Category: Technology

All acid towers eventually require replacement. In this article, K. Sirikan, A. Mahecha-Botero et al of NORAM Engineering and Constructors Ltd discuss two recently executed acid tower replacement projects. The first project involved the replacement of a brick-lined tower by an alloy acid tower for a sulphur burning plant in North America. The second project involved the replacement of a brick-lined acid tower with a NORAM designed brick-lined tower for a smelter off gas acid plant in South America. The impacts of various design considerations on acid tower replacement projects are compared, including in-situ replacement versus a new location; brick-lined versus alloy shell, and selection criteria for mist eliminators.

Prayon’s Hadrien Leruth and Marc Sonveaux highlight the latest phosphate production developments at the company – and share their experience of how innovative ideas are validated, industrialised and turned into commercially-viable technologies.

Newly-developed froth flotation equipment and reagents are improving selectivity and the grade and recovery of phosphate concentrates.

NOx emissions from chemical processes such as steam methane reforming contribute to air pollution. The chemical industry is required to take steps to lower such emissions. Technology, developed for related industries, can be designed and optimised to reduce NOx emissions from steam methane reformers. Emission control experts can use a combination of modelling and experience to guide plant operators in recommending and designing optimum, sometimes tailor-made solutions. In this article different options are discussed including low NOx burners, selective catalytic reduction, selective non-catalytic reduction and high emissivity ceramic coatings.

Dr MP Sukumaran Nair, policy analyst and director of the Centre for Green Technology & Management in Cochin, India, discusses the ways that digitisation is improving fertilizer plant operation.

In a carbon-constrained world, carbon capture and utilisation or storage (CCUS) installed on a methanol plant is a necessary and feasible solution. The new, patented AdWinMethanol CC® technology, jointly developed by thyssenkrupp Industrial Solutions AG and GasConTec GmbH, integrates carbon capture into large-scale, natural gas-fuelled methanol production to yield a drastically reduced carbon footprint. U. Koss and W. Balthasar of GasConTec and J. Wagner of thyssenkrupp Industrial Solutions discuss how it removes CO 2 emissions in an efficient, cost effective, and environmentally friendly manner, taking advantage of the design features of AdWinMethanol ® .

Process and simulation models can be valuable tools when troubleshooting to solve operational issues in sulphur recovery units. Two examples are provided. In the first case study it is shown how a tuned model was useful in troubleshooting an SRU that was experiencing lower than expected recovery efficiency and apparent channelling in the first catalytic converter. In the second case study an SRU simulation tool is used to investigate sulphidic corrosion in a waste heat boiler.

Selecting the right catalysts for the SO2 converter in a sulphuric acid plant has always been about balancing expenses, gains, and compliance. With increasing demands for sustainability and in challenging economic times, operators need to adjust their plants to get even more from less. This has led to market demand for new catalytic solutions that offer better productivity and a lower climate footprint, all at the lowest cost possible. Catalyst design and formulations continue to evolve with Haldor Topsoe, DuPont Clean Technologies and BASF all adding new types of sulphuric acid catalysts to their portfolios.

Failure investigations, equipment design and process upgrade projects for SRUs often overlook the impact of water quality. In this article E. Nasat o of Nasato Consulting and L. Huchler of MarTech Systems explore impacts of higher heat transfer rates, control of boiler and condenser water chemistry, conventional equipment design/configurations and monitoring program designs. SRU operators can improve the effectiveness of their failure investigations by implementing a broader, more holistic approach that assesses equipment design, process conditions, operating protocols and water quality issues.

Several highly corrosion resistant materials are available today for use in handling process fluids encountered in the production of concentrated sulphuric acid. These alloys, properly selected for the operating conditions, provide the benefits of long operating life under harsh operating conditions extending the period of uninterrupted production cycles and lowering the incidence of catastrophic equipment failure. In this article, M. J. Cooke of Weir Minerals discusses materials of construction for pumps, valves and piping used in the production of sulphuric acid.