Stamicarbon

Stamicarbon is the licensing and IP center of Maire Tecnimont SpA and market leader in licensing technology for manufacturing urea.^[1] as well as provide follow-up services designed to ensure the best possible operation of the urea plant throughout its working life.^[2]

History

Introduction

From its inception in 1947 until 2009 Stamicarbon was a subsidiary of DSM (formerly Dutch State Mines). In 2009 it was sold to Maire Tecnimont.^[1][3] DSM created Stamicarbon for the purpose of managing its patent portfolio and licensing its technology. In 1947 DSM was primarily a coal mining company and initially Stamicarbon was responsible for selling coal preparation plant technology. The company’s name reflects its origin: ‘Stami’ (from ‘State Mines’) and ‘carbon’(coal).^[1][3] n the succeeding years, reflecting the progressive shift of DSM’s activities from coal mining to chemicals derived from coal and, later, from natural gas, Stamicarbon’s technology portfolio grew to include a number of other products, including urea and the urea derivative melamine, caprolactam, polyethylene, phenol, and EPDM rubber.

Following the takeover of DSM’s petrochemical activities in 2002 by the Saudi Arabian company SABIC, licensing activities for all but urea and LLDPE technology were also transferred to SABIC’s licensing subsidiary, SABTEC. The melamine license was taken over by OCI Nitrogen.^[3]

The move to urea

Although urea has a number of industrial uses, these are dwarfed by the scale of its use as a nitrogen fertilizer. Urea has the highest nitrogen content (46 wt-%) of all the recognized solid nitrogen fertilizer materials and, from the early 1950s onwards, its use has continually increased, progressively displacing both ammonium sulphate, which was formerly the dominant product, and a later contender, ammonium nitrate.^[4] Today the market stands at about 170 million metric tonnes per year and is still growing at an annual rate of about 3%.^[5] By 2025 world food production will have to double to cater for the food demand of approximately 8 billion people. Since the area under cultivation is tending to decrease rather than increase, the extra food will have to be produced by further increasing the yield per hectare of existing agricultural land. The use of fertilizers, urea in particular, can assist with this problem.^[6] In December 1953, when DSM was establishing its urea manufacturing activity, it made the decision not to seek a license for any existing urea technology but rather to develop its own technology in house.^[5] In 1957, Stamicarbon sold its first urea license to Société Carbochimique in Tertre, Belgium, for a plant with a capacity of 70 metric tons per day (mtpd).^[5] Due to the growth of the world urea market, urea occupied an important position in Stamicarbon’s portfolio.

Technology and Innovation

Addressing plant corrosion and energy consumption

A key reason why DSM decided to develop its own urea technology was because the existing technologies did not properly address the problem of corrosion of the steels used in urea synthesis.

Stamicarbon discovered that continuously adding a small amount of oxygen (by adding air) to the plant feed caused a passive oxide layer to build up on the inner surfaces of the plant equipment, substantially reducing the rate of corrosion and thus allowing a considerable reduction in the required thickness of vessels and piping in the high-pressure synthesis section. In the fullness of time this major advance became standard practice in most urea plants, not just Stamicarbon’s. .^[7] In the 1960s Stamicarbon introduced the so-called stripping concept, later adopted by its competitors, which boosted the efficiency of the synthesis section by cutting the amount of recycled water, and also simplified the plant equipment, thus (again) reducing its cost.^[8] Subsequent refinements to the process, including changes in the disposition of the major equipment items in the synthesis section, have further reduced both capital and operating costs.

A further breakthrough in corrosion control came in 1996 with the introduction of a new duplex stainless steel called Safurex®, which had been developed jointly by Stamicarbon and the Swedish steel manufacturer Sandvik.^[9] This material is not only corrosion-resistant in a low-oxygen or oxygen-free environment, but also much less susceptible to stress corrosion cracking (SCC) than the urea-grade steels in previous use.

Improvement of the impact strength and transportation of urea

Until the 1970s most urea plants produced their fertilizer in the form of prills. In the prilling process, droplets of urea ‘melt’ (obtained by concentrating the product solution from the urea plant to a very high level) are cast into an upward flow of air, solidifying as they fall. For air prilling, a concrete tower is required between 40 and 70 meters high, depending on the production capacity and climatic conditions.^[10] On account of their relatively low strength, prills are susceptible to breakage during handling and transportation, which increases the risk of caking (concretion) of the product during storage and gives rise to dust when the urea is spread on the land.^[11] Stamicarbon developed a new technology to improve the impact strength, known as ‘seeding’.^[12] This process involves blowing tiny urea particles (seeds) into the prilling tower. The seeds act as kernels for the crystallization of the urea melt droplets, and in so doing their strength is increased.

Since the 1970s the urea industry has been gradually changing over from prilling to granulation, which produces stronger particles of a more suitable size for fertilizer use. In the 1990s Stamicarbon introduced its own fluidized-bed granulation process, which rapidly gained acceptance in the world nitrogen fertilizer industry.^[13]

Urea Symposium

Once every four years Stamicarbon holds its Urea Symposium, at which new technical developments are introduced and social contacts are established or refreshed. First held in 1966, when it was attended by 31 participants, representing 16 licensees from 11 countries, the invited audience has been expanded to include contractors and equipment suppliers. Attendance at the most recent symposium in 2012 numbered 320.

References