CN101181685A - Catalyst for preparing hydrogen-rich gas by coke oven gas and preparation method thereof - Google Patents

Abstract

The invention relates to a catalyst which is used for preparing hydrogen-rich gas from coke-oven gas in coking and chemical industry and a preparation method thereof, pertaining to coke-oven gas catalytic pyrolysis technique and catalyst technology field. The catalyst of the invention consists of a carrier, active components and auxiliary components. Natural olivine powder is adopted as the carrier, which accounts for 90 to 98 percent of total weight of the catalyst; the active component is Ni, which accounts for 1 to 5 percent of total weight; the auxiliary component is rare earth or alkaline earth metal element, which accounts for 0 to 5 percent of total weight; the rare earth element is one of La, Ce, Pr and Nd, and the alkaline earth metal element is any of Mg, Ca, Si and Ba. The olivine is grinded and screened, and then the natural olivine powder is obtained. The components of the olivine are: (wt percent) MgO 45 to 55, SiO2 35 to 45, Fe2O3 7.1 to 9.2, Al2O3 0.7 to 0.9, CaO 0.35 to 0.38, Cr2O3 0.55 to 0.65 and NiO 0.34 to 0.38. The preparation method of the catalyst comprises pretreatment of the carrier and processes which adopt active components and auxiliary components like soaking, drying and roasting, etc. The invention has the advantages that: tar scission reaction of the catalyst has high reactivity, good stability and long service life.

Description

The Catalysts and its preparation method that is used for preparing hydrogen-rich gas by coke oven gas

Technical field

The present invention relates to a kind of Catalysts and its preparation method that is used for the coking industry preparing hydrogen-rich gas by coke oven gas, belong to coke-stove gas Deep Catalytic Cracking process and catalyst technical field.

Background technology

Remove in the coal oven dithio-gas of coal through gasification and Pintsch process generation in the coking industry production and contain H ₂, H ₂O, CH ₄, CO and CO ₂Outside main component, also contain from ethane to coal tar wet goods volatile organic component.Coal tar can be divided into low temperature tar and high-temperature coke temperature by the difference of pyrolysis temperature, and the tar that modern coking obtains in producing belongs to high temperature tar.High temperature tar is the complex mixture of mainly being made up of aromatic hydrocarbon such as benzene, naphthalenes, and its content in raw coke oven gas generally is about 100g/m ³Coal oven dithio-gas can obtain chemical products such as crude benzol and tar through purifying, but the income of these products compensates the expense of gas purification not enough, therefore consider from economy and environmental protection aspect, by making full use of the physics heat and the chemical energy of moisture component of coke oven gas self, directly high temperature coke oven coal coal gas is carried out cracking, reformation dry gasification, the hydrogen component is increased considerably, make coke-stove gas be able to the cheap hydrogen-rich gas of production high added value on a large scale.At present, it is one of the most effective, most reasonable approach that efficiently increases hydrogen that catalytic pyrolysis transforms coke-stove gas, thus develop high efficiency, long-life, easily regeneration, catalyst cheap and easy to get have become various countries and have pressed for one of emphasis problem of solution.

The article of one piece " by the tar in pyrolysis and the steam reformation critical heat coke-stove gas " that " Journal of Chemical Engineering of Japan " (2003 the 36th volume the 7th phase 735-714 pages or leaves) delivered, openly reported the catalyst of two kinds of catalytic cracking of tar, they are respectively the Ni/K of S ü d-Chemie company ₂OAl ₂O ₃The Ni/MgOAl of commercialization catalyst and Haldor-Tops ф e company ₂O ₃The commercialization catalyst.

One piece of delivering in " Journal of Chemical Engineering of Japan " (2006 the 39th volume the 4th phase 461-468 page or leaf) " passes through Ni/Al ₂O ₃Catalyst is converted into light Fuel gas with hot coke-stove gas " article, openly reported a kind of catalytic cracking of tar catalyst, it is the Ni/Al of S ü d-Chemie company ₂O ₃Commercialization catalyst (No.C13-4).

Application number is the catalyst that discloses a kind of coke-stove gas partial oxidation preparing hydrogen-rich gas in 200610018740.3 the Chinese invention patent.This catalyst is the Z204/Z205/CN-20 catalyst, 450 ℃ of this catalyst initial activity temperature, anti-1600 ℃ of maximum temperature; Wherein Z204 is that southwestern chemical research institute produces product, and reforming catalyst is shaped as Ф 19 * 19 * 9 mm rounds, main component quality %:NiO 〉=14%, CaO ≈ 10%, Al ₂O ₃≈ 55%; Z205 is that southwestern chemical research institute produces product, and reforming catalyst is shaped as Ф 25 * 17 * Ф 10 mm rounds, main component quality %:NiO 6 ± 1%, CaO ≈ 3.5%, Al ₂O ₃≈ 90%; CN-20 is that southwestern chemical research institute produces product, and reforming catalyst is shaped as Ф 19 * 19 * 9 mm rounds, main component quality %:NiO 〉=14%, CaO ≈ 6%, Al ₂O ₃≈ 76%.

