Fuel Range Hydrocarbons Research Articles

Catalytic pyrolysis of plastic waste using activated carbon from cotton waste

This study introduces a novel approach to plastic waste management and energy recovery by synthesizing highly porous activated carbon from an often-overlooked resource, waste cotton fabric (WCF), using H3PO4 as an activating agent. The synthesized waste cotton fabric activated carbon samples (WCF-AC) were utilized as a solid acid catalyst in the catalytic pyrolysis of low-density polyethylene (LDPE), with the aim of converting LDPE into fuel-range hydrocarbons. This research highlights the potential of bio-based waste materials in the synthesis of eco-friendly and cost-effective catalysts for feedstock recycling. The impact of the H3PO4 impregnation ratio and the carbonization/activation temperature on the physicochemical properties of the resulting WCF-AC samples was investigated, providing valuable insights into the optimization of activated carbon production. The catalytic activity of the synthesized WCF-AC samples was evaluated, demonstrating a reduction of 12°C in the LDPE degradation temperature. Furthermore, this work revealed a substantial increase in the formation of carbocyclic compounds, with light aromatics such as benzene, toluene, and xylene constituting up to 43 % of the pyrolysis output. In certain instances, a decrease in heavier hydrocarbons beyond C11 was observed, indicating the selective yield of specific range hydrocarbons. This study underscores the potential of bio-based acid catalysts, such as the synthesized activated carbon presented here, in plastic recycling. The approach adopted in this research aligns with the principles of the circular economy, promoting resource efficiency and sustainability.

The Role of Zeolite (Microporous Crystalline Aluminosilicates) In Catalytic Pyrolysis of Waste High- and Low-Density Polyethylene Bags for Production of Fuel and Chemicals: A Review

This review provides a state-of-the-art summary of the role which zeolite plays as a catalyst via pyrolysis as a way of recovering fuels and chemicals from waste high and or low density polyethylene bags. It also highlighted the two types of zeolite (natural or synthetic) which are used as a two-stage pyrolysis−catalysis in giving a free waxing product to pure fuel and chemicals which can be subjected to further analyzing and or upgrading. As yield of oil/wax decreased with the addition of a zeolite as catalyst from 44 and 51 wt.%, (depending on the waste high density polyethylene “HDPE” or low density polyethylene bags “LDPE” and other factors). However, the composition of the pyrolysis−catalysis oils significantly increased in aromatic hydrocarbon content accordingly. In addition, the composition of the oils shifted from high molecular weight hydrocarbons (C16+) to fuel range hydrocarbons (C5−C15), with a high content of single-ring aromatic hydrocarbons such as benzene, toluene, ethylbenzene, xylenes, and styrene. This process shows great potential for production of fuels or chemicals, and also addresses the urgent issue of waste HDPE and or LDPE disposal.

Jet fuel range hydrocarbon generation from catalytic pyrolysis of lignin and polypropylene with iron-modified activated carbon

In this study, iron was used to modify pyrolytic activated carbon (AC) to synthesize a bifunctional catalyst (Fe/AC). It was applied to the catalytic co-pyrolysis of lignin with polypropylene (PP) for the preparation of jet fuel range hydrocarbons. Relationships between iron loading, reaction temperature, catalyst/feedstock ratio, and lignin/PP ratio were investigated in connection to the yield, component distribution, carbon number distribution, and chain structure of pyrolysis products. The results indicated that the hydrocarbons with carbon numbers in the jet fuel range dominated the products obtained from the catalytic co-pyrolysis of lignin and polypropylene. Owing to the oxytropism of Fe3 + , the selectivity of oxygenated chemicals in pyrolysis oil decreased as the Fe loading rose. Consequently, the production of hydrocarbons in the jet fuel range was increased. Furthermore, the deoxygenation and alkylation reactions of phenols to high-carbon aromatics were facilitated by Fe3 + . The cyclization and dehydrogenation reactions were promoted with the reaction temperature increased, thus enhancing the selectivity of cyclic hydrocarbons (cycloalkanes and aromatics) in the jet fuel range. However, secondary reactions were boosted with the excessive temperature, reducing the yield of hydrocarbons and the percentage of high-carbon hydrocarbons in the jet fuel range. The reduction of the proportion of oxygenated compounds was facilitated by the use of catalysts. Thus, the selectivity of hydrocarbons in the jet fuel range was improved, but the yield of high-carbon hydrocarbons would be reduced. In addition, the cleavage of PP-derived chain hydrocarbons was promoted by the hydrogen abstraction reaction of lignin-derived oxygenates during co-pyrolysis. The hydrogen transfer reaction between hydrocarbons and phenols was enhanced, it was pushed for phenols to convert to aromatics. Thus, the yield of hydrocarbons in the range of jet fuel was improved. A new approach to the efficient application of lignin with PP might be offered by the current work.

