Hydrothermal Cracking Research Articles

In-situ hydrothermal upgrading and mechanism of heavy oil with nano-Fe2O3 in the porous media

Hydrothermal upgrading is a promising technology for heavy oil, yet the impact of reservoir conditions on the catalytic effect of catalysts and the pathway are not clear. In this study, the effect of the formation environment on the catalytic upgrading process was investigated through simulating the reservoir conditions (2000 mD permeability, 25 % porosity) for catalytic hydrothermal cracking of heavy oil. Under the hydrothermal upgrading conditions（240 ℃, 24 h, 50 wt%, 0.1 wt% nano-Fe2O3）, 9.15 % of the heavy component(5.1 % resin and 4.05 % asphaltene) was converted to light component. The content of hydrocarbons below C17 in the saturated fraction increased from 36.29 % to 59.85 %. The structure of the asphaltene was disrupted resulting in a lower level of asphaltene stacking, and NC/NH ratio increased 13.61 % compared to heavy oil. In addition, the reservoir condition with quartz as the supporting medium improved the catalytic ability of iron oxide nanoparticles. When injected into the reservoir medium, nano-size facilitated dispersion on the surface of the proppant and inhibited the aggregation of nanoparticles, which ensured the continuous operation of the active sites on the surface of the catalyst. Electron transfer of Fe2+/Fe3+ catalyzed the heterolytic cleavage of covalent bonds of H2O/heavy oil molecules was the mechanism for heavy oil upgrading. These findings demonstrated the feasibility of in-situ upgrading of heavy oil through the use of nano-catalysts under reservoir conditions.

Alkaline hydrothermal cracking effect and substance transformation characteristics of caprolactam-containing sludge

Caprolactam is a crucial chemical intermediate, but its wastewater treatment process generates a significant amount of caprolactam-containing sludge. This study represented the first exploration of the effects of alkaline hydrothermal technology on the cracking and transformation of substances in this sludge. The cracking effect of caprolactam-containing sludge during hydrothermal treatment increased with rising reaction temperature and longer reaction time. With NaOH dosage in hydrothermal treatment increasing from 0 to 2 wt%, the volatile suspended solids (VSS) removal rate of the sludge increased from 44.5% to 74.8%, soluble chemical oxygen demand (SCOD) in the cracking liquid increased from 12772 mg/L to 22976 mg/L, and ammonia nitrogen concentration increased from 398.0 mg/L to 851.2 mg/L. However, the addition of Ca(OH)2 did not significantly affect the changes of sludge suspended solids, VSS and SCOD concentration, but increased the leaching of ammonia nitrogen (up to 745.0 mg/L). This was due to the secondary flocculation of Ca2+, which rebound with dissolved non-proteinaceous organic matter. Increasing temperature, reaction time, and alkaline dosage all enhanced the fluorescence intensity of dissolved organic matter (DOM). Moreover, higher reaction temperature and alkaline dosage reduced the proportion of proteinaceous products in DOM while increasing the proportions of fulvic acids, soluble microbial metabolites, and humic acid-like substances. The study provided crucial theoretical support for engineering application of this technology.

Synergistic Catalysis of Water-Soluble Exogenous Catalysts and Reservoir Minerals during the Aquathermolysis of Heavy Oil.

