Weekly Topic: Control of Volatiles in Petroleum Coke – Issue 25, 2011.8.16-8.22
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This post was last edited by lijianhuai on 2011-8-16 at 23:33. There are weekly topic-related activities in the refining area; everyone is welcome to participate actively, and it is hoped that more valuable topics will be proposed. The moderators will award rewards of 5-20 wealth points. Those who post excellently will receive a reward of 10 to 50 Wealth or an equivalent amount of Charm. Please do not hide your responses to this question. For delayed coking units, the yield of petroleum coke is quite high. Especially these days, the quality of the feedstock residue oil is getting worse, and the quality of petroleum coke thus affects the efficiency of the unit. We should try to produce as little petroleum coke as possible and increase the yield of liquids, while still ensuring the quality of the petroleum coke. Please share your own criteria for controlling petroleum coke quality – what are the levels of ash and volatiles? How do people control the volatiles? The ratio of the ash content of residue to that of petroleum coke (an empirical value) is 1:3. To reduce the volatility of petroleum coke, in addition to improving the properties of the raw materials, we can increase the reaction temperature and extend the steam injection time. What other control measures are available?
The volatility of our petroleum coke is generally between 7 and 13. We cannot change the properties of the raw material; instead, we adjust the reaction temperature. Increasing the amount of gas blown in can lead to the presence of coke dust, so the reaction temperature can be raised before changing the reactor.
Reply 1# lijianhuai: The sulfur content and ash content of petroleum coke are determined by the properties of the raw materials and cannot be adjusted. Generally, the properties of the raw materials are controlled to ensure that the ash content of petroleum coke is no more than 0.4, the sulfur content is no more than 3.5, and the volatile matter content is less than 10； Regarding volatile matter, low-pressure and high-temperature operations are employed; before and after tower replacement, the furnace outlet temperature is increased by 3–5 degrees for 2 hours each time. The duration of the partial steam supply is extended to over 2 hours. It was found that this approach results in lower levels of volatile matter in the coke and higher liquid yield compared to using a larger amount of steam