A new route to liquid fuels from coal

1981 ◽  
Vol 300 (1453) ◽  
pp. 157-169 ◽  
Keyword(s):  
Process Development ◽  
Fixed Bed ◽  
Building Blocks ◽  
Major Product ◽  
Liquid Fuels ◽  
Light Olefins ◽  
Chemical Components ◽  
Exploratory Research ◽  
Hydrogen Atoms ◽  
R And D

For many decades to come, the transformation of coal to high-grade liquid fuels and chemicals will be a continuing challenge. Chemically speaking, this conversion requires a gradual rearrangement of the carbon and hydrogen atoms and the addition of hydrogen, or the complete transformation of coal into building blocks containing a single carbon atom, and putting them together selectively with hydrogen to form the desired molecules. A catalyst discovered at Mobil will convert methanol, made from such building blocks, into high-octane gasoline. A simple process based on this catalyst produces the final link in a new route from coal to gasoline. A fluidized-bed version of this methanol-to-gasoline process will be tested in a 100 barrels ( ca . 16 m 3 ) per day pilot plant in Germany. A fixed-bed, commercial-size version has been selected by the New Zealand government for the conversion of methanol made from natural gas. This unit will produce 13 000 barrels ( ca . 2100 m 3 ) of gasoline per day. If the catalyst is modified, we can command it to construct basic chemical components such as light olefins, including ethylene, or BTX aromatics (benzene, toluene, xylenes) as the major product. The emergence of these new conversion processes exemplifies industrial R. and D., which spans the technology spectrum from basic and exploratory research by a few scientists to process development and commercialization involving industries and governments.

Microscopic versus process parameters in heavy-oil upgrading

1992 ◽  
Vol 50 (1) ◽  
pp. 366-367
Author(s):  
V.A. Munoz ◽  
R.J. Mikula ◽  
C. Payette ◽  
W.W. Lam
Keyword(s):  
Molecular Weight ◽  
Liquid Fuels ◽  
Chemical Components ◽  
Heavy Oils ◽  
Synthetic Fuels ◽  
High Hydrogen ◽  
Optical Texture ◽  
Polar Groups ◽  
Anisotropic Character ◽  
Planar Molecules

The transformation of high molecular weight components present in heavy oils into useable liquid fuels requires their decomposition by means of a variety of processes. The low molecular weight species produced recombine under controlled conditions to generate synthetic fuels. However, an important fraction undergo further recombination into higher molecular weight components, leading to the formation of coke. The optical texture of the coke can be related to its originating components. Those with high sulfur and oxygen content tend to produce cokes with small optical texture or fine mosaic, whereas compounds with relatively high hydrogen content are likely to produce large optical texture or domains. In addition, the structure of the parent chemical components, planar or nonplanar, determines the isotropic or anisotropic character of the coke. Planar molecules have a tendency to align in an approximately parallel arrangement to initiate the formation of the nematic mesophase leading to the formation of anisotropic coke. Nonplanar highly alkylated compounds and/or those rich in polar groups form isotropic coke. The aliphatic branches produce steric hindrance to alignment, whereas the polar groups participate in cross-linking reactions.

Dimethyl Ether Conversion to Olefins over the SAPO-34/ZrO2 Catalysts: Effect of the ZrO2 Supporter

2011 ◽  
Vol 347-353 ◽  
pp. 3681-3684 ◽  
Author(s):  
Young Ho Kim ◽  
Su Gyung Lee ◽  
Byoung Kwan Yoo ◽  
Han Sol Je ◽  
Chu Sik Park
Keyword(s):  
Physicochemical Properties ◽  
Dimethyl Ether ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Coke Deposition ◽  
Light Olefins ◽  
Similar Activity ◽  
Dimethyl Ether Conversion ◽  
Zro2 Catalyst ◽  
Catalyst Lifetime

A SAPO-34 catalyst is well known to be one of the best catalysts for DME to olefins (DTO) reaction. Main products of the reaction were light olefins such as ethylene, propylene and butenes. However, the main problem is rapid deactivation of the SAPO-34 catalyst due to coke deposition during DTO reaction. In this study, various SAPO-34/ZrO2 catalysts added with ZrO2 were prepared for improving the lifetime and their physicochemical properties have been characterized by XRD and SEM. The DTO reaction over various SAPO-34/ZrO2 catalysts was carried out using a fixed bed reactor. All SAPO-34/ZrO2 catalysts showed similar activity and selectivity in the DTO reaction. The SAPO-34(9wt%)/ZrO2 catalyst was showed the best performance for the catalyst lifetime.