Oil serves as the essential fuel and economic foundation of contemporary industry. However, the use of traditional light crude oil has exceeded its supply, making it challenging to meet the energy needs of humanity. Consequently, the extraction of heavy oil has become crucial in addressing this demand. This research focuses on the synthesis of several water-soluble catalysts that can work along with reservoir minerals to catalyze the hydrothermal cracking process of heavy oil. The goal is to effectively reduce the viscosity of heavy oil and lower the cost of its extraction. Based on the experimental findings, it was observed that when oil sample 1 underwent hydrothermal cracking at a temperature of 180 °C for a duration of 4 h, the amount of water added and catalyst used were 30% and 0.2% of the oil sample dosage, respectively. It was further discovered that the synthesized Mn(II)C was able to reduce the viscosity of oil sample 1 by 50.38%. The investigation revealed that the combination of Mn(II)C + K exhibited a significant synergistic catalytic impact on reducing viscosity. Initially, the viscosity reduction rate was 50.38%, which climbed to 61.02%. Subsequently, when catalyzed by the hydrogen supply agent isopropanol, the rate of viscosity reduction rose further to 91.22%. Several methods, such as freezing point analysis, thermogravimetric analysis, DSC analysis, component analysis, gas chromatography, wax crystal morphology analysis, and GC-MS analysis, were conducted on aqueous organic matter derived from heavy oil after undergoing different reaction systems. These analyses confirmed that the viscosity of the heavy oil was decreased. By studying the reaction mechanism of the model compound and analyzing the aqueous phase, the reaction largely involves depolymerization between macromolecules, breakdown of heteroatom chains, hydrogenation, ring opening, and other related consequences. These actions diminish the strength of the van der Waals force and hydrogen bond in the recombinant interval, impede the creation of a grid-like structure in heavy oil, and efficiently decrease its viscosity.

Comprehensive compositional analysis of liquid organic product prepared by industrialized hydrothermal cracking of biomass waste and its potential application as fertilizer

Hydrothermal cracking involves the conversion of organic waste into efficient fertilizer through hydrolysis at temperatures ranging from 180 to 220 °C and pressures of 1.5 to 2.45 MPa, which offers significant advantages in shortening the production cycle, enhancing efficiency, and decomposing antibiotics. As a result, it holds immense practical value for promoting organic fertilizer manufacturing processes globally. The products derived from hydrothermal cracking can be categorized into solid and liquid components. Extensive research has focused on the composition and use of solids, while studies on liquids have mainly examined basic characteristics. The study aimed to comprehensively analyze the components in liquid products prepared through hydrothermal cracking and evaluate their suitability as liquid fertilizers. Specifically, we employed rigorous analytical techniques to accurately identify and quantify medium and trace elements, organic acids, amino acids, and plant growth regulators. Furthermore, we carried out a planting experiment to assess the yield and soil changes following the application of liquid products in maize cultivation. The experimental data revealed that the liquid product contained abundant medium and trace elements, along with 6.22 g/L free amino acids and 9.22 g/L organic acids. It is noteworthy that this liquid product contained 1.22 × 105 pg/mL ABA, 6.26 × 103 pg/mL IAA, 1.07 × 102 pg/mL IBA, and 3.60 × 10−2 pg/mL GA3. The utilization of this liquid product has the potential to enhance the disease resistance of maize crops and promote the accumulation of nitrate nitrogen in the soil. By understanding the composition of liquid products via hydrothermal cracking, valuable insights can be gained into their potential benefits for agricultural and ecological applications.

Supercritical water upgrading of heavy oil: Effects of reservoir minerals on pyrolysis product distribution

Supercritical water upgrading (SCWU) is a promising technology for heavy oil recovery and refining, in which minerals could act as catalysts, but the effect on the upgraded product distribution remains unclear. In this study, heavy oil upgrading experiments in supercritical water (SCW) were carried out at 400°C and 25 MPa to investigate the effects of reservoir minerals such as quartz, carbonate, feldspar and clay minerals on the upgrading process. The result indicated that carbonate minerals and clay-bearing minerals produced noticeable benefits to the SCWU of heavy oil process. In carbonate minerals, dolomite showed the strongest catalytic effect in promoting hydrothermal cracking of hydrocarbon macromolecules, with a 5.6 % reduction in heavy fraction and a 12.2 % increase in light fraction of the upgraded oil. Clay-bearing minerals mainly exhibited oil-enhancing and coking-inhibiting benefits, calcium montmorillonite exhibited the most significant increase in oil production of 9 %, while zeolite most significantly reduced the coke activation energy by 62 %. Regarding the catalytic mechanism, the catalytic effect of carbonates originated from the MgO and CaO sites on the surface. For clay minerals, the acidic catalytic sites exist in the interlayer domains of montmorillonite and in the pores of zeolite provided higher catalytic efficiencies in oil production. This study demonstrated the feasibility of using natural minerals as inexpensive catalysts for supercritical water upgrading of heavy oil.