Thermo-catalytic decomposition of cotton seed press cake over nickel doped zeolite Y, hydrogen: enhanced yield of bio-oil with highly selective fuel-range hydrocarbons.

This research reports the yield of bio-oil from cotton seed press cake (CSPC) via an optimized thermo-catalytic pyrolysis using nickel impregnated zeolite Y, hydrogen catalyst. The catalyst, raw biomass and catalyst impregnated biomass were characterized using different analytical techniques. The ideal temperature, duration, and catalyst concentration for pyrolysis experiments were determined to be 300 °C, 20 minutes, and 5% of Ni-doped zeolite Y, hydrogen, respectively, in order to achieve the best bio-oil yield (35%). Gas chromatography-mass spectrometry (GC-MS) of pyrolytic bio-oil depicted the presence of C2-C26 hydrocarbons. The findings of this investigation showed that the synthesis of bio-oil with highly selective fuel-range hydrocarbons could be efficiently induced through the pyrolysis of CSPC biomass employing nickel impregnated zeolite Y, hydrogen catalyst. Moreover, thermogravimetric analysis (TGA) of cotton seed press cake with catalyst was carried out at various heating rates to find out the kinetic parameters. Employing Kissinger model, activation energy (E a) and frequency factor (A) for various components of biomass i.e., hemicellulose, cellulose and lignin were calculated as 83.14 kJ mol-1, 99.76 kJ mol-1, 124.71 kJ mol-1 and 1.9 × 107 min-1, 1.0 × 108 min-1, 1.0 × 1010 min-1, respectively. It can be concluded from the results that cotton seed press cake waste has potential for use as a pyrolysis feedstock in large-scale bio-fuel production.

Performance evaluation of a newly developed transition metal-doped HZSM-5 zeolite catalyst for single-step conversion of C1–C3 alcohols to fuel-range hydrocarbons

This study investigated the performance of metal-doped HZSM-5 catalysts in the conversion of low alcohols to hydrocarbons (LATH).

Effects of transition metal doping on the properties and catalytic performance of ZSM-5 zeolite catalyst on ethanol-to-hydrocarbons conversion

In this study, the effects of transition metal-doping on the physicochemical properties and catalytic performance of HZSM-5 catalysts for the conversion of ethanol to hydrocarbons are investigated using experimental data and secondary data from the literature. Hydrothermally synthesized novel ZSM-5 catalysts were modified with different concentrations (0.5 and 10 wt%) of transition metals (Co, Fe, Ni). Characterizations, including X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, particle size distribution, N2 adsorption and NH3 temperature-programmed desorption, revealed the changes in catalyst properties. The introduction of transition metals affected the surface area, particle size and acidity without altering the MFI structures. In particular, a reduction in surface area was observed, ranging from 2.6 to 23 %, corresponding to the different metal loading of 0.5–10 wt% compared to the surface area of the pure catalyst (397.5 m²/g). In addition, metal-doping led to an increase in Lewis acid sites, accompanied by a decrease in strong acid sites. Catalytic evaluation at 350 °C and a space velocity of 12 h−1 showed improved performance in metal-doped ZSM-5 catalysts, which exhibited high selectivity towards fuel-range hydrocarbons, compared to the unmodified catalyst. Catalysts with low metal doping showed optimal catalytic activity, while high metal doping led to increased coke deposition and deactivation of the catalyst due to an increased concentration of strong acids. These results underline the suitability of metal-modified ZSM-5 for hydrocarbon reactions and provide valuable insights for the optimization of catalysts for ethanol conversion to fuel-range hydrocarbons.

