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Weighing up the options for acid cooling

Summary

For decades, anodically proctected (AP) stainless steel, shell-and-tube coolers have been the traditional, reliable and economic choice for acid cooling applications in the sulphuric acid industry. Over the past ten years non-AP, high silicon (Si) alloy acid coolers have been gaining acceptance in the industry due to their ease of operation and reduced maintenance, but which is the better option?

Abstract

Acid cooling in a sulphuric acid plant is primarily accomplished with one of three heat exchanger options: anodically protected (AP) stainless steel heat exchangers, high silicon (Si) alloy heat exchangers, or plate and frame heat exchangers. There are pros and cons to each choice depending on the size of the cooler and site specific requirements. Each sulphuric acid cooler application is unique and requires careful consideration of all the variables. This article explores the benefits and potential pitfalls of the two most popular options, AP acid coolers and high Si alloy acid coolers. Keywords: anodically protected coolers, alloy coolers, metallurgy, corrosion, cooling water, cooler failure, stress corrosion cracking, pitting.

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Extending the life of sulphur recovery units

Summary

A plant that has been well designed and fabricated, is operated and maintained well and equipped with all necessary tools can easily reach a life of 40 years. In this article KT and Jacobs Comprimo® Sulfur Solutions discuss how to maximise the life of sulphur recovery plants.

Abstract

Historically, sulphur recovery units (SRUs) have been considered as a source of problems for plant operation and in many cases just an imposition of the environmental authorities. The trend towards “zero emissions” and total respect for the environment has become a focus for all industrial complexes and is strongly linked to the primary target of plant profitability. Since acid gas flaring is no longer tolerated or allowed, any potential problems affecting the SRU is considered a potential loss of profit. Keywords: plant design, SRU life, corrosion, catalyst life, welding, amine degradation, ferrule, oxygen enrichment, furnace temperature measurement, engineered refractory, thermal maintenance, sulphur pit, caustic scrubber.

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Sulphur pits for durable service

Summary

Subsurface reinforced concrete sulphur pits can provide excellent service for many years. Thomas Kline of Structural Technologies discusses original reinforced concrete design aspects, detailing and materials of construction. Common pitfalls in design, detailing and construction defects that shorten service life and actions to correct original design/construction deficiencies prior to commissioning a new subsurface reinforced concrete sulphur pit are highlighted.

Abstract

For decades, molten sulphur containment has been successfully provided by reinforced concrete structures placed in the ground for process stream delivery. These subsurface sulphur pits temporarily accommodate elemental sulphur extracted from the hydrocarbon process stream. The structures then convey the molten sulphur via suction pumping to various modes of transportation that can include barges, railcars or tanker trucks. Keywords: sulphur pit, materials of construction, concrete steel reinforcement, water stops, sealants, drainage.

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Copper and sulphuric acid

Summary

The copper industry has a major influence on sulphuric acid markets on both the demand side, for leaching, and on the supply side, for smelting. With the copper industry in the doldrums, Sulphur looks at the impact on sulphuric acid markets.

Abstract

Around one third of all sulphuric acid production comes as a by-product from smelting of primary metals, especially copper. With regulations on emissions of SO2 from smelters continuing to tighten around the world, this means that almost any new smelting capacity will generate more acid. On the debit side, the share of acid for metal leaching as a component of overall sulphuric acid demand is not as great – around 10% of all acid demand, of which around two thirds goes to copper extraction. Although copper production via leaching has grown faster than smelting over the past couple of decades, it still only accounts for around 20% of copper production. Keywords: CHILE, DRC, GLENCORE, XSTRATA, SX/EW, FREEPORT

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Refinery sulphur recovery – an Indian perspective

Summary

Prajwal Adiga and Nilesh Mangukia, Linde Engineering India Pvt Ltd, look at the impact of tightening sulphur fuel regulations and increased fuel demand on Indian refiners.

Abstract

India’s rapid growth and urbanisation has also put a number of its cities on the World Health Organisation’s list of highly polluted cities. The government has therefore mandated a jump in fuel sulphur standards from Bharat Stage IV to VI (equivalent to Euro 6 fuel specifications) by April 2020. This will require a cut in sulphur content of fuel from 50 ppmw to 10 ppmw. This deeper sulphur removal challenges the capacity of currently operating sulphur recovery units (SRUs) across Indian refineries. This article is a theoretical case study of one such refinery SRU requiring a revamp to enhance sulphur handling capacity. Keywords: HYDROTREATER, DHT, DHDS, CAPEX, OPEX, OXYGEN, ENRICHMENT, O2

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Sulphur-assisted carbon capture and utilisation

Summary

Gary Albarelli and Mike Lloyd of the Florida Industrial and Phosphate Research Institute describe work conducted with researcher Bogdan Wojak which has opened up the possibility of recovering CO2 for carbon capture and utilisation via sulphur intermediates.

Abstract

The unrelenting rise in coal use without deployment of carbon capture and storage (CCS) is fundamentally incompatible with climate change objectives. The world faces an unabated global demand for energy, both for livelihood and for pure economic growth, as well as an existing, sizeable, carbon-intense infrastructure. There is no rational near-term energy future that does not involve continued use of fossil fuel. Maintaining coal-fired power generation would make practical sense if control of carbon dioxide could be made affordable. Keywords: HYBRID, WESTINGHOUSE, THERMOCHEMICAL, CYCLE, EQUILIBRIUM, DEPOLARISED

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US taps into new sulphur sources

Summary

Mosaic's new million tonne sulphur melter at New Wales in Florida has the potential to radically change the US sulphur market by allowing access to large tonnages of solid sulphur from overseas.

Abstract

Formed from the merger of Cargill and IMC Global, and supplemented by its 2014 purchase of the phosphate assets of CF Industries, Mosaic is the world’s largest producer of finished phosphates, with an annual operational capacity of 11.7 million t/a of processed phosphates (including DAP, MAP, animal feed, and its MicroEssentials speciality nutrient). It also has the capacity to mine 16 million t/a of phosphate rock in Florida, second only to Morocco’s OCP in size. The company is also North America’s largest single buyer and consumer of sulphur. At the start of 2016 it completed work on a new 1 million t/a sulphur melter at its New Wales site near Mulberry, Florida, which means that the company can now take solid sulphur as well as the liquid cargoes it has been used to. Keywords: MODULAR, TAMPA, FLORIDA, PHOSPHATE, CTI, CRESCENT TECHNOLOGY, MARKET, CONSTRUCTION, COMMISIONING

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Do oil prices affect sulphur production?

Summary

While the precipitous drop in oil prices in 2014-15 has led to many project postponements and delays on upgrading and processing plants in the heavy oil/oil sands sector, will there actually be a significant effect on overall sulphur production?

Abstract

The slowdown in the Chinese economy has had a huge knock-on effect on oil prices, coming as it did at the same time as a surge in oil supply from a number of different sources, but most particularly from US tight oil production, extending the fracking techniques developed in gas extraction into oil-bearing shales. However, what has really kept oil prices at their current relatively low level for the past year (see Figure 1) has been Saudi Arabia’s decision to continue to keep pumping oil in order to maintain or gain market share. So, given that 48% of sulphur production comes from refining of crude, does the crude price have any impact on sulphur production? Keywords: SANDs, REFINERY, USA, TIGHT OIL, SHALE, PADD, VENEZUELA, IEA, EIA

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