Synergistic Catalysis of Reservoir Minerals and Exogenous Catalysts on Aquathermolysis of Heavy Oil

In this study, based on existing heavy oil extraction technology, combined with the mineral composition in a reservoir, the synergistic catalytic effect of reservoir minerals and exogenous catalysts under the reaction system of a hydrogen-rich environment not only reduces the viscosity of thick oil but also reduces the extraction cost and further improves the recovery rate of heavy oil. In this study, the impacts of different reservoir minerals and exogenous catalysts on the aquathermolysis of heavy oil were investigated. The research results showed that the sodium montmorillonite within the reservoir minerals exhibited an optimal catalytic effect, and the synergistic catalytic effect of sodium montmorillonite and catalyst C-Fe (catechol iron) resulted in a viscosity reduction rate of 60.47%. Furthermore, the efficiency of different alcohols as hydrogen donors was screened, among which ethanol had the best catalytic effect. Under the optimal reaction conditions, the viscosity reduction rate after the addition of ethanol was 75.25%. Infrared spectroscopy, elemental analysis, thermogravimetry, and differential scanning calorimetry were used to study the changes in heavy oil before and after hydrothermal cracking. Element analysis showed that the synergistic catalytic effect of sodium-based montmorillonite and catalyst C-Fe increased the hydrocarbon ratio from 0.116 to 0.117, and the content of S and N elements decreased. This fully confirms the catalytic effect of sodium-based montmorillonite and C-Fe catalyst for he hydrogenation reaction of the unsaturated carbon in heavy oil.

Study on Hydrothermal Cracking of Heavy Oil under the Coexisting Conditions of Supercritical Water and Non-condensate Gas.

This study looked at the effects of temperature, water-oil ratio, and the addition of non-condensable gas on the thermal cracking of extra-heavy oil in the lab. The goal was to learn more about the properties and reaction rates of deep extra-heavy oil under supercritical water conditions, which are not well understood. The changes in the composition of the extra-heavy oil were analyzed with and without the presence of non-condensable gas. The reaction kinetics of the thermal cracking of extra-heavy oil were quantitatively characterized and compared between the two conditions of supercritical water alone and supercritical water mixed with non-condensable gas. The results showed that (1) under supercritical water conditions, the extra-heavy oil underwent significant thermal cracking, which led to a significant increase in the amount of light components, the release of CH4, and the formation of a new component, coke, which led to a noticeable decrease in the viscosity of the oil; (2) increasing the water-oil ratio could promote the thermal cracking of extra-heavy oil and led to a significant decrease in oil viscosity, indicating a more complete thermal cracking reaction. Moreover, increasing the water-oil ratio was found to facilitate the flowability of the cracked oil; (3) the addition of non-condensable gas intensified the conversion of coke but inhibited and slowed down the thermal cracking of asphaltene, which is detrimental to the thermal cracking of extra-heavy oil; and (4) the kinetic analysis showed that the addition of non-condensable gas resulted in a decrease in the thermal cracking rate of asphaltene, which is detrimental to the thermal cracking of heavy oil.

