Question 45: What are the procedures/rules governing the transportation and disposal of catalyst contaminated with arsenic, mercury, barium, or other heavy metals? Are there maximum limits for any of these?
SHARPE (Flint Hills Resources, LP)
The spent catalyst needs to be shipped offsite and sent for metals reclamation or disposal. If it is going for disposal, it will have to be characterized to determine if 1) it is a hazardous waste, which it is most of the time, and 2) it meets the applicable Land Disposal Restrictions (LDRs). It would have to be treated, as part of disposal, to meet the LDRs.
Regarding transportation, if the catalyst needs to be shipped offsite for reclamation, it will have to be determined if it is hazardous material or contains hazardous substance. So by default, spent catalysts generally fit into that category. Take a look at the Hazardous Materials’ Table listed on the slide.
Overall, there are no maximum limits for disposal or transportation, but the catalyst does have to be transported and disposed of properly. It ends up being classified as a hazardous waste and subject to all the laws regarding that classification.
CHRIS STEVES (Norton Engineering)
The transportation and disposal of spent catalysts are governed by DOT (Department of Transportation) and RCRA (Resource Conservation and Recovery Act) regulations. A spent catalyst with leachable levels of arsenic, mercury, or barium (or five other regulated heavy metals) above their TCLP limit, will be regulated by the U.S. EPA (Environmental Protection Agency) as RCRA hazardous waste. If the material is spent hydrotreating catalyst from the petroleum refining industry, it will automatically be regulated as RCRA hazardous waste regardless of the metals content. Regulated RCRA hazardous waste must be properly disposed of at an approved treatment, storage, and disposal facility (TSDF). The actual levels of contamination will affect the options and cost for disposal. All RCRA hazardous wastes are regulated as DOT hazardous materials when shipped offsite, and all the basic rules for hazardous materials shipment must be followed.
Question 75: What are the potential problems or negative impacts of utilizing FCC slurry/decant oil as coke drum OH (overhead) line quench oil?
SRIVATSAN (Foster Wheeler USA Corporation)
Again, FCC slurry/decant oil has a similar distillation range to HCGO but a higher endpoint. Although it could possibly be used as just overhead quench, we caution that if the slurry/decant oil is not be filtered properly, it will contain catalyst fines that could accelerate the coke deposition by settling in equipment or piping. We normally recommend using the blowdown tower bottoms as the primary source for quenching the overhead vapor line. The secondary means of quenching is provided using HCGO. LCGO and other gas oils, including slops, can also be used as desired.
PRIBNOW (CITGO Petroleum Corporation)
We do not have any experience using slurry oil as coke drum overhead quench. We utilize slop oil, as Srini mentioned, as a way to vaporize and reprocess that material. We charged slurry oil to our coker when excess capacity was available. However, we found that it degraded the heavy coker gas oil quality back to the FCC. The FCC conversion drops, and catalyst becomes dark; so, we tend not to do that much anymore.
SRINI SRIVATSAN (Foster Wheeler USA Corporation)
The purpose of the coke drum overhead quench oil is to reduce coking reaction by lowering vapor temperature and mitigating coke formation. A portion of the overhead quench is also condensed and forms recycle. Foster Wheeler recommends using the blowdown tower bottoms liquid as the primary means to quench the overhead vapor line, the secondary being the use of HCGO. LCGO and other gas oils including slops can also be used as desired. FCC slurry/decant oil has a similar distillation range as HCGO with a higher endpoint. Although it could possibly be used as an overhead quench, we caution that if the slurry/decant oil is not filtered properly, it may contain catalyst fines that could accelerate coke deposition by settling in equipment or piping.
EBERHARD LUCKE (CH2M Hill)
Although I never worked in a unit that used FCC slurry/decant oil as quench oil, we used it as coker feed; so, my concerns are based on that experience. FCC slurry/decant oil carries a significant amount of cat fines that are difficult to remove from the stream. So I would assume that with the injection of the slurry/decant oil, these cat fines will be introduced into the coke drum overhead system. The fines will end up either on the inside of the vapor line, in the bottom of the fractionator, or carried even further through the system and will act as seeds for coke buildup and cause accelerated fouling/coking of equipment. The cat fines will also most likely cause erosion in the nozzle that is used for quench oil injection. Additionally, quench oil distribution will be poor (but can be fixed by the selection of the correct material).
ROBERTSON (AFPM)
Before we get to the last question, I want to remind you that the Crude P&P is this afternoon at 2:00. During that time, a lot of these issues we have covered will be discussed in more depth. Tomorrow, the Light Tight Oil and FCC P&Ps are run concurrently. If you have any other issues you want to discuss that were not raised in this forum, please attend those P&Ps.