CN103288603B - Optimized dimethyl ether device driving method - Google Patents

Abstract

The invention discloses an optimized dimethyl ether device driving method. The optimized dimethyl ether device driving method comprises the following steps of: (1) firstly putting medium-pressure nitrogen before a dimethyl ether device drives; (2) in an initial stage, strictly controlling an inlet temperature of a reactor; (3) rapidly increasing a dimethyl ether load to 1.5%, stabilizing for a period of time, and observing bed temperature change; (4) after bed temperature is penetrated, continuously increasing the dimethyl ether load to more than 10%; (5) when the dimethyl ether load reaches the using standard, starting to eliminate a medium-pressure nitrogen system for increasing pressure; (6) increasing a system pressure to an operating pressure; and (7) producing a qualified dimethyl ether product. The optimized dimethyl ether device driving method has the beneficial effects that high pressure batch charging is adopted, a system pressure increasing process is reduced, driving time is reduced to less than 2 hours at present from the originally about 5 hours, the driving time is reduced by 3 hours, consumption of methanol during batch charging is reduced, driving cost is saved, and overtemperature of a catalyst bed layer in a driving process is prevented and charging time of the dimethyl ether device is reduced.

Description

A kind of dimethyl ether device starting method of optimization

Technical field

The present invention relates to a kind of dimethyl ether device starting method of optimization, belong to dimethyl ether device technical field of producing.

Background technology

Dme is a kind of important industrial chemicals, can be used for the synthesis of chemical, is a kind of emerging energy substitute, the physical property good due to it and chemical property, dme is made in the chemical industry such as pharmacy, fuel, agricultural chemicals, to have unique purposes, as easily compression, condensation, vaporization etc.Dme has very important effect in national economy, is one of new forms of energy product of greatly developing of country.At present both at home and abroad dimethyl ether production method is mainly methanol vapor phase method, this technical characterstic be technology maturation reliable, invest low, product adjustment flexibly, technique is simple, production cost is low.

China's dme production technology was through the development of nearly ten years, reach its maturity, but still there are some difficult problems in dme production process, feed intake in process as adopted the dme of heat-insulating fixed bed device, because feed intake pressure and air speed are well below normal design load (approximately only having 15%) of producing, the reaction times causing methanol steam to be detained at catalyst surface is long, a large amount of gatherings of reaction heat cause bed overtemperature, and only have by regulating methanol steam input to carry out control temperature, means are single, are difficult to the normal rising controlling bed temperature; Simultaneously because pressure of foundation when reaching dme pressure-raising load is too low, by long for the charging time that pressure of foundation during pressure-raising brings up to systems in operation pressure, and it is all continuous with system gas emptying in the startup procedure of whole dme, cause consuming quantity of methyl alcohol in startup procedure to increase, these problems cause larger potential safety hazard and financial loss to enterprise.

Summary of the invention

The object of the present invention is to provide a kind of dimethyl ether device starting method of optimization, beds overtemperature and shortening dimethyl ether device charging time in startup procedure can be prevented.

The object of the invention is to be achieved through the following technical solutions: a kind of dimethyl ether device starting method of optimization, increase a medium pressure nitrogen gas pipeline in the Reactor inlet of dimethyl ether device, feed intake in process in dimethyl ether device, it carries out according to following steps:

(1), first device drop into 3.5MPa medium pressure nitrogen gas before driving, and prevents the bed overtemperature that causes because catalyst activity under underload is high and improve pressure of initially driving;

(2), the initial stage, strict control dme load under corresponding reactor inlet temperatures, dme load is increased to 1.5%, slowly increases the inlet temperature of reactor until the inlet temperature of reactor reaches more than 245 DEG C;

(3), fast dme load is increased to 1.5%--10%, keeps bed temperature within design temperature 380 DEG C, and stablize temperature in, observe bed temperature change;

(4), after bed temperature penetrates, continue to increase more than dme load to 10%, wherein dme load often increases by 1.5%, and the inlet temperature of reactor increases 1-5 DEG C, prevents beds overtemperature in startup procedure;

(5) until dme load reaches use standard, start to move back medium pressure nitrogen gas system pressure-raising;

(6), system pressure is increased to working pressure;

(7) the dme product that, output is qualified.

Described medium pressure nitrogen gas pipeline is arranged twice gate valve with together with vacuum breaker, controlled the medium pressure nitrogen airshed entered in reactor by gate valve.

Beneficial effect of the present invention is: at Reactor inlet preparation medium pressure nitrogen gas pipeline, solve the reactor air speed in process that feeds intake low and cause the difficult problem of overtemperature, employing high pressure feeds intake, minimizing system pressure-raising process, the driving time foreshortens within current 2 hours by 5 original hours, driving time shorten 3 hours, reduces the consumption of methyl alcohol when feeding intake, save driving cost, to have prevented in startup procedure beds overtemperature simultaneously and shorten dimethyl ether device charging time.