Research and Development Trend of Viscosity Reduction by Catalytic Coupling Reaction of Crude Oil

In view of the increasing consumption of fossil energy, heavy oil with large reserves and wide distribution, as an important unconventional oil and gas resource, has attracted more and more attention in its exploration and development. However, due to the high content of heavy components in heavy oil, its viscosity is high, its fluidity is low, and its quality is poor. Therefore, the key to enhance heavy oil recovery is to reduce its viscosity, improve its fluidity and improve its quality. At present, steam huff and puff, steam flooding and in-situ upgrading and viscosity reduction of heavy oil are the conventional methods for heavy oil recovery. Considering the production cost, the hydrothermal catalytic cracking technology for heavy oil recovery is studied. However, most of these researches only focus on the preparation and application of catalytic viscosity reducer, and there is still a lack of in-depth and systematic research on its specific viscosity reduction mechanism. Therefore, on the basis of abundant active hydrogen provided by alcohol water reforming reaction, it is of great theoretical value and practical significance to design the application of high-efficiency heavy oil viscosity reduction catalyst by using the super molecular interaction of in-situ active minerals and exogenous metal complexes to catalyze the high-efficiency hydrothermal cracking of heavy oil.

Study on the technique of flue-gas detection and combustion state identification of in-situ combustion process

In this study, the relationship between the flue gases and combustion state of In-Situ Combustion(ISC) were systemically studied by analysis of combustion mechanism, simulate static and dynamic oil flooding experiments. On-site detection gas method was established and used for the detection the content of O2, CO2, H2S, CO, CH4 in the flue gases. The results showed that the CO2 content was higher than 10%, the O2 content was lower than 3%, and the range from 70-85% of N2 in the flue gases, it can be evaluated as high temperature burning state. The CH4 content in the flue gases was higher than 30%, the heavy oil reservoir would undergo hydro-thermal cracking reaction and the corresponding wells were in the combustion preheating stage. The gases content was conducted to evaluated the combustion state and ensure the safety of underground production Well. Based on that, the identification of combustion state and application in the fire flooding industrial pilot area of Hongqian-1 Wellblock was further explained. The results showed that 67% of ignition wells were in high temperature combustion state, and other 25% wells were evaluated as stalled. This study provided technique support for scheme formulation and production dynamic control.

Molecular simulation on mechanism of thiophene hydrodesulfurization on surface of Ni2P

Hydrodesulfurization reaction, as the last step of hydrothermal cracking reaction, is of great significance for the reduction of viscosity and desulfurization of heavy oil. Based on Density Functional Theory and using Dmol3 module of Materials Studio, this research simulated the adsorption and hydrodesulfurization of thiophene on Ni2P (001) surface, and discussed the hydrodesulfurization reaction mechanism of thiophene on Ni2P (001) surface. It was found that the direct hydrodesulfurization of thiophene had more advantages than the indirect hydrodesulfurization of thiophene. Finally, the optimal reaction path was determined: C4H4S+H2→C4H6.

Chemical activation of biochar for energy and environmental applications: a comprehensive review

Abstract Biochar (BC) generated from thermal and hydrothermal cracking of biomass is a carbon-rich product with the microporous structure. The graphene-like structure of BC contains different chemical functional groups (e.g. phenolic, carboxylic, carbonylic, etc.), making it a very attractive tool for wastewater treatment, CO2 capture, toxic gas adsorption, soil amendment, supercapacitors, catalytic applications, etc. However, the carbonaceous and mineral structure of BC has a potential to accept more favorable functional groups and discard undesirable groups through different chemical processes. The current review aims at providing a comprehensive overview on different chemical modification mechanisms and exploring their effects on BC physicochemical properties, functionalities, and applications. To reach these objectives, the processes of oxidation (using either acidic or alkaline oxidizing agents), amination, sulfonation, metal oxide impregnation, and magnetization are investigated and compared. The nature of precursor materials, modification preparatory/conditions, and post-modification processes as the key factors which influence the final product properties are considered in detail; however, the focus is dedicated to the most common methods and those with technological importance.

