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From HF to sulphuric acid alkylation

Summary

DuPont has introduced new technology for converting HF alkylation units into sulphuric acid alkylation units, while also achieving significant capacity increases. By significantly minimising capital expenses and maximising alkylate production, the DuPont™ ConvEXSM HF alkylation conversion technology makes HF conversion projects much more attractive to refiners than in the past.

Abstract

With a ban on hydrofluoric acid (HF) being considered in some parts of the US and significant doubt around the long-term viability of HF alkylation technology, refiners must consider whether additional investment in existing HF alkylation units is wise. Although HF conversion to sulphuric acid alkylation has been considered by refiners for many years, due to the risks associated with the use of HF, several factors have led to refiner inaction to date. These factors include: the perceived high cost of conversion and the lack of economic value from a conversion. Keywords: alkylation, HF, hydrofluoric acid, sulphuric acid, refiners, STRATCO Contactor, DuPont, conversion, isobutane recycle, metallurgy

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Improving sulphur plant performance

Summary

Elmo Nasato of Nasato Consulting describes some of the key design and operating parameters that are to be considered in the sulphur recovery unit, amine acid gas unit and sour water stripper unit in order to improve performance and online reliability of the SRU.

Abstract

Current trends in the characteristics of crude oil supply, petroleum product demand, and tightening environmental regulations require continuous change in the worldwide refining and gas producing industry. Refiners and gas producers are confronted with more stringent environmental, safety and regulatory requirements that must be met while maintaining very high on-line factors in a safe and highly efficient operation. Keywords: sulphur recovery unit, SRU, reliability, plant performance, design, acid gas unit, sour water stripper, TGU, instrumentation, amine regeneration unit, human error, utilities, steam, boiler feed water, blowdown, fuel, natural gas, nitrogen, instrument air, electricity

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CPC refineries improve SRU reliability

Summary

Taiwanese refining corporation CPC has installed DynaWave® scrubber technology in sulphur recovery units at two of its refineries to provide a low maintenance, efficient and flexible emission control system that is easy to operate and achieves very high SO2 removal efficiency.

Abstract

Refineries around the world are faced with the challenge of meeting increasingly stringent SO2 emissions regulations from their sulphur recovery units (SRUs), while minimising their capital and operating expenditure. The reliability and efficiency of the SRU and its tail gas treatment process is key to meeting emission targets, minimising maintenance requirements and operator time. Keywords: refinery, CPC, SO2 emissions, sulphur recovery units, DynaWave, scrubber, Taiwan, MECS, DuPont, wet gas scrubbing, reverse jet scrubber

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Meeting capex, opex and emissions challenges

Summary

To help customers address increasingly stringent capital expenditure (capex), operational expenditure (opex), and emissions challenges in a competitive marketplace, MECS continues to engineer creative and cost-efficient solutions to maximise heat recovery in sulphuric acid plants.

Abstract

MECS has been designing and improving sulphuric acid plants and related processes since 1917. Technologies such as MECS’s Heat Recovery System (HRS™) allow customers to gain more value from their plant by recovering heat from the formation of acid and transforming that energy into intermediate-pressure steam. As emissions requirements become increasingly strict and capex becomes tougher to control, companies in the sulphuric acid industry want heat recovery solutions that offer them both reliability and value. This can be difficult to achieve, especially with regards to maximising heat recovery in a plant while minimising capital cost. Keywords: heat recovery, sulphuric acid, HRS, SteaMax, steam injection, SolvR, MECS, boiler, MAX3, regenerative process, single absorption, steam export, customisation

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Enhanced HEROS™ for better safety

Summary

Outotec has introduced an improved, safe and robust HEROS™ concept, which will enhance the acceptance and reliability of heat recovery systems in the industry. Stefan Brauener of Outotec describes a reference case in a metallurgical sulphuric acid plant where it has demonstrated its reliability over the past three years under various operating scenarios, i.e. gas flow and SO2 fluctuations induced by the upstream smelter operation.

Abstract

Outotec’s heat recovery system, known as HEROS™, was first introduced to the industry in 1989. It was developed with particular emphasis on ease of operation and high safety standards. The key element of the system is a venturi absorber with a dedicated acid circulation system that is installed upstream of the intermediate absorption tower (see Fig. 1). Heat generated in this system is transformed into low-pressure steam in a specially designed boiler. Keywords: HEROS, safety, heat recovery, reliability, sulphuric acid, smelter, metallurgical acid plant, Outotec, venture, FiDi, acid distribution, corrosion, alloy, stainless steels, boiler, loss prevention

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Steam or water?

