JPS6354756B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method and apparatus for simultaneously distilling different feedstocks. Generally, crude oil is separated into the desired components according to their boiling point differences using atmospheric distillation equipment, but the types of crude oil that must be processed are extremely diverse, and their physical properties also vary depending on their sulfur content, pour point, and the composition of each component. They often differ in terms of profit margin, etc. Conventionally, when processing crude oils with different physical properties, it has been necessary to perform switching operations for each crude oil or to use two devices in order to obtain products that take advantage of the physical properties. Therefore, the present inventors have conducted extensive research in order to overcome the drawbacks of the above-mentioned conventional techniques and to develop a method and device that can simultaneously and efficiently process many types of raw material oils using one device. As a result, the objective can be achieved by guiding each type of raw oil to separate small distillation columns, where the necessary fractions are side-cut, and then the overhead fraction is collected in one distillation column for fractional distillation. This discovery led to the completion of the present invention. That is, in the present invention, when simultaneously distilling at least two types of feedstock oils having different pour points, each feedstock oil is heated in a heating furnace, and then each is introduced into a flash zone of a separate distillation column to perform fractional distillation. , provides a method for distilling feedstock oil characterized by side-cutting necessary fractions in each distillation column, and then collecting the top fractions in one distillation column for fractional distillation, and implementing this distillation method. The purpose of this project is to provide equipment to be used when The invention for this device consists of: (A) one or more heating furnaces that separately heat feedstocks having at least two different pour points; (B) a distillation column of the same number as types of heated feedstocks; A distillation column in which each distillation column has at least one side stream outlet, (C) a pipe that guides the heated raw oil derived from the heating furnace to the bottom of each distillation column by type, and (D) the maximum number of stages. This is a feedstock distillation device consisting of pipes that introduce the fractions distilled from the top of all other distillation columns to the side of a distillation column having distillation shelves. The method and apparatus of the present invention will be explained as follows based on the drawings. FIG. 1 shows an example of simultaneous distillation of two types of raw material oils. Different types of raw oils A and B are preheated by passing through heat exchange groups 8 and 9, respectively, and then introduced into a heating furnace 3. Heating furnace 3
may be provided separately for each raw material oil, or may be provided as one heating furnace as shown in FIG. However, in any case, it is necessary to heat each raw material oil separately in this heating furnace, and each raw material oil must not be mixed. After heating, the raw oils A and B are guided from the bottoms of the distillation columns 1 and 2 to the flash zone through pipes 4 and 5, respectively. Here, the number of distillation columns should be the same as the types of feedstocks to be simultaneously distilled, and a separate distillation column is used for each feedstock. One of these distillation columns has the same number of plates as conventionally used distillation columns, for example, 40 to 50 distillation shelves (first
In the figure, it corresponds to distillation column 1), but all other distillation columns are small and the number of distillation plates is 20 to 35.
is sufficient. Each raw material oil is distilled under appropriate conditions in this small-sized distillation column (corresponding to distillation column 2 in FIG. 1). In this distillation column, it is sufficient to side-cut mainly gas oil fractions and heavy gas oil fractions, and there is no need to perform fractional distillation of lower boiling point fractions. In the above-mentioned small distillation column, gas oil and heavy gas oil fractions are distilled out from the column side, and residual oil is extracted from the bottom of the column.
On the other hand, distillate vapor containing kerosene and naphtha is distilled from the top of the tower. Subsequently, the fraction distilled from the column section of each distillation column is introduced through a pipe into the side of the aforementioned distillation column having 40 to 50 distillation plates. In FIG. 1, the top fraction of distillation column 2 is introduced into the side of distillation column 1 through pipe 6. The physical properties of the overhead fraction vary depending on the type of feedstock oil. Therefore, the position on the side of the distillation column to be introduced may be appropriately selected depending on the properties of the overhead fraction. For example, an overhead fraction containing a relatively large amount of low-boiling fractions can be introduced from the side near the top of the distillation column, whereas an overhead fraction containing a large amount of high-boiling fractions can be introduced from the bottom of the column. It should be introduced from the side closest to the The fraction collected from the top of each small distillation column into the distillation column having the highest number of distillation shelves is further fractionated together with the low boiling point fraction of the feedstock oil previously introduced from the bottom of the distillation column to produce kerosene and naphtha. It becomes a distillate. According to the method and apparatus of the present invention, fractions of various feedstock oils up to gas oil are fractionated under appropriate conditions, and then fractions with a boiling point lower than that of gas oil are collected in one distillation column and fractionated all at once. Therefore, it is possible to perform distillation according to the properties of various raw material oils, and at the same time, it is possible to perform extremely efficient operations that can obtain the maximum amount of white oil. In addition, even when processing feedstock oils with high and low pour points at the same time, it is possible to separately obtain light oil with a satisfactory pour point at a good yield, resulting in products that take advantage of the physical properties of each feedstock. be able to. Therefore, the method and apparatus of the present invention can be effectively used in the petroleum refining industry, the petrochemical industry, and various other industries that perform distillation operations. Next, the present invention will be explained in more detail with reference to Examples. Example Using the raw material oils A and B shown in Table 1, distillation was carried out in a pilot apparatus shown in FIG. The conditions and results are shown in Table 2. Note that the distillation column 2 was a fractionation column, and the light oil was side-cut from the column side. Comparative Example In the example, the distillation column 2 was used as a stripper,
The same operation as in Example was carried out except that the side cut of light oil was not performed. The conditions and results are shown in Table 2.

【table】

[Table] The above example shows the results when operating the heating furnace outlet temperature at a relatively low temperature, but the heavy gas oil yield can be increased arbitrarily by raising the heating furnace exit temperature to 375 to 380°C. It is. Furthermore, when crude oil A and crude oil B are processed simultaneously, it is understood that in order to set the pour point of light gas oil to -10°C, the yield in the comparative example is reduced by about 1 vol% compared to the example.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the apparatus of the present invention. 1... Distillation column, 2... Small distillation column, 3... Heating furnace,
4,5,6...Pipe, 7...Cooler, 8,9,1
0,11...heat exchange group, 12,13,14,15...
pump.

Claims (1)

[Claims] 1. When simultaneously distilling at least two types of feedstock oils having different pour points, each feedstock oil is heated in a heating furnace and then introduced into a flashing zone of a separate distillation column for separation. 1. A method for distilling raw oil, which comprises side-cutting necessary fractions in each distillation column, and then collecting the top fractions in one distillation column for fractional distillation. 2. (A) one or more heating furnaces that separately heat at least two types of feedstocks having different pour points; (B) distillation columns as many as types of heated feedstocks, each distillation column; a distillation column having at least one side stream outlet, (C) a pipe that guides the heated raw oil derived from the heating furnace to the bottom of each distillation column by type, and (D) a distillation column having the maximum number of distillation shelves. A feedstock distillation device consisting of pipes that introduce the fractions distilled from the top of all other distillation columns into the side of the column.