Structure comparison of asphaltene aggregates from hydrothermal and catalytic hydrothermal cracking of C5-isolated asphaltene

The main purpose of this study is to elucidate the effect of catalyst on asphaltene molecular structure during hydrocracking of C5-isolated asphaltene. Remained asphaltene and coke were obtained after hydrothermal and catalytic hydrothermal cracking of C5-isolated asphaltene at 380–430 °C, using 1000 ppm Mo from Mo-octoate precursor. XRD and NMR analyses were used to investigate the change of molecular structure of asphaltene during the reaction. It was revealed that aggregation of asphaltene increased with increasing the reaction severity resulted in coke formation. The presence of catalyst reduced the aggregation of asphaltene molecules in comparison with the hydrothermal cracking. It was also observed that the average number of stacked polyaromatic sheets in the remained asphaltene decreased with increasing the reaction temperature because of the transformation of high stacked asphaltene into coke during the reaction. Moreover, it was confirmed that the main reason for asphaltene aggregation was the reduction of steric hindrance of asphaltene molecules by the change in molecular structure of asphaltenes.

Catechol production from lignin by Al-doped mesoporous silica catalytic cracking

Two synthesized mesoporous aluminosilicate catalysts were tested for their performance in the lignin hydrothermal cracking to benzenediol derivatives, and especially to catechol (1,2-benzenediol), compared to non-catalytic cracking. In this study, Al-doped MCM-41 catalysts were synthesized by direct and post-synthesis methods while Al-doped SBA-15 was prepared by post-synthesis method. The catalytic performance of these synthesized mesoporous aluminosilicate catalysts was compared with microporous HZSM-5 in terms of their selectivity for catechol production. All the tested catalysts gave markedly higher catechol selectivity than the non-catalytic reaction. The acidity and porosity of the catalyst played an important role in the selectivity for catechol. The highest selectivity for catechol (35.5%) was achieved from lignin hydrothermal cracking at a low temperature (300°C) for 30min with the Al-MCM-41 catalyst prepared by post-synthesis method, and at a catalyst to lignin weight ratio of 0.75.

Scientists prepare elusive organocatalysts for drug, fine chemical synthesis

Two synthesized mesoporous aluminosilicate catalysts were tested for their performance in the lignin hydrothermal cracking to benzenediol derivatives, and especially to catechol (1,2-benzenediol), compared to non-catalytic cracking. In this study, Al-doped MCM-41 catalysts were synthesized by direct and post-synthesis methods while Al-doped SBA-15 was prepared by post-synthesis method. The catalytic performance of these synthesized mesoporous aluminosilicate catalysts was compared with microporous HZSM-5 in terms of their selectivity for catechol production. All the tested catalysts gave markedly higher catechol selectivity than the non-catalytic reaction. The acidity and porosity of the catalyst played an important role in the selectivity for catechol. The highest selectivity for catechol (35.5%) was achieved from lignin hydrothermal cracking at a low temperature (300 °C) for 30 min with the Al-MCM-41 catalyst prepared by post-synthesis method, and at a catalyst to lignin weight ratio of 0.75.

Hydrothermal Catalytic Cracking of Fatty Acids with HZSM-5

We explored the hydrothermal cracking of palmitic acid by HZSM-5 zeolite in a batch reactor. The major liquid products were aromatic hydrocarbons (e.g., xylenes, toluene) and alkanes (e.g., 2-methyl-pentane, heptane). The major gaseous products were CO and CO2, but appreciable yields of propane and butane were also obtained. The effects of batch holding time, temperature, hydrogen pressure, and water density on product yields were elucidated. Total yields of gas and liquid products exceeding 90 wt % are available at reaction conditions of 400 °C, 180 min, and either with no added H2 and a water density of 0.1 g/mL or less or with added H2 and a water density of 0.15 g/mL. The activation energy for palmitic acid disappearance is 31 ± 1 kJ/mol. The zeolite catalyst undergoes some modest structural changes under the hydrothermal reaction conditions employed, but the catalyst can be regenerated by controlled oxidation to remove coke and calcination to restore the structure. These results demonstrate the technical feasibility of using HZSM-5 under hydrothermal conditions to produce valuable chemicals from renewable fatty acid feedstocks.

