Diesel Range Hydrocarbons Research Articles

Thermal and catalytic pyrolysis of automotive plastic wastes to diesel range fuel

This study investigated the pyrolysis of automotive plastic wastes (APW) for the production of diesel-grade oil products using a modified calcium bentonite clay catalyst. The research aimed to optimize the process for maximum oil yield and diesel range organics yield. The APW was characterized by its chemical composition and physical properties and the optimal temperature and catalyst amount were determined for maximum oil yield and diesel range hydrocarbons. The results showed that the APW contained mixed Acrylonitrile Butadiene Styrene (ABS), High/Low Density Polyethylene (H/LDPE), Polypropylene (PP), Polystrene (PS) and fiberglass, with a large quantity of volatiles and ash. The average oil yield was higher in the catalytic process compared to that in the thermal process. Generally, higher temperature above 450 °C produced waxy oil, thus lower temperature favoured more Diesel Range Organics (DRO). Both processes yield similar yields of C8–C24 DRO, and in both cases, lower temperature favoured high yield of C8-C24 hydrocarbons. The catalyst significantly increased the yield of oil, but did not significantly increase C8–C24 DRO yield. The optimal conditions for a maximum oil yield of 78.6 % and DRO yield of 79.5 % was a temperature of 416 °C and 24.3 wt% clay. Thus, the modified calcium bentonite clay can be used to improve oil yield from pyrolysis of APW. The oil produced had properties such as calorific value (49.85 MJ/kg), flash point (113 °C) and total aromatics 3.55 area%, similar to those of commercial diesel, and comprised mostly of 2,4-Dimethyl-1-heptene (25.37 ± 2.01 %) of thermal and 2, 4 – Dimethyl – 1 – heptane (23.44 ± 2.42) in the catalytic process. The study suggests further research to explore different catalysts, maximization of both DRO and gasoline range organics, recover energy from residues, and conduct techno-economic assessments for plant-scale operations. Additionally, policies on the management of end-of-life vehicles should include provisions for stripping and segregation of plastic components by accredited providers for the purpose of plastics recycling.

Catalytic hydrothermal liquefaction of Azolla filiculoides into hydrocarbon rich bio-oil over a nickel catalyst in supercritical ethanol

Hydrothermal liquefaction (HTL) is one of the most promising thermochemical techniques for converting wet biomass into crude oil-like products (bio-oil). In this study, Catalytic hydrothermal liquefaction of Azolla filiculoides (AZ) was performed over a various loading of nickel (Ni) on magnesium oxide (MgO) catalyst for the higher and quality bio-oil production. The key operating parameters such as temperature, reaction holding time, amount of Ni on MgO supports catalyst, and reaction solvents were investigated in the presence of a hydrogen environment. There was a 12.8 wt% increase in bio-oil yield and a 6.3 wt% decrease in biochar yield with addition of 15 wt% Ni catalysts compared to the non-catalytic reaction bio-oil yield (44.0 wt%). Results confirmed the highest total bio-oil yield of 56.8 wt% was attained at 280 °C with the catalyst amount of 15 wt% at a residence time of 45 min. Gas chromatography-mass spectrometry (GC-MS), FT-IR, CHNS, TGA, and NMR analyses were performed on the bio-oil, identifying 32.8 % long-chain hydrocarbons (C12-C16) along with small amounts of alcohols, alkanes, and esters. The boiling point distribution revealed that bio-oil produced using the Ni/MgO catalyst contained a significantly higher proportion of diesel-range hydrocarbons (42.4 %). Furthermore, the bio-oil yield under ethanol solvent and Ni catalysts showed higher heating value (HHV) 42.2 MJ/kg. Overall in the presence of Ni hydrogenation efficient catalysts on MgO in the liquefaction reaction promoted the deoxygenation and hydrogenation reaction.

