“I’m saving energy; where are you? Direct feeding in Petrochemical 301
Thread Content
This post was last edited by Yitailong'er on 2016-4-23 at 16:36. The catalytic cracking unit, as an intermediate unit in an oil refinery, serves to connect different processes together； As is well known, catalytic feedstocks come from products of atmospheric and vacuum distillation as well as coking; catalytic products serve as feedstocks for gas separation, hydrogenation, and reforming processes ； Under normal circumstances, materials are dispatched from the tank farm or products are sent to the tank farm. After modification, coker wax oil and vacuum wax oil go directly into the catalytic feed buffer tank; catalytic liquefied gas goes directly into the gas feed buffer tank; gasoline goes directly into the hydrogenation feed buffer tank; diesel goes into the reforming feed tank ； This eliminates the intermediate steps in the tank area, saving on the electricity costs associated with the feed pumps as well as the maintenance costs for those pumps.
The original poster is absolutely correct; that’s how new refineries are designed these days.
Energy conservation and consumption reduction, sustainable development
It also has its advantages to have an intermediate tank, as it facilitates the removal of material during shutdowns for maintenance, and serves as a buffer
A intermediate tank system must be available as a backup buffer.
Optimize processes to improve the overall efficiency of the entire plant!
This post was last edited by 328104062 on 2016-4-23 at 22:08. The proportion of material supplied directly has been increased to 90% (the original design called for 80% to be supplied directly, with 20% supplied from the tank area using two pumps, one large and one small). With this increase, 1) less circulating water is needed for the coolers in the upstream units; 2) the load on the heating furnaces in the downstream units decreases, the frequency of backwashing the filters drops, and processing losses are reduced; 3) less heating steam is required for the intermediate raw material tanks (which were designed to hold the material for 2–3 days), resulting in fewer losses in that area as well; 4) the power consumption of the pumps that supply material from the tank area is reduced; 5) the formation of gums, which occurs in an oxygen-free environment due to the saturation and coking of dienes, is significantly reduced. At the same time, we have increased the temperature of the material supplied directly: the original temperature for normal residue was 90°C, but it has now been raised to 120°C. The original temperature for normal line 2 and line 3 was also 90°C, and it has been increased to 110°C. The original temperature for kerosene was 50°C, and it has been raised to 70°C. . . . . . Some of the design data may contain errors; please use them as a reference only. The energy consumption of the entire plant has been significantly reduced, by about 2-3 units
Direct feeding can save a lot on cooling and heating costs, but it also has the drawback of requiring shutdown for purging, which is not easy to handle. It is therefore necessary to have pipelines and equipment that allow direct feeding to the oil products available, to facilitate purging during shutdowns.
A sweep valve was already added during the modification. The most important thing is that all departments need to cooperate well during the shutdown and line cleaning.
If direct feeding is possible now, there’s no need to make a detour to the tank area