Total Hydrocarbon Yield Research Articles

Catalytic pyrolysis of wheat straw based on dual catalyst CaO/ZSM-5 with acid washing and torrefaction pretreatment to enhance aromatic yield in bio-oils

In this paper, the catalytic pyrolysis integrating combined pretreatment (acid washing and torrefaction) and dual catalysts was adopted to improve the quality of bio-oil and the selectivity of aromatic hydrocarbons. Combined pretreatment is a highly effective method to improve the quality of biomass feedstock. It was capable of the removal of alkali and alkaline earth metals from wheat straw, with a K removal rate of 97.79 %. Under the combined pretreatment, the aromatic hydrocarbon content in bio-oil increased to 68.8 % using the ZSM-5 catalyst alone. Compared with ZSM-5, CaO could remove part of the oxygenated functional groups and had a better acid removal effect, but the aromatic hydrocarbon yield was low to 7.95 %. After combined pretreatment using simulated aqueous phase bio-oil for acid washing, catalytic pyrolysis using CaO/ZSM-5 dual catalysts greatly enhanced the quality of the bio-oil. The oxygenated compounds content was reduced to 17.58 %, and the total hydrocarbon yield was increased to 82.42 %, especially the aromatic hydrocarbons yield was increased to 79.91 %, of which the monocyclic aromatic hydrocarbons were as high as 68.38 %, and the benzene, toluene, and xylene content reaching 49.39 %. Thus, integrating dual catalysts (CaO/ZSM-5) with combined pretreatment can effectively increase the aromatic yield for producing high-quality bio-oil.

Investigation of the effect of thermal conversion of propane-butane mixture with various metals on the yield of main products

In the work, the effect of thermal conversion of the propane-butane mixture on the yield of the main products and the effect of transformation with different metals was studied. In the temperature range of 750-800 ℃, compared to the results with the catalyst created for the decomposition process of the propane-butane mixture at high temperatures, a decrease in the total yield of lower molecular unsaturated hydrocarbons, i.e., ethylene, propylene, and butylene, and an increase in the formation of hydrogen solids were observed. However, the conversion rate increased with increasing temperature, and the catalyst developed for propane-butane cracking at high temperatures was higher in the presence of 5%Ni. The transformation of 5%CoO*5%NiO*2%ZrO2*8%Na2SO4 with chromium in the temperature range of 600-750℃ allows to obtain ethylene 5.85-13.41%, propylene 3.56-7.14% and the total yield of lower molecular unsaturated hydrocarbons, i.e. ethylene, propylene and butylene 15.42-31.77%. At the same time, the conversion rate has increased. In this case, its values were much higher in the relatively low process temperature range compared to the results of untransformed 5%CoO*5%NiO*2%ZrO2*8%Na2SO4. In addition, the highest yield of propylene at 750 ℃ was 17.47%, the highest yield of propylene in the presence of untransformed 5%CoO*5%NiO*2%ZrO2*8%Na2SO4 was 16%, and -15.12% as a result of temperature-induced changes. The purpose of the work is to study the effect of transformation of the catalyst with different metals on the rate of decomposition reaction of propane-butane mixture at high temperatures and yield of main products.

Hydrocarbon composition of liquid products of catalytic oxy-cracking of vacuum gasoil

The hydrocarbon composition of liquid products of oxycracking of vacuum gas oil obtained in the presence of a zeolite-containing catalyst has been studied. It has been established that the group hydrocarbon composition of the liquid oxycracking catalyzate is significantly affected by the process parameters. When considering the influence of the process temperature, it was found that the concentration of C5-C9 and C10+ alkanes has an opposite temperature dependence: the C5-C9 yield passes through a maximum at a temperature of 500°C, while for C10+ it is a minimum temperature; there is a linear relationship between the temperature and the yield of unsaturated; the yield of naphthenes gradually decreases with increasing temperature; elevated temperatures contribute to an increase in the total yield of aromatic hydrocarbons. When varying the duration of the process, it was revealed: within 900 seconds from the beginning of the process, the most significant decrease in concentration was noted for aromatic hydrocarbons. The low oxidation state of 0.5% contributes to the intensive conversion of high molecular weight alkanes and aromatic hydrocarbons with long side chains; the concentration of oxygen-containing compounds raises with an increase in the degree of oxidation to 1%, passing through a maximum. The contact time with the catalyst had a complex effect on the hydrocarbon composition of the liquid products of vacuum gas oil oxycracking: a short contact time contributes to a decrease in the concentration of high molecular weight paraffinic and naphthenic hydrocarbons and an increase in aromatic hydrocarbons; with a subsequent increase to 2 s, it drops sharply. The obtained data made it possible to establish the fundamental distinguishing features of the catalytic oxycracking of vacuum gas oil from the traditional catalytic and noncatalytic oxidative ones, and also to propose a list of reactions occurring during the catalytic oxycracking of vacuum gas oil.

