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Summary
Highlights of the ASRL core research program – sulphur recoveryAbstract
The ASRL basic research program focuses on many aspects of sour gas production, sulphur recovery and handling. Space limitations here preclude a description of all of these programs (Figure 1) so, given the continued drive to improve the economics of sulphur production, this report concentrates on ASRL research which is aimed to improve the economics and engineering of sulphur plants. In essence, these potential technologies, if translated to the field would increase overall sulphur recovery and thermal efficiency and decrease emissions. These research programs are selected by the ASRL members through its Technical Advisory Committee and include new options for handling poor quality acid gas laden with BTX, a novel approach to tail gas treatment, catalytic tail gas incineration, degassing of liquid sulphur and concrete corrosion in liquid sulphur run-down systems.
Let’s start with low quality acid gas processing, although please remember, these projects are works-in-progress with lots of research still on the laboratory bench.
Summary
BAYQIK® is a new process using an innovative, multi-tube reactor for treating high-grade SO2 gases from non-ferrous metallurgical plants. The process offers a variety of economical and process benefits, including the reduction of both capital investment and operating costs. T. Weber, M. Kuerten, B. Erkes and K. Stemmer of Bayer Technology Services GmbH discuss the process concept and its recent succesful implementation in a smelter process.Abstract
Sulphuric acid produced from sulphur dioxide (SO2) has been one of the most important basic chemicals since the very early years of the chemical industry. Despite encountering a number of problems in the development of an industrial-scale process, Bayer AG has never given up in its efforts to improve the production process for this chemical. Up to now, the zenith of these efforts was the development and granting of the patent for the double contact process for converting SO2 to sulphur trioxide (SO3) in 1960. Today, this process still represents the state of the art for this process sector, regardless of the feedstocks that are used.
The feedstocks presently used for producing SO2 consist basically of elemental sulphur, sulphide ores, such as Cu2S, PbS, etc., or are created from the thermal cracking of liquid wastes containing sulphuric acid.
Summary
To coincide with Sulphur 2009 in Vancouver, Sulphur presents a brief overview of leading companies in the Canadian sulphur industry.Abstract
Companies looked at are:
Summary
The Central Florida Section of the American Institute of Chemical Engineers (AIChE) held its 33rd Annual Clearwater Convention at the welcoming venue of the Sheraton Sand Key Resort on Clearwater Beach on 12-13 June. An examination of current issues in sulphuric acid and phosphoric acid technology prompted the familiar lively exchange of views and ideas.Abstract
Welcoming participants to the 2009 Clearwater Conference, Chair Robert Andrew said, “Our Central Florida Chapter has worked hard to organise the conference and we want your experience to be great!” His wish was assuredly fulfilled as this year’s meeting again met the goal of convening a forum for the exchange of ideas and viewpoints in a relaxing ambience.
The 2009 Clearwater meeting was held on Friday and Saturday, 12-13 June and comprised two half-day sessions. The conference began with the 12th Annual Sulphuric Acid Workshop, which was again expertly chaired by Rick Davies and Jim Dougherty. The topic this year was the Design, Implementation and Maintenance of Storage Tanks. This embraced sulphuric acid tanks, molten sulphur tanks and spent acid storage tanks and took the form of presentations from four industry experts, followed by a panel discussion.
Summary
By quantifying the payback time of the investment, this article shows that low grade heat recovery using plate heat exchanger technology can be very profitable for a sulphuric acid plant. What you need, say Magnus Edmén and Erland Elwin of Alfa Laval, is a large, low temperature energy consumer, such as a zinc or copper plant, nearby.Abstract
A 1,000 t/d sulphuric acid plant releases around 65 MW of heat. Around one-third of the heat is released from absorption and drying towers at low temperatures. Most plants waste this low temperature heat to cooling towers, rivers or the air. In order to make recovery of low temperature heat profitable, a large low temperature energy consumer nearby is needed.
A simplified flow chart of the considered low temperature heat recovery system is shown in Fig. 1.
Summary
Often an overlooked area of refinery output, bunker fuels will see a radical shake-up over the next decade.Abstract
Marine fuel accounts for a large percentage of a vessel’s annual operating cost due to the large fuel consumption required by the vessel’s engines. Shipping lines study the bunker fuel market to make decisions as to where to buy the fuel based on price. However, they are about to get a whole new series of factors with which to juggle.
Summary
MECS Sulfox is a new joint venture formed by MECS Inc. and Kanzler Verfahrenstechnik GmbH (KVT) to offer a unique wet acid process to the market. The Sulfox process is a highly energy efficient technology, developed by KVT more than 15 years ago, for cleaning waste gases containing sulphur compounds that produces a saleable product, i.e. sulphuric acid.Abstract
By combining MECS’s vast experience in the design and construction of sulphuric acid plants (over 900 built worldwide) with KVT’s innovative equipment design, MECS SULFOX is able to offer a very reliable and proven sulphuric acid plant for gas desulphurisation and sulphurous waste regeneration. The individual plant is designed according to the feed gas concentrations and customers’ requirements while keeping the investment and operating costs as low as possible.
