Development of Vanadium-phosphate Catalysts for Methanol Production by Selective Oxidation of Methane. Quarterly Technical Progress Report 8, January-March, 1995 PDF Download

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 18

View

Book Description
During the second quarter, we initiated Task 2 (Process and Catalyst Variable Study). This task involves an investigation of methods for vanadium phosphate (VPO) catalyst synthesis and activation as well as detailed testing of the catalysts produced for activity and selectivity in methane selective oxidation. As we initiated work on Task 2, three problem areas were identified: Preparation of catalysts with P:V ratio greater than 1. Activation of the precursor to produce the B-phase described in the patent literature. Achieving high (>95 percent) carbon balances in the bench-scale test unit. Each of these problems has been addressed and overcome during this quarter. Several catalysts with P:V ratios ranging from 0.95 to 1.1 have been prepared. Activation procedures are continuing to be investigated. We have found several procedures which yield catalysts having the desired X-ray diffraction pattern. The reactor system was modified and analytical procedures improved so that in a 7-day run using V2O5 as the catalyst, carbon balances ranged from 95 to 105 percent.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 20

View

Book Description
This document is the ninth quarterly technical progress report under Contract No. DE-AC22-92PC92110 {open_quotes}Development of Vanadium-Phosphate Catalysts for Methanol Production by Selective Oxidation of Methane{close_quotes}. Activities were focused on fine tuning of the microreactor system by elimination of transport effects and improvements in the analytical system. Process variable studies were conducted on vanadyl pyrophosphate and screening studies were conducted on several modified catalyst. One additional catalyst was prepared and characterization studies continued. These results are reported.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 15

View

Book Description
This document is the tenth quarterly technical progress report under Contract No. DE-AC22-92PC92110 {open_quotes}Development of Vanadium-Phosphate Catalysts for Methanol Production by Selective Oxidation of Methane{close_quotes}. Activities focused on testing of additional modified and promoted catalysts and characterization of these materials. Attempts at improving the sensitivity of our GC based analytical systems were also made with some success. Methanol oxidation studies were initiated. These results are reported. Specific accomplishments include: (1) Methane oxidation testing of a suite of catalysts promoted with most of the first row transition metals was completed. Several of these materials produced low, difficult to quantify yields of formaldehyde. (2) Characterization of these materials by XRD and FTIR was performed with the goal of correlating activity and selectivity with catalyst properties. (3) We began to characterize catalysts prepared via modified synthesis methods designed to enhance acidity using TGA measurements of acetonitrile chemisorption and methanol dehydration to dimethyl ether as a test reaction. (4) A catalyst prepared in the presence of naphthalene methanol as a structural disrupter was tested for activity in methane oxidation. It was found that this material produced low yields of formaldehyde which were difficult to quantify. (5) Preparation of catalysts with no Bronsted acid sites. This was accomplished by replacement of exchangeable protons with potassium, and (6) Methanol oxidation studies were initiated to provide an indication of catalyst activity for decomposition of this desired product and as a method of characterizing the catalyst surface.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 94

View

Book Description
Martin Huber, son of Henry Huber and Maria Wenger, married Annie Wenger (b. 1799). They had four children. After Martin's death, Annie married John Gayman. They had five children. They lived in Pennsylvania. Includes Bricker, Thrush and related families.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 19

View

Book Description
This document is the third quarterly technical progress report under Contract No. AC22-92PC92110, ''Development of Vanadium-Phosphate Catalysts for Methanol Production by Selective Oxidation of Methane.'' During this quarter, we have continued to develop methods for catalyst activation by investigating activation in wet gas environments. This procedure leads to the formation of highly crystalline (VO)2P2O--, while activation under identical conditions, but with no moisture, leads to a poorly crystalline sample. Published data indicate that the highly crystalline form is representative of commercial butane oxidation catalysts. The main focus of our work during this quarter has been in the area of catalyst testing in the microreactor system. In order to confirm that our microreactor system was providing reliable data, we tested a V2O5/SiO2 catalyst at atmospheric pressure and temperatures from 500 to 600°C using 90 to 95 percent CH4/O2. Several studies of methane oxidation using this catalyst have been published with reasonably good agreement between different research groups. We were not able to reproduce the literature data using steel reactors. However, when the steel reactor was lined with quartz and the postcatalyst reactor volume was minimized by packing with quartz chips, we obtained results which agree closely with those previously published. Using the same quartz reactor and test conditions, we also tested a highly crystalline (wet activated) VPO catalyst.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 17

View

Book Description
This document is the fifteenth quarterly technical progress report under Contract No. DE-AC22-92PC921 'Development of Vanadium- Phosphate Catalysts for Methanol Production by Selective Oxidation of Methane' and covers the period October-December, 1996. Vanadium phosphate, vanadyl pyrophosphate specifically, is used commercially to oxidize butane to maleic anhydride and is one of the few examples of an active and selective oxidation catalyst for alkanes. In this project we are examining this catalyst for the methane oxidation reaction. Initial process variable and kinetic studies indicated that vanadyl pyrophosphate is a reasonably active catalyst below 5000°C but produces CO as the primary product, no formaldehyde or methanol were observed. A number of approaches for modification of the phosphate catalyst to improve selectivity have been tried during this project. During this quarter we have obtained surface areas of catalysts prepared with modified surface acidity. The results confirm the enhanced activity of two of the modified preparations in methanol conversion (a test reaction for surface acid sites). In previous work we noted no improvement in methane oxidation selectivity for these catalysts. Surface areas, surface analysis by XPS, and bulk analysis by ICP-AA have been obtained for vanadyl pyrophosphate promoted by Cr, Cu, and Fe. These data indicate that roughly one tenth of the surface metal atoms are promoter. A similar analysis was obtained for the bulk. Preliminary examination of binding energies suggests a slightly more reduced surface for the Cr and Fe promoted catalysts which exhibit a significant selectivity to formaldehyde in methane oxidation. A more detailed kinetic model has also been developed to aid in comparing the promoted catalysts and is discussed. Plans for the coming months are outlined.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 17

View

Book Description
This document is the fourth quarterly technical progress report under Contract No. DE-AC22-92PC92110, {open_quotes}Development of Vanadium-Phosphate Catalysts for Methanol Production by Selective Oxidation of Methane.{close_quotes} During this quarter, the authors focused primarily on catalyst activity testing in the microreactor. Additional blank runs using methane and methanol were performed. Initial attempts at preparing a silica supported catalyst are described. These results are discussed in detail and plans for the coming quarter are outlined.