Organic Matter Distribution and Characteristics among Rock Formations in Malaysia: Implications on Hydrocarbon Generation Potential

Numerous studies have been done to determine the hydrocarbon potential of Malaysia’s formations and basins due to the need to identify more conventional or unconventional hydrocarbon resources. Due to the fact that none of these investigations were carried out with any prior knowledge in the relevant regions with hydrocarbon potential, some of them did not, however, yield the expected results. This study aims to provide researchers with all the necessary information about potential hydrocarbon-producing areas in Malaysia and the various lithologies connected to them by analyzing all earlier studies carried out in Malaysia. This was accomplished by determining patterns in the distribution of organic matter and characteristics of the formations in Malaysia. Total Organic Carbon (TOC), Generic Potential (GP), Vitrinite Reflectance (Ro), and Hydrocarbon Yield (S2) were the most important hydrocarbon generation potential indicators discussed. A heat map was created using a statistical weight ranking with a weight of 45% for the TOC value and 30%, 15%, and 10% for the GP, S2, and Ro values, respectively. According to the data, the Bintulu, Pinangah, Begrih, Liang, and Tanjong formations have the highest potential to generate hydrocarbons in Malaysia, while the Kroh, Setap, Kalabakan, Temburong, and Belaga have the least potential. Majority of formations with high hydrocarbon potential are tertiary in age and consist primarily of coal and carbonaceous shale formations. The most promising formations are mostly immature, with type II or type III kerogen quality. It is recommended that critical exploration activities be focused on the tertiary-aged formations, particularly those in East Malaysia, in order to increase Malaysia’s hydrocarbon production.

Evaluation of organic geochemical characteristics and experiments of thermal pressure simulation of Jurassic coal measure source rocks in the Yanqi Basin

The Yanqi Basin is a coal-bearing basin in Western China. In order to determine the hydrocarbon generation potential of the Jurassic source rocks in this area, the organic matter composition of coal-measure mudstone, carbonaceous mudstone and coal rocks, the yields of liquid and gaseous hydrocarbons, and the comparison of hydrocarbon sources were studied by means of hydrocarbon-generating thermal simulation experiments. The results showed that the micro-composition of the Jurassic coal rocks in the Yanqi Basin showed the characteristics of rich vitrinite-inertinite and poor chitinite + saprolite components; however, the micro-composition of the mudstone showed the characteristics of poor inertinite and rich vitrinite–chitinite + saprolite components. The Jurassic mudstone has a wide distribution range of hydrogen and oxygen indexes, among which the hydrogen index is distributed between 2 and 266 mg/gTOC, and the oxygen index is distributed between 3 and 183 mg/g TOC. The organic matter in the mudstone belongs to Type II2-III kerogen. The hydrogen index of coal is distributed in the range of 100–300 mg/gTOC, which is obviously larger than that of mudstone. The total liquid hydrocarbon yield of the coal rock is the highest (43.2 mg/gTOC), followed by mudstone (16.4–20.4 mg/gTOC), while that of the carbonaceous mudstone is the lowest (5.36 mg/gTOC). In addition, mudstone has the highest yield of gaseous hydrocarbons, followed by coal, while that of carbonaceous mudstone is the lowest. The oil-source comparison showed that the Jurassic crude oil has a certain affinity with its main source rocks (mudstone, carbonaceous mudstone, and coal). At the same time, the comparison results of steroid and terpene biomarker parameters with crude oil showed that the Middle and Lower Jurassic mudstone, carbonaceous mudstone, and coal rock in this area are all source rocks and the Badaowan Formation mudstone is the main hydrocarbon source.