Conversion of soybean oil under subcritical water conditions into liquid biofuels with low oxygen contents

Although the hydrotreatment of natural triglycerides is a well-established route for producing sustainable aviation fuel and renewable diesel, its high hydrogen consumption is a concern. The hydrothermolysis of natural triglycerides is considered a highly promising alternative route; however, the correlation between process parameters and fuel properties and detailed chemical structures of the produced fuel have not been established. Herein, we investigated the conversion of soybean oil to gasoline-, jet fuel- and diesel-fraction hydrocarbons with low oxygen contents. The properties of fuels produced under various reaction conditions were analyzed comprehensively using simulated distillation, total acid number (TAN), and elemental analysis. Under the optimized reaction conditions of 420 °C, 4.5 MPa, an oil-to-water ratio of 6:1, and reaction time of 10 min, 26 % gasoline-, 62 % jet fuel-, and 90 % diesel-range hydrocarbons with a low oxygen content of 5.1 %, low TAN of 0.04 mg KOH g−1, and high calorific value of 42.7 MJ kg−1 resulted. To elucidate the reaction mechanism, the liquid products produced from soybean oil were analyzed using comprehensive two-dimensional gas chromatography combined with time-of-flight mass spectrometry. In addition, based on the oleic acid conversion under varying hydrothermal conditions, we proposed deoxygenation, cracking, cyclization, and aromatization pathways. The findings of this study present possibilities for producing sustainable biofuels with low oxygen contents for the aviation industry.

Single-step and stepwise pyrolysis to recover high-value chemicals from mixed polyolefins and polylactide

Biodegradable plastics are increasingly utilized due to environmental concerns but are typically disposed of together with conventional plastics. Valuable chemicals could be recovered from waste plastics by chemical recycling, but the mixing of different types of waste plastic affects the efficiency of the process. In this study, high-value chemicals were produced from a mixture of polyolefins and biodegradable polylactide by single and stepwise pyrolysis processes. The pyrolysis of polyolefins yielded fuel-like hydrocarbons, and the pyrolysis of polylactide yielded lactide and lactic acid. In the stepwise process, oxygenated compounds were only produced in the low-temperature step, and fuel-like hydrocarbons produced in the high-temperature step were not contaminated by oxygenated compounds. The influence of different catalysts on yields was investigated in the single-step and stepwise processes. The yield and selectivity of each product were significantly influenced by the type of catalyst and the composition of the plastic feedstock. Using a mixed feedstock of polyolefins and polylactide, low-temperature pyrolysis with a zeolite LTA catalyst favored the formation of lactide and lactic acid, while diesel-range hydrocarbons were obtained in the second step at a higher temperature. Aromatic and gasoline-range hydrocarbons were preferably produced from the single-step pyrolysis of polyolefins with spent FCC catalyst.

Evaluation of an alternative process for the production of hydrocarbons from CO2: Techno-economic and environmental analysis

This study aims to evaluate and compare two integrated processes (Plant A and B) for hydrocarbon production from CO2. They involve proton exchange membrane water electrolysis for H2 production, reverse water-gas shift reaction for syngas production, pressure swing adsorption for syngas purification, Fischer-Tropsch synthesis for diesel-range hydrocarbons from CO2, and atmospheric distillation for product separation. Plant B additionally integrates a hydrocracking-based upgrading section. The simulations were performed using Aspen Plus® v10, Aspen Adsorption® v10, and Aspen Custom Modeler® v10. The evaluation covers technical, economic, environmental, and multi-criteria assessment (GREENSCOPE). The proposed processes demonstrate the potential to convert CO2 to hydrocarbons, with carbon conversion rates of 75% and 71% for Plants A and B, respectively. Process energy intensity is 155 and 170 MJ/kgLP for Plants A and B, respectively. Environmental assessment reveals CO2 reduction, resulting in negative global warming potentials of −2.20 and −0.84 kgCO2-eq/kgLP for Plants A and B, respectively. The sustainability degree indices for Plants A and B are 1.00 and 0.06, respectively, indicating Plant A as the more sustainable process alternative based on both quantitative and qualitative metrics. Economic analysis shows project unviability in the Brazilian context due to reliance on H2 production and prevailing pricing conditions. Economic viability requires a price increase of liquid products by 266% and 302% or CO2-eq abatement costs ranging from 2.05 to 3.43 US$/kgCO2-eq for Plants A and B, respectively. GREENSCOPE methodology indicates better performance for Plant A across all scores, highlighting a clear connection between the hydrocracking unit and performance indicators. The findings show that these processes align with sustainable development goals (SDGs) targets for climate action (SDG 13), clean energy (SDG 7), industry, innovation, and infrastructure (SDG 9), decent work and economic growth (SDG 8), and responsible consumption and production (SDG 12). Overall, the research moves forward SDGs by offering solutions to cut carbon emissions and promote sustainable industrial practices.

