The effect of oyster shell powder and rice husk ash on the pyrolysis of rice husk for bio-oil

The aim of this study was to investigate the effect of oyster shell powder (OSP) and rice husk ash (RHA) on the pyrolysis of rice husk (RH) for bio-oil. The present study focuses on the effect of catalysts on pyrolysis of RH for bio-oil and the quantity of bio-oil produced. The results showed that both OSP and RHA could improve the yield and quality of bio-oil, and the catalytic effect of OSP was better than that of RHA. With the content of the two catalysts increased, the net increase range of bio-oil yield decreased gradually. With 3 wt.% of OSP or 2 wt.% of RHA, the yield of bio-oil achieved to 57.06% and 56.07% respectively, which increased by 6.03% and 4.20% compared to that of single pyrolysis of rice husk. Both OSP and RHA can increase the bio-oil heating value and decrease the acid value. With the presence of 1–5 wt.% of OSP or RHA in the RH pyrolysis process, the heating value of the bio-oil can be increased by 5.04–10.25% and 4.32–5.78%, the acid value of the bio-oil can be decreased by 5.30–13.54% and 9.81–33.01%, respectively. OSP was better than RHA on the heating value improvement, while RHA was superior to OSP in decreasing the acid value. The gas chromatography/mass spectrometry (GC-MS) analysis of bio-oil composition indicated that the formation of phenols, acids and ketones compounds were inhibited and alcohols and furan compounds were promoted with the addition of OSP and RHA catalysts. The study made the catalytic pyrolysis process more favorable for the production of high heating value fuel.     

Multi-response optimization of bio-oil production from catalytic solar pyrolysis of Spirulina platensis

In this work, the solar catalytic pyrolysis of Spirulina platensis microalgae using hydrotalcite as a catalyst was studied to improve the yield and quality of the bio-oil obtained from the algae. The effects of biomass loading, reaction time, and catalyst percentage on the product distribution and bio-oil composition were evaluated. The desirability function was used to identify the pyrolysis conditions that maximize the bio-oil yield and its hydrocarbon content. The experimental results indicated that the catalytic pyrolysis of Spirulina platensis produced considerable solid product content, and high liquid yields were reached in some tests favored by the catalyst presence. The hydrotalcite contributed to increasing the hydrocarbon formation in the bio-oil at lower reaction times, demonstrating the great performance of this catalyst for microalgae pyrolysis. At the optimal conditions, a bio-oil yield of 35.94% with 21.71% hydrocarbon content was achieved.     

In-situ catalytic upgrading of biomass-derived vapors using HZSM-5 and MCM-41: Effects of mixing ratios on bio-oil preparation

In this paper, two molecular sieves with different pore sizes, namely HZSM-5 and MCM-41, were mixed using different ratios and used in the in-situ catalytic pyrolysis of rape straw. The effects of different HZSM -5 and MCM -41 mixing ratios on the quality of the bio-oil were studied by physicochemical properties, product yields and compositions. Moreover, Brunauer-Emmett-Teller (BET) catalyst analysis was performed. The results showed that the liquid yield and organic phase decreased first and then increased, whereas the gas yield showed an opposite trend. The density, O/C and kinematic viscosity of the bio-oil organic phase decreased first then increased, whereas the H/C, pH values and higher heating values initially increased, then declined. The oxygen content, H/C, O/C, kinematic viscosity, density, higher heating value and pH value of the bio-oil organic phase obtained at 1:1 mixed ratio were 12.81%, 1.701, 0.126, 5.06 mm²/s, 0.94 g/cm³, 34.31 MJ/kg and 5.41, respectively. The organic phase included numerous organic compounds, such as carboxylic acids, aldehydes, ketones, hydrocarbons, alcohols, ethers and esters. The hydrocarbon content in the bio-oil organic phase gradually increased and the carbonyl groups content gradually decreased as the MCM-41 content increased from 0 to 50%. In contrast, the hydrocarbon content gradually decreased and the carbonyl groups content gradually increased as the MCM-41 content increased from 50% to 100%. The hydrocarbon and carbonyl groups contents were 53.83% and 6.35%, respectively, at the MCM-41 content of 50%. The mixed catalyst activity increased with the increase in MCM-41 content (up to 50%), and tended to be stable once the MCM-41 contents surpassed 50%.     

