BC Insight - Nitrogen+Syngas, Sulphur, Fertilizer International
Login
BCInsight Ltd
China Works
Black Prince Road
London, SE1 7SJ
United Kingdom
Tel: +44 (0)20 7793 2567
Fax: +44 (0)20 7793 2577

Publication > Issue > Articles

Safe design and operation of SRUs

Summary

Many factors contribute to the safe design and operation of sulphur recovery units. In this article, Foster Wheeler, Fluor, RATE and Siirtec Nigi, examine the most important safety issues affecting SRU plant design, plant layout and operation with regard to protecting plant operating personnel, local communities and the environment.

Abstract

By their nature, sulphur recovery units demand that the highest level of process and personnel safety be practiced continually. Hydrogen sulphide is present in deadly concentrations in the feed and most process streams. Highly toxic sulphur dioxide is created in the process. The process includes a high-temperature partial oxidation step that creates a severe operating environment and potentially extreme safety issues. As a result, design and operating practices emphasise process and personnel safety as the highest priority. Maximum attention is given to the safe handling of hydrogen sulphide, combustion safety, and equipment design for a high-temperature operating environment. Operating instructions include procedures that have been proven to result in safe start-up, operation, and shutdown. Engineering controls must be provided to prevent dangerous process conditions from occurring that might result in equipment damage or personnel hazards. The operating conditions are extensively monitored, and supervised with permissives and interlocks to ensure that abnormal conditions are managed in a safe manner. The scope and complexity of the safety systems required to ensure the safety of the equipment and operators are apparent in typical cause and effect tables. Keywords: safety, H2S monitoring, piping, equipment, fire protection, reaction furnace, tube rupture, refractory dry out, start-up, shutdown, vent gases, sulphur loading arm, vapour adsorption system

Add to basket


SRU shutdown systems - Part 2: Causes and consequences

Summary

This is the second of a two part article on sulphur recovery unit shutdowns. In Part 2, Jim Hampsten of Principal Technology, Inc. provides an overview of the process considerations of sulphur facility shutdown causes and consequences.

Abstract

A key component of all sulphur recovery units (SRUs) is the shutdown system, and the necessity of a well implemented shutdown system is increasingly critical with today’s attention to safety and environmental containment. The industry’s experience with the development of proven shutdown functionality needs to be broadened to assure safe and reliable operations in refining and gas facilities. Many of the reasons to automatically shut down a sulphur unit have been unclear to some plant designers and operators over the years. This article will identify many of the conditions that could lead to a shutdown, the monitors to initiate a shut down when necessary, and to note possible consequences from each condition if the shutdown were to not occur. A similar treatment of shutdowns for tail gas units (TGUs) is also included. Keywords: waste heat boiler, overpressure, flame failure, catalytic reactor, furnace temperature, TGU, incinerator

Add to basket


Saudi Arabia's phosphate boom

Summary

After years of running an oil-based economy, Saudi Arabia has begun to diversity, making use of its other natural resources. Foremost among these are phosphates, with plans for several massive projects which will absorb a great deal of sulphur over the coming years.

Abstract

While Saudi Arabia has grown wealthy from its vast oil reserves, especially at times of high oil prices such as in 1973, 1989 and 2006, it has also faced economic difficulties in times of low oil prices, as happened in the early 1980s and early 1990s. Early fruits of the country’s oil bonanza were infrastructure developments; highways, airports, schools and hospitals, but in an attempt to diversify the economy away from its reliance on oil, there has been some attempt to move into other industries. Natural gas has been tapped for fertilizer and methanol production, and there has been a progressive move towards more downstream petrochemical production and oil refining. But the country also has considerable mineral wealth, and in 1997 the Saudi Arabian Mining Company (Ma’aden) was founded to exploit these, as what Saudi Arabia describes as the “third pillar” of its economy (beyond oil and petrochemicals). Ma’aden’s initial move was into gold mining, and the company now runs five gold mines and has a further two under development, but more recently it has begun to move into aluminium and especially phosphate developments. These have had a profound effect on the shape of the company, as income from its phosphate operations has already come to dominate its balance sheet. And there are further expansions afoot; Ma’aden has stated that it aims to become a “decisive” player on the world phosphate stage by 2020. Keywords: MA’ADEN, SABIC, JALAMID, WUAL, KHABRA, MOSAIC

