Shell Global Solutions Technology Licensing

Shell Global Solutions works with customers to develop safe, cost effective designs that are tuned to meet local market conditions and customers' needs. The organisation is one of the market's leading Ethylene Oxide (EO) /EG process licensors. Since 1958, Shell has licensed over 70 EO/EG processes worldwide. Many of these plants are still in commercial operation. Moreover, the Shell Group is a major producer of EO and EG through its production facilities in Canada, China, the Netherlands, Singapore and the USA.

CRI is the leading EO catalyst producer and a pioneer in the industry. For more than 50 years, CRI and Shell have led the industry in improving the performance and lifespan of EO catalysts. Over 50% of the world's current EO production is manufactured using a CRI EO catalyst.

Shell EO/EG Process Support
Shell remains committed to process licensees after the plant has been successfully started up with CRI catalyst. Here are some of the process services available to licensees:
• Debottlenecking studies
• Revamps
• Process safety updates
• Process improvements
• Global exchange meetings (hosted jointly with CRI)

Master Process
Shell is the world's leading process licensor of EO/EG Technology. Shell-designed plants produce 40% of the world's glycol. Shell has pioneered many of the advances in EO/EG process technology. The Shell MASTER Process has been proven over many years to be safe, flexible and cost-effective. Features of the Shell MASTER Process include:

• Optimal reactor conditions to maximise performance of CRI's High Selectivity catalysts
• Heat and energy integration
• Advance process control and safety shutdown systems
• Compliance with the strictest environmental standards
• High purity EO and EG
• Conventional thermal hydration process for the production of MEG, DEG, and TEG
• Flexible, customised designs to meet desired product slates

Performance data
The Shell MASTER process makes use of CRI's latest high-selectivity EO catalyst that can run for three years at about 90% average selectivity. Longer run lengths can also be accommodated. The process co-produces DEG and TEG. The MEG yield is typically 90–92%, depending on customer requirements.

Business value
As every plant is tailor-made and tuned to customer wishes and local conditions and constraints, capital investment costs will vary from plant to plant. In 2004, the capital cost of a 600-kt/y MEG unit was estimated at $120–160 million for the inside-battery limits portion, but prices have fluctuated significantly since. After plant start-up, Shell and CRI will continue to provide operational support. Process design studies relating to plant modifications or debottlenecking can also be accommodated.

The Shell Group has operated Pygas Hydrogenation Units (PHU) in its chemical plants around the globe for over 40 years. Shell Global Solutions draws on this operational experience with a range of PHU designs that are based on commercially proven technology and that provide safe, reliable and cost-effective operations.

In addition, CRI is an established leader in pygas catalysts – a crucial aspect of the pygas hydrogenation process. This arrangement helps to provide continuous technology improvements and innovations, which are then applied to licensing unit design and optimisation.

Process description
At the core of any PHU, lie the reactor and the hydrotreating technology. Shell Global Solutions has long been an industry leader in hydrotreating technology, and offers high-level expertise in reactor design and operation. Although multiple arrangements are possible, pygas hydrotreating typically involves two stages: a diolefin removal step followed by an olefin and sulphur removal step.

The first stage involves hydroprocessing the feed to remove diolefins, alkenylaromatics (styrene) and some olefins in preparation for optimal downstream processing. The second stage involves hydroprocessing all or a specific cut of the first-stage product to remove olefins and sulphur, which prepares the feed for aromatic extraction and/or motor gasoline pool addition.

Shell Global Solutions' pygas hydrotreating technology is complemented by CRI's catalyst technology. Through its hydrogenation catalyst line, CRI provides a comprehensive range of high-performance catalyst products for first- and second-stage pygas reactors:

• Ni and Pd first-stage catalysts;
• NiMo and CoMo second-stage catalysts; and
• specialised bed grading.

CRI’s pygas catalysts are designed to maximise performance while mitigating certain operational issues that can be experienced in pygas operations, such as large pressure drops and short cycle lengths.

Performance data
CRI’s pygas catalysts products have established strong commercial track records in some of the world's largest pygas reaction systems. This catalyst product line features inert and active grading, which is specially designed to minimise the potential for pressure drop build-up in both first- and second-stage reactors. In commercial settings, these products have been shown to extend cycle lengths by up to 50% or more. Over the past seven years, CRI's share of the pygas catalyst market has grown from approximately 4 to 20%, and these products are being used by some of the world's major pygas processing companies.

Reactor internal design also plays a key role in the pygas hydrogenation process. By using Shell Global Solutions' proprietary reactor internals, operators will be helped to maximise the effectiveness of their chosen catalyst and the available reactor volume. These internals achieve nearly 100% uniform gas and liquid dispersion, which enables complete catalyst volume utilisation and reduces the potential for hot spots. The reactor internals provide optimum liquid dispersion and fouling abatement, and have achieved excellent market penetration in pygas and other hydrotreating and hydrocracking applications.

The Shell Global Solutions pygas hydrogenation design was developed to have minimal environmental impact. There are no normal process vents to atmosphere in the design, and the hydrogen consumption is optimised.

Business value
Shell Global Solutions' reactor internals have been used to retrofit pygas units for Shell and non-Shell customers, and, in each case, the plants have experienced improvements in cycle length, production rate, temperature uniformity and product conversion. Shell Global Solutions has wide experience of combining the pygas hydrogenation process with ethylene cracking and of integrating the products into the refinery. Operators can also benefit from inhouse tools designed to help them optimise the performance and economics of pygas units and to find the best solution for specific plant requirements.