Wax Hydrotreating Process by Bechtel Corp

Application: Hydrogen finishing technology has largely replaced clay treatment of low-oil-content waxes to produce food- and medicinalgrade product specifications (color, UV absorbency and sulfur) in new units. Advantages include lower operating costs, elimination of environmental concerns regarding clay disposal and regeneration, and higher net wax product yields.

Bechtel has been offering for license the Wax Hy-Finishing process. Bechtel now is marketing a line of modular, standard hydrogen finishing units for wax treatment. Standard sizes are 500, 1,000, 2,000 and 3,000-bpsd feedrate.

The core of the unit is standardized; however, individual modules are modified as needed for specific client needs. This unit will be fabricated to industry standards in a shop environment and delivered to the plant site as an essentially complete unit. Cost and schedule reductions of at least 20% over conventional stick-built units are expected. The standard licensor’s process guarantees and contractor’s performance guarantees (hydraulic and mechanical) come with the modules.

Description: Hard-wax feed is mixed with hydrogen (recycle plus makeup), preheated, and charged to a fixed-bed hydrotreating reactor (1). The reactor effluent is cooled in exchange with the mixed feed-hydrogen stream. Gas-liquid separation of the effluent occurs first in the hot separator (2) then in the cold separator (3). The hydrocarbon liquid stream from each of the two separators is sent to the product stripper (4) to remove the remaining gas and unstabilized distillate from the wax product, and the product is dried in a vacuum flash (5). Gas from the cold separator is either compressed and recycled to the reactor or purged from the unit if the design is for once-through hydrogen.

Licensor: Bechtel Corp.