Polycyclic aromatic hydrocarbons in biochar originated from pyrolysis of aseptic packages (Tetra Pak®)

Determination of the total yield of polycyclic aromatic hydrocarbons (PAHs) and their derivatives in a Tetra Pak® biochar was the leading target of this study. It was also evaluated the toxicity of Tetra Pak® biochars originated from pyrolysis performed at different temperatures. The relationship between the pyrolysis temperature and the yield of PAHs contained in Tetra Pak® biochars was also investigated. The material (Tetra Pak® packages, aseptic type) was decomposed in a laboratory pyrolysis reaction unit at different temperatures (400 °C, 500 °C, 600 °C, 700 °C). The concentrations of PAHs in Tetra Pak® biochars were determined using the method of pyrolysis gas chromatography combined with mass spectrometric detection. The toxicity of Tetra Pak® biochars was evaluated by Sinapis alba test and calculating of toxic equivalents.The total PAHs concentration in Tetra Pak® biochars oscillated between 79.6 mg/kg and 173.0 mg/kg. The measured concentrations of 16 priority PAHs U.S. Environmental Protection Agency (US EPA) reached the range from 38.4 mg/kg to 73.7 mg/kg. The yields of methylated derivatives of Tetra Pak®-biochar-borne PAHs varied from 5.2 mg/kg to 77.1 mg/kg. A phytotoxicity index of Sinapis alba has shown that biochar produced at temperatures above 500 °C is more likely to have a stimulating effect, supported by the leaching of Ca after the thermal decomposition of calcite and water extractable organic carbon. The stimulating effect of the addition of Tetra Pak® biochar increases with the decreasing concentration of biochar-borne PAHs. Given the financial cost and the minimisation of environmental risk, the addition of biochar in the range of 5–10% can be recommended.

Catalytic deoxygenation of carboxyl compounds in the hydrothermal liquefaction crude bio-oil via in-situ hydrogen supply by CuO-CeO2/[formula omitted]-Al2O3 catalyst

Hydrothermal liquefaction (HTL) has drawn great attention as a potential method to produce bio-oil from biomass waste. However, bio-crude from HTL shows undesired high-oxygen content and needs further deoxygenation upgrading. Herein, stearic acids as a model carboxylic compounds in HTL bio-crude was employed to investigate catalytic deoxygenation performance. Results showed that (CuO)10-CeO2/γ-Al2O3 had the most superior catalytic deoxygenation performance for the stearic acids. The maximum stearic acid conversion rate (96.36%) and total hydrocarbon yield (88.79%) were obtained at 300°C, 12h, ratio of stearic acid to water 1:4. The main catalytic deoxygenation pathways were proposed: carbon monoxide generation (decarbonylation) – in-situ hydrogen generation (water–gas shift) – short-chain fatty acid generation (hydrogenolysis) – n-alkanes generation (decarboxylation, hydrodeoxygenation and hydrogenation). DFT calculation elucidated that CuO-CeO2 reduced the activation energy from 24.8kcalmol−1 (vacuum) to 15.0kcalmol−1 (catalytic). Thus, deoxygenation via CuO-CeO2/γ-Al2O3 would be an effective method for upgrading HTL bio-crude.

Treatment of Oil Wastewater Containing High Salinity with Ultrafıltratıon (UF) and Reverse Osmosıs (RO)

The high salinity oil wastewaters contained high salt, chloride, total hydrocarbon concentrations with COD and TSS. In order to treat this wastewater a sequential UF and RO ractor system was used. Before membrane treatment the oil was floated with an API oil separator. The effects of increasing fluxes ( 12 L/h, 30 L/h and 50 l /h) and pressures (4 bar , 8 bar and 16 bar ) on the removals of pollutant parametres were studied in the UF. The influence of the main operating parameters suh as operating pressure (15, 35 and 50 bar), temperature (25, 40 and 55 °C) and feed flowrate (7, 14, 28 L/min, were studied in RO. The maximum salt , chloride, total hydrocarbon, COD,dis-COD, and TSS yields were 90%, 91%, 89%, 89%, 89% and 90%, respectively, at a flux of 60 L/m2.h and at a pressure of 16 bar in UF, respectively. The maximum RO yields in the permeate were around 99% for the pollutant parameters given above at afed flowrate of 28 L/min at 24 bar pressure.