Nucleophilic addition at u 3 -alkyne clusters leading to carbon-carbon bond formation

1982 ◽  
Vol 308 (1501) ◽  
pp. 59-66 ◽  
Keyword(s):  
Bond Formation ◽  
Organic Ligand ◽  
Major Product ◽  
Unsaturated Hydrocarbon ◽  
Terminal Alkynes ◽  
Hydrogen Atoms ◽  
Metal Atoms ◽  
Carbon Carbon Bond ◽  
Anionic Species ◽  
A Minor

Reactions of nucleophiles with triosmium carbonyl clusters, especially those containing unsaturated hydrocarbon ligands, are discussed. Attack may be at CO, the metal atoms, at carbon of the organic ligand, or, where there are acidic metal-bound hydrogen atoms, deprotonation to give anionic clusters may occur. New results on the reactions of LiBHEt3 with p3-alkyne clusters of type Os3(CO)10 (RC2R') are considered in the light of the range of possible sites of attack. Protonation of anionic species that are formed gives hydrogenation products with or without the loss of CO. Os3H2(CO)9(RC2R') is usually a minor product, while C-C coupling leads to Os3H(CO)9(CRCR'COH) (in general the major product) and to Os3H(CO)9- (CRCR'CH). With terminal alkynes RC2H H-atom transfer accompanies C-C coupling to give Os3H(CO)9(RC—C =C H 2) in substantial amounts. The initial site of hydride attack (CO, alkyne or metal) is considered in the context of low-temperature 1H n.m.r. results.

Comparison and assessment of zeolite catalysts performance dimethyl ether and light olefins production through methanol: a review

2019 ◽  
Vol 39 (3) ◽  
pp. 157-177 ◽  
Author(s):  
Ehsan Kianfar
Keyword(s):  
Dimethyl Ether ◽  
Raw Materials ◽  
Fixed Bed ◽  
Value Added ◽  
Zeolite Catalysts ◽  
Present Review ◽  
Light Olefins ◽  
Light Olefin ◽  
Production Methods ◽  
Olefin Production

AbstractThe present review focuses on a comparison and assessment of zeolite catalyst performance of dimethyl ether and light olefin production through methanol. Dimethyl ether is a clean fuel which needs diverse processes to be produced. Methanol to dimethyl ether is a very novel process which offers considerable advantages versus additional processes for the production of dimethyl ether. The corresponding fixed-bed reactors compose the most important section of such a process. Production of dimethyl ether by the mentioned process is of high importance since it can be catalytically transferred to a substance with the value of propylene. Furthermore, in case of capability to transfer low-purity methanol into dimethyl ether, less expensive methanol can be consequently achieved with higher value added. In the petrochemical industry, light olefins, for example, ethylene and propylene, can be used as raw materials for the production of polyolefin. The present review aims to produce dimethyl ether in order to reach olefin substances, initially conducting a compressive assessment on production methods of olefin substances.

scholarly journals Analysis and Model-Based Description of the Total Process of Periodic Deactivation and Regeneration of a VOx Catalyst for Selective Dehydrogenation of Propane

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1374
Author(s):  
Andreas Brune ◽  
Andreas Seidel-Morgenstern ◽  
Christof Hamel
Keyword(s):  
Catalyst Deactivation ◽  
Process Development ◽  
Coke Formation ◽  
Fixed Bed ◽  
Reaction Network ◽  
Fixed Bed Reactor ◽  
Side Reactions ◽  
Model Based ◽  
Total Process

This study intends to provide insights into various aspects related to the reaction kinetics of the VOx catalyzed propane dehydrogenation including main and side reactions and, in particular, catalyst deactivation and regeneration, which can be hardly found in combination in current literature. To kinetically describe the complex reaction network, a reduced model was fitted to lab scale experiments performed in a fixed bed reactor. Additionally, thermogravimetric analysis (TGA) was applied to investigate the coking behavior of the catalyst under defined conditions considering propane and propene as precursors for coke formation. Propene was identified to be the main coke precursor, which agrees with results of experiments using a segmented fixed bed reactor (FBR). A mechanistic multilayer-monolayer coke growth model was developed to mathematically describe the catalyst coking. Samples from long-term deactivation experiments in an FBR were used for regeneration experiments with oxygen to gasify the coke deposits in a TGA. A power law approach was able to describe the regeneration behavior well. Finally, the results of periodic experiments consisting of several deactivation and regeneration cycles verified the long-term stability of the catalyst and confirmed the validity of the derived and parametrized kinetic models for deactivation and regeneration, which will allow model-based process development and optimization.

scholarly journals The Generated Databases (GDBs) as a Source of 3D-shaped Building Blocks for Use in Medicinal Chemistry and Drug Discovery

