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(2017) Question 24: What are you doing to meet the Euro VI/BS VI/China VI fuel quality specifications for gasoline and diesel product streams?

This is a global question, so I will try to give you a broad answer. Looking at the specifications, you will notice that whether it is Euro VI, a Bharat stage VI, or a China VI, the specifications are similar with minor variations. All of them are attempting to get to the 10 ppm (parts per million) level for the sulfur while trying to reduce aromatics and olefins in the fuel. This is the general intent of all the specifications and changes happening globally. 
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(2017) Question 25: What is the optimum role for hydrocrackers in refineries that do not utilize or are eliminating their bottom-of-the-barrel processes due to lighter crude blends?

There have been many refiners who have either been fortunate enough to have existing assets that have allowed them to capitalize on the U.S. shale boom or who have re-tooled to take advantage of availability of shale crudes. I will go through a few case studies to show where the hydrocracking unit fits in. 
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(2017) Question 26: How are developments in hydroprocessing catalyst adjusting to changes in feedstock quality? Are the new developments able to cope with and provide high activity with varying feedstock severity? 

Catalyst development has focused on this very issue in its development of several of the highest activity hydrotreating catalysts in the Unity™ hydrotreating catalyst portfolio. The catalyst support is engineered to facilitate less diffusion resistance in the same extrudate size/shape class relative to its peers, but with improved interaction between the active phase and the support, leading to greater relative effectiveness for HDN/HDS/HDA and for uptake of metals like vanadium and nickel.
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(2017) Question 27: The sulfur block is a crucial downstream component of hydroprocessing operations. What are some of your Best Practices or new developments for optimizing operations and increasing reliability?

The sulfur block is a very mature technology. There have been few new developments to optimize operations. Optimizing operations of a sulfur plant can indicate an increase of sulfur production while reducing all related sulfur emissions. Some of the new developments in a sulfur plant consist of catalyst-burner design, dip leg improvement, upgrade of ferrule types, oxygen enhancement, oxygen enrichment, TGU developments, and increase in safety stewardship.
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(2010) Question 1: What is your experience with emergency isolation equipment (such as a check valve or actuated valve) on the outlet of reactor charge heaters to prevent loss of containment of the reactor loop in a tube rupture scenario? What are the advantages and disadvantages of having this type of equipment?

Sunoco typically looks at the use of isolation equipment on the reactor charge heaters on a case by case basis. The need for these devices is driven by the design configuration of the unit, the process stream being charged to the heater, the emergency depressuring capabilities installed on the unit, and LOPA/HAZOP analysis.
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(2010) Question 2: Please discuss your experience regarding the need to add an emergency shutdown (ESD) valve between the cold high pressure separator and the product stripper. The typical design for vapor blow through is to size the stripper relief valve for this case.

Vern Mallett (UOP) UOP considers that an ESD valve between the cold separator and product stripper is not required and not recommended. The design philosophy behind this practice is to prevent liquid from filling the cold high pressure separator and carrying over into the auto depressuring system and filling the relief header.
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(2010) Question 6: The use of infrared pyrometers for monitoring tube temperatures in steam reformers is a well known practice. What is your recommended frequency for use of these devices ( how many times per week)? Can you offer any recommended alternate devices or methods available such as fixed infrared pyrometer skin thermocouples or infrared imaging?

CITGO’s operating philosophy is to monitor our tubes with an optical pyrometer every shift. We monitor the tubes from multiple locations on each level of our terraced wall furnace. This method has been extremely effective in extending the life of the furnace tubes and catalyst.
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