Reduction of Carbon Dioxide in Hydrothermal Cracking of Polymer Wastes

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationReduction of Carbon Dioxide in Hydrothermal Cracking of Polymer WastesXu Zeng†, Fangming Jin*‡, Zhibao Huo†, Takeo Mogi‡, Atsushi Kishita‡, and Heiji Enomoto‡View Author Information† State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, People’s Republic of China‡ Graduate School of Environmental Studies, Tohoku University, Sendai 980-8579, JapanE-mail: [email protected]Cite this: Energy Fuels 2011, 25, 6, 2749–2752Publication Date (Web):May 16, 2011Publication History Received25 March 2011Revised16 May 2011Published online17 May 2011Published inissue 16 June 2011https://doi.org/10.1021/ef200440kCopyright © 2011 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views581Altmetric-Citations6LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (2 MB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information SUBJECTS:Deformation,Hydrocarbons,Hydrogen,Organic acids,Redox reactions Get e-Alerts

超臨界水を用いた重質油のアップグレーディング(第1報)ビチューメンの分解特性

超臨界水を用いた重質油のアップグレーディング(第1報)ビチューメンの分解特性

超臨界水を用いた重質原油のアップグレーディング(第2報)分解反応モデルと反応速度解析

超臨界水を用いた重質原油のアップグレーディング(第2報)分解反応モデルと反応速度解析

Seismic identification of along-axis hydrothermal flow on the East Pacific Rise

Hydrothermal circulation at the axis of mid-ocean ridges affects the chemistry of the lithosphere and overlying ocean, supports chemosynthetic biological communities and is responsible for significant heat transfer from the lithosphere to the ocean. It is commonly thought that flow in these systems is oriented across the ridge axis, with recharge occurring along off-axis faults, but the structure and scale of hydrothermal systems are usually inferred from thermal and geochemical models constrained by the geophysical setting, rather than direct observations. The presence of microearthquakes may shed light on hydrothermal pathways by revealing zones of thermal cracking where cold sea water extracts heat from hot crustal rocks, as well as regions where magmatic and tectonic stresses create fractures that increase porosity and permeability. Here we show that hypocentres beneath a well-studied hydrothermal vent field on the East Pacific Rise cluster in a vertical pipe-like zone near a small axial discontinuity, and in a band that lies directly above the axial magma chamber. The location of the shallow pipe-like cluster relative to the distribution and temperature of hydrothermal vents along this section of the ridge suggests that hydrothermal recharge may be concentrated there as a consequence of the permeability generated by tectonic fracturing. Furthermore, we interpret the band of seismicity above the magma chamber as a zone of hydrothermal cracking, which suggests that hydrothermal circulation may be strongly aligned along the ridge axis. We conclude that models that suggest that hydrothermal cells are oriented across-axis, with diffuse off-axis recharge zones, may not apply to the fast-spreading East Pacific Rise.

A kinetic study on non-catalytic reactions in hydroprocessing Boscan crude oil

Non-catalytic hydrothermal cracking reactions are known to associate with catalytic hydrocracking reactions. In a recent study on hydroprocessing of Boscan crude over a specific catalyst system containing three distinct catalysts, it was found that hydrodesulfurization (HDS) and hydrodemetallation (HDM) reactions continued even when the catalyst is severely deactivated. Since the reactor was packed with considerable amount of inert material besides the three catalysts, it will be advantage to determine if the inert materials can also facilitate hydroprocessing reactions. A series of kinetic experiments for the inert particles was undertaken under different space velocity and temperature conditions.The extent of catalytic and non-catalytic hydroprocessing reactions was assessed. Through statistical analysis, the initial reaction rate constant, reaction order and activation energy for various hydroprocessing reactions were then determined. The absolute average deviations (AAD) of the kinetics values obtained for inert materials are less than 10%.