Technology

Technology Sumary

Axens Prime-D™ is a deep hydrotreatment (HDT) technology designed to produce ultra-low sulfur diesel (ULSD) and improve cetane and density properties.^[1]

Key Features

• Deep HDT: Prime-D technology employs a unique combination of catalysts and process conditions to achieve deep hydrogenation, enabling the removal of sulfur, nitrogen, and aromatics from diesel fuels.
• Cetane and density improvement: The technology is optimized to improve cetane and density properties, making it suitable for processing refractory feedstocks and producing high-quality diesel fuels.
• Flexibility: Prime-D can be applied to various feedstocks, including straight-run and cracked diesel streams, and can be integrated with other Axens technologies, such as dewaxing and hydrotreating.
• Wide applicability: The technology has been successfully implemented in numerous refineries worldwide, with over 500 catalyst references globally.^[1]

Applications

• Conventional Prime-D™ ensures achievement of ultra-low sulfur diesel (ULSD) specification, density and cetane improvement over a large range of diesels cuts: from straight run to large cracked feedstocks;
• Prime-D™ with dewaxing is a competitive alternative for cold flow properties improvement compared to feed undercutting, kerosene blending, or chemical additive addition, costly options, leading to high operating costs and loss in diesel yield;
• Prime-D™ with cracking is the optimal solution when deep hydrogenation is not enough to reach stringent specifications on density and/or cetane for refractory feedstocks, or when additional gasoline production is desired.^[2]

Benefits

• Improved fuel quality: Prime-D technology produces high-quality diesel fuels with excellent cetane and density properties.
• Increased refinery flexibility: The technology allows refineries to process a wide range of feedstocks and produce multiple grades of diesel fuels.
• Reduced operating costs: Prime-D’s optimized process conditions and advanced catalyst systems help minimize operating costs and reduce maintenance requirements.^[1]

Process Flow Diagram

The process flow diagram is shown in Fig.1:

Figure 1 - Prime-D simplified Process Flow Diagram.^[3]

As shown in the process diagram above , the hydrocarbon feed and hydrogen are heated together in the feed-reactor effluent exchanger (1) and furnace (2)  and then supplied to the reaction section (3) . The reactor effluent that has undergone the reaction is cooled in the feed-reactor effluent exchanger (1) and air cooler (4) and undergoes gas - liquid separation in the separator (5) . The hydrogen-rich gas undergoes a H₂S removal process in the amine absorber (6), and the hydrogen from which H₂S has been removed is recycled to the reactor. The liquid hydrocarbon separated at the bottom of the separator is supplied to the stripper (7), where a small amount of gas and naphtha are removed to produce high-quality product diesel.^[3]

References

1. 18^th Nov 2024, Brave Search Summarizer, Search term: 'Axens Prime-D'.
2. 18^th Nov 2024, Axens, Diesel Hydrotreating, Commercial Bulletin.
3. 19^th Apr 2018, Axens Prime-D Toolbox - Middle Distillates Hydrotreating Process.