Rapid Waste Motor Oil Conversion into Diesel-Range Hydrocarbons Using Hydrochar as Catalyst: Kinetic Study and Product Characterization

Herein, raw and alkali-treated hydrochars from biomass waste are prepared as a highly active catalyst for the conversion of waste motor oil into diesel-like fuels. Among all materials, hydrochar obtained at 250 °C and subsequent alkali activation with KOH showed a 600% improvement of the kinetic constant from 0.0088 to 0.0614 m−1. Conversion values at the same conditions were also improved from 66 to 80% regarding thermal and catalytic cracking, respectively. Moreover, the activation energy was also reduced from 293 to 246 kJ mol−1 for thermal and catalytic cracking, respectively. After characterization, the enhanced catalytic activity was correlated to an increased surface area and functionalization due to the alkali activation. Finally, the liquid product characterization demonstrated that catalytic cracking is more effective than thermal cracking for producing hydrocarbons in the diesel range. In particular, hydrochar-based catalysts are suggested to promote the formation of specific hydrocarbons so that the carbon distribution can be tailored by modifying the hydrothermal treatment temperature.

Frustrated Lewis pair catalyst realizes efficient green diesel production

Hydrotreating renewable oils over sulfided metal catalysts is commercially applied to produce green diesel, but it requires a continuous sulfur replenishment to maintain catalyst activity, which inevitably results in sulfur contamination and increases production costs. We report a robust P-doped NiAl-oxide catalyst with frustrated Lewis pairs (i.e., P atom bonded with the O atom acts as an electron donor, while the spatially separated Ni atom acts as an electron acceptor) that allows efficient green diesel production without sulfur replenishment. The catalyst runs more than 500 h at a weight hourly space velocity (WHSV) of 28.3 h−1 without deactivation (methyl laurate as a model compound), and is able to completely convert a real feedstock of soybean oil to diesel-range hydrocarbons with selectivity >90% during 500 h of operation. This work is expected to open up a new avenue for designing non-sulfur catalysts that can make the green diesel production greener.

Catalytic conversion of castor seed oil to diesel range hydrocarbons using NiO –CuO catalyst supported on ZSM-5

Bio-oils are an alternative fuel that can be produced from organic resources such as vegetable oils in which castor seed oil is an example. In this research work castor seed oil was converted to diesel range hydrocarbons using NiO-CuO/ZSM-5 as catalyst. The catalyst was synthesized using wet impregnation method which was characterized using Fourier Transform Infrared (FT-IR) and Energy Dispersive X-ray Fluorescence (EDXRF). The castor seed oil was extracted by using hot water stirring method. The extracted raw oil and catalytically cracked bio-oil were also characterized by FT-IR. The optimum yield of bio-oil 80.70 % was attained at the temperature of 300 0C, reaction time 60 mins and catalyst loading of 2 wt% respectively. The Bio-oil was also characterized using GC-MS to determine the molecular compositions of the raw, thermally and catalytically cracked bio-oil. However, this makes castor seed oil a good feedstock for bio-oil production with little modifications on its properties. This indicates that the products can be used as an alternative fuel in diesel engines.

Partitioning of Per‐ and Polyfluoroalkyl Substances to Weathered Light Non‐Aqueous Phase Liquid

AbstractPer‐ and polyfluoroalkyl substances (PFAS) and weathered petroleum hydrocarbons can be co‐contaminants at sites where aqueous film‐forming foam (AFFF) was used to extinguish high‐temperature petroleum fires. Here, we report on the partitioning of six PFAS between water and a weathered diesel and gasoline range hydrocarbon light non‐aqueous phase liquid (LNAPL) collected from the subsurface of a decommissioned refinery. Results showed that both the structural features of PFAS and the characteristics of LNAPL exhibited significant impacts on the magnitude of PFAS partitioned to the LNAPL. The LNAPL–water partition coefficients (Kl) of PFOA and PFOS to the weathered LNAPL measured in this work were nearly or more than 10 times greater than Kl values calculated by others for partitioning to single‐component, unweathered NAPLs, indicating that laboratory studies evaluating LNAPL–water partitioning studies using single component NAPLs can largely underestimate the Kl expected to be encountered at contaminated AFFF sites. Interactions with LNAPL can be important controllers of PFAS fate and transport, and the Kl values estimated in this work suggest that LNAPL could be a significant transport sink for PFAS in the field. Results from this work suggest that PFAS partitioning to weathered LNAPL is an important process to be considered when designing remedial strategies, particularly those incorporating monitored natural attenuation or natural source zone depletion.

