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RAR: a multipurpose technology

Summary

RAR Claus tail gas treatment satisfies the most demanding environmental requirements in refineries and in gas fields. Luciano Sala of Technip KTI highlights the main features of the process, its applications, and the possibilities of integration with existing facilities in order to optimise the investment and operating cost.

Abstract

Refiners are facing more stringent specifications on motor transportation fuels and greater demand for lighter product mix to be produced from a heavier crude slate. These developments are leading to the reconfiguration of refining processes with greater use of hydroprocessing to upgrade oil into light transportation fuels and to improve the fuel quality.

More hydrotreating and increased processing severity is required for removing sulphur and nitrogen compounds from fuels to meet environmental regulations.

The resulting increase in production of hydrogen sulphide and ammonia places new demands on the processing capability of the sulphur recovery units in refineries.

Greater demands are also being made on the processing capability of sulphur recovery facilities in natural gas treatment, where growing quantities of gas with higher sulphur content are extracted to satisfy ever increasing demands worldwide.

The introduction of more severe sulphur requirements for oil refinery products and the additional production of natural gas has forced refineries and gas fields to expand the capacity of existing sulphur recovery units and to install new units.

All these units are a source of substantial SO2 emissions, which are strictly controlled by the public authorities. Require­ments of the authorities vary considerably from country to country but regulations for the sulphur recovery unit efficiency are much stricter now than in the past.

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Increasing acid plant capacities

Summary

In the sulphuric acid industry, recent trends to expand plant capacities involve avoiding extended shut­downs and reducing the pressure drop of equipment throughout the acid plant. Lisa Connock reports.

Abstract

Nowadays, companies have become more focused on reducing operating costs and maximising plant efficiency and output, while at the same time minimising capital expenditures. This trend is particularly noticeable in the sulphuric acid industry, where operators face pressure to expand plant capacity through incremental modifications, rather than the installation of new capacity. In addition, sulphuric acid plant operators are under constant pressure to reduce emissions, increase energy efficiency and increase plant availability by eliminating maintenance issues that can cause unscheduled shutdowns. However, in order to conduct modifications to counter these issues, an extended shutdown of the plant is required, which invariably means a direct loss of production.

This is particularly an issue for metallurgical plants, where modern smelter technology is allowing longer runs between major overhauls, so a shutdown in the acid plant for maintenance quite often means a forced suspension of metal production. The problem of sulphuric acid plant stoppage is made worse by modern environmental regulations that do not allow the smelter to operate unless the acid plant is operating normally.

There are a number of retrofit strategies that can be used to reduce the length of a shutdown.

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Take two…

Summary

When faced with the need to increase sulphur removal capacity to comply with environmental regulations, refiners may consider the possibility of duplicating an existing sulphur recovery unit or investing in an off-the-shelf design. Sulphur investigates the two approaches and highlights key considerations.

Abstract

Refiners around the world are faced with the need for additional sulphur removal capability. The public and environmental agencies are dictating a lower level of SO2 emissions. Worldwide, the ­advent of low sulphur gasoline and low sulphur diesel production has created a need for additional sulphur recovery capacity.

The economics of an environmental pro­cess are complex. As sulphur recovery units are not profit generators, refiners typically do not want to invest a lot of capital; however, the reliability requirements of the units are quite high. When the sulphur recovery unit is out of service, the refinery operations must be cut back or units shut down, severely impacting refinery revenues.

In addition, refiners can suffer penalties, both monetary and damage to reputation, if they are not operating within the defined limits of their environmental permits. The inability to consistently meet environmental permits can have implications on the ease of future permitting for plant expansion and continued operation.

The challenge is to find the right balance of capital investment and reliability to ensure that the sulphur recovery unit does not impair the refinery from realising its full commercial potential. Two approaches will be discussed: sulphur plant cloning and off-the-shelf sulphur recovery units.

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Chemical registration moves within reach

Summary

Rules to introduce an EU-wide registration procedure for chemicals producers has passed its first hurdle. Sulphur reports on what looks to be the final shape of REACH.

Abstract

It’s quite a conondrum – how to protect people and the environment from possible risks introduced by the chemicals industry while at the same time trying to protect the chemicals industry from undue vulnerability to external competition as a result of too much red tape. Through the usual process of compromise in the European Union’s 25-­nation talking shops, the legislation that aims to achieve this remarkable balancing act, REACH (registration, authorisation, evaluation of chemicals) seems to be making headway.

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Moscow sets the agenda for markets

Summary

Moscow proved to be a popular venue for the Sulphur 2005 conference, where delegates heard about the chief issues affecting buoyant markets for sulphur and sulphuric acid.

Abstract

Another relatively steady year for prices, with no sign of a supply glut on the horizon, could have meant a quiet day for the markets sessions of Sulphur 2005. Whilst all seemed agreed that the medium-term outlook was for more of the same, the opening of the conference was marked by storm warnings for the century’s second decade from Canadian speakers. Bill Kennedy of Shell Canada put out a call for the industry to pay attention to predictions of future prospects for severe over-supply, and went on to describe some of the applications that Shell is backing to absorb some of the world’s possible future surpluses.

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