Selective catalytic fast pyrolysis of Jatropha curcas residue with metal oxide impregnated activated carbon for upgrading bio-oil

Jatropha curcas waste was subjected to catalytic pyrolysis at 873 K using an analytical pyrolysis–gas chromatography/mass spectrometry in order to investigate the relative effect of various metal oxide/activated carbon (M/AC) catalysts on upgrading bio-oil from fast pyrolysis vapors of Jatropha waste residue. A commercial AC support was impregnated with Ce, Pd, Ru or Ni salts and calcined at 523 K to yield the 5 wt.% M/AC catalysts, which were then evaluated for their catalytic deoxygenation ability and selectivity towards desirable compounds. Without a catalyst, the main vapor products were fatty acids of 60.74% (area of GC/MS chromatogram), while aromatic and aliphatic hydrocarbon compounds were presented at only 11.32%. Catalytic pyrolysis with the AC and the M/AC catalysts reduced the oxygen-containing (including carboxylic acids) products in the pyrolytic vapors from 73.68% (no catalyst) to 1.60–36.25%, with Ce/AC being the most effective catalyst. Increasing the Jatropha waste residue to catalyst (J/C) ratio to 1:10 increased the aromatic and aliphatic hydrocarbon yields in the order of Ce/AC > AC > Pd/AC > Ni/AC, with the highest total hydrocarbon proportion obtained being 86.57%. Thus, these catalysts were effective for deoxygenation of the pyrolysis vapors to form hydrocarbons, with Ce/AC, which promotes aromatics, Pd/AC and Ni/AC as promising catalysts. In addition, only a low yield (0.62–7.80%) of toxic polycyclic aromatic hydrocarbons was obtained in the catalytic fast pyrolysis (highest with AC), which is one advantage of applying these catalysts to the pyrolysis process. The overall performance of these catalysts was acceptable and they can be considered for upgrading bio-oil.     

Tailoring Cu/Al2O3 catalysts for the catalytic pyrolysis of tomato waste

In this study, pyrolysis of tomato waste has been performed in fixed bed tubular reactor at 500 °C, both in absence and presence of Cu/Al₂O₃ catalyst. The influences of heating rate, catalyst preparation method and catalyst loading on bio-oil yields and properties were examined. According to pyrolysis experiments, the highest bio-oil yield was obtained as 30.31% with a heating rate of 100 °C/min, 5% Cu/Al₂O₃ catalyst loading ratio and co-precipitation method. Results showed that the catalysts have strong positive effect on bio-oil yields. Bio-oil quality obtained from fast catalytic pyrolysis was more favorable than that obtained from non-catalytic and slow catalytic pyrolysis.     

Pyrolysis of chlorine contaminated municipal plastic waste: In-situ upgrading of pyrolysis oils by Ni/ZSM-5, Ni/SAPO-11, red mud and Ca(OH)2 containing catalysts

This work is focussing to the thermo-catalytic batch pyrolysis of contaminated real municipal plastic waste using different catalyst mixtures in their different ratios: Ni/ZSM-5, red mud, Ca(OH)₂ and Ni/SAPO-11, red mud, Ca(OH)₂. The effect of the catalysts to the pyrolysis oil properties and the in-situ upgrading (especially the storage, transportation and corrosion stability) of pyrolysis oil was investigated. High concentration of Ni/ZSM-5 and Ni/SAPO-11 zeolites in catalyst mixtures can increase the yield of gases and pyrolysis oil, the concentration of aromatics or the hydrogen content in gases; however the presence of red mud in higher content can further increase the hydrogen concentration. ZSM-5 based catalysts showed higher efficiency in aromatization reactions. An accelerated aging test at 80 °C till 1 week was performed to investigate the storage and transportation stability of pyrolysis oils. Only slight increase was found in the density and viscosity, on the other hand there was a bit greater increase using SAPO-11 based catalysts than ZSM-5. The change in the olefin content was followed via bromine number and FTIR spectra of pyrolysis oil, which resulted ～3% and ～4% decreasing using Ni/ZSM-5 and Ni/SAPO-11 containing catalyst mixtures. Regarding acidic components, they significantly increased by aging time, while the high red mud and/or Ca(OH)₂ in catalyst mixtures had notable benefit, because they can drastically decrease the concentration of chlorinated compounds, which led to less weight loss during corrosion test using copper plate till 60 days at 20 °C.     