Pyrolysis-catalysis of medical waste over metal-doping porous biochar to co-harvest jet fuel range hydrocarbons and H2-rich fuel gas

This study developed a dual-stage pyrolysis-catalysis pathway to valorize disposal syringe waste into liquid hydrocarbons and H2-rich fuel gas. Two typical biomass sources (corn stover and cotton stalk) were used to synthesize metal-doping porous biochar catalysts through in situ carbothermal reduction treatment. For corn stover-derived biochar catalysts, Fe/C1 (Fe-doping corn stover biochar catalyst) presented a high yield (61.06 wt%) of liquid hydrocarbons with over 78% of jet fuel range (C8 – C16) hydrocarbons, and the 2,4-dimethyl-1-heptene (C9H18) yield reached 101.6 mg/gsyringe. Bimetallic Zn-Fe/C1 (Zn-Fe co-doped corn stover biochar catalyst) was in favor of H2 production, with a proportion of over 37 vol%. Among the cotton stalk-derived biochar catalysts, bimetallic Zn-Fe/C2 (Zn-Fe co-doped cotton stalk biochar catalyst) achieved a highest yield (62.76 wt%) of liquid hydrocarbons, indicating a positive synergistic effect of bimetallic Zn-Fe composite on liquid hydrocarbons production. However, Fe/C2 (Fe-doping cotton stalk biochar catalyst) was responsible for a high yield (over 93 mg/gsyringe) of 2,4-dimethyl-1-heptene and a high selectivity (over 76%) of jet fuel range hydrocarbons. Additionally, a logical reaction mechanism was provided for dual-stage pyrolysis-catalysis of syringe waste over metal-doping porous biochar catalysts. Briefly, this work provides a green route by using metal-doping biochar for valorization of medical wastes into liquid hydrocarbons and H2-rich fuel gas.

Production of jet fuel range hydrocarbons using a magnetic Ni–Fe/SAPO-11 catalyst for solvent-free hydrodeoxygenation of jatropha oil

A novel, multifunctional Nix–Fe/SAPO-11 catalyst was synthesized and characterized, and its activity was evaluated for the solvent-free hydrodeoxygenation of jatropha oil. The catalyst has a spherical structure and moderate acid strength, and exhibited excellent cyclization and deoxidation activity. The inclusion of iron facilitated the dispersion of active components. Consequently, the iron-nickel alloy particle size remained small, resulting in an optimal distribution of the product. The composition of the products is linear alkanes (59.83%), isoparaffins (4.16%), aromatics (8.41%), and naphthenes (12.03%), where jet fuel components are relatively high, accounting for 55.04% of C8–C16 hydrocarbons. Interestingly, the iron present in the catalyst allowed the use of an external magnetic field for the rapid separation and recycling of the catalyst. Despite multiple uses, the recycled catalyst maintained high activity following five cycles, with hydrocarbon content consistently above 85%. The synergic effect of the metallic and acid sites of the catalyst, let to realize one-pot hydrodeoxygenation, isomerization, aromatization, and cracking of substrate forming bio-jet fuel range hydrocarbons.