Exploring the potential of clay catalysts in catalytic pyrolysis of mixed plastic waste for fuel and energy recovery

Developing low-cost and high-activity catalysts is one of the keys to promoting the catalytic pyrolysis of waste plastics to fuels for plastic recycling. This work studied the effect of clay as the catalyst on mixed plastic pyrolysis for fuel and energy recovery. Four kinds of clay, including nanoclay, montmorillonite, kaolin, and hydrotalcite, were used as catalysts for the pyrolysis of mixed plastic consisted of polyethylene terephthalate, polystyrene, polypropylene, low-density polyethylene, and high-density polyethylene. The product yield and distribution varied with different clay in pyrolysis. The highest yield of oil was 71.0 % when using montmorillonite as the catalyst. While the highest contents of gasoline range hydrocarbons and diesel range hydrocarbons in the oil were achieved when using kaolin and nanoclay, respectively as catalysts. For the gas products, the CO, C2H4, C2H6, C3H6, and C4H10 increased with decreased CO2 in the gaseous products when using clay as catalysts. In general, the mild acidity of clay catalyst was essential to improve the oil yields and the proportion of the gasoline or diesel range fuels in the catalytic pyrolysis of mixed plastic waste.

Surface-silanised and alkoxylated micro-mesoporous Ni/hierarchical nanozeolites for oleic acid hydrodeoxygenation

In this work, we report a novel and green method for the synthesis of hierarchical nanozeolites for the hydrodeoxygenation of oleic acid to diesel-range hydrocarbons. Hierarchical nanozeolites based on HZSM-5 and HBEA with appropriate mesopores (8–20 nm) were synthesised through the surface silanisation of zeolitic seeds. In this method, organosilane (hexadecyltrimethoxysilane) was used as a growth inhibitor while biomass-derived alcohols (1-decanol and isobutanol) were used to improve the miscibility and dispersion of the organosilane. 1H MAS NMR analysis confirmed the silanisation and alkoxylation of the zeolitic seeds. The physicochemical properties of the catalysts were analysed by XRD, N2 porosimetry, NH3-TPD, pyridine-DRIFTS, XPS and TEM, and the catalytic performance of bifunctional 10 wt.% Ni/h-HZSM-5 and Ni/h-HBEA were then evaluated in the HDO of a bulky feedstock, oleic acid. The hierarchical zeolites supported Ni catalysts achieved more than 86% conversion of oleic acid. Compared with their microporous nanozeolite counterparts, Ni/h-HBEA and Ni/h-HZSM-5 exhibited comparable or higher Brønsted/Lewis acid ratios, leading to high selectivity towards C18 alkanes (65% and 71%, respectively); they also demonstrated similar catalytic yields. More importantly, while their microporous analogues lost much of their activity after the first cycle, Ni/h-HZSM-5, in particular, displayed excellent stability, even after four cycles. Thus, our approach appears to be a promising way of preparing catalyst supports for efficient hydrotreatment of bulky substrates.

Possible use of spent FCC catalyst for upgrading of wax from the pyrolysis of plastics to liquid fuel

The cracking of heavy wax derived from mixed plastics (high-density polyethylene, low-density polyethylene, and polypropylene) to chemical and fuel purposes was explored using spent fluid catalytic cracking catalyst (spent FCC). The wax cracking was performed by a fixed-bed pyrolysis reactor with a slow heating rate. All catalysts, when compared to other catalysts (HY zeolite and MCM-41), could enhance liquid oil and gas production. While the spent FCC catalyst produced the highest liquid oil with least amount of coke production. The influence of spent FCC catalyst ratio on product distribution revealed that a catalyst-wax ratio of up to 1:1 resulted in a higher liquid oil yield than a low ratio. Additionally, the increase of cracking temperature promoted more oil production; however, at high temperature (above 400 °C) the evaporation of wax became more significant, and consequently a high portion of produced wax was obtained. Therefore, under suitable conditions, the spent FCC catalyst demonstrated the possibility of upgrading the heavy wax into liquid fuels and chemicals. In addition, this study also compared the products obtained from two processing routes using the spent FCC catalyst. The first route involved the pyrolysis of plastics into wax and then cracking the wax into liquid fuel, while the second route involved a one-step process that directly converted plastics into liquid fuel. The spent FCC catalyst promoted the production of diesel-range hydrocarbons and suppressed the aromatic production for the wax cracking. By contrast, the spent FCC catalyst significantly enhanced aromatic production during the cracking of mixed plastics.