A comparative study on the quality of bioproducts derived from catalytic pyrolysis of green microalgae Spirulina (Arthrospira) plantensis over transition metals supported on HMS-ZSM5 composite

This study investigated three different types of catalysts: Ni/HMS-ZSM5, Fe/HMS-ZSM5, and Ce/HMS-ZSM5 in the thermochemical decomposition of green microalgae Spirulina (Arthrospira) plantensis. First, non-catalytic pyrolysis tests were conducted in a temperature ranges of 400–700 °C in a dual-bed pyrolysis reactor. The optimum temperature for maximized liquid yield was determined as 500 °C. Then, the influence of acid washing on bio-products upgrading was studied at the optimum temperature. Compared to the product yields from the pyrolysis of raw spirulina, a higher bio-oil yield (from 34.488 to 37.778 %wt.) and a lower bio-char yield (from 37 to 35 %wt.) were observed for pretreated spirulina, indicating that pretreatment promoted the formation of bio-oil, while it inhibited the formation of biochar from biomass pyrolysis. Finally, catalytic pyrolysis experiments of pretreated-spirulina resulted that Fe as an active phase in catalyst exhibited excellent catalytic activity, toward producing hydrocarbons and the highest hydrogen yield (3.81 mmol/gr spirulina).     

A comparative study of the behavior of Chlamydomonas reinhardtii and Spirulina platensis in solar catalytic pyrolysis

The aim of this study was to investigate the behavior of two distinct microalgae species during solar catalytic pyrolysis and the influence of their chemical composition and the process variables (biomass charge, reaction time, and catalyst percentage) on the product yields and bio-oil composition. For this purpose, solar catalytic pyrolysis of Spirulina platensis and Chlamydomonas reinhardtii was performed using hydrotalcite-derived mixed oxides as the catalyst. To gain more insight into the effect of composition on pyrolysis behavior, the biomasses were analyzed using various analytical techniques. The results indicated that a high percentage of catalyst (47.1%) culminated in liquid yields of 42.48% and 21.31% for Chlamydomonas pyrolysis and Spirulina pyrolysis, respectively. Additionally, Spirulina pyrolysis resulted in higher solid yields compared with Chlamydomonas pyrolysis. The results also showed that Spirulina bio-oil was rich in oxygenated compounds, probably due to its high carbohydrate content, whereas Chlamydomonas bio-oil was rich in nitrogenated compounds because of its higher protein content. The microalgae composition (lipids, protein, carbohydrates) exerted a large influence on the catalytic pathways and led to differences in yield and product distribution. A high percentage of catalysts preferentially promoted a deoxygenation of the bio-oil obtained from Spirulina solar pyrolysis compared with that obtained from Chlamydomonas pyrolysis.     

Hydrogen production via catalytic steam reforming of the aqueous fraction of bio-oil using nickel-based coprecipitated catalysts

Hydrogen production was studied in the catalytic steam reforming of a synthetic and a real aqueous fraction of bio-oil. Ni/Al coprecipitated catalysts with varying nickel content (23, 28 and 33 relative atomic %) were prepared by an increasing pH technique and tested during 2 h under different experimental conditions in a small bench scale fixed bed setup. The 28% Ni catalyst yielded a more stable performance over time (steam-to-carbon molar ratio, S/C = 5.58) at 650 °C and a catalyst weight/organic flow rate (W/m_org) ratio of 1.7 g catalyst min/g organic. Using the synthetic aqueous fraction as feed, almost complete overall carbon conversion to gas and hydrogen yields close to equilibrium could be obtained with the 28% Ni catalyst throughout. Up to 63% of overall carbon conversion to gas and an overall hydrogen yield of 0.09 g/g organic could be achieved when using the real aqueous fraction of bio-oil, but the catalyst performance showed a decay with time after 20 min of reaction due to severe coke deposition. Increasing the W/m_org ratio up to 5 g catalyst min/g organic yielded a more stable catalyst performance throughout, but overall carbon conversion to gas did not surpass 83% and the overall hydrogen yield was only ca. 77% of the thermodynamic equilibrium. Increasing reaction temperatures (600–800 °C) up to 750 °C enhanced the overall carbon conversion to gas and the overall yield to hydrogen. However, at 800 °C the catalyst performance was slightly worse, as a result of an increase in thermal cracking reactions leading to an increased formation of carbon deposits.     

