JPS5817791B2 - Abra gas seizouhouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION When producing oil and gas by the normal pressure catalytic partial combustion method, the present invention provides for the production of oil and gas by the method immediately after the mixer of the raw material oil and gas and the gasifying agent or the evaporator of the raw material oil. A part of the gas is recycled, and the effect of this recycled gas increases the partial combustion rate of the raw material oil and gas in the reforming furnace, lowers the partial pressure of the raw material oil and gas, and minimizes carbon precipitation. To easily enable long-term stable low-load operation of around 45 cm even if the preheating temperature of raw oil gas and gasifying agents such as air and steam at the inlet of the quality furnace decreases, and to prevent a decrease in the activity of the reforming catalyst. On the other hand, the present invention relates to an oil and gas production method that aims to activate a catalyst using the effect of recycled gas and extend the life of the catalyst.

Generally, in the production of oil and gas using the normal pressure catalytic partial combustion method, a part of the feedstock oil and gas is combusted with air in a device called an internal heating type, and this combustion heat is used to decompose the feedstock oil and gas and combine it with water vapor. The system is designed and operated in such a way that it compensates for the amount of heat required for the reaction and the heat radiation loss from the gas production equipment, and allows continuous operation while maintaining thermal equilibrium throughout the equipment.

Therefore, the raw oil gas and the air and water vapor used as the gasifying agent are preheated to a temperature at which the partial combustion reaction is likely to occur by recovering the sensible heat of the production gas using a heat recovery device such as a heat exchanger, and maintaining thermal equilibrium. This enables continuous operation.

However, if the raw material throughput of the gas production equipment is lowered to reduce the operational load, the heat loss from the equipment is almost constant, but the reforming catalyst, such as nickel-magnesia, nickel-alumina, or nickel-magnesia, Due to the restriction of the optimum temperature range of the alumina-dolomite catalyst, the amount of partial combustion of the raw material oil and gas is restricted, and the partial combustion heat is reduced to 100% of the operating load.
It becomes relatively smaller than the relevant time (design value), the amount of heat for recovery also decreases, and the preheating temperature of the raw material oil gas and gasification agent becomes low.

For this reason, the cooling rate of the catalyst is faster than the rate at which the raw material mixture gas is partially combusted in the catalyst layer and the temperature is raised from the preheating humidity to the reaction temperature. The partial combustion reaction zone recedes and the reforming reaction zone becomes shorter.

A so-called "blow-through" phenomenon occurs, eventually making continuous operation impossible.

In addition, when operating at a low load, the flow of gas within the reforming catalyst layer becomes non-uniform, the temperature distribution becomes disturbed, carbon is generated, and the catalyst collapses, making long-term continuous operation impossible.

Generally, this operating load is considered to be at a minimum of around 60%, so in the city gas business, in addition to changing the operating load, it is necessary to change the operating load in response to demand fluctuations depending on the day and night and seasons (summer, winter), as well as intermittent operation of gas production equipment. The current situation is to accommodate operating fluctuations by installing backup manufacturing equipment or by installing larger gas holders than necessary.

Moreover, intermittent operation of the device, which is characterized by continuous operation, shortens the life of the catalyst and complicates work management.

In contrast, the present invention uses petroleum-based feedstock oil (hereinafter referred to as feedstock oil) in an atmospheric pressure partial combustion type oil and gas generator,
When producing oil and gas, a part of the production gas produced through a reformer (hereinafter referred to as recycled gas) is used as raw material oil and gas obtained by vaporizing raw material oil (hereinafter referred to as raw material oil and gas) and as a gasifying agent. A method for producing oil and gas by a normal pressure catalytic partial combustion method, which is characterized in that oil and gas are mixed with air and steam, and then returned to a reforming furnace. A part of the gas generated from the equipment, such as reformed gas from the furnace, CO converted gas from the CO conversion furnace, and manufactured gas with adjusted combustibility, is recycled and added to the feed oil gas, and hydrogen in the recycled gas is recycled. As a result, the combustion rate of the raw material oil gas, gasification agent, recycled gas, and mixed gas of the three (hereinafter referred to as raw material mixed gas) in the reforming catalyst bed is accelerated, and the preliminary temperature of the raw material mixed gas is low. Even if this happens, the blow-out phenomenon will not occur in the reforming catalyst layer, and the partial pressure of the raw material oil and gas in the raw material mixed gas will be reduced by the recycled gas, and the effect of hydrogen will be combined with that of carbon.