Effect of ethane and ethylene on catalytic non oxidative coupling of methane.

The effect of addition of ethane and ethylene (C2) on methane coupling at 1000 °C was investigated. A Fe/SiO2 catalyst was used to determine the contributions of catalytic as well as C2 initiated methane activation. The catalyst load as well as the residence times at 1000 °C downstream of the catalyst bed were varied. C2 addition significantly increases methane conversion rates, similarly for both ethane and ethylene, although ethylene is more effective when operating with long residence times in the post-catalytic volume. Methane activation via C2 addition proceeds dominantly in the gas-phase whereas catalytic C2 activation is negligible. The catalyst has no effect on methane conversion when the feed contains more than 2 vol% C2. Product selectivity distribution as well as total hydrocarbon yield at 10% conversion is not influenced by C2 addition, but is influenced by the amount of catalyst as well as residence time in the post-catalytic volume at high temperature. It is proposed that C2 impurities in natural gas change from a nuisance to an advantage by enhancing methane conversion and simplifying purification of the natural gas feed. A process is proposed in which ethylene is recycled back into the reactor to initiate methane coupling, leading to a process converting methane to aromatics.

Efficient hydrothermal deoxygenation of tall oil fatty acids into n-paraffinic hydrocarbons and alcohols in the presence of aqueous formic acid

Hydrothermal deoxygenation of tall oil fatty acids (TOFA) was investigated in the presence of aqueous formic acid (0.5–7.5 wt%) as a H2 donor in the presence of subcritical H2O pressure (569–599 K). Pd and Ru nanoparticles supported on carbon (5% Pd/CSigma, 5% Ru/CSigma, 10% Pd/CO850_DP, and 5% Ru/COPcomm_DP) were found to be efficient catalysts for deoxygenation of TOFA. The reaction pathway was mainly influenced by the concentration of formic acid and the catalyst. In case of Pd catalysts, in the presence of 0–2.5 wt% formic acid, decarboxylation was the dominant pathway producing n-paraffinic hydrocarbons with one less carbon atom (heptadecane yield up to 94 wt%), while with 5–7.5% formic acid, a hydrodeoxygenation/hydrogenation mechanism was favored producing C18 deoxygenation products octadecanol and octadecane as the main products (yields up to 70 wt%). In contrast, Ru catalysts produced a mixture of C5-C20 (n-and iso-paraffinic) hydrocarbons via decarboxylation, cracking and isomerization (up to 58 wt% C17 yield and total hydrocarbon yield up to 95 wt%) irrespective of formic acid concentration. Kinetic studies showed that the rates of deoxygenation displayed Arrhenius type behavior with apparent activation energies of 134.44 ± 31.36 kJ/mol and 148.92 ± 3.66 kJ/mol, for the 5% Pd/CSigma and 5% Ru/CSigma catalyst, respectively. Furthermore, the experiments with glycerol tristearate, rapeseed oil, sunflower oil, rapeseed biodiesel, and hydrolyzed rapeseed oil produced identical products confirming the versatility of the aforementioned catalytic systems for deoxygenation of C18 feedstocks.

Upgrading of cyclohexanone to hydrocarbons by hydrodeoxygenation over nickel–molybdenum catalysts

Cyclohexanone is largely generated in the direct or indirect conversion of lignin-derived bio-oils. Hence, the upgrading of cyclohexanone, i.e. deoxygenation in the presence of hydrogen is of great interest. In this regard, two nickel-molybdenum catalysts on alumina support were investigated in the temperatures up to 400 °C and pressures up to 15 bar. High activity, selectivity, and yield were achieved by utilizing these catalysts at the studied condition. The main products of the upgrading of cyclohexanone were C6, C7, and C12 cyclic, aromatic, and bicyclic including cyclohexane, cyclohexene, benzene, and cyclohexylbenzene. The results of the present study imply that these catalysts are beneficial in producing hydrocarbon-rich products from cyclohexanone and lignin-derived bio-oils. Based on the achievements of the present study, the nickel-molybdenum catalyst composed of 1.14 wt% nickel and 14.27 wt% molybdenum showed about 87%, 100%, and 116% conversion of cyclohexanone, total hydrocarbon selectivity, and total hydrocarbon yield, respectively. The optimum condition for obtaining such results was at 400 °C and 8 bar.