Add to basket


Looking back, looking forward

Summary

A look back at how 2013 turned out in the world of sulphur, and a look forward towards some of the important events coming up next year.

Abstract

As we near the end of 2013, perhaps there is a moment for taking stock of another eventful year before we press on into 2013. The year was one of milestones, with January 1st marking the official demise of Canada’s Prism Sulphur Corporation, once the largest marketer of sulphur in the world. Although legal winding up continued this year, the last cargo of sulphur was sold at the end of 2012. Prism’s demise is symptomatic of larger changes working their way through the sulphur industry, as North American shale gas contributes to the downfall of the Canadian sour gas industry which had been the mainstay of the world’s sulphur supply for the past 40 years. This year also saw the demolition of the iconic red and white chimneys at the Balzac sour gas plant, and there is definitely the feeling of the end of an era in Canadian sulphur production. Keywords: PHOSPHATE, ACID, OIL, GAS, MARKETS, SOUR

Add to basket


Sulphuric Acid Markets

Summary

While the big Pacific acid-consuming nickel leaching projects are all now largely up and running, the pattern of consumption across the Pacific is changing as demand is switching from Chile to the Philippines, while in North America US demand seems set to rise, possibly matched by new domestic supply.

Abstract

Sulphuric acid remains the largest chemical produced in terms of tonnage, with a market estimated at 250 million t/a for 2013. As Figure 1 shows, supply is mainly (just over 60%) from on-purpose burning of sulphur, although the involuntary component provided by the output from metal smelters also continues to increase. There is some recycling of spent acid, and in China there is a continuing output from pyrite roasting (there is some pyrite roasting elsewhere, but China represents 95% of pyrite-based acid production). Acid consumption is split fairly evenly between agricultural/fertilizer uses on the one hand (mainly via the treatment of phosphate rock to produce phosphate fertilizers) and a wide variety of industrial uses on the other. Consequently consumption is highest in countries with large phosphate fertilizer industries and with a significant industrial base. This has meant that in China, which has both of these characteristics, consumption has been rising very rapidly indeed, from 51.5 million t/a in 2006 to 85 million t/a in 2012, according to the China Sulphuric Acid Industries Association, now representing over one third of all global sulphuric acid demand. Keywords: ZAMBIA, CHINA, PERU, PHILIPPINES, SX/EW, SMELTING, PHOSPHATES, CHILE

Add to basket


Sulphur pit deflagration venting

Summary

A new paper by WorleyParsons investigates the use of deflagration vents on sulphur pits for sulphur pit explosion protection. The paper provides interpretation of the guidelines and design methods included in the applicable NFPA standards and reviews the different types of vent designs commonly used.

Abstract

While a great deal of information related to deflagration venting is available in general literature, sulphur industry literature has been noticeably silent on this subject. Many papers have been written on safe sulphur storage practices for sulphur pits, but few mention the role of explosion hatches in the overall safety scheme of the sulphur pit. Those that do, mention them only briefly and don’t discuss the specific details and challenges associated with their implementation in this service. Seeking to raise the profile of this important issue within the sulphur industry, WorleyParsons has recently written a paper on sulphur pit explosion protection for the purpose of presenting available information on the subject matter and discussing and evaluating the advantages and possible disadvantages of utilising deflagration vents on sulphur pits. This article is an abridged version of the WorleyParsons paper*. Keywords: explosion prevention, pit design, safety, NFPA standards, European standards, enclosure design, vent closure

Add to basket