It is possible to suppress the precipitation phenomenon, expand the minimum operating load limit to around 45%, and enable long-term stable continuous operation.

In addition, in the catalytic partial combustion reaction, a similar phenomenon occurs when the activity of the reforming catalyst decreases, making continuous operation impossible. The hydrogen also activates the reforming catalyst to create a reducing atmosphere for the raw material mixed gas, thereby extending the life of the catalyst.

In addition, during low-load operation, the amount of recycled gas increases by the amount equivalent to the recycled gas, which prevents uneven gas flow within the reforming catalyst, uniforms the temperature distribution of the catalyst layer, and prevents carbon generation and catalyst damage. It also has the effect of suppressing collapse, etc.

In this way, when the recycled gas method of the present invention is adopted in gas production equipment as opposed to the conventional method, it is possible to expand the range of fluctuations in the operating load, reducing equipment costs such as spare production equipment and gas holders. It has been discovered that the present invention has very industrially significant features in terms of operational management, equipment costs, catalyst costs, etc., such as the ability to produce equivalent oil and gas with very low equipment costs. Ta.

Part 8 of the case where the method of the present invention uses LPG as a raw material and partially recycles the produced gas at the 9th station.
The details are as follows with reference to the drawings.

First, the raw material LPGS that indicates the operational load is the process LPGa.
The process LPGa is mixed with the recycle gas h immediately after the evaporator 12 and preheated as the raw material gas C through the LPG/gas heat exchanger 5, and then preheated in the mixer 1 in a separate system. It is mixed with process air i and supplied to the reforming furnace 2 as raw material mixed gas d.

This raw material mixed gas d can prevent carbon precipitation,
The combustion rate (CP), which is generally used to express the combustibility of gas under the Gas Business Law, is determined by the ratio of recycled gas (recycled gas h to total process LPGc') as shown in Figure 1.
The larger the ratio), the more effective it is.

Here, all processes L P G c' are processes LP, G
It is the sum of the heat-enhanced LPG in a and the recycled gas h.

Furthermore, the preheating temperature of this raw material mixed gas d is about 340 to 360 degrees Celsius in the case of low load operation of 44 to 50 degrees, which is about 50 degrees lower than 415 degrees Celsius when the operating load is north of 70 degrees. However, as mentioned above, the combustion rate increases and the linear velocity within the catalyst bed decreases, so the inlet part of the catalyst bed of the reformer 2 is the biggest drawback of low-load operation. There is no phenomenon in the atrium (as shown in the example, it shows a good temperature distribution, becomes reformed gas e, passes through the air secondary heat exchanger 3, and is converted into CO transformed gas f in the CO transformation furnace 4. After that, the heated LPG passes through heat exchangers 5, 6, scrubber 7.
b. The production gas G whose combustibility has been adjusted using the adjusted air j is pressurized in the pressure feeder 11, and most of the gas is sent into the fabric as city gas G, and a portion is recirculated as recycled gas h, resulting in low This makes continuous load operation possible.

Note that 9 is an air saturation tower.

In addition, a catalyst with reduced activity will cause a phenomenon in the blowhole, making continuous operation impossible, but as shown in the example, by adopting the recycled gas method, even with a catalyst with reduced activity, the humidity at the entrance of the catalyst bed will increase. The catalyst was activated without any phenomenon in the blowout, and continuous operation was possible even in low-load operation where the preheating temperature was low, and it was clear that the catalyst, which had become unusable using known methods, was now even more durable. This extends the life of the catalyst.

Furthermore, even if naphtha, which is commonly used as a raw material, is compared with the properties of LPG, such as the number of carbon atoms and the ratio of carbon to hydrogen (C/H), it is possible to expect the same effects of recycled gas as when using LPG as a raw material. It is easy to make an analogy.

Next, examples using the method of the present invention will be shown.

An example of the properties of the raw material LPG used is shown in Table 1.

In the basic test equipment, the raw LPG was gasified using the conventional atmospheric pressure catalytic partial combustion method using 31 catalysts A showing normal activity and 31 catalysts B showing reduced activity, and the results are shown in Table 2. .

