Tag: Safety

The fact that biuret is toxic to plants has been known for a long time – since the middle of the last century. Very sensitive (pineapple, citrus), moderately sensitive (cereals, legumes) and resistant (conifers) plant species were identified. The maximum concentration of biuret in urea for each species has been established for soil application and foliar application. Most field crops easily tolerate foliar fertilization with urea, which contains 1 wt-% biuret. Potatoes and tomatoes are more sensitive – for foliar feeding of these crops, it is advisable to use urea with an admixture of biuret of no more than 0.5 wt-%. Citrus fruits and pineapples are so sensitive that biuret in urea for foliar feeding should be no more than 0.35 wt-%.

Corrosion is one of the most critical aspects regarding sulphuric acid plant lifespan. One important cause of corrosion in sulphuric acid plants is acid condensation from the process gas due to inadequate drying. E. Almeida, B. Ferraro, N. Clark, V. Machida and V. Sturm of Clark Solutions discuss this problem and how it can be avoided with proper tower and internals design.

John M. Bryant , President and CEO of The Sulphur Institute, looks at how the sulphur supply chain has reacted to the extraordinary circumstances of the pandemic over the past 18 months, and the key principles of a successful sulphur supply chain.

T. Hentrich and B. Nowak of VDM Metals provide an overview of the development of VDM® Alloy 699 XA, a new generation, metal dusting resistant alloy, available in a wide range of product forms, for demanding applications in the chemical process industry.

The heart of any urea plant is the high-pressure urea synthesis section. Properly functioning safety valves are vital to protect the high-pressure section against ruptures due to pressures that are too high in case of upset conditions. However, the very corrosive intermediate ammonium carbamate makes the reliable and proper functioning of safety valves more challenging.

The internals of ammonia synthesis converters are generally made of austenitic stainless steel to withstand the harsh operating conditions (high temperature, high pressure and synthesis gas containing hydrogen and ammonia). Since nitriding is the most critical material degradation for the converter internals, Casale has set up a large nitriding analysis campaign. In the last decade, samples of materials operated under different pressures and temperatures and for different time spans have been tested and analysed. The data obtained has been used to increase nitriding knowledge and to establish a correlation to predict nitriding rate to allow the most suitable material and relevant thickness to be selected. L. Redaelli and G. Deodato of Casale report on how this correlation was established and provide valuable insight on this phenomenon and how to predict and control it.

The continuing spread of alkylation technology and the preference for the sulphuric acid route are leading to increased demand for acid in refineries.

Temperature monitoring and measurement of the Claus thermal reactor in sulphur recovery units is one of the most challenging applications in the oil and gas industry. Recently, market interest in unpurged thermocouples has increased with the introduction of new unpurged thermocouple designs utilising alternative thermowell materials such as monocrystalline sapphire.

In August 2020 the tragic explosion of ammonium nitrate fertilizer in the port of Beirut caused many fatalities and injuries. This was a wake-up call for the entire industry to review the design of plants and storage facilities, as well as the procedures for plant operation and the handling of products. The key factor for safe new installations is the process design: the right choice of unit operations, operating temperatures and pressures, the control of process variables and the design of key items of equipment. A modern ammonium nitrate (AN) plant design not only mitigates the environmental impact, but also reduces investment costs and contributes to the key factors mentioned. M. Pieper and P. Kamermann of thyssenkrupp Industrial Solutions discuss how, by using the right design, safety in ammonium nitrate plants can be easily achieved, while maintaining outstanding product quality.

N. Clark, B. Avancini and V. Sturm of Clark Solutions discuss a novel technology, SAFEHX® , providing a new approach to the cooling of strong sulphuric acid. Prototype results are shown and indicate a safe and stable cost-effective technology. SAFEHX® can be extended to every heat exchanger system where corrosion, mixture risks, fouling, process liquid loss (or contamination) and temperature control are key concerns.