<Here is recent Hydrocarbon Processing article on New coking technology from US Cokertech LLC folks – sort turns Delayed Coker into quasi Fluid coker (see comments) – CER>
Delayed coker processing for new or operating units
Hydrocarbon Processing Jan09
The improved delayed coker unit (IDCU) technology is claimed to be an enhanced design of the already proven delayed coking process presently in use at many facilities globally. US Cokertech LLC has developed the IDCU process.
The new technology is a combination of delayed coking and fluid coking methods that convert heavy hydrocarbons (vacuum residuum, extra heavy oil or bitumen) into a full-range of lighter liquid products and coke (Fig. 1).
Fig. 1 Delayed coking technology is applicable for both new and operating units.
This patent-pending process is claimed to greatly reduce the required duration of the alternating drum-fill, decoking cycles. The need to perform drum quenching, draining, unheading, hydraulic decoking, reheading and pressure-testing procedures in the decoking cycle is eliminated.
Operation. The de-coking cycle includes simply a steam-out stage and a coke-product removing step. The coke product produced in the coking drums is a hot, solid, flowable material. Heat can be recovered to produce steam. The flowable coke is directed to the pit or trucks.
The reaction proceeds at lowered cracked-oil partial pressure by injecting steam into the drum. This keeps the petroleum pitch in a homogeneous liquid state and strips out liquids. Unlike with conventional delayed cokers, a higher cracked oil yield can be obtained.
The driving force to remove the coke from the drum includes a pressure system to keep the drum at constant pressure during the de-coking process, a heavy-duty crusher located at the drum bottom to provide smaller-part icle-sized coke and a lifting steam system to move the coke through the exchangers. Other processing benefits of the IDCU are claimed to include:
- Increased drum capacity in excess of 200%
- Greatly reduced coking cycle from 18 hours to 6 hours
- Longer drum service life
- Significant heat recovery through steam production
- Elimination of hydraulic de-coking, heading and de-heading system, blowdown and related operations
- Lower utility usage as well as operations and maintenance costs
- Lower capital cost for new installations
- Significant volume increase for liquid products
- Improved quality of liquid products
- Reduced coke yield
- Virtually any pumpable hydrocarbon feed handled.
All existing delayed cokers can be converted to IDCU with minimum expense within a short time. Unit shutdown is not required.
