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Publication > Issue > Articles

Facing new challenges

Summary

Although buoyed by record prices and margins, US refiners face technical, environmental and legislative challenges going forward.

Abstract

Over the past few years, the US refining industry has faced a number of challenges, from the disruption wrought by hurricanes Rita and Katrina to the challenges presented by tightening environmental legislation and even public concerns over pricing.

Speaking at the National Petrochemical & Refiners Association (NPRA) meeting at San Antonio, Texas in March this year, NPRA Chairman Jim Mahoney, VP of Operations for Koch Industries, enumerated the challenges facing US refiners. “So far this year, legislation that eliminates economically sound tax incentives has passed the House and awaits Senate action. Both chambers of Congress are considering legislation that mandates vast increases in renewable fuel content and purports to address climate change through emissions reductions and cap and trade mechanisms. Price-gouging legislation that could result in major adverse market impacts has also been introduced. And although the 109th Congress passed modest legislation that opened up a relatively small area of the Outer Continental Shelf for development, there remains a pressing demand for more access to available domestic natural gas reserves to help maintain the competitiveness of the petrochemical and other US manufacturers. On the regulatory front, proposals to further tighten National Ambient Air Quality Standards for ozone are being given serious consideration, and we expect final chemical security regulations early in April. Individually, any one of these actions will have major impacts on our businesses. Taken collectively, they represent perhaps the greatest challenges we may ever face.”

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Biofuels and BTL

Summary

Biofuels were the watchword at the 8th European Fuels Conference, held from March 14th-15th at the Westin Hotel, Paris

Abstract

The EU biofuels directive was adopted in 2003, and seeks to mandate a 5.75% target market share for biofuels by 2010. Although many have felt that the target was a (deliberately) ambitious one, pressure to meet the target is increasing as time passes, and so it was perhaps no surprise that the major concern at the European Fuels Conference was whether and how the target could be reached, and what steps European refiners might have to take in the light of that and Europe’s continuing surplus of gasoline and deficit in diesel.

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A new Russian portal

Summary

The Ust-Luga Multi-Purpose Terminal envisages a major increase in Russia's ability to handle dry bulk and other freight via the Baltic Sea. The latest stage in this ambitious project is about to come on stream, with the impending inauguration of the European Sulphur Terminal (EST). This terminal is being equipped with state-of-the-art bulk handling equipment that will meet the highest environmental standards.

Abstract

The impending inauguration of a modern sulphur handling terminal marks the latest stage in the development of the new Ust-Luga Multi-Purpose Terminal. This is a project which is of considerable economic and strategic significance to Russia, which envisages a total freight turnover of up to 35 million t/a – a considerable increase on the capacity offered by Russia’s principal Baltic port of St. Petersburg, which has handled around 28-30 million t/a. The project has the support of the European Bank for Reconstruction and Development (EBRD).

The Multi-Purpose Terminal is being developed to consist of dry bulk cargo transhipment facilities, a container terminal, and RoRo/ferry facilities. The project reflects the increased volumes of trade that are being conducted in the Baltic Sea region, which already had some of the busiest shipping routes in the world. Once the Ust-Luga Multi-Purpose Terminal becomes fully operational, traffic on the Baltic Sea is expected to increase by between 10-15%.

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New catalyst boosts TGTU efficiency

Summary

A new low-temperature hydrogenation catalyst has demonstrated that it boosts Claus TGTU efficiency. Among the dozen units in commercial operation, the oldest one has been operated for three years. E. Roisin, J.-L. Ray and C. NÚdez of Axens discuss the chemistry of reductive tail gas treatment and describe the main features and improved performance of the new catalyst TG 107.

Abstract

Most Claus sulphur recovery units include a reduction-based Tail Gas Treatment Unit (TGTU) that enables overall sulphur recovery yields above 99.8% to be achieved. The basic concept employed by these units is to hydrogenate all sulphur-containing species to H2S, which is in turn recycled to the Claus furnace. Various commercially available processes such as SCOT, Resulf, BSR, RAR, and HCR make use of a catalytic reduction section. The reduction step is typically performed at start-of-run temperatures around 280 °C (540 °F) through catalyst end-of-life temperatures of up to 320 °C (610 °F). This implies that the tail gas leaving the sulphur condenser in the Claus unit must be heated prior to entering the catalytic converter.

Attaining such temperatures consumes energy and may also cause operating problems1. When a direct-flame burner is used, gas composition must be kept as constant as possible to avoid oxygen breakthrough, as this would jeopardise the reduction environment in the catalytic converter. Indirect fired heating may be the solution, but it is less energy efficient. Steam reheating is difficult as the high temperatures require high pressure steam with potential problems of cost, capacity and corrosion resistance.

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Mitigating acid mist in sulphuric acid plants

Summary

Selection of the best mist eliminator device to meet specific sulphuric acid plant requirements involves careful consideration of overall mist efficiency, particle regeneration, pressure drop, service life, maintenance and installation costs. Sulphur discusses the main issues affecting mist eliminator performance and reports on current industry practices.

Abstract

Any time a liquid comes into intimate contact with a flowing gas – as happens in the sulphuric acid manufacturing process – the entrainment of liquid droplets into the gas stream generates a mist. This mist can result in process inefficiencies, product losses, and equipment damage.

The basic function of a mist eliminator is to collect and remove droplets from a gas stream. This is accomplished when the drop­lets within the flowing gas strike the mist eliminator media and are captured. The material coalesces on the media, and the larger droplets that form flow by gravity to a drainage area and are recovered.

The type of mist eliminator appropriate for a particular application is determined by the particle size of the mist to be collected. In order to select a mist eliminator and ensure that it functions efficiently, it is necessary to define the size of the droplets present in the system1. Droplets are classified based on their particle diameters:

  • sprays: larger than 10 microns
  • mists: 10 microns to 1 micron
  • aerosols: smaller than 1 micron

Depending on the droplet size, the fibres of the mist eliminator media collect droplets by three different mechanisms: inertial impaction, interception, and Brownian diffusion (see Fig. 1). During inertial impaction, large ( 20 microns) droplets traveling in a straight line deviate from the flow of the gas, strike the surface of the cylindrical fibre, and are collected as they impinge on the fibres. Interception, which applies to droplets down to about one micron in diameter, takes place when the droplets travel along the flow path but are caught (intercepted) because they cannot pass between the fibres. Brownian diffusion affects particles smaller than one micron in diameter. When gas molecules collide with small mist droplets, the droplets gain kinetic energy in the form of random motion; the smaller the particle, the greater its random motion, and the greater the likelihood that it will contact and be collected by the fibres.

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Sulphur forming plant

Summary

Sulphur's regular update of recent and scheduled projects worldwide to supply equipment for the manufacture of formed product.

Abstract

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