headerdrawing1.jpg (96365 bytes)

Sulphuric Acid on the WebTM Technical Manual DKL Engineering, Inc.

Knowledge for the Sulphuric Acid Industry Line.jpg (1139 bytes)

Sulphuric Acid on the Web

Introduction
General
Equipment Suppliers
Contractor

Instrumentation
Industry News
Maintenance
Acid Traders
Organizations
Fabricators
Conferences

Used Plants
Intellectual Propoerty
Acid Plant Database
Market Information
Library

Technical Manual

Introduction
General

Definitions
Instrumentation
Plant Safety
Metallurgial Processes
Metallurgical
Sulphur Burning
Acid Regeneration
Lead Chamber
Technology
Gas Cleaning
Contact
Strong Acid
Acid Storage
Loading/Unloading

Transportation
Sulphur Systems
Liquid SO2
Boiler Feed Water
Steam Systems

Cooling Water
Effluent Treatment
Utilities
Construction
Maintenance
Inspection
Analytical Procedures
Materials of Construction
Corrosion
Properties
Vendor Data

DKL Engineering, Inc.

Handbook of Sulphuric Acid Manufacturing
Order Form
Preface
Contents
Feedback

Sulphuric Acid Decolourization
Order Form
Preface
Table of Contents

Process Engineering Data Sheets - PEDS
Order Form
Table of Contents

Introduction

Bibliography of Sulphuric Acid Technology
Order Form

Preface
Contents

Sulphuric Acid Plant Specifications
 

Google Search new2.gif (111 bytes)

 

log 2.JPG (76785 bytes)

Sharplex.jpg (28953 bytes)

MAHLEInd.jpg (21078 bytes)

 


Contact Section - Catalysts - Haldor Topsoe A/S
Janaury 18, 2003

Introduction
Catalyst Types

        VK38
        VK48
        VK58
        VK69
        VK-WSA
Associated Links

Catalyst Unloading
Catalyst Loading


Introduction

During the second World War, Dr. Haldor Topsøe and Dr. Anders Nielsen developed an extruded vanadium pentoxide catalyst for use in Danish and Swedish sulphuric acid plants because they were not able to obtain new catalyst from their usual suppliers.  The catalyst operated successfully even though it was crudely manufactured.

Topsoehouston.jpg (11216 bytes)

Topsoe Houston Plant

Based on their research, it was revealed that the active ingredients of the vanadium pentoxide catalyst exists as melt within the pores of the porous silica carrier.  Dr. Topsøe and Dr. Nielsen also discovered that different alkali-metal promoters such as rubidium and caesium instead of potassium increased the activity of the catalyst.  Unfortunately, it wasn’t until 1988 that the first caesium-promoted catalyst was introduced by Haldor Topsøe A/S.

In 1976, Haldor Topsøe A/S introduced the first ring shaped extrudates.  The ring shaped catalyst provides several advantages over the traditional cylindrical catalyst.  The ring shape exposes more catalyst surface area to the process gas per catalyst volume than the cylindrical shaped.  Pressure drop across the catalyst bed is also reduced due to a higher void volume for the ring shape.

Further development in catalyst shapes occurred in 1984 when Haldor Topsøe A/S introduced the daisy shaped catalyst.  The daisy shape provides further enhancement of the ring shaped by creating ribs on the outside surface of the ring.  Pressure drops across daisy shaped catalyst are further reduced compared to equivalent beds of ring shaped catalysts.

A major advancement in sulphuric acid catalyst occurred in 1988 with the introduction of cesium-promoted catalyst.

Catalyst Types

The physical properties of the catalyst are provided in the following table and a brief description of each catalyst is given below.

  VK38 VK48 VK58 VK69 VK-WSA
Shapes 6 mm pellets
10 mm rings
12 mm daisy
20 mm rings
6 mm pellets
10 mm rings
12 mm daisy
6 mm pellets
10 mm rings
12 mm daisy
14 mm rings
9 mm daisy 6 mm pellets
10 mm rings
20 mm rings
V2O5 Content 6-8 wt% 7-9 wt% 6-8 wt%   6-8 wt%
Alkali-metal oxides 11-15 wt% 11-15 wt% 20-25 wt%   11-15 wt%
Operating Temperature 400-630oC 400-550oC 370-450oC   400-550oC

VK38

VK38 can be used throughout the converter in all beds but is optimized for use in the first two passes.   Fresh catalyst has an ignition temperature of 360oC increasing to 380oC for after years of operation.  Maximum continuous operating temperature is 630oC with peaks up to 650oC for short periods of time.

VK48

VK48 has been optimized for use in the final catalyst passes.  This is achieve by a higher vanadium pentoxide content combined with a change in the active phase.

VK58

VK58 is a caesium-promoted catalyst designed for use in the first pass as an ignition layer and in the final pass to enhance overall conversion.  Ignition temperatures are as low as 320-330oC.

VK69

VK69 is a caesium-promoted catalyst optimized for operation in the last bed(s) of a double absorption process.  The catalyst is manufactured by a special extrusion process resulting in a highly porous catalyst.   The catalyst combines an increase in vanadium content with a revised composition of the active phase to achieve its enhanced performance.

VK-WSA

VK-WSA catalyst was developed specifically for use in Haldor Topsøe’s WSA desulphurization process.   This process involves the direct oxidation of SO2 and formation of sulphuric acid in humid process gases.  The catalyst possesses higher strength which is desirable in the water vapour containing process gases.