Application number is the method that discloses a kind of coke oven gas adsorption reinforced catalysis preparing hydrogen-rich gas in 200610155081.7 the Chinese invention patent.The catalyst that this method adopts is mainly by being the calcium oxide of presoma with micron order and/or nano level calcium carbonate and/or calcium hydroxide powder and being composited with nickelous carbonate, nickel oxide or nickel nitrate composition and aluminium oxide, silica supports.

Summary of the invention

The object of the present invention is to provide a kind of Catalysts and its preparation method that is used for the coking industry preparing hydrogen-rich gas by coke oven gas.

A kind of catalyst that is used for preparing hydrogen-rich gas by coke oven gas of the present invention is characterized in that having following composition:

Natural olivine powder 90～98wt% is as the carrier of catalyst;

Metal Ni element 1～5wt% is as the activity of such catalysts component;

Rare earth or alkali earth metal 0～5wt% are helper component;

Above-mentioned natural olivine powder for no right olivine through pulverizing, sieve, and after high-temperature roasting the powder of gained; The constituent of this olivine is as follows: (wt%)

MgO 45～55，SiO ₂ 35～45，Fe ₂O ₃ 7.1～9.2，Al ₂O ₃ 0.7～0.9，CaO 0.35～0.38，Cr ₂O ₃ 0.55～0.65，NiO 0.34～0.38；

Above-mentioned rare earth element is any among La, Ce, Pr, the Nd;

Above-mentioned alkali earth metal is any among Mg, Ca, Sr, the Ba.

A kind ofly be used for the Preparation of catalysts method that the coke oven furnace gas is produced hydrogen-rich gas, it is characterized in that having following process and step:

A. natural olivine is pulverized, sieved, keep the powder of 20～40 orders or 60～80 order granular sizes, be put in the Muffle furnace and calcined 3～5 hours down at 700～1000 ℃;

B. with above-mentioned gained powder as catalyst carrier, adopt and to soak mode altogether or branch soaks the mode load active component; The mode of soaking is altogether: the mixed nitrate solution that calculates and prepare nickel salt, rare earth element or alkali earth metal by carrier loaded active component and helper component with stoichiometry; Described carrier is soaked in the described solution, under 50～80 ℃ of temperature, soaked 1～5 hour, fry and do, be put in dried overnight in 110 ℃ of baking ovens again; The another kind of mode of soaking of dividing is: carrier is soaked in respectively in the nitrate solution of rare earth or alkaline-earth metal, under 50～80 ℃ of temperature, soaked 1～5 hour, fry and do, again 350 ℃ of following roastings 2 hours, and then be soaked in the nickel nitrate solution, under 50～80 ℃ of temperature, soaked 1～5 hour, fry and do, be put in dried overnight in 110 ℃ of baking ovens;

C. with above-mentioned soaked carrier again 300～400 ℃ of roasting temperatures 0.5～3 hour, nitrate is all decomposed; At last 800～1200 ℃ of following roastings 4～8 hours; Finally obtain catalyst.

The catalyst that the inventive method makes is applied in the reaction of preparing hydrogen-rich gas by coke oven gas, and its every technological parameter is as follows: reaction temperature is 650～900 ℃, air speed 500～100,000h ^-1, the tar volume content is 0.01～5% in the reaction, H ₂Volume content is 30～60%, CH ₄Volume content is 5～25%, H ₂The O volume content is 10～40%, N ₂Volume content is 0～10%, H ₂The S volume content is 0～0.5%, C ₂-C ₅Cut 0～2%.

The inventive method prepares pyrolysis reactivity height, good stability, the long service life of the catalyst of gained to tar; In addition, the inventive method technology is simple, and is easy and simple to handle, low cost of manufacture.

Description of drawings

Fig. 1 is nitrogen adsorption isotherm and the graph of pore diameter distribution of the used olivine of one embodiment of the invention (900 ℃ of roasting 3h).

Wherein (a) is nitrogen adsorption desorption thermoisopleth, (b) is graph of pore diameter distribution.