A two-stage strategy for upcycling chlorine-contaminated plastic waste

AbstractChemical upcycling of polyolefin plastic waste to lubricant, wax and fuel-range hydrocarbons over metal-based catalysts is a crucial technological solution to the enormous environmental threat posed by plastic waste. However, currently available methods are incompatible with chlorine-contaminated feedstocks. Here we report a two-stage strategy for upcycling chlorine-contaminated polypropylene. First, magnesia–alumina mixed oxide at 30 bar H2 and 250 °C serves as a chlorine trap by rapidly forming solid chloride, resulting in nearly complete chlorine extraction from the polyolefin melt. This enables the upcycling of plastic waste with up to 10% polyvinyl chloride content to lubricants over ruthenium-based catalysts, in the second stage. The strategy is also applicable to chlorinated aromatics and alkanes. The proposed strategy renders hydrocracking and hydrogenolysis catalysts less sensitive to the chlorine impurities in feedstocks while eliminating HCl emissions and chlorine contamination in products. It could incentivize further progress in plastics upcycling.

Hydrodeoxygenation of safflower oil over cobalt-doped metal oxide catalysts for bio-aviation fuel production

The catalytic hydrodeoxygenation process provides an alternative route for the production of renewable jet fuel, which can directly replace petroleum-derived hydrocarbons. To this end, the catalytic performance of Co-based catalysts supported by different metal oxides, γ-Al2O3, TiO2, ZnO and ZrO2 was tested to evaluate their catalytic activity and product selectivity in hydrodeoxygenation of safflower oil. The results indicated that catalytic performance changed in response to acidity, morphologies and particle size of catalysts. Benefiting from these combined characteristics, Co/ZnO catalyst exhibited a highly catalytic activity, being capable of producing jet fuel-range hydrocarbon selectivity of 65.96% under reaction parameters of 350 °C of reaction temperature, 8 h of reaction time and 75 bar of H2 initial pressure. In addition to superior activity, the coke content of Co/ZnO was much lower compared to other employed catalysts thereby affecting the stability of the catalyst and resulting in less deactivation and coke formation.

Towards improved conversion of wet waste to jet fuel with atomic layer deposition-coated hydrodeoxygenation catalysts

The conversion of wet waste-derived volatile fatty acids into jet fuel-range hydrocarbons is a promising route for increasing the production of sustainable aviation fuel; however, the cost and moderate alkane selectivity of Pt-based hydrodeoxygenation catalysts present challenges for commercialization. To address this, we used atomic layer deposition to apply TiO2 overcoats to Pt/Al2O3 catalysts and create new interface sites that exhibited 8 times higher site time yield of the desirable n-alkane product than uncoated catalyst. Through TPR/TPD, XPS, CO DRIFTS, and DFT calculations, we found that the increased selectivity of the ALD-coated catalyst was due to the creation of O vacancies at the Pt-TiO2 interface under reducing conditions, resulting in new Ti3+ acid sites near the active metal. Maximum conversion and alkane selectivity during HDO was achieved with an ALD-coated 0.5% wt Pt catalyst, indicating that TiO2 ALD can be used to maximize the utility of precious-metal catalysts.

Selective Production of Gasoline Fuel Blendstock from Methanol using a Metal-doped HZSM-5 Zeolite Catalyst