The utilization of synthesis gas for the deoxygenation of cyclohexanone over alumina‐supported catalysts: Screening catalysts

AbstractEnvironmental regulations motivate the industries to replace conventional fuels and chemicals by those produced from biomass. In this regard, hydrodeoxygenation of lignin compounds is of a great deal of attention. Synthesis gas could be utilized instead of pure hydrogen for the cleavage of oxygen‐containing chemical bonds through hydrodeoxygenation. Following this, the utilization of synthesis gas is investigated in the present contribution. A wide range of commercial alumina‐supported catalysts is investigated. The experimental results of cyclohexanone hydrodeoxygenation in the presence of pure hydrogen and synthesis gas at 573 K and 20 bar of total pressure are presented and discussed. The whole investigated catalysts show good activity toward the hydrodeoxygenation of cyclohexanone. Methylatedbenzene derivatives are produced from cyclohexanone hydrodeoxygenation for the first time. The catalysts composed of platinum showed the best performance. By utilizing a chlorinated platinum catalyst, 89.6% cyclohexanone conversion, 100% total hydrocarbon selectivity, and 44.6% total hydrocarbon yield are obtained. In the case of syngas‐assisted hydrodeoxygenation, 80.1% cyclohexanone conversion, 100% total hydrocarbon selectivity, and 29.6% total hydrocarbon yield are obtained by utilizing the same catalyst. The presence of methylated aromatics proves the accomplishment of methanation or direct aromatization reactions in the presence of carbon oxides and hydrogen.

The Effect of the Polymer Type in the Three-Phases Fischer-Tropsch Synthesis Catalyzed by suspended Iron Nanocatalysts

Fischer-Tropsch synthesis (FTS) was conducted over paraffin-iron catalysts of three phases system with synthetic polymers that contains different compositions. The suspended iron nanocatalyst was introduced into the slurry reactors Fischer-Tropsch with range temperature (220-320)oC at 2.0 MPa, the atomic ratio contains: 100Fe/100 Paraffin/10 wt% polymer. The study of phase, structure and morphology of the nanocatalyst using x-ray diffraction (XRD) and atomic force microscope (AFM) techniques confirmed that there are two phases of iron oxides Fe3O4 and δ-FeOOH are existed. Maximum conversion of CO to yields of total liquid hydrocarbons that obtained was 74% and 62 g/m3 of FTS over the catalyst Fe-Paraffin/ Polyethylene glycol (Fe-P/PEG) compared to Fe-Paraffin/ Polyethylene terephthalate (Fe-P/PET) and Fe-Paraffin/polycarbonate (Fe-P/PC) systems. The results shows that the polymer type and their structure as well as preparation time of the iron nanocatalysts have high influence on the particle size value. A selectivity of 65% of syngas converted C5+ liquid hydrocarbons achieved using (Fe-P/PEG) catalyst.

Catalytic assessment of Fe-La-Zr trimetallic mixed oxides in the Fischer-Tropsch synthesis using bio-syngas

H2/CO/CO2 gaseous mixtures obtained by biomass gasification (bio-syngas) could be used to obtain hydrocarbons by the Fischer-Tropsch synthesis (FTS). In this work, trimetallic Fe–La–Zr mixed oxides prepared by coprecipitation with oxalic acid were studied in the synthesis of hydrocarbons from bio-syngas at 300 °C and 10 bar. Catalysts obtained by calcination at 700 °C are activated by the bio-syngas and the one that contains 30 wt% of Fe attains steady CO conversion levels of 75% and a total hydrocarbon yield of 34%–36%. A liquid product containing hydrocarbons in the range C5–C13 is formed together with C1–C4 products. Potassium promotion (6 wt%) allows to increase CO conversion (∼89%) and hydrocarbons yield (∼44%). Catalysts obtained by calcination at 900 °C display higher activation times due to their crystalline structure, although they attain final activity levels close to the amorphous ones obtained by calcination at 700 °C.

