactions during catalysis. It provides a possibility for the control of O/M ratio of hydrocarbon products and the enhancement of light olefins production from CFP of biomass.

Ex-situ catalytic fast pyrolysis of soapstock for aromatic oil over microwave-driven HZSM-5@SiC ceramic foam

In view of the poor selectivity of aromatic hydrocarbons in bio-oil from biomass pyrolysis and the high pressure drop and rapid coking and deactivation of catalyst in industrial scale, a microwave-driven HZSM-5@SiC ceramic foam has been constructed, and applied to the ex-situ catalytic fast pyrolysis of soapstock to improve the content of aromatic hydrocarbons in bio-oil. The effects of different catalysts and heating modes and mass ratios of HZSM-5@SiC ceramic foam to soapstock on the distribution of pyrolysis products have been investigated. In addition, combined with the comparison of microwave and electric heating, the deactivation characteristics of HZSM-5@SiC ceramic foam have been studied. Finally, the process of preparing aromatic oil by microwave-driven catalytic pyrolysis of soapstock was discussed. Experimental results indicate that compared with HZSM-5, HZSM-5@SiC ceramic foam has a higher yield of bio-oil and higher aromatization activity. Under microwave heating, the relative content of aromatic hydrocarbons increases from 25.18% to 100% when the mass ratio of HZSM-5@SiC ceramic foam to soapstock increases from 0:1 to 1:1. Compared with electric heating catalysis, HZSM-5@SiC ceramic foam has the lowest yield of coke under microwave heating. After five consecutive uses, it still maintains more than 90% catalytic activity and has higher stability, which provides a scientific basis for the pilot scale experiments of soapstock catalytic pyrolysis.

Calcium formate assisted catalytic pyrolysis of pine for enhanced production of monocyclic aromatic hydrocarbons over bimetal-modified HZSM-5

An efficient process was developed to selectively produce monocyclic aromatic hydrocarbons (MAHs) from ex-situ catalytic fast pyrolysis (CFP) of pine assisted with calcium formate (CF) over bimetal-modified HZSM-5. Mo and another metal (Mg, Ga or Zn) were used to modify the HZSM-5, and the as-synthesized bimetal-modified HZSM-5 catalysts were utilized for both pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and lab-scale CFP tests with CF as a hydrogen donor to selectively obtain MAHs. The results revealed that the presence of CF and Mg-Mo modified HZSM-5 (0.5Mg1Mo/HZ) exhibited excellent capability for MAHs production with tiny generation of polycyclic aromatic hydrocarbons (PAHs). The maximum MAHs yield attained 12.79 wt% at 650 °C from Py-GC/MS with the CF-to-pine (CF-to-PN) ratio of 3 and catalyst-to-pine (CA-to-PN) ratio of 11, and became 9.67 wt% from lab-scale device with CF-to-PN and CA-to-PN ratios of 0.5 and 4, respectively. In addition, compared with HZSM-5, 0.5Mg1Mo/HZ possessed better anti-deactivation ability.

Molecular shape selectivity of HZSM-5 in catalytic conversion of biomass pyrolysis vapors: The effective pore size

This article is intended to deepen the understanding of molecular shape selectivity of HZSM-5 in catalytic conversion of biomass pyrolysis vapors through the study of catalyst effective pore size. Ex-situ catalytic fast pyrolysis (CFP) of biomass over HZSM-5 with varied catalyst loadings were carried out using a continuous feeding two-stage fluidized-bed/fixed-bed combination reactor. Results showed that in addition to the shape selective reactions inside catalyst channels, cracking and aggregating reactions occur at the external surface of HZSM-5. The catalytic activity of HZSM-5 external surface for some heavy compounds was observed to be relatively low. On the basis of the molecular dimension information provided by quantum chemical calculations, it was found that HZSM-5 has an effective pore size which is significantly larger than its static pore size at CFP temperature. Catalytic alkylation of naphthalene with methanol over HZSM-5, HZSM-5@silicalite-1, HSAPO-34, HM, Hβ, HUSY and HMCM-41 were further compared to determine the effective pore size of HZSM-5. It is proposed that the effective pore size of HZSM-5 at CFP temperature is between the critical molecular diameters of 2,3- and 1,6-dimethylnaphthalene (between 7.520 and 7.961 Å).

Product distribution of the thermal and catalytic fast pyrolysis of karanja (Pongamia pinnata) fruit hulls over a reusable silica-alumina catalyst

The conversion of karanja fruit hulls by fast pyrolysis was investigated using a drop-type two-stage reactor. The ex-situ catalytic fast pyrolysis of karanja fruit hulls over a silica-alumina catalyst was performed at 500 °C and at a catalyst loading of 0.1 g. The obtained bio-oil yield was 41.09 wt%. The bio-oil contained 84.38% carbonyls. The silica-alumina catalyst reduced the liquid yield to 39.73 wt%. The production of aromatics and hydrocarbons in bio-oil was enhanced, whereas the yield of carbonyls was reduced from 84.38% (non-catalytic) to 7.83% (catalytic). After catalyst regeneration, the aromatic yield was increased from 30.08% (1st run) to 52.18% (5th run), and the deoxygenation degree was increased from 35.15% (1st run) to 57.13% (5th run), thereby demonstrating that the silica-alumina catalyst had satisfactory reusability. The amount of catalytic coke was reduced after catalyst regeneration, because less hard coke was formed.

Selective preparation of monocyclic aromatic hydrocarbons from ex-situ catalytic fast pyrolysis of pine over Ti(SO4)2-Mo2N/HZSM-5 catalyst

To selectively produce monocyclic aromatic hydrocarbons (MAHs) with low amount of polycyclic aromatic hydrocarbons (PAHs), modified HZSM-5 catalysts (Mo2N/HZSM-5, Ti(SO4)2/HZSM-5 and Ti(SO4)2-Mo2N/HZSM-5) were prepared and employed for ex-situ catalytic fast pyrolysis (CFP) of pine wood. Both analytical pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and lab-scale pyrolysis experiments were conducted to investigate the effects of catalyst, pyrolysis temperature and catalyst-to-pine ratio on the distribution of aromatic hydrocarbon products. Py-GC/MS results showed that the maximal MAHs yields from the HZSM-5, Mo2N/HZSM-5, Ti(SO4)2/HZSM-5 and Ti(SO4)2-Mo2N/HZSM-5 catalysts were 7.57 wt%, 8.11 wt%, 8.71 wt% and 12.53 wt% at 650 °C and catalyst-to-pine ratio of 7. Corresponding PAHs yields from the four catalysts were 2.55 wt%, 0.97 wt%, 1.47 wt% and 1.10 wt%, which clearly indicated that the Ti(SO4)2-Mo2N/HZSM-5 significantly increased MAHs formation and decreased PAHs formation as compared with HZSM-5. Furthermore, lab-scale experiments were conducted to quantitatively determine the pyrolytic product distribution. Results showed that Ti(SO4)2-Mo2N/HZSM-5 catalyst increased the yield of liquid and gas products, and decreased solid products as compared with HZSM-5. Under optimal conditions of 650 °C and catalyst-to-pine ratio of 4/3, the actual yields of MAHs and PAHs from Ti(SO4)2-Mo2N/HZSM-5 catalyst were 9.71 wt% and 1.45 wt%, respectively. In addition, stability tests confirmed that the Ti(SO4)2-Mo2N/HZSM-5 catalyst possessed better effects on MAHs production as well as anti-deactivation than the HZSM-5.