2020 ◽  
Vol 74 (4) ◽  
pp. 241-246 ◽  
Author(s):  
Kris Meier ◽  
Sven Bühlmann ◽  
Josep Arús-Pous ◽  
Jean-Louis Reymond
Keyword(s):  
Drug Discovery ◽  
Medicinal Chemistry ◽  
Organic Molecules ◽  
Chemical Space ◽  
Building Blocks ◽  
Chiral Molecules ◽  
Hydrogen Atoms ◽  
Quaternary Centers ◽  
Medical Needs ◽  
Unmet Medical Needs

Drug discovery is in constant need of new molecules to develop drugs addressing unmet medical needs. To assess the chemical space available for drug design, our group investigates the generated databases (GDBs) listing all possible organic molecules up to a defined size, the largest of which is GDB-17 featuring 166.4 billion molecules up to 17 non-hydrogen atoms. While known drugs and bioactive compounds are mostly aromatic and planar, the GDBs contain a plethora of non-aromatic 3D-shaped molecules, which are very useful for drug discovery since they generally have more desirable absorption, distribution, metabolism, excretion and toxicity (ADMET) properties. Here we review GDB enumeration methods and the selection and synthesis of GDB molecules as modulators of ion channels. We summarize the constitution of GDB subsets focusing on fragments (FDB17), medicinal chemistry (GDBMedChem) and ChEMBL-like molecules (GDBChEMBL), and the ring system database GDB4c as a rich source of novel 3D-shaped chiral molecules containing quaternary centers, such as the recently reported trinorbornane.

Analysis of wood vacuum pyrolysis solid residues by diffuse reflectance infrared Fourier transform spectrometry

1989 ◽  
Vol 67 (2) ◽  
pp. 310-314 ◽  
Author(s):  
H. Pakdel ◽  
J. L. Grandmaison ◽  
C. Roy
Keyword(s):  
Fourier Transform ◽  
Diffuse Reflectance ◽  
Process Development ◽  
Liquid Fuels ◽  
Solid Residue ◽  
Vacuum Pyrolysis ◽  
Development Unit ◽  
Diffuse Reflectance Infrared ◽  
High Yields ◽  
Increasing Temperature

Vacuum pyrolysis of wood furnishes high yields of oils which are a source of liquid fuels and chemicals. Wood charcoal is a solid residual by-product. Solid residues produced at 200, 263, 327, 363, 401, and 448 °C in a Process Development Unit were analyzed using wet chemical methods and chromatography and infrared spectrometry.A Diffuse Reflectance Infrared Fourier Transform (DRIFT) study of the solid residues which contained various proportions of organic polymeric constituents consisting of unconverted lignin, polysaccharides, and recondensed materials was performed. Polysaccharide contents were determined by hydrolysis in trifluoroacetic acid followed by derivatization and gas-chromatographic analysis. The DRIFT study showed that the solid residue retained its wood nature below 263 °C. Significant degradation, decomposition, and recondensation reactions occurred with increasing temperature and coal-like nature prevailed above 327 °C. Occurrence of a new band at 1700 cm−1 in samples produced at 363 °C and above was found to be indicative of a new carbonyl group, presumably in recondensed material.A series of equations were also developed to predict semiquantitatively Klason residue, glucose and xylose content of the solid residues. The usefulness of each equation is discussed in the article. Keywords: wood, vacuum pyrolysis, solid residue, DRIFT, spectrometry.

scholarly journals NUMERICAL MODELLING OF THE ENDOTHERMIC PROCESS OF THE STEAM REFORMING OF METHANE IN A FIXED BED REFORMER

2021 ◽  
Vol 20 (1) ◽  
pp. 03
Author(s):  
D. R. Dessaune ◽  
V. F. Dias ◽  
J. D. Silva
Keyword(s):  
Steam Reforming ◽  
Fixed Bed ◽  
Packed Bed ◽  
Theoretical Modelling ◽  
Chemical Components ◽  
The Past ◽  
Open Cell Foam ◽  
Conversion Of Methane ◽  
Endothermic Process ◽  
Steam Reforming Of Methane

Thermochemical Packed-Bed (TPB) reformer has been substantially studiedin the past years as a promising equipment to investigate thethermochemical conversion of methane (CH4). This work has as mainobjective a theoretical modelling to describe the process variables of SteamReforming of Methane (SRM) method in the TPB reformer. The TPBreformer is filled with β-SiC open-cell foam where the thermochemicalconversion of CH4 is carried out. The model variables describe the specificaims of work and these objectives can be identified from each equation ofthe developed mathematical model. This work has been proposed to studytwo specific aims as (i) the effective thermal conductivity's effect of thesolid phase (λs,eff.) and (ii) molar flows of chemical components. Theendothermic reaction temperature's profiles are notably increased as thenumeral value of λs,eff. is raised. The Steam Reforming of Methane (SRM)method is suggested to improve the Production Rate (PR) of H2 regardingthe PR of CO. As results, the PR of H2 is of 29.48% while the PR of CO isof 2.76%.

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