Catalytic cracking of raw bio-oil under FCC unit conditions over different zeolite-based catalysts

The performance of different zeolite-based catalysts (HY, HZSM-5 and HBeta) on the catalytic cracking of bio-oil has been explored, using a simulated riser reactor and resembling industrial FCC conditions. The effect of the C/O (catalyst/bio-oil) ratio and the zeolite types have been assessed. The level of deoxygenation is >61% (increasing with C/O ratio). Total hydrocarbon yield was higher for the HBeta catalyst (56wt%), while the liquid hydrocarbons yields were relatively similar for all catalysts, obtaining higher gasoline yields with the HY catalyst (46–55wt%), and higher LPG yields with the HZSM-5 catalyst (12–14wt%) due to its higher acidity. The HY zeolite produced more coke (4–7wt%) given its capacity for retaining coke precursors within its micropores.

Green diesel production over nickel-alumina nanostructured catalysts promoted by zinc

Abstract Following the one step co-precipitation technique we have synthesized a series of Ni-Zn catalysts supported on alumina. The series involves one non-promoted sample containing 60 wt % Ni and three zinc promoted samples containing 1, 2 and 5 wt % Zn and 59, 58 and 55 wt % Ni, respectively. The specimens were characterized using nitrogen sorption isotherms, H2-TPR, NH3-TPD, XRD, SEM-EDX, TEM and XPS. The catalytic performance of the samples prepared was evaluated in the selective deoxygenation of sunflower oil using a semi-batch reactor (310 °C, 40 bar of hydrogen, hydrogen flow rate equal to 100 mL/min and reactant to catalyst ratio equal to 100 mL/g). The control of the co-precipitation procedure and the direct reduction of dried precipitate resulted to mesoporous nano-structured catalysts with high surface area (247–290 m2 g−1). The non-promoted sample was mainly comprised from NiAl2O4 particles and the promoted ones from Ni-Zn alloys and intermetallic oxo-phases (IMPs) supported on largely amorphous Al2O3 nano-grains. Zinc increased the total yield of alkanes in the diesel range (n-15, n-16, n-17, n-18) though it does not affect the mechanistic scheme of the selective deoxygenation of sunflower oil which is largely realized via decarbonylation/decarboxylation. The promoting action of zinc was attributed to the favoring of the Ni-Zn alloys and IMPs formation. It is more pronounced in the sample with the medium zinc content (58 wt % Ni, 2 wt % Zn, 40 wt % Al2O3) in which an increase of 18% in the total yield of hydrocarbons has been obtained. The maximization of the zinc promoting action in this sample reflects the good compromise between the extent of alloying and surface acidity.

Effects of temperature on pyrolysis characteristics of Indonesia oil sands

In this work, pyrolysis experiments were conducted on Indonesia oil sands in a Cracking device at different pyrolysis temperatures. The effects of pyrolysis temperature on total hydrocarbon yield, liquid hydrocarbon production rate and gas production rate were investigated. Below 300 °C, the pyrolysis products were mainly gaseous. However, the proportions of liquid and gas products were identical above the temperature of 300 °C. The relationship between the volume fraction of gaseous products and temperature was analyzed using gas chromatography. The presence of functional groups of methyl, methylene, aldehyde, ketone, acid, fat, alkene and aromatic hydrocarbons in liquid pyrolysis products was investigated at different pyrolysis temperatures. The pore structure, electron microscope and fractal dimension of the chars were also analyzed. The result showed that the amount of adsorbed nitrogen reached the maximum value at 450 °C. The adsorption loop of char was close to the B-type loop, and the pore was mainly the slit hole. In addition, the pore structure was very well developed. The BET specific surface area and pore volume presented their peak values at 450 °C and the fractal dimension was obtained using FHH equation, which peaked at the temperature of 450 °C. The pore structure was loose and there was no obvious connection between the particles. Finally, the overall fractal value was slightly lower than the nitrogen adsorption fractal value.