Fig. 2 is the XRD figure spectrum of used olivine of one embodiment of the invention (900 ℃ of roasting 3h) and nickel-loaded catalyst.

Fig. 3 is the curve map over time of micro-molecular gas volume percent content in one embodiment of the invention cracking and catalyzing reaction.

Wherein (a) is olivine (SV=3154h ^-1); (b) be olivine (SV=6308 ^-1H); (c) be olivine (SV=6308h for Ni/ ^-1).

The specific embodiment

After now specific embodiments of the invention being described in.

Embodiment 1

Active component Ni weight percent content is the preparation of 2% catalyst sample:

Natural olivine grinding screen is got 20～40 order particles, 900 ℃ of roasting 3h, take by weighing 0.6066g nickel nitrate hexahydrate, be dissolved in the deionized water, again the pretreated olivine of 6g was soaked in the above-mentioned solution 4 hours at 80 ℃, fries and do, dried overnight in 110 ℃ of baking ovens, 800 ℃ of roasting 4h get catalyst n i/olivine.

Olivine in addition is the English name of olivine.

The composition analysis of olivine (Olivine) behind 900 ℃ of roasting 3h sees the following form 1.

The composition analysis (XRF) of table 1 olive olive stone (900 ℃ of roasting 3h)

	MgO	SiO 2	Fe 2O 3	Al 2O 3	CaO	Cr 2O 3	NiO
								Olivine	51.80	36.50	9.14	0.88	0.37	0.60	0.36

Referring to Fig. 1, Fig. 1 is nitrogen adsorption isotherm and the graph of pore diameter distribution of the used olivine of present embodiment (Olivine is in 900 ℃ of roasting 3h).

Wherein (a) is nitrogen adsorption desorption thermoisopleth, (b) is graph of pore diameter distribution.

Its specific area is 12.271m ²/ g, pore volume are 0.056cc/g, and the aperture is 3.745mm.

Referring to Fig. 2, Fig. 2 is the XRD figure spectrum of present embodiment with olivine (Olivine is in 900 ℃ of roasting 3h) and nickel-loaded catalyst.

Embodiment 2

Active component Ni weight percent content is 2%, and the La weight percent content is the preparation of 2% catalyst sample:

Natural olivine grinding screen is got 20～40 order particles, 900 ℃ of roasting 3h, take by weighing 0.6215g nickel nitrate hexahydrate and 0.3911g lanthanum nitrate hexahydrate, be dissolved in the deionized water, the more pretreated olivine of 6g was soaked in the above-mentioned solution 4 hours at 80 ℃, adopt the above-mentioned mode of soaking altogether, solution is loaded on the carrier, fry and do, dried overnight in 110 ℃ of baking ovens, 800 ℃ of roasting 4h get catalyst n i-La/olivine.

Embodiment 3

Active component Ni weight percent content is 2%, and the Mg weight percent content is the preparation of 2% catalyst sample:

Natural olivine grinding screen is got 20～40 order particles, 900 ℃ of roasting 3h, take by weighing 0.6278g nickel nitrate hexahydrate and 1.337g magnesium nitrate hexahydrate, be dissolved in the deionized water, the more pretreated olivine of 6g was soaked in the above-mentioned solution 4 hours at 80 ℃, adopt the above-mentioned mode of soaking altogether, solution is loaded on the carrier, fry and do, dried overnight in 110 ℃ of baking ovens, 800 ℃ of roasting 4h get catalyst n i-Mg/olivine.

Embodiment 4

Active component Ni weight percent content is 1%, and the Ce weight percent content is the preparation of 2% catalyst sample:

Natural olivine grinding screen is got 20～40 order particles, and 900 ℃ of roasting 3h adopt above-mentioned branch to soak mode, take by weighing the 0.3883g cerous nitrate hexahydrate, be dissolved in the deionized water, the more pretreated olivine of 6g be soaked in the above-mentioned solution 4 hours at 80 ℃, fry and do, 350 ℃ of roastings 2 hours, the carrier that will soak cerous nitrate again was soaked in the 0.6207g nickel nitrate aqueous solution 4 hours at 80 ℃, fried and did, dried overnight in 110 ℃ of baking ovens, 800 ℃ of roasting 4h get catalyst n i-Ce/olivine.

Catalyst of the present invention is applied to the reaction of preparing hydrogen-rich gas by coke oven gas, is the model compound of coal tar with toluene, and its result is as shown in table 2 below.