Summary

Chemetics provides a number of solutions to extract more of the energy released from the production of sulphuric acid. R. Dijkstra of Chemetics gives an overview of these process systems and how each is designed as an independent system from the main process.

Abstract

Extracting more of the energy released during the production of sulphuric acid is increasingly important to create additional revenue for plant operators. Chemetics has developed a family of process add-on systems that recover additional energy without causing a reduction in plant availability. Marketed as Chemetics Energy Solutions (CES), they provide options for production of low pressure steam, preheating boiler feed water upstream of the deaerator and for the production of hot water. Keywords: energy, steam, water, sulphuric acid, Chemetics Energy Solutions, CES, ALPHA System, dew point temperature, multiple effect distillation, MED, desalinated sea water

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Safely increasing energy generation

Summary

Clark Solutions' SAFEHR® heat recovery technology is a new approach to sulphuric acid production which addresses issues and concerns with regard to corrosion, shutdown and hydrogen explosions to make heat recovery safer than conventional operation. Nelson Clark describes the SAFEHR® technology, benefits and uses to help the acid plant operator recover energy efficiently and safely.

Abstract

Sulphuric acid plants are energy producers. Sulphur burning and spent acid recovery plants burn sulphur or fuel to produce SO2 gases while generating heat. The reaction of oxidation of SO2 into SO3 is also exothermic and produces heat. Finally, both moisture and SO3 absorption into the strong acid generates heat along towers packings. The major exothermic reactions on which heat is generated in a typical plant are: Sulphur combustion: S + O2 → SO2 Keywords: heat recovery, Clark Solutions, SAFEHR, safety, sulphuric acid, corrosion, hydrogen explosions, shutdowns, sulphur burning plant, heat generation, isocorrosion curve, CS fluid, intermediate cooling, materials of construction, steam production, energy options, steam system

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Phosphate market outlook

Summary

Phosphate processing remains the key demand segment for sulphur and sulphuric acid. In spite of overcapacity in the phosphate market, new plants in the Middle East and North Africa are poised to add more acid demand over the coming years.

Abstract

While its industrial uses, particularly for metals processing, are a large slice of sulphuric acid demand, as detailed elsewhere in this issue, the processing of phosphates, mainly for fertilizer use, continues to represent the majority of sulphuric acid demand – something around 55%, of which 90% is accounted for by fertilizer demand. Keywords: P2O5, MOROCCO, OCP, SAUDI ARABIA, MAADEN, MA’ADEN, MPC, TUNISIA, JORDAN, EGYPT, BRAZIL, INDIA, PHOSPHORIC, PPA, SUPERPHOSPHATE, SSP

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Sulphur in South America

Summary

Changing patterns of leaching and smelting in Chile and Peru's copper industries, the growth of Brazil's phosphate fertilizer demand and troubles in oil major Venezuela are contributing to changing supply and demand patterns across the continent.

Abstract

South America’s sulphur industry ranges from sulphur production from refining, consumption in fertilizers and sulphuric acid generation and consumption from the region’s extensive copper smelting and leaching operations. The region had been forecast to be a major rising star in the global economy, but the past few years have seen the economy stagnate during 2015 and even contract by 1% during 2016. Keywords: VENEZULEA, OIL SANDS, REFINERY, FAJA, BRAZIL, PHOSPHATE, SSP, DAP, CHILE, PERU, TIA MARIA

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Metal markets and acid production

Summary

Low prices for copper and nickel have dramatically scaled back mining projects, especially on the leaching side, but smelter capacity continues to increase in China and Indonesia.

Abstract

Out of total global sulphuric acid production of around 260 million t/a, the amount represented by metallurgical acid was just under 80 million t/a in 2016, or just over 30%. This acid is generally the product of smelting to recover ores of ‘base metals’ – a catch-all term for all non-precious metals, including iron, nickel, copper, zinc, lead and aluminium. Smelting of oxide ores like iron typically uses carbon as a reducing agent and generates carbon dioxide, but smelting of sulphide ores is an oxidative process which generates sulphur dioxide. Keywords: COPPER, NICKEL, ZINC, LEAD, SMELTING, SMELTER, LEACH, INDONESIA, FREEPORT, CHINA, MEXICO, PERU, CHILE

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