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Overall solution for denitrification of coked wax oil

Non-hydrogenation complex denitrification process · Dealkalization nitrogen rate 70%~81% · Improve FCC/hydrogenation feed · Dongying Zhenghang and Hongrun Changyi Petrochemical have been implemented and verified

High alkali nitrogen problem in coked wax oil

Coked wax oil is a secondary processed distillate obtained by coking vacuum residue. Due to the enrichment of nitrogen compounds in the raw material,Basic nitrogen content Usually as high as 800~1500 μg/g, which is 2~4 times that of straight-run wax oil. Core problems caused by high alkali nitrogen:

  • 📉 Damage the FCC catalyst: Basic nitrogen preferentially adsorbs the acidic center of the catalyst, resulting in decreased activity, increased coke yield, and reduced gasoline yield.
  • 📉 Poisoning the Hydrogenation Catalyst: Basic nitrogen competes for adsorption with active components such as hydrogenation catalyst Mo, W, Ni, etc., shortening the operation cycle
  • 📉 Affect blending quality: When used as a fuel oil blending component, high nitrogen affects combustion cleanliness and NOx emissions.

Non-hydrogenation complex denitrification process plan

Hubei’s true heart Coked wax oil denitrification agent Using national patented technology, complex denitrification is achieved under normal temperature to 60°C and normal pressure conditions, without the need for a hydrogenation device:

Process ParametersTypical Value
Add dose1.0%~1.4% (w/w, adjusted according to alkali nitrogen content)
reaction temperature80~100℃ (existing temperature in the tank area, no additional heating required)
Settling time24~48 hours (gravity settling)
dealkalization nitrogen rate70%~81% (alkali nitrogen reduced from 1000ppm+ to 300~600ppm)
Acid value after removal≤0.3 mgKOH/g (low acid value type)
Oil yield≥99.98%

Implemented cases: Dongying Zhenghang Petrochemical Industry Coked wax oil denitrification project,Hongrun Group Changyi/Qingzhou Petrochemical The alkali nitrogen dropped from 1136/1585 μg/g to 429.8/772.5 μg/g, the nitrogen removal rate was 61%~73%, and the acid value after removal was 0.15~0.19 mgKOH/g.

Economic benefit calculation

Take the 100,000 tons/year coking wax oil denitrification device (alkali nitrogen 1000 ppm, target 300 ppm) as an example:

  • 💰 After denitrification, the FCC gasoline yield increases by 2~4%. Based on 100,000 tons of raw material/year, the efficiency increase is about More than 8 million yuan/year
  • 💰 Reduce FCC catalyst consumption (catalyst dosage can be reduced by 10~20%), saving approximately 1 million to 2 million yuan/year
  • 💰 The initial investment for the non-hydrogenation process is only hundreds of thousands of yuan, usually Investment will be recovered within 3~6 months
  • 💰 Simultaneous demetallization (Fe, Ni, etc.) to reduce the risk of downstream catalyst poisoning

Frequently Asked Questions about Denitrification of Coked Wax Oil

Q: How to choose denitrification agent? What are the key indicators?
Three key indicators for evaluating coked wax oil denitrification agents: ①De-alkali nitrogen rate - the target is usually more than 70% (alkali nitrogen is reduced from 1000ppm+ to 300ppm level); ②Acid value after removal-low acid value type (≤0.3mgKOH/g) eliminates the need for additional refining steps; ③Oil product yield-the oil yield of high-quality denitrification agent is ≥99.98%, which does not affect product quality. We can provide free small test service. Submit your oil sample to get a targeted evaluation report.
Q: How to verify the denitrification effect index?
Standard verification process: ① Take 200ml of coked wax oil sample, add denitrification agent according to the recommended dosage, and stir at a constant temperature of 60 to 80°C for 30 minutes; ② Let it stand for 12 to 24 hours; ③ Take the upper purified oil sample to measure the alkaline nitrogen content (Claus method), acid value, and metal content. Our laboratory can provide test reports free of charge. It is recommended to conduct ton-scale pilot test verification before industrial scale-up.
Q: What are the actual benefits of denitrification of lubricating oil before hydrogenation?
The lubricating oil hydrorefining catalyst is extremely sensitive to alkaline nitrogen (required <200 ppm). If the feed alkaline nitrogen is 200~500 ppm, the operating cycle of each batch of catalyst may be shortened to 1/3~1/2 of the normal one. After complex denitrification pretreatment, the catalyst operating cycle is extended by 2 to 3 times. The catalyst cost saved in a single operation is usually between 500,000 and 2 million yuan, and the return on investment is extremely high.

Free trial evaluation

Mail a 100ml sample of coked wax oil and obtain a professional denitrification effect report (full test of alkali nitrogen, acid value, and yield).

Contact us to apply for a trial