The increasing demand for substitutes for petroleum has become a global concern due to the looming petroleum crisis and the need to reduce carbon dioxide emissions. This study seeks a viable approach for converting methanol into petrochemicals and fuel-range hydrocarbons. A ZSM-5 zeolite catalyst was synthesised and modified with 0.5 wt% transition metals (Co and Ni) to improve selectivity towards the desired liquid product (gasoline) in the methanol-to-hydrocarbon (MTH) conversion. The synthesised catalyst was characterised using various techniques. The catalysts were further evaluated for methanol conversion into fuels and petrochemicals (BTX) under varying weight hourly space velocity (WHSV) (7 and 12 h-1) at 350 oC. Results showed that the synthesised catalyst exhibited characteristic features of a typical MFI framework of a zeolite catalyst. The catalyst evaluation results revealed that changes in operating conditions affected product distribution. A WHSV of 12 h-¹ favoured the production of gasoline range hydrocarbons (C5-C12) with a yield of over 80 % for all catalysts. In addition, C12+ hydrocarbons were produced with a selectivity of 12.6 %, 0.7 % and 7.5 % for Ni-doped, Co-doped and HZSM-5 catalysts, respectively. In particular, the Co-doped catalyst showed a 7.1 % higher BTX yield under these specific operating conditions (12 h-1 and 350 oC). Compared to 7 h-1, increasing the WHSV to 12 h-1 favoured the production of liquid hydrocarbons. Incorporating a small amount of transition metal into the parent catalyst improved the selectivity of the target products and overall liquid hydrocarbon yield. The results concluded that the synthesised catalyst is promising for the MTH process, and catalytic performance can be enhanced by metal modification and optimising reaction conditions to improve biofuel production.

Compositional dependence of Co- and Mo-supported beta zeolite for selective one-step hydrotreatment of methyl palmitate to produce bio jet fuel range hydrocarbons.

For producing a drop-in bio jet fuel, one-step hydrotreatment, which includes deoxygenation, isomerization and cracking in one step, is essential to overcome the typical biofuel drawbacks due to high oxygen content, out of jet fuel range hydrocarbons, and low isomerization degree. Herein, Co- or/and Mo-supported Beta(25) zeolites with various Co/Mo ratios were prepared as transition metal-supported zeolite catalysts without the need for sulfidation of conventional transition metal catalysts. Based on the catalyst characterization, the Co/Mo ratio alters the metal phase with the appearance of CoMoO4 and the altered Co metal phase strongly influences the acidic properties of Beta(25) by the formation of Lewis (L) acid sites with different strengths as Co3O4 and CoMoO4 for strong and weak L acid sites, respectively. The catalytic activities were investigated for hydrotreatment of methyl palmitate as a biofuel model compound of fatty acid methyl esters. Primarily, Co is required for deoxygenation and Mo suppresses overcracking to enhance the yield of jet fuel range hydrocarbons. The Co/Mo ratio plays an important role to improve the C8-C16 selectivity by modifying the acidic properties to inhibit excessive cracking. Co5Mo10/Beta(25) achieved the best catalytic performance with the conversion of 94.2%, C8-C16 selectivity of 89.7 wt%, and high isomer ratio of 83.8% in organic liquid product. This unique modification of acidic properties will find use in the design of optimal transition metal-supported zeolite catalysts for selective one-step hydrotreatment to produce bio jet fuel range hydrocarbons.

Production of Fuel Range Hydrocarbons from Pyrolysis of Lignin over Zeolite Y, Hydrogen

In the current study, plain and lignin loaded with Zeolite Y, hydrogen was decomposed in a pyrolysis chamber. The reaction parameters were optimized and 390 °C, 3% catalyst with a reaction time of 40 min were observed as the most suitable conditions for better oil yield. The bio-oil collected from the catalyzed and non-catalyzed pyrolytic reactions was analyzed by gas chromatography mass spectrometry (GCMS). Catalytic pyrolysis resulted in the production of bio-oil consisting of 15 components ranging from C3 to C18 with a high percentage of fuel range benzene derivatives. Non-catalytic pyrolysis produced bio-oil that consists of 58 components ranging from C3 to C24; however, the number and quantity of fuel range hydrocarbons were lower than in the catalyzed products. The pyrolysis reaction was studied kinetically for both samples using thermogravimetry at heating rates of 5, 10, 15 and 20 °C/min in the temperature range 20–600 °C. The activation energies and pre-exponential factors were calculated using the Kissinger equation for both non-catalytic and catalytic decomposition and found to be 157.96 kJ/mol, 141.33 kJ/mol, 2.66 × 1013 min−1 and 2.17 × 1010 min−1, respectively. It was concluded that Zeolite Y, hydrogen worked well as a catalyst to decrease activation energy and enhance the quality of the bio-oil generated.

