Reactor for synthesizing dimethyl ether by biomass synthesis gas through one-step method and temperature control system

[0026] Example:

[0027] like Figure 1 to Figure 3 As shown, the reactor and temperature control system for the one-step synthesis of dimethyl ether from biomass synthesis gas in this embodiment is mainly composed of a steam drum 15 , a boiler 16 and a fixed bed reactor 17 . The fixed-bed reactor 17 is a tubular fixed-bed reactor. In the fixed-bed reactor 17, 36 reaction tubes 8 are distributed in parallel along the longitudinal direction of the reactor 17. The diameter of the reaction tubes 8 is 40 mm, and the adjacent The distance D between the cores of the two reaction tubes 8 is 2.5 times the diameter d of the reaction tubes 8, which is 100 mm in this embodiment; a reaction gas inlet 1 is provided at the top of the fixed-bed reactor 17, and the reactor near the top is The shell side 9 of 17 is provided with an exhaust port 5, and a superheated water outlet 6 is provided on both sides of the reactor 17 close to the exhaust port 5; the bottom end of the fixed-bed reactor 17 is provided with a reaction gas outlet 2, A liquid discharge port 4 is provided on the shell side 9 of the reactor 17 near the bottom end, and superheated water inlets 3 are respectively provided on both sides of the reactor 17 near the liquid discharge port 4; at the temperature measuring point 7 for measuring the temperature of the reaction tube 8;

[0028] Also includes a boiler 16, a steam drum 15 for storing superheated water transmitted from the boiler 16; a safety valve 19, a pressure gauge 22, a pressure regulating valve 12 are provided on the steam drum 15, and one end of the steam drum 15 is provided A liquid level gauge 18 is connected, and the other end is provided with a liquid discharge port 13. It also includes a superheated water inlet pipe 20 and a superheated water return pipe 21. One end of the superheated water inlet pipe 20 is connected to the steam drum. 15 is communicated, the other end is communicated with the superheated water inlet 3, one end of the superheated water return pipe 21 is communicated with the steam drum 15, and the other end is communicated with the superheated water outlet 6.

[0029] The operation steps of the temperature control system of the reactor for the one-step production of dimethyl ether from biomass synthesis gas in the present embodiment are as follows:

[0030] The dimethyl ether synthesis catalyst is packed in the reactor tube, and the reducing gas (95% N 2 +5%H 2, volume ratio), the catalyst is reductively activated, and the reacted reducing gas is discharged from the reaction gas outlet 2;

[0031] Turn on the boiler 16 and deliver superheated water to the steam drum 15 . Open the exhaust port 5 at the upper end of the shell side of the reactor, close the liquid drain port 4 at the bottom of the shell side, and the superheated water in the steam drum 15 slowly enters the reactor shell side from the superheated water outlet 11 through the hot water inlet 3 until When a small amount of water overflows from the upper exhaust port 5, the exhaust port 5 is closed, and the superheated water is returned to the steam drum 15 through the hot water return port 10 on the hot water return pipe 21.

[0032] Adjust the pressure regulating valve 12 on the steam drum 15 to maintain the pressure in the steam drum 15 at 0.14MPa, 0.62MPa and 2.32MPa respectively. At this time, the corresponding temperatures of the superheated water are 110°C, 160°C and 220°C, respectively. The synthesis catalyst was reductively activated according to this temperature program.

[0033] After the catalyst activation reaction is completed, the reducing gas is switched to biomass synthesis gas, and the pressure of the steam drum is adjusted to 2.32MPa through the pressure regulating valve 12. At this time, the temperature corresponding to the superheated water is 220°C. The dimethyl ether synthesis reaction is carried out at this temperature.

[0034] When the system needs to be stopped after running, first close the boiler 16, stop the delivery of superheated water to the steam drum 15, reduce the pressure in the steam drum 15 through the pressure regulating valve until it is consistent with the outside air pressure; open the liquid outlet 13 to exhaust the steam The liquid in the bag 15 is opened, and the liquid drain 4 is opened again to drain the liquid in the shell side 9 of the reactor. The catalyst in the reaction column 8 is cooled to room temperature, and the N 2 After purging, the reactor can be opened to remove the catalyst.

[0035] Said catalyst in the present embodiment is the bifunctional catalyst for the one-step synthesis of dimethyl ether with the patent number of CN1785519, and the biomass synthesis gas component is: H 2 37.60% (volume ratio, the same below), CO 35.39%, CO 2 8.54%, CH 4 2.82%, N 2 15.65%. The main results of system operation are as follows:

[0036] Airspeed/(h -1 )