Non-catalytic and catalytic pyrolysis of Ulva prolifera macroalgae for production of quality bio-oil

Pyrolysis of Ulva prolifera macroalgae (UM), an aquatic biomass, was carried out in a fixed-bed reactor in the presence of three zeolites based catalysts (ZSM-5, Y-Zeolite and Mordenite) with the different catalyst to biomass ratio. A comparison between non-catalytic and catalytic behavior of ZSM-5, Y-Zeolite and Mordenite catalyst in the conversion of UM showed that is affected by properties of zeolites. Bio-oil yield was increased in the presence of Y-Zeolite while decreased with ZSM-5 and Mordenite catalyst. Maximum bio-oil yield for non-catalytic pyrolysis was (38.5 wt%) and with Y-Zeolite catalyst (41.3 wt%) was obtained at 400 °C respectively. All catalyst showed a higher gas yield. The higher gas yield might be attributed to that catalytic pyrolysis did the secondary cracking of pyrolytic volatiles and promoted the larger small molecules. The chemical components and functional groups present in the pyrolytic bio-oils are identified by GC–MS, FT-IR, ¹H-NMR and elemental analysis techniques. Phenol observed very less percentage in the case of non-catalytic pyrolysis bio-oil (9.9%), whereas catalytic pyrolysis bio-oil showed a higher percentage (16.1%). The higher amount of oxygen present in raw biomass reduced significantly when used catalyst due to the oxygen reacts with carbon and produce (CO and CO₂) and water.     

Hydrogen production by glycerol reforming in a two-fixed-bed reactor

A two-stage fixed bed system was used in the hydrogen production from glycerol reforming. The calcined dolomite catalyst was used in the first fixed bed, and the Nickel-based catalyst was used in the second fixed bed to produce hydrogen from the glycerol steam reforming. The results showed that the hydrogen yield and carbon conversion gradually increased with the temperature increasing. When the temperature exceeded 800 °C, the growth rate of hydrogen yield and carbon conversion decreased. As the space velocity increased, the hydrogen yield and carbon conversion gradually decreased. When the space velocity was greater than 2 h^?1, the decline rate of hydrogen yield and carbon conversion decreased rapidly. As the water-to-carbon ratio (S/C) increased, the hydrogen yield and carbon conversion gradually increased. The growth rate of hydrogen yield and carbon conversion became smaller when the S/C was more than 5. Compared with the single-stage fixed-bed reactor, the utilization of two-stage fixed-bed catalytic reaction system can not only increase the hydrogen yield and carbon conversion, but extend the life of the Nickel-based catalyst. Under the optimal reaction conditions, the hydrogen yield is as high as 84.3%, and the carbon conversion is as high as 88.23%.     

Catalytic pyrolysis of microalgae to high-quality liquid bio-fuels

The pyrolytic conversion of chlorella algae to liquid fuel precursor in presence of a catalyst (Na₂CO₃) has been studied. Thermal decomposition studies of the algae samples were performed using TGA coupled with MS. Liquid oil samples were collected from pyrolysis experiments in a fixed-bed reactor and characterized for water content and heating value. The oil composition was analyzed by GC-MS. Pretreatment of chlorella with Na₂CO₃ influences the primary conversion of chlorella by shifting the decomposition temperature to a lower value. In the presence of Na₂CO₃, gas yield increased and liquid yield decreased when compared with non-catalytic pyrolysis at the same temperatures. However, pyrolysis oil from catalytic runs carries higher heating value and lower acidity. Lower content of acids in the bio-oil, higher aromatics, combined with higher heating value show promise for production of high-quality bio-oil from algae via catalytic pyrolysis, resulting in energy recovery in bio-oil of 40%.     

Catalytic steam reforming of bio-oil model compounds for hydrogen production over coal ash supported Ni catalyst

The development of a high performance and low cost catalyst is an important contribution to clean hydrogen production via the catalytic steam reforming of renewable bio-oil. Solid waste coal ash, which contains SiO₂, Al₂O₃, Fe₂O₃ and many alkali and alkaline earth metal oxides, was selected as a superior support for a Ni-based catalyst. The chemical composition and textural structures of the ash and the Ni/Ash catalysts were systematically characterized. Acetic acid and phenol were selected as two typical bio-oil model compounds to test the catalyst activity and stability. The conversion of acetic acid and phenol reached as much as 98.4% and 83.5%, respectively, at 700 °C. It is shown that the performance of the Ni/Ash catalyst was comparable with other commercial Ni-based steam reforming catalysts.     