Upgradation of Eugenol to ASTM D 1655 standard Bio-Jet(A) fuel range hydrocarbons via hydrodeoxygenation process over Ru-Ni supported KIT-6/HZSM-5

A novel hierarchical Zeolite composite was successfully synthesized for bio-fuel application via catalytic hydrodeoxygenation of Lignin-Derived Phenolic Model Compound (LDPMC) in a downflow fixed bed reactor. The utilization of massive noble metals in the hydrodeoxygenation process in factories leads to an increase in the total cost of LDPMC technology. A fractional replacement of Ruthenium (Ru) by another transition metal Nickel (Ni), is a potentially effective method. The core asset of the novel synthesized catalyst displayed the advantageous properties of both micro- and mesoporous. This could be confirmed by the results of XRD, BET, and surface analyzing microscopes. The synthesis of Rux-Ni10-x/KIT-6-HZSM-5 (x = 2, 4 & 6) bimetallic-monometallic catalysts and their catalytic performance for hydrodeoxygenation of Eugenol are reported in the present study. The hierarchical Zeolite composite catalysts were synthesized by a wet-chemistry method. The active catalysts were characterized by ATR-IR, H2-TPR, NH3-TPD, HR-SEM, HR-TEM, XPS, and TGA techniques. The synthesized 2 %Ru-8 %Ni/KIT-6-HZSM-5 exhibited 100 % conversion with a maximum yield of 48.70 % of the complete deoxygenated product (Jet A range fuel) due to the synergistic effect between Ru and Ni on hierarchical Zeolite composite support and superior catalytic activity compared to the other synthesized catalysts with the highest metal dispersion. The stability and reproducibility of catalysts were steady even after 4 cycles. The Ruthenium and Nickel loaded hierarchical Zeolite composite support showed superior activity related to other reported catalysts even at atmospheric pressure under variable experimental conditions.

Jet fuel-range hydrocarbons generation from the pyrolysis of saw dust over Fe and Mo-loaded HZSM-5(38) catalysts

In this research, we studied the catalytic pyrolysis of sawdust over monometal (1 wt% Fe or 1 wt%Mo) and bimetal (1 wt% Fe-1 wt% Mo or 0.5 wt% Fe-0.5 wt% Mo)-loaded HZSM-5(38) catalysts, synthesized via wet impregnation method, for the generation of jet fuel-range hydrocarbons. In particular, we aimed to generate jet fuel-range aromatic hydrocarbons (C8-C12) and a high amount of organic-phase bio-oil at the same time from this pyrolysis. In addition, the bimetal-loaded HZSM-5(38) catalysts (1 wt% Fe-1 wt% Mo/HZSM-5(38) and 0.5 wt% Fe-0.5 wt% Mo/HZSM-5(38)) helped achieve a higher organic phase bio-oil yield (20.74 and 17.14 wt%) compared to those under the pristine HZSM-5 (9.57 wt%) and monometal-loaded HZSM-5(38) catalysts (1 wt%Fe/HZSM-5(38) and 1 wt% Mo/HZSM-5(38)) (13.04 and 11.45 wt%, respectively). The exchange of the strong Brønsted acidity in the HZSM-5(38) support with an added metal (Mo and Fe) ion of this catalyst might have prevented excessive cracking and dehydration of the bio-oil intermediates, thereby increasing the organic-phase bio-oil yield of the pyrolysis. The coke amount of bimetal-loaded HZSM-5(38) catalyst was lower than that of monometal-loaded HZSM-5(38). Overall, the bimetal-loaded HZSM-5(38) catalysts possessed a synergistic effect leading to their high activity, generating the higher amount of jet fuel-range hydrocarbons because of the enhanced deoxygenation such as hydrodeoxygenation and dehydrogenation reactions of the pyrolysis under this catalyst.