Catalysts A and B used were both nickel-magnesia catalysts (Nip, containing 11%).

Catalyst B, which has decreased activity, has less hydrogen, more methane and nitrogen in the reformed gas than catalyst A, and has a higher calorific value, so it is less likely to produce LPG.
decomposition was poor, and the temperature at the bottom of the catalyst (raw material mixed gas inlet side) was low, causing problems in the atrium.

Actual equipment for the above catalysts A and B (furnace diameter 2120 mm)
) were filled with 3.5 m3 each, and LPG was gasified by the conventional atmospheric pressure catalytic partial combustion method. The results are shown in Table 3.

Since the operation was carried out using an actual device, the gasification results with catalyst A and catalyst B resulted in the same level of LPG decomposition, but when comparing Figures 2 and 3 showing the catalyst layer temperature distribution, the catalyst in Figure 3 In case B, the temperature at the center of the catalyst layer was low and the blow-out phenomenon clearly occurred, making continuous operation with about 10 holes impossible.

The height of the temperature recorder inside the reforming furnace is as follows.

Temperature recorder TR-1 is located at the bottom of the furnace and indicates the preheating humidity of the raw material mixed gas.

The humidity recorder TR-2 is located at a height of 240 mm from the bottom of the furnace, and indicates the temperature at the bottom of the catalyst layer (inlet side of the raw material mixed gas).

Temperature recorder TR-3 is located at a height of 540 m above the bottom of the furnace and indicates the humidity in the middle of the catalyst layer.

Temperature recorder TR-4 is located at a height of 750 mm from the bottom of the furnace and indicates the temperature above the catalyst layer.

The positions of the thermometers in FIGS. 4 to T below are also the same.

Next, by employing the recycled gas method of the present invention, 3.5 m3 of the catalyst with reduced activity was filled into an actual device to gasify LPG gas. The results are shown in Table 4.

The catalyst layer humidity distributions of test numbers A3 to A6 are shown in FIGS. 4 to 7, respectively.

By adopting the recycled gas method of the present invention even with catalyst B whose activity has decreased, gasification results as shown in Table 4 and humidity distributions as shown in Figures 4 to 7, which are equivalent to those of a normal catalyst, can be achieved. Continuous operation is possible, especially at low load of the 44th section as in test number A6, where the preheating temperature is 346°C.
Despite this, the effects of recycled gas enable continuous low-load operation, activating catalyst activity and extending the life of the catalyst.

[Brief explanation of drawings]

FIG. 1 shows the relationship between the recycled gas ratio and the combustion rate (c-p). FIG. 2 and FIG. 3 are the test number A I in the example,
16.2 shows the catalyst layer temperature distribution. FIG. 4 to FIG. 7 show the catalyst layer temperature distributions of test numbers 3 to A6 in Examples, respectively. FIG. 8 is a diagram of the oil and gas production process of an illegal example. 1... Raw material mixer, 2... Reforming furnace, 3... Air 2
Secondary heat exchanger, 4... CO conversion furnace, 5... LPG/gas heat exchanger, 6... Air primary heat exchanger, 7... Primary scrubber, 8... Secondary scrubber , 9... Air saturation column, 10... Flammability regulator, 11... Pressure feeder, 1
2... Process LPG evaporator, 13... Heating LPG
Evaporator, S... Raw material LPG, G... City gas, a.
... Process LPG, b... Heat-enhanced LPG, c... Raw material gas (process LPG + recycled gas), d...
Raw material mixed gas, e...Reformed gas, f...CO converted gas, g...Production gas, h...Recycled gas, i...
...process air, j...conditioned air.

Claims (1)

[Claims] 1 When producing oil and gas using petroleum-based feedstock (hereinafter referred to as feedstock) in an atmospheric pressure partial combustion oil and gas generator, a portion of the produced gas (hereinafter referred to as recycled gas) is produced through a reforming furnace. ), raw material oil gas (hereinafter referred to as raw material oil gas) obtained by vaporizing raw material oil, and air as a gasification agent,
A method for producing oil and gas using a normal pressure contact partial combustion method, which is characterized by mixing with water vapor and then returning the mixture to a reforming furnace.