Table 2 catalysis preparing hydrogen-rich gas from coke oven gas reactivity test result

Oliveine(SV＝3154h -1)
										H 2	CO	CH 4	CO 2	C 7H 8	H 2O	C 7H 8Average conversion	CH 4Average conversion
Charge flow rate (ml/min)	54.76	6.80	29.16	3.00	1.76	62.22	97.55％	10.70％
									Go out throughput (ml/min)	79.44	16.33	26.04	7.77	-	-
oliveine(SV＝6308h -1)
										H 2	CO	CH 4	CO 2	C 7H 8	H 2O	C 7H 8Average conversion	CH 4Average conversion
Charge flow rate (ml/min)	109.54	13.61	58.32	6.00	3.52	124.45	82.45％	4.41％
									Go out throughput (ml/min)	137.20	28.68	55.75	10.11	-	-
Ni/oliveine(SV＝6308h -1)
										H 2	CO	CH 4	CO 2	C 7H 8	H 2O	C 7H 8Average conversion	CH 4Average conversion
Charge flow rate (ml/min)	109.54	13.61	58.32	6.00	3.52	124.45	100.00％	56.89％
									Go out throughput (ml/min)	243.45	62.82	25.14	15.22	-	-

Referring to Fig. 3, Fig. 3 is the curve map over time of micro-molecular gas volumn concentration in the cracking and catalyzing of the present invention reaction.

Wherein (1) is olivine (SV=3154h ^-1); (b) be olivine (SV=6308h ^-1); (c) be Ni olivine (SV=6308h ^-1).SV is air speed.

The reactivity test result listed by last table 2 illustrates: 800 ℃ of reaction temperatures, air speed are 6308h ^-1The time, toluene conversion is respectively 82.45% and 100% on olivine and the nickel-loaded catalyst, and methane conversion is respectively 4.41% and 56.89%, and hydrogen content has all that hydrogen content doubles above in the raising, particularly nickel-loaded catalyst in the aerogenesis.This shows that nickel-loaded catalyst has very high conversion ratio to toluene and methane.H in the course of reaction of 10h ₂, CO, CH ₄And CO ₂Flow all keep stable, illustrate that course of reaction do not have the generation of deactivation phenomenom.When reaction velocity is reduced to 3154h ^-1The time, toluene and methane conversion all are greatly improved on the olivine, are respectively 97.55% and 10.70%.

Claims (2)

1. catalyst that is used for preparing hydrogen-rich gas by coke oven gas is characterized in that having following composition:

Natural olivine powder 90～98wt% is as the carrier of catalyst;

Metal Ni element 1～5wt% is as the activity of such catalysts component;

Rare earth or alkali earth metal 0～5wt% are helper component;

Above-mentioned natural olivine powder be natural olivine through pulverize, screening, and after high-temperature roasting the powder of gained; The constituent of this olivine is as follows: (wt%)

MgO 45～55，SiO ₂ 35～45，Fe ₂O ₃ 7.1～9.2，Al ₂O ₃ 0.7～0.9，CaO 0.35～0.38，Cr ₂O ₃ 0.55～0.65，NiO 0.34～0.38；

Above-mentioned rare earth element is any among La, Ce, Pr, the Nd;

Above-mentioned alkali earth metal is any among Mg, Ca, Sr, the Ba.

2. Preparation of catalysts method that is used for preparing hydrogen-rich gas by coke oven gas is characterized in that having following process and step:

A. natural olivine is pulverized, sieved, keep the powder of 20～40 orders or 60～80 order granular sizes, be put in the Muffle furnace and calcined 3～5 hours down at 700～1000 ℃;

B. with above-mentioned gained powder as catalyst carrier, adopt and to soak mode altogether or branch soaks the mode load active component; The mode of soaking is altogether: the mixed nitrate solution that calculates and prepare nickel salt, rare earth element or alkali earth metal by carrier loaded active component and helper component with stoichiometry; Described carrier is soaked in the described solution, under 50～80 ℃ of temperature, soaked 1～5 hour, fry and do, be put in dried overnight in 110 ℃ of baking ovens again; The another kind of mode of soaking of dividing is: carrier is soaked in respectively in the nitrate solution of rare earth or alkaline-earth metal, under 50～80 ℃ of temperature, soaked 1～5 hour, fry and do, again 350 ℃ of following roastings 2 hours, and then be soaked in the nickel nitrate solution, under 50～80 ℃ of temperature, soaked 1～5 hour, fry and do, be put in dried overnight in 110 ℃ of baking ovens;

C. with above-mentioned soaked carrier again 300～400 ℃ of roasting temperatures 0.5～3 hour, nitrate is all decomposed; At last 800～1200 ℃ of following roastings 4～8 hours; Finally obtain catalyst.

Images