Shell, thyssenkrupp partner on sulfur-enhanced technology for urea

Shell and Uhde Fertilizer Technologies (UFT), part of thyssenkrupp's industrial solutions business, are partnering to integrate UFT’s fluid-bed granulation technology with Shell’s Urea-ES technology, which was introduced in May 2015. 

Today's announcement comes after the two companies successfully granulated Shell-developed Urea-ES emulsion in UFT’s fluid-bed granulation pilot plant in Leuna, Germany.

The Urea-ES technology seeks to provide vital sulfur nutrient to soils by incorporating elemental sulfur into the world’s most commonly used fertilizer, urea, helping to unlock higher crop yields and improved soil health. 

Combining Shell Thiogro’s sulfur-enhanced urea technology with UFT’s fluid-bed granulation process will enable the largest urea plants in the world to produce granulated sulfur-containing urea.

Since 2014, Shell and UFT have been developing a partnership on Urea-ES technology. The successful pilot plant run demonstrates that sulfur-enhanced urea can be safely produced at UFT fluid-bed granulation plants, the companies say.

“Fertiliser producers had been asking us about incorporating sulfur into their urea for a long time,” said Matthias Potthoff, director of Uhde Fertilizer Technologies. “From the first discussions with Shell Thiogro about a partnership to granulate the product of their sulfur-enhanced urea technology, it was clear this would be a win-win relationship.”

“We are pleased to be working with UFT, the foremost licensor of fluidised-bed granulation plants in the world, on our latest Shell Thiogro technology. UFT’s urea granulation expertise and Shell’s sulfur know-how complement each other perfectly. We are pleased to see a positive outcome from this partnership – we successfully granulated several formulations of Urea-ES in UFT’s pilot plant,” said Rafael Garcia, global technology manager for Shell Thiogro technologies.

The companies announced their cooperation at a joint presentation at the CRU Nitrogen + Syngas conference in March, in which they presented samples of fluid bed granulated product made with Urea-ES technology.

Urea-ES technology utilizes Shell Thiogro's patented technology to emulsify micron-sized particles of elemental sulfur evenly throughout urea, forming a homogeneous emulsion. This is in contrast to existing elemental sulfur-containing urea technologies, which typically coat urea in a layer of elemental sulfur. The microscopic size of the sulfur particles, at under 40 micrometers (µm), promotes the oxidation of the sulfur within the crop season.

The advantages of Shell’s technology have been combined with the industry-leading features of UFT’s fluid-bed granulation process, where the granulation mode is accretion instead of layering. The elemental sulfur liquor is finely dispersed in the urea melt before the solution is fed to the granulator. The flexibility of the UFT granulation process allows the production of Urea-ES without any significant changes. Just as in the normal urea granulation, the Urea-ES particles grow collectively through the solidification of tiny droplets on the seed material.

The result is a very hard granule, far superior in quality to granules produced through layering or agglomeration-based processes, company officials say. This slow accretion process is unique in permitting the water present in the urea solution to be thoroughly stripped on a continuous basi,  resulting in the end product having a remarkably low moisture content.

The dispersion of the sulfur in the urea results in a homogeneous distribution of micron-sized sulfur particles in the Urea-ES granules.

The bulk of the crystallization heat released as the Urea-ES solidifies is removed by evaporating the water in the urea solution. This method of heat release reduces the amount of ambient air required for cooling and the evaporation is highly efficient because it takes place directly on the granule surface.

Operation of the fluid-bed granulation plant is simple and very reliable, the companies say, guaranteeing a high on-stream factor. The granulator itself contains no moving parts, and its design is optimized to limit downtime for cleaning to a strict minimum.