Summary
Venezuela's oil and tar sands, Brazil's agriculture and rapidly developing economy and Chile's copper mining form a triangle of sulphur and sulphuric acid production and consumption across this large and diverse continent.Abstract
South America is a large and diverse region and its industries cover many of the diverse facets of the modern sulphur industry. There is major metal mining and smelting, in Chile and Peru, with associated sulphuric acid production and consumption, considerable oil production and refining capacity in Venezuela and Brazil, large-scale phosphate use and fertilizer demand – particularly in Brazil – and the wild card of Venezuela’s Orinoco tar sands to top things off.
Summary
Jim Beres and Franco Chakkalakal of Tyco Thermal Controls explore the physical properties of sulphur and present the basic features of safe pipeline transport of liquid sulphur employing skin effect heating with fibre optic distributed temperature sensing technology. Also included are observations from a recently completed large sulphur pipeline project which incorporates these technologies.Abstract
Today’s demand for energy has resulted in intensive search for oil of all grades and compositions. As many of the process crudes commonly found are sour, large quantities of sulphur result. However, sulphur demand is far less than the global quantities produced. This scenario has compelled producers to transport sulphur to offsite locations, jetties and other remote locations for storage, palletising or transportation.
Heated sulphur pipelines have been a continual challenge to the industry because molten sulphur operates within a tight temperature window, often within 30 to 40°C. To pump sulphur efficiently, a minimum of 5°C over the sulphur solidification temperature is needed, but if heated to an excessive temperature the sulphur becomes too viscous to transport. Another important consideration is the challenge of re-melting solidified sulphur in the pipeline. Recently, there is an increased preference for these pipelines to be buried underground to safeguard against terrorist attacks and to enhance reliability and safety.
Summary
Hellenic Petroleum S.A. is installing a sulphur granulation and handling plant as part of its upgrade to the Elefsis refinery in Greece. Sandvik Group reports on the installation.Abstract
Hellenic Petroleum S.A, one of the largest commercial and industrial groups in Greece, is an energy company primarily engaged in refining and marketing of petroleum products, petrochemicals, power production and natural gas in south-eastern Europe. The company operates three refineries – in Thessalonica, Elefsina and Aspropyrgos – which, between them, account for around 73% of Greece’s total refining capacity.
Summary
CS Combustion Solutions GmbH is introducing a new generation of spent acid oxidation facilities. The horizontal construction and unique design of CS combustion chamber components create new possibilities for the refitting, optimising and debottlenecking of existing facilities used for separating sulphuric acid.Abstract
Up to now, the facilities used to effectively complete the oxidation process of spent acid when separating sulphuric acid has consisted of a heating system containing a standing combustion chamber built in two separate sections. A burner for pre-heating/support combustion along with nozzles for injection of sulphuric acid is positioned at the beginning of the first section of the combustion chamber. In this system the spent acid is injected top down in the first chamber section where it is vaporised, after which it is carried into the second chamber section where it is oxidised. The two chamber sections are linked with another shorter horizontal connecting element. The space, materials and residence time for flue gas necessary with this long established process is considerable because of the many steps required in separating the sulphuric acid.
Summary
Brandon T. Vincent and Thomas C. Willingham of Controls Southeast, Inc discuss the importance of adequate heating to prevent plugging and corrosion problems in sulphur tail gas lines and compare the economics of ControTrace versus tube tracing.Abstract
Throughout the world, refineries and natural gas plants utilise large-bore piping systems to transport hot tail gas. Tail gas is a by-product of an equilibrium-limited Claus reaction designed to convert H2S to elemental sulphur. Its chemistry generally includes N2, H2O, CO2, and a variety of sulphur compounds such as H2S, SO2, Sx, COS, and CS2. Tail gas flows from the last sulphur condenser to the tail gas unit (TGU); during upset conditions, tail gas can bypass the TGU to go directly to the incinerator. Tail gas processing can be frustrated by plugging and corrosion in the piping. Figure 1 shows a tail gas line failure due to plugging at a butterfly valve. Figure 2 shows a tail gas line from another plant which failed due to extreme corrosion. Corrosion in a tail gas line can be quite aggressive, and rates as high as 0.75 mm/month have been recorded. Tail gas processing varies from plant to plant due to differences in licensed technology, feedstock chemistry, and site operations. This variability contributes to a lack of industry consensus on the root cause mechanisms of tail gas line failures. However, it is generally agreed that inadequate heating is a contributing factor to tail gas line failure.