A versatile hybrid catalyst platform of Na/ZnFe2O4 and zeolite for selective hydrocarbon production from CO2 hydrogenation

Catalytic CO2 hydrogenation faces great challenges in both reaction rates and selectivity to desired high-value products. Herein, we present a one-pot reaction platform that converts CO2 into various long-chain hydrocarbons selectively by combining a Na/ZnFe2O4-based catalyst for CO2 activation and carbon–carbon coupling, and a zeolite for fine-tuning the selectivity of desired products by exploiting its shape selectivity. Thus, the Na/ZnFe2O4 catalyst without zeolite produces highly olefinic diesel range hydrocarbons, and a hybrid catalyst with ZSM-5 produces highly aromatic gasoline range hydrocarbons, that with ZSM-11 produces branched kerosene range hydrocarbons, and that with SSZ-13 produces hydrocarbons rich in C2-C4 olefins. In all cases, high CO2 conversions of over 35% and low CO selectivity of near 10% are maintained. Therefore, the hybrid catalyst platform proposed here demonstrates that an elaborate catalyst design enables fine-tuning of the reaction pathway of CO2 hydrogenation to produce selectively versatile value-added hydrocarbons.

Zeolite Supported Pt for Depolymerization of Polyethylene by Induction Heating.

We demonstrate that for polyethylene depolymerization with induction heating (IH), using a bifunctional (Pt- or Pt-Sn-containing zeolite) hydrocracking catalyst, we can obtain high hydrocarbon product yields (up to 95 wt % in 2 h) at a relatively low surface temperature (375 °C) and with a tunable product distribution ranging from light gas products to gasoline- to diesel-range hydrocarbons. Four zeolite types [MFI, LTL, CHA(SSZ-13), and TON] were chosen as the supports due to their varying pore sizes and structures. These depolymerization results are obtained at atmospheric pressure and without the use of H2 and result in an alkane/alkene mixture with virtually no methane, aromatics, or coke formation. We also demonstrate how IH helps overcome diffusional resistances associated with conventional thermal heating and thereby shortens reaction times.

Low-temperature destructive hydrodechlorination of long-chain chlorinated paraffins to diesel and gasoline range hydrocarbons over a novel low-cost reusable ZSM-5@Al-MCM nanocatalyst: a new approach toward reuse instead of common mineralization

Low-temperature destructive hydrodechlorination of long-chain chlorinated paraffins to diesel and gasoline range hydrocarbons over a novel low-cost reusable ZSM-5@Al-MCM nanocatalyst: a new approach toward reuse instead of common mineralization

Bifunctional CaCO3/HY Catalyst in the Simultaneous Cracking-Deoxygenation of Palm Oil to Diesel-Range Hydrocarbons

Palm oil is a promising raw material for biofuel production using the simultaneous catalytic mechanism of the bifunctional cracking-deoxygenation reactions. Through the cracking-deoxygenation process, the chains of palmitic acid and oleic acid in the palm oil were converted to diesel-range hydrocarbons. The combination effects of CaCO3 and HY zeolite enhanced the bifunctional catalytic cracking-deoxygenation of palm oil into biofuel, because of the increasing acid and basic sites in the catalysts due to the synergistic roles of CaCO3 and HY. The introduction of CaCO3 on HY zeolite generated both a strong acid and strong basic sites simultaneously on the designed catalyst, which supports the bifunctional mechanisms of hybrid cracking-deoxygenation, respectively. The CaCO3 impregnated on the HY catalyst has a synergistic and bifunctional effect on the catalyst supporting cracking-deoxygenation reaction mechanisms as mentioned previously. The deoxygenation reaction required the bifunctional strong acid and strong basic sites on the CaCO3/HY catalyst through decarboxylation, decarbonylation, and hydrodeoxygenation reaction mechanisms. Meanwhile, the cracking reaction pathway was supported by the strong acid sites generated on the CaCO3/HY catalyst. In other words, the high acidity strength promotes diesel selectivity, whereas the high strength of basicity leads to the deoxygenation reaction.

