SAMIR Bitumen Plant, Morocco

The Moroccan refinery company SAMIR is building a new bitumen plant in the port city of Mohammedia, Morocco. Bitumen is a highly viscous and elastic organic liquid composed of a complex mixture of chemical compounds. The plant will produce 40/50 grade road-making bitumen and will have a capacity of 270,000tpa.

The project includes the construction of two bitumen storage tanks with a 5,500m³ capacity and a HGV filling station. Work on the project began in January 2010 and is scheduled for completion in summer 2011. The project is estimated to cost €21m.

The SAMIR bitumen plant will be based on Biturox, a process technology developed by the Austrian engineering company, Pörner. Biturox makes use of the oxidation process in producing bitumen polymers. Pörner has built 37 Biturox licence plants across the world.

Biturox technology can produce bitumen from less expensive crudes. Residues from the distillation process can be blended with other refinery bottoms for optimising feed compositions. The feedstock compositions can be further processed through the controlled reactor system. The Biturox process efficiently uses the utilities such as steam, air and water. The conventional distillation process of bitumen production requires proper crude blends and sophisticated refinery technology.

SAMIR bitumen plant feedstock

The downstream processing of Biturox utilises the feedstock composition of different crude blends for producing bitumen. The main components in the feedstock include a harmonised balance of aromatics, naphthenes, asphaltenes, saturates and resins. The properties of the final product are controlled by varying crude compositions. The lifetime of a road made of multi-grade bitumen is enhanced by increasing the polarity of the aromatic components in the feed crude.

Biturox process technology

The Biturox process is used to produce different quality bitumen grades such as industrial heavy-duty binders and multi-grade bitumen for road surfacing. The primary component of the Biturox technology plant will be a loop aeration reactor, which will enable the thermo-chemical conversion of the feedstock and the air-oxygen. The oxidation will be a continuous process under repeatable specifications. Parameters such as residence time, temperature, pressure and flow rates of the chemical process will be controlled.

During the Biturox process, the medium molecular-weight aromatic compounds formed will be preserved in the reaction mixture. The bitumen produced will improve elastic and adhesive properties.

The reactor will have a cylindrical cone coated with three stages of the Biturox agitator, which will result in a homogeneous reaction of the circulating product with the fresh feed. The process will reduce the overheating of the chemicals and eliminate dead zones of the reactor for maintaining a uniform product quality.

The temperature of the reactor will be maintained by injecting water along with the processing air in the system. Controlling the flow rate and increasing the polarity of aromatic components will prevent bottom coking and an excessive reaction from occurring.

The Biturox reactor will utilise optimum oxygen, which reduces the processing time and operating costs. The maximum utilisation of oxygen in the reactor will decrease the risk of ignition and ensure the safety of the plant. The gentle introduction of air during the process will limit the bitumen from thermo-cracking.

Homogeneity and steam exposure will be maintained throughout the process for stripping effect. Controlling the temperature inside the reactor and continuity will produce a homogeneous bitumen product. Biturox plants do not require any maintenance and can be operated for several years. The continuous operation can also be altered by varying flow-rates to change the bitumen grades without any interruptions. In addition, the plants can be automated.

Bitumen project contractors

In October 2009, SAMIR awarded a lump-sum turnkey contract to Pörner Ingenieurgesellschaft for the planning and construction of the bitumen plant. Pörner will install its Biturox technology for the production of bitumen polymers.

Pörner+Partner Ziviltechnikergesellschaft, part of the Pörner Group, is responsible for the civil engineering. An export contribution for the project was funded by the Austrian Control Bank (OeKB).

Bitumen market growth

Bitumen is mainly used for the construction of roads. The high-quality bitumen binders are used as a component of road paving material to make it durable and cost efficient. The product is, thus, an important downstream business for the refineries. It is also used for construction coatings, bitumen emulsions and roofing felts in the speciality chemicals industry.