Potentiality of combined catalyst for high quality bio-oil production from catalytic pyrolysis of pinewood using an analytical Py-GC/MS and fixed bed reactor

The aim of this study was to investigate the potential of combined catalyst (ZSM-5 and CaO) for high quality bio-oil production from the catalytic pyrolysis of pinewood sawdust that was performed in Py-GC/MS and fixed bed reactor at 500 °C. In Py-GC/MS, the maximum yield of aromatic hydrocarbon was 36 wt% at biomass to combined catalyst ratio of 1:4 where the mass ratio of ZSM-5 to CaO in the combined catalyst was 4:1. An increasing trend of phenolic compounds was observed with an increasing amount of CaO, whereas the highest yield of phenolic compounds (31 wt%) was recorded at biomass to combined catalyst ratio of 1:4 (ZSM-5: CaO - 4:1). Large molecule compounds could be found to crack into small molecules over CaO and then undergo further reactions over zeolites. The water content, higher heating value, and acidity of bio-oil from the fixed bed reactor were 21%, 24.27 MJkg⁻¹, and 4.1, respectively, which indicates that the quality of obtained bio-oil meets the liquid biofuel standard ASTM D7544-12 for grade G biofuel. This research will provide a significant reference to produce a high-quality bio-oil from the catalytic pyrolysis of woody biomass over the combined catalyst at different mass ratios of biomass to catalyst.     

Upgrading of liquid fuel from the vacuum pyrolysis of biomass over the Mo–Ni/γ-Al2O3 catalysts

High amounts of acid compounds in bio-oil not only lead to the deleterious properties such as corrosiveness and high acidity, but also set up many obstacles to its wide applications. By hydrotreating the bio-oil under mild conditions, some carboxylic acid compounds could be converted to alcohols which would esterify with the unconverted acids in the bio-oil to produce esters. The properties of the bio-oil could be improved by this method. In the paper, the raw bio-oil was produced by vacuum pyrolysis of pine sawdust. The optimal production conditions were investigated. A series of nickel-based catalysts were prepared. Their catalytic activities were evaluated by upgrading of model compound (glacial acetic acid). Results showed that the reduced Mo–10Ni/γ-Al₂O₃ catalyst had the highest activity with the acetic acid conversion of 33.2%. Upgrading of the raw bio-oil was investigated over reduced Mo–10Ni/γ-Al₂O₃ catalyst. After the upgrading process, the pH value of the bio-oil increased from 2.16 to 2.84. The water content increased from 46.2 wt.% to 58.99 wt.%. The H element content in the bio-oil increased from 6.61 wt.% to 6.93 wt.%. The dynamic viscosity decreased a little. The results of GC–MS spectrometry analysis showed that the ester compounds in the upgraded bio-oil increased by 3 times. It is possible to improve the properties of bio-oil by hydrotreating and esterifying carboxyl group compounds in the bio-oil.     

Distributed production of hydrogen by auto-thermal reforming of fast pyrolysis bio-oil

We demonstrated an auto-thermal reforming process for producing hydrogen from biomass pyrolysis liquids. Using a noble metal catalyst (0.5% Pt/Al₂O₃ from BASF) at a methane-equivalent space velocity of around 2000 h⁻¹, a reformer temperature of 800 °C–850 °C, a steam-to-carbon ratio of 2.8–4.0, and an oxygen-to-carbon ratio of 0.9–1.1, we produced 9–11 g of hydrogen per 100 g of fast pyrolysis bio-oil, which corresponds to 70%–83% of the stoichiometric potential. The elemental composition of bio-oil and the bio-oil carbon-to-gas conversion, which ranged from 70% to 89%, had the most significant impact on the yield of hydrogen. Because of incomplete volatility the remaining 11%–30% of bio-oil carbon formed deposits in the evaporator. Assuming the same process efficiency as that in the laboratory unit, the cost of hydrogen production in a 1500 kg/day plant was estimated at $4.26/kg with the feedstock, fast pyrolysis bio-oil, contributing 56.3% of the production cost.     

