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The big nickel sale

Summary

Whilst demand for nickel booms, life in the still-fledgling laterite processing industry has been complicated by business deals more than technical issues.

Abstract

What a difference a few weeks can make in the nickel business. Just a year ago, South African platinum group metals miner Implats announced that it would pull out of the Ambatovy laterite nickel project in Madagascar. The company had signed up to the project the previous May with the projectís principal, Dynatec of Canada, acquiring the partnership of Japan≠ese commodities company Sumitomo the following August.

By April 2006 Implats had signed an ≠option agreement covering another nickel project in Madagascar, at Ambodilafa. Unlike Ambatovy, Implatsís new interest is closer to its core operation, boasting resources of platinum group metals.

Sumitomo kept faith with Ambatovy, reckoned to be one of the most important new sources of demand for sulphur that is currently in development, but Implatsís sudden departure was a severe blow to the future prospects of the project. Then, only a few months ago, Dynatecís biggest shareholder was forced to liquidate its interest in the company.

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Sulphur technology at Jamnagar Refinery

Summary

When complete in 2008, Jamnagar Refinery in India is destined to be the largest in the world. Sulphur reports on the sulphur technologies selected to process the heavy sour crude, comply with strict environmental regulations and to produce high quality formed sulphur.

Abstract

Reliance Industries built the world’s largest grassroots refinery in 1996-1999, and is currently in the process of expanding to double the capacity, which will make the Jamnagar Refinery the largest in the world. In addition to its impressive size, Reliance’s Jamnagar Refinery can process a wide variety of crude oils ranging from sweet to heavy, with sulphur content up to 4.5 ­wt-%. Reliance’s current refinery and petrochemical complex handles 660,000 b/d of heavy, sour crude and is presently exporting most of its products with very high margins – the best in the world. As the Jamnagar Refinery is designed to produce the highest grade petroleum products, Reliance sees excellent potential to export products to the United States and Europe.

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Successful ammonia destruction

Summary

It is well known that the processing of more than a few per cent of ammonia in the total feed gases to a modified Claus unit can lead to operational difficulties unless special design features have been incorporated into the plant. Lisa Connock reviews the chemistry of ammonia destruction and the different approaches adopted in refineries to achieve destruction to the required level of less than 50 ppm.

Abstract

Ammonia (NH3) is a byproduct from the hydrotreating of crude oils containing nitrogen compounds. The quantity of nitrogen contained in the crude is generally larger if the crude is low API, low quality. Although ammonia is a valuable commodity, transportation of it from the refinery to market is often precluded by either economic or regulatory factors. In addition, due to its harm­ful properties, it cannot be disposed of directly to the atmosphere. Consequently, several methods have been developed in which a combined stream of H2S and NH3 is processed in a Claus furnace with the aim of producing N2 as the sole nitrogen-containing product. The individual steps for conversion of NH3 to N2 will involve a sequence of radical intermediates but the elementary reactions can be summarised as shown in Fig. 1.1

The ammonia from the hydrotreater is gathered as sour water containing H2S and hydrocarbons and, after flash, the water is stripped with steam to produce an acid gas containing typically 30-33 vol-% NH3, 30-33 vol-% H2S and H2O as balance. Ammonia is also present in significant amounts in the sour water stripper (SWS) acid gas feed from coker units.

The SWS gas is co-fired with amine acid gas (AAG) in the thermal reactor stage of the Claus plant to recover sulphur. Ammonia must be destroyed adequately in the sulphur recovery unit (SRU) reaction furnace to ensure trouble-free operation of the SRU.

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Optimum performance of sulphur plants

Summary

Investigations have been carried out in Russia to determine the optimum operating conditions to achieve maximum H2S conversion in modified Claus sulphur recovery units. S.V. Krashennikov, L.V. Morgun, S.V. Shurupov, N.V. Motin, O.E. Filatova, V.V. Chupin of VNIIGAZ report on their findings.

Abstract

The basic process parameters for ensuring efficient operation of Claus units were determined back in the late 1970s and early 1980s (papers by J. Hyne, H. Paskall, H. Fischer and J. Sames) and have remained virtually unchallenged ever since. In accordance with the prescribed requirements, the maximum degree of hydrogen sulphide conversion in a modified Claus sulphur recovery unit is attained under the following conditions: 

  • ratio H2S/SO2 in process gas equals 2;
  • the first reactor temperature is 343 °C, the others are minimum allowable temperatures limited by possible sulphur condensation in catalyst pores;
  • each process stage ensures equilibrium sulphur yield.

Most of the above requirements are self-evident, being governed by the stoichiometry and thermodynamics of the interaction between H2S and SO2, but these requirements also involve contradictions.

 

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Treatise in Vienna

Summary

The Sulphur 2006 conference in Vienna addressed future uncertainties in supply and demand. Sulphur reviews highlights of the meeting.

Abstract

The mood at Sulphur 2006 was for the most part upbeat with plenty of activity reported among the industries that support the production and trans-global supply of sulphur and sulphuric acid. The possible huge surpluses of sulphur that were such a point of discussion at the previous year’s conference remained somewhere in the middle distance.

For shorter term needs, the meeting had an opportunity to hear from Dick van Meurs of ICEC about a new and world-scale sulphur exporting terminal, at Ust-Luga on the Baltic Sea. An industry that demands such a scale of development is on top of its game, at least for the time being.

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