Catalytic hydrogenolysis of plastic to liquid hydrocarbons over a nickel-based catalyst

The catalytic hydrogenolysis of a typical model compound of mulching film waste, polyethylene, was investigated as a potential way to improve economic efficiency of mulching film recycling. Nickel-based heterogeneous catalysts are proposed for polyethylene hydrogenolysis to produce liquid hydrocarbons. Among catalysts supported on various carriers, Ni/SiO2 catalyst shows the highest activity which may due to the interactions between nickel and silica with the formation of nickel phyllosilicate. As high as 81.18% total gasoline and diesel range hydrocarbon was obtained from the polyethylene hydrogenolysis at relatively mild condition of 280 °C, and 3 MPa cold hydrogen pressure. The result is comparable to what have been reported in previous studies using noble metal catalysts. The gasoline and diesel range hydrocarbon are n-alkanes with a distribution at a range of C4–C22. The gas products are primarily CH4 along with a small amount of C2H6 and C3H8. High yield of CH4 as much as 9.68% was observed for the cleavage of molecule occurs along the alkane chain.

Green diesel rich product (C-15) from the hydro-deoxygenation of refined palm oil over activated NH4 +-Indonesian natural zeolite

ABSTRACT Zeolite is a potential material for use as a catalyst in various catalytic reactions. In this research, green diesel-range hydrocarbons were successfully derived from refined palm oil via a hydrotreating process in a batch-stirred autoclave reactor using activated Indonesian natural zeolite (ANZ) as a catalyst. A series of detailed characterizations, including XRD, XRF, SEM, FTIR, N2 sorption isotherm, and NH3-TPD, were utilized to investigate the physicochemical properties of the catalyst. Herein, the ANZ, dominated by the mordenite phase, was prepared through dealumination and NH4 +-exchange, and directly used without calcination that is commonly performed to convert NH4 + into a proton. Moreover, the hydrotreating reaction was carried out at 375°C with a weight ratio of feed to catalyst of 100:1. The catalytic tests showed that C15 alkanes were the most dominant liquid product obtained via the decarbonylation reaction mechanism of refined palm oil. In addition, the highest activity of the ANZ catalyst exhibited up to ~36 wt.% and selectivity up to 70% toward the formation of C15 diesel-range with cetane numbers in the range 71 and 77.

EFFECT OF CATALYST PROPERTIES ON THE DEOXYGENATION REACTION OF VEGETABLE OIL AND MODEL COMPOUND TO PRODUCE DIESEL RANGE HYDROCARBON FUELS: A REVIEW

The concern associated with the depletion of fossil fuel energy has opened up windows of opportunity for researchers to develop potential energy from renewable resources. The renewable green diesel with diesel range hydrocarbon structure has gained increasing popularity by removing oxygen molecule via direct or hydrodeoxygenation (HDO) and indirect or deoxygenation (DO) reaction. The catalyst design is an important key to achieve the high quality of diesel range hydrocarbon fuels. The different catalyst properties effect to the distribution of deoxygenated liquid product, the catalytic activity and coke formation during the reaction process. The interaction between metal and support catalyst causes electron transfer to give the synestistic effect. The acidity and basicity play important role in C-C and C-O breaking bond in triglyceride and prevent the coke formation. The pore structure and pore size catalyst provide the accessibility of active sites alleviates the diffusion limitation of reactants/ products.

Analysis of CaCO3 Impregnation on HY Zeolite Surface Area, Pore Size, and Activity in the Catalytic Cracking of Palm Oil to Biofuels

Fossil energy sources are currently decreasing, requiring the development of alternative energy sources. Vegetable oil is a raw material for alternative renewable energy supplies. This study produced biofuels from vegetable oil using calcium carbonate (CaCO3)-impregnated HY catalysts. In addition, this study aimed to investigate the effect of CaCO3 impregnation on the surface area and the catalytic activity of catalysts in the palm oil cracking process to produce biofuels. The HY catalyst was modified by the wet impregnation method in 5 wt% CaCO3 solution and was further calcined at 550°C for three h. Furthermore, the catalysts were tested in a continuous fixed-bed catalytic reactor at 450°C. The catalyst properties were characterized using Brunauer–Emmett–Teller (BET) surface area, Barrett–Joyner–Halenda (BJH) for pore size distribution, and X-Ray Diffraction (XRD) for crystal structure and phases. The results showed that the addition of CaCO3 decreased surface area and pore volume; however, the pore size increased, which resulted in the production of heavy hydrocarbons. Interestingly, the introduction of CaCO3 enhanced the yield of Organic Liquid Product (OLP) and diesel-range hydrocarbons selectivity to reach 79.09% and 30.54%, respectively. Furthermore, the introduction of CaCO3 increased deoxygenation activity.