Accompanying drawing explanation

Fig. 1 is production scheme of the present invention;

Fig. 2 is the structural representation of dimethyl ether device of the present invention.

Wherein, 1-reactor, 2-methanol evaporator, 3-input and output material interchanger, 4-medium pressure nitrogen gas pipeline, 5-well heater.

Embodiment

Technical scheme of the present invention is further described below in conjunction with accompanying drawing, but described in claimed scope is not limited to.

As Fig. 1, the dimethyl ether device that the present invention adopts is two step synthesis technology, take methyl alcohol as raw material, in dimethyl ether reactor, there is dehydration reaction after methyl alcohol vaporizing produce dme, then in dme rectifying tower, obtain the dme product that purity is greater than 99%wt, in waste water, methanol content is less than 200ppmwt, discharge amount of exhaust gas is few, dme is produced controlled methanol consumption and is determined primarily of dme startup procedure, beds overtemperature in dimethyl ether device startup procedure, charging time are long, directly affect the production cost of dme.In control dimethyl ether device startup procedure, reaction bed temperature and shortening start-of-run time are to reduction dme production cost, improve dme competitiveness of product in market important role.

A kind of dimethyl ether device starting method of optimization, a medium pressure nitrogen gas pipeline is increased in the Reactor inlet of dimethyl ether device, specifically between methanol evaporator 2 and input and output material interchanger 3, increase by a medium pressure nitrogen gas pipeline 4, feed intake in process in dimethyl ether device, it carries out according to following steps:

(1), first device drop into 3.5MPa medium pressure nitrogen gas before driving, and the temperature of nitrogen is normal temperature, and at this moment system pressure is at 0.1-0.3MPa, can prevent the bed overtemperature that causes because catalyst activity under underload is high and improve pressure of initially driving;

(2), the initial stage, reactor inlet temperatures corresponding under strict control dme load, shown in Fig. 2, the methanol steam flow that variable valve increase enters system is flowed to by b, the flow of governor valve control phlegma is flowed to by d, temperature required under making its outlet process gas meet corresponding load, is increased to 1.5% by dme load, slowly increases the inlet temperature of reactor until the inlet temperature of reactor reaches more than 245 DEG C;

(3), fast dme load is increased to 1.5%--10%, keeps bed temperature within design temperature 380 DEG C, and stablize temperature in, observe bed temperature change;

(4), after bed temperature penetrates, continue to increase more than dme load to 10%, wherein dme load often increases by 1.5%, the inlet temperature of reactor increases 1-5 DEG C, prevent beds overtemperature in startup procedure, wherein, the corresponding relation of the inlet temperature of dme load and reactor is as table one.

The corresponding relation of table one load and inlet temperature

	Dimethyl ether reactor load %	Inlet temperature DEG C
			1	0～1.5	245
2	8.5	250
			3	16.5	255
4	23.5	260

(5) until dme load reaches use standard, start to move back medium pressure nitrogen gas system pressure-raising;

(6), system pressure is increased to working pressure;

(7) the dme product that, output is qualified.

Described medium pressure nitrogen gas pipeline is arranged twice gate valve with together with vacuum breaker, controlled the medium pressure nitrogen airshed entered in reactor by gate valve.

Claims (1)

1. the dimethyl ether device starting method optimized, it is characterized in that: increase a medium pressure nitrogen gas pipeline in the Reactor inlet of dimethyl ether device, described medium pressure nitrogen gas pipeline is arranged twice gate valve with together with vacuum breaker, controlled the medium pressure nitrogen airshed entered in reactor by gate valve;

Feed intake in process in dimethyl ether device, it carries out according to following steps:

(1), first device drop into 3.5MPa medium pressure nitrogen gas before driving, and prevents the bed overtemperature that causes because catalyst activity under underload is high and improve pressure of initially driving;

(2), the initial stage, strict control dme load under corresponding reactor inlet temperatures, dme load is increased to 1.5%, slowly increases the inlet temperature of reactor until the inlet temperature of reactor reaches more than 245 DEG C;

(3), fast dme load is increased to 1.5%--10%, keeps bed temperature within design temperature 380 DEG C, and stablize temperature in, observe bed temperature change;

(4), after bed temperature penetrates, continue to increase more than dme load to 10%, wherein dme load often increases by 1.5%, and the inlet temperature of reactor increases 1-5 DEG C, prevents beds overtemperature in startup procedure;

(5) until dme load reaches use standard, start to move back medium pressure nitrogen gas system pressure-raising;

(6), system pressure is increased to working pressure;

(7) the dme product that, output is qualified.