Hydrocarbon-generated potential of bark coal components from Southern China

Barkinite is only found in Chinese coal and it has not been recognized by the International Committee for Coal and Organic Petrology. The hydrocarbon-generated ability of barkinite is still vague. In this work, the hydrocarbon-generated potential of barkinite and vitrinite from Mingshan coal mine in the South of China was investigated by Rock–Eval pyrolysis and solvent extraction analysis. Barkinite and vitrinite were separated by the density gradient centrifugation method. The results showed that barkinite had high hydrocarbon generation potential, as reflected by evidently high hydrogen index (HI) values (607.0 mg HC g−1 TOC), S1 + S2 values (297.4–475.7 mg HC g−1), total hydrocarbon yield (23.55–30.20 mass%), and H/C atomic ratio (1.01). Both the S1 + S2 and HI values of barkinite are higher than those of vitrinite. For barkinite, the range values of the temperature at which the S2 peak is at its maximum (Tmax) are from 437 to 446 °C, and for vitrinite are 436 °C. The extraction results represented that the total hydrocarbon yield of barkinite is from 23.55 to 30.20 mass%, while that of vitrinite is 23.99 mass%. This indicated that the high hydrocarbon generation ability of bark coal is greatly controlled by high barkinite content and followed by vitrinite content.

Catalytic pyrolysis of raw and hydrothermally carbonized Chlamydomonas debaryana microalgae for denitrogenation and production of aromatic hydrocarbons

Pyrolysis of raw and hydrothermally carbonized (HTC) Chlamydomonas debaryana with and without activated carbon (AC) or β-zeolite as the catalyst were studied. Monoaromatic hydrocarbon yields from the pyrolysis of raw and HTC treated algae without a catalyst were relatively low at optimum yields of 11.2% and 12.0% obtained at 600 °C, respectively. The maximum yields of monoaromatic hydrocarbons from the AC catalyzed pyrolysis of raw and HTC treated algae were 43.8% obtained at 600 °C and 43.5% obtained at 800 °C, respectively, compared to 32.3% and 32.7% for the maximum yields from the β-zeolite catalyzed pyrolysis at 500 °C and 600 °C, respectively. However, β-zeolite catalyzed pyrolysis produced higher yields of total hydrocarbons (aromatic + aliphatic) for raw and HTC algae compared to AC catalyzed pyrolysis. This means while β-zeolite was more effective in producing total hydrocarbon content, AC was more effective in aromatization of oxygenates. The combination of HTC pretreatment and catalytic pyrolysis were effective in reducing nitrogen content in bio-oil. The yields of nitriles and nitrogenous compounds were negligible for the AC catalyzed pyrolysis of HTC treated algae at 600 °C, compared to 8.3% using the β-zeolite at the same temperature. The AC catalyst had a lower tendency towards coking.

Catalytic fast co-pyrolysis of biomass and fusel alcohol to enhance aromatic hydrocarbon production over ZSM-5 catalyst in a fluidized bed reactor

In order to enhance aromatic hydrocarbon production, catalytic fast co-pyrolysis (co-CFP) of corn stover and fusel alcohol is conducted with ZSM-5 catalyst in a fluidized bed reactor. Effects of co-CFP temperature, catalyst loading and mass ratio of fusel alcohol to biomass on aromatic hydrocarbon yields are investigated and the experimental results show that bio-derived aromatic hydrocarbons can be formed through Diels-Alder cycloaddition and catalyst-induced hydrocarbon pool. It is found that co-CFP temperature of 550 °C results in the maximum aromatic hydrocarbon yield and the carbon and hydrogen yields of individual and total aromatic hydrocarbons increase dramatically with an elevated catalyst loading amount. Additionally, an apparent synergy between biomass and fusel alcohol is observed during co-CFP. With the consideration of aromatic hydrocarbon yields in bio-oil, the mass ratio of fusel alcohol to biomass of 1:1 in the blends is the best option. Moreover, isotopic labeling technique is utilized to unearth the origin of carbon and hydrogen in aromatic hydrocarbons, and the results demonstrate that carbon and hydrogen atoms from both feedstocks can coexist in the individual aromatic hydrocarbon and make up the targeted products during co-CFP of the blends.