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Fit for purpose

Summary

Pumps that handle sulphuric acid need to be able to withstand a range of conditions and stresses, depending on the concentration and operating temperature. Dr Gerhard Pracht of the Rheinhütte Pumps Division at Friatec AG discusses the pros and cons of different materials used to construct sulphuric acid pumps, and highlights the best material for a range of different applications.

Abstract

Sulphuric acid is one of the most important raw materials in the chemical industry. In 2005, 194 million tonnes of sulphuric acid were produced worldwide, and production is expected to continue to increase to 240 million tonnes in 20101.

Sulphuric acid is chiefly manufactured through the combustion of sulphur, or ores containing sulphur. In 2006, over 51 million tonnes of sulphuric acid were manufactured from the preparation of ore and production using this method is set to expand in the next few years.

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ASRL REVIEW

Summary

Mechanisms of BTX Conversion in the Claus Furnace -- A twice yearly review contributed by Alberta Sulphur Research Ltd.

Abstract

Introduction

Sulphur recovery from low H2S content acid gas is often complicated by BTX and other hydrocarbons which are present due to their solubility in rich amine solutions. The major complication arises from the low adiabatic temperature of Claus combustion for acid gas with <50% H2S, which limits BTX conversion. BTX residues then lead to degradation of catalyst in the first converter by interaction with sulphur. In extreme cases, discoloured sulphur may also be produced because of hydrocarbon contamination. Potential solutions to this problem revolve around raising the furnace temperature by acid gas enrichment, pre-heating of acid gas and combustion air, methane co-firing and oxygen enrichment (Figure 1). These approaches can be applied individually or in concert but, at the end of the day, a less economic and less efficient sulphur recovery system may result. From a chemical viewpoint, insufficient information has been available to make a rationale choice for determining what the best strategy might be for low H2S-content acid gas processing. So, we set out to determine if, by understanding the mechanisms of BTX conversion, we could gain some insight for an improved technology.

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Gas cleaning designs for smooth operations

Summary

Klaus Hasselwander of Outotec discusses the key design features of gas treatment systems for sulphuric acid plants in non-ferrous smelters

Abstract

Pyrometallurgical processes for the treatment of sulphide ores are operated at temperatures between 800 and 1,500°C. In the metallurgical furnace, the sulphur contained in the ore is released into the gas phase as sulphur dioxide (SO2), an acidic gas that can be harmful to humans, vegetation and property if released into the atmosphere. Thus, in most regions of the world, SO2 must be removed before the off-gas is released. In general, SO2 is processed into sulphuric acid in a contact acid plant. Unfortunately, in the pyrometallurgical process, besides SO2, there are also many other gaseous and non-gaseous substances. In addition, a lot of dust and fumes also leave the furnace along with the hot SO2 gas. Depending on the ores, the substances released can have very different properties in terms of the build-up formation, stickiness and sometimes even ignitability.

In order to allow the continuous production of sulphuric acid the gas must be thoroughly cleaned. All inorganic matter, which can contaminate the acid or have an impact on plant operation by decreasing the onstream time, must be removed from the gas. This requires careful design of both the hot gas system and the wet gas cleaning system. The design data for gas treatment systems are usually within the ranges provided in Fig. 1.

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Reducing sulphur emissions from FCCUs

Summary

Regulatory agencies are applying increasingly severe limits on SOx emissions from FCCUs around the world. A variety of emissions reduction options, such as wet gas scrubbing and SOx additives, exist for refiners who are challenged to meet these ever-increasing limits.

Abstract

Topics covered include:

  • Regulation of SOx emissions
  • FCCU SOx emissions
  • FCCU SOx reduction technologies
  • SOx reduction additives
  • An economic comparision
  • etc.

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Sour gas in the Middle East

Summary

The Emirate of Abu Dhabi is leading the way in the development of some very sour gas fields with a H2S content of up to 30%. Needless to say, the potential increase in sulphur production from these fields is considerable.

Abstract

The Middle East still has huge untapped reserves of hydrocarbons, which has drawn the oil and gas industry there over the past decades. Hitherto, much of the exploitation has been aimed at exports of ol and gas, to Europe, Asia, and beyond. But now local demand for natural gas is also rising rapidly as econo - mies there expand and industrialise, especially in more populous countries like Saudi Arabia and Iran. In countries such the UAE, meanwhile, new tourist resorts and other facilities are also expected to have significant power requirements. It is estimated by Shell that the Arabian Gulf and South Asian region needs $150 billion in spending to meet natural gas demand that will surge about 75% by 2020. Demand for gas in the region will rise to 35 billion cubic feet a day in 2020 from 20 billion cubic feet in 2007, according to the company (Table 1).

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New sulphuric acid producing plants

Summary

From sulphur burning to smelter gas capture, Sulphur's annual survey covers recent and planned construction projects for sulphuric acid production.

Abstract

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