Blend Prediction Model for the Freeze Point of Jet Fuel Range Hydrocarbons

Blend Prediction Model for the Freeze Point of Jet Fuel Range Hydrocarbons

Synthesis of nanocrystalline cellulose induced hierarchical porous ZSM-5 for catalytic conversion of low-density polyethylene

The catalytic pyrolysis of low-density polyethylene over hierarchical HZSM-5 zeolite was studied to improve liquid oil quality in a facile reactor for the first time. The HZZ was successfully synthesized by using green and inexpensive nanocrystalline cellulose as a mesoporous template. Nanocrystalline cellulose played a disturbing role in the crystallization process of hierarchical HZSM-5 zeolite, which facilitated the formation of ordered surface morphology and excellent porous structure. Compared with conventional HZSM-5, hierarchical HZSM-5 zeolite can significantly improve the bio-oil yield. The relative content of cycloalkanes increased while the relative content of aromatics decreased. The 94.4 area.% of jet fuel range hydrocarbons with 51.8 area.% cycloalkanes and 25.0 area.% of aromatics can be obtained. Hierarchical HZSM-5 zeolite with a low Si/Al ratio had high acidity favors high liquid yield and aromatic hydrocarbon selectivity. The current work contributes to the green synthesis of Hierarchical HZSM-5 zeolite while providing a novel catalyst for value-added fuels production from waste plastics pyrolysis.

Catalytic co‐pyrolysis of low‐density polyethylene (LDPE) and lignin for jet fuel range hydrocarbons over activated carbon catalyst

The catalytic conversion of low-density polyethylene (LDPE) and lignin over activated carbon into jet fuel range hydrocarbons was studied. A fixed bed furnace was used to investigate the impacts of temperature, LDPE to lignin ratio, and catalyst to feedstock ratio on the composition of bio-oils, and up to 100 area% jet fuel range hydrocarbons can be acquired from the catalytic co-pyrolysis of LDPE and lignin. The results showed that the activated carbon has an excellent catalytic performance to convert LDPE and lignin into jet fuel range hydrocarbons. The properties of activated carbon catalyst were characterized by nitrogen gas adsorption, Fourier transform infrared spectrometer, and scanning electron microscope. There is a synergistic effect between the higher pyrolysis temperature and the acid sites of activated carbon on the dissociation and conversion of alkanes to form the aromatics. In addition, the yield of jet fuel range hydrocarbons could be enhanced by the synergistic effect of LDPE on the catalytic conversion of lignin. This work provided an environment friendly, economical, convenient, simple, and effective route to acquire jet fuel range hydrocarbons from daily waste plastics and biomass.

Towards jet fuel from technical lignins: Feedstock-catalyst-product interactions revealed during catalytic hydrogenolysis

One-pot conversion of technical lignins to jet fuel is limited by recondensation of unstable intermediates. A two-stage process that first generates stabilized fragments by reductive depolymerization, then upgrades oligomers to hydrocarbons may increase yield. Insights into factors affecting initial depolymerization of industrially relevant lignins were revealed, whereas many studies have focused on upgrading bio-oil or model compounds. Feedstocks, catalysts, and process conditions were varied to identify effects on product composition. Hydrogen and temperature synergistically suppressed coking during pine kraft depolymerization to increase monomer production. Ruthenium was more effective than cobalt at limiting solid residue and improving liquid product yield by promoting hydrogenation and hydrogenolysis. Besides ruthenium, a strong acid-base catalyst effectively deconstructed hardwood biorefinery lignin, targeting alkyl-aryl ether bonds. Ruthenium and zinc converted hardwood kraft lignin to oligomers most suitable for upgrading to jet fuel-range hydrocarbons based on yield (79 % on dry lignin), weight-average molecular weight (1290 g/mol), and chemical structure.