| Why is IsoThermingSM typically cheaper than alternative technologies? |
The IsoThermingSM process can be built independently as a pretreat unit for a conventional hydrotreater. This allows the IsoThermingSM unit to be a high pressure unit with smaller reactors and no recycle gas compressors. Also, there is no need to change out the existing unit for higher pressures and mass loadings often required when revamping a conventional unit.
In a grassroots unit, the multiple IsoThermingSM reactors would be expected to typically cost less than some high pressure trickle bed reactors with the accompanying recycle gas circuit. IsoThermingSM as a pretreat unit in a grassroots hydrotreater may also be the most viable processing option. The IsoThermingSM process has a cost advantage in most applications. |
| With no recycle gas, doesn't the catalyst coke up? |
| No, not if you keep a presence of excess hydrogen. The absence of recycle gas to keep sweeping through the catalyst is a new concept for refiners. However, recycle gas is not necessary to prevent coking in normal hydrotreating reactions--the presence of hydrogen is the important factor. The IsoThermingSM process assures that hydrogen is always present in the catalyst bed, thus reducing coking concerns. |
| How do you predict catalyst life? |
| It is widely known that the closer to isothermal operation in a catalyst bed, the longer the catalyst life. Although there has not been any reliable commercial data available on catalyst life for this new technology, longer catalyst life and/or higher LHSV than a conventional revamp are expected due to the nearer to isothermal operation. |
| Do you have any commercial applications in FCC feed pretreatment? |
| Not at this time, but there is strong interest in this area and the application of the technology looks very desirable. Process Dynamics expects big growth in this area in the near future. |
| What purpose does a recycle liquid serve? |
| It is the delivery mechanism for hydrogen to each reactor and provides the heat sink for the reaction exotherms. It is a principle element in the IsoThermingSM technology. |
| Why do you have to have multiple reactors? |
| As hydrogen is consumed in the hydrotreating reactions of each reactor, it is important not to consume all of it. Therefore, the interim product must be resaturated with hydrogen and reintroduced into another reactor as necessary to keep the desired reactions going. |
| How are the typical problems of poor distribution of the oil and hydrogen in the catalyst bed addressed by the IsoThermingSM technology? |
| Hydrogen is directly mixed in an excess amount with the oil as it enters into each reactor. With the reactor being in a liquid full state, the distribution and catalyst contact concerns are eliminated. |
| Is IsoThermingSM technology simple to operate? |
| Yes. The reactions are basically the same but the recycle gas rate variable is replaced with a recycle liquid rate. Both are responsible for delivering hydrogen to the reaction sites and providing a heat sink. The liquid recycle in the IsoThermingSM process is a much better heat sink thus making the reactors operate closer to isothermal operation. This operational advantage led to the naming of the process IsoThermingSM. |
| When built for a pretreat application, can the downtime on my existing unit be minimized for tie-ins? |
| Yes. The unit can be constructed almost independently from the existing process; thus allowing for shortened downtime for tie-ins. |