Preparation of bio-oil derived from catalytic upgrading of biomass vacuum pyrolysis vapor over metal-loaded HZSM-5 zeolites

The Fe-, Co-, Cu-loaded HZSM-5 zeolites were prepared via impregnation method. The upgrading by catalyst on biomass pyrolysis vapors was conducted over modified zeolites to investigate their catalytic upgrading performance and anti-coking performance. The Brønsted acid sites amount on Cu-,Co-loaded HZSM-5 decreased sharply, while that of Lewis both increased. The yield of liquid fraction and refined bio-oil over metal loaded ZSM-5 catalysts decreased, while that of char almost kept constant. The physical property of refined bio-oil was promoted in terms of pH value, dynamic viscosity and higher heating value (HHV). FT-IR analysis revealed that the chemical structure of refined bio-oil obtained over Fe-, Co-, Cu-loaded HZSM-5 zeolites was highly similar. The yield of monocyclic aromatic and aliphatic hydrocarbon over Fe-,Co-loaded HZSM-5 were boosted by around 2.5 times compared with original ZSM-5 zeolites. Data analysis revealed that Cu/HZSM-5 presented the worst deoxygenation ability. The anti-coking capability of Fe/HZSM-5 was obviously better, i.e., the coke content showed an approximate decrease of 38%. Thus, this study provided an efficient Fe/HZSM-5 catalysts for preparation of bio-oil derived from catalytic upgrading of biomass pyrolysis vapor.     

High efficient production of hydrogen from crude bio-oil via an integrative process between gasification and current-enhanced catalytic steam reforming

High efficient production of hydrogen from the crude bio-oil was performed in the gasification-reforming dual beds. A recently developed electrochemical catalytic reforming method was applied in the downstream reforming bed using NiCuZnAl catalyst. Production of hydrogen from the crude bio-oil through both the single gasification and integrative gasification-reforming processes was investigated. The maximum hydrogen yield of 81.4% with carbon conversion of 87.6% was obtained through the integrative process. Hydrogen is a major product (∼73 vol%) together with by-products of CO₂ (∼26 vol%) as well as very low content of CO (<1%) and a trace amount of CH₄ through the integrative route. In particular, the deactivation of the catalyst was significantly depressed by using the integrative gasification-reforming method, comparing to the direct reforming of the crude bio-oil. The mechanism and evaluation for the downstream electrochemical catalytic reforming were also discussed. The integrative process with higher hydrogen yield and carbon conversion, potentially, would be a useful route to produce hydrogen from the crude bio-oil.     

生物油模型物乙酸水蒸汽催化重整制氢研究

选择乙酸作为生物质快速裂解油(生物油)的模型物,自制了一系列Ni基催化剂,进行水蒸汽催化重整制氢研究,实验结果表明Ni/Al_2O_3催化剂添加碱性氧化物MgO或(与)La_2O_3可以使得催化剂的活性有重大改善。Al_2O_3载体负载Ni金属后能够减缓碳的沉积速率,Ni/Al_2O_3添加MgO与(或)La_2O_3能够有效减少碳的沉积速率。选择催化剂Ni/MgO-La_2O_3-Al_2O_3以反应气中的H_2、CO、CH_4、CO_2产率为考察指标,考察反应温度、水碳比、进料流量对水蒸汽催化重整乙酸制氢反应的影响,获得较佳的条件为:反应温度为750～850℃,水碳摩尔比[W]/[C]为5～9,进料流量为15～25mL/h,H_2产率较高,大于80%。     

Investigation on hydrogen production by catalytic steam reforming of maize stalk fast pyrolysis bio-oil

Hydrogen production via catalytic steam reforming of maize stalk fast pyrolysis bio-oil over the nickel/alumina supported catalysts promoted with cerium was studied using a laboratory scale fixed bed coupled with Fourier transform infrared spectroscopy/thermal conductivity detection analysis (FTIR/TCD). The effects of nickel loading, reaction temperature, water to carbon molar ratio (WCMR) and bio-oil weight hourly space velocity (W_bHSV) on hydrogen production were investigated. The highest hydrogen yield of 71.4% was obtained over the 14.9%Ni-2.0%Ce/A1₂O₃ catalyst under the reforming conditions of temperature = 900 °C, WCMR = 6 and W_bHSV = 12 h⁻¹. Increasing reaction temperature from 600 to 900 °C resulted in the significant increase of hydrogen yield. The hydrogen yield was significantly enhanced by increasing the WCMR from 1 to 3, whereas it increased slightly by further increasing WCMR. The hydrogen yield decreased with the increase of W_bHSV. Meanwhile, the coke deposition percentage changed little with increasing W_bHSV up to 12 h⁻¹ and then it increased by 4.5% with the further increase of W_bHSV from 12 to 24 h⁻¹.