JPS58193738A - Catalyst for production of gas enriched with hydrogen - Google Patents

Abstract

PURPOSE:To provide a catalyst for production of a gas enriched with H2 is provided with high activity, high selectivity and a long service life, by depositing the oxide f copper, zinc and chromium on a carrier. CONSTITUTION:A carrier of alumina or the like is immersed in an aq. nitrate soln., etc. of active metals such as copper, zinc and chromium and is dried and calcined, whereby the oxide of copper and zinc or the oxide of copper, zinc and chromium is deposited thereon and a catalyst for production of a gas enriched with H2 is obtained. The catalyst active component is dispersed satisfactorily in the carrier of such catalyst and there is no crystallization of the catalyst active component; therefore, the catalyst has excellent durability. The catalyst has high activity at low temp. and excellent selectivity as well.

Description

【発明の詳細な説明】 本発明は水素富化ガス製造用触媒に関し、更に詳しくは
メタノールと水との反応により水素富化ガスを製造する
際に用いられる高活性、高選択性、長寿命の触媒に関す
るものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a catalyst for producing hydrogen-enriched gas, and more specifically, a catalyst with high activity, high selectivity, and long life that is used when producing hydrogen-enriched gas by the reaction of methanol and water. It is related to catalysts.

現在、発電用ボイラ、内燃機関などに用いられる液体燃
料や、気体燃料及び還元カス製造用原料には原油及びそ
れから精製された石油類が使用されているが、最近の原
油価格の高騰のため燃料の多様化が指向されて原油以外
の化石燃料から合成されるメタノールが注目されている
。Currently, crude oil and petroleum products refined from it are used as liquid fuel for power generation boilers, internal combustion engines, etc., as well as gaseous fuel and raw materials for producing reduced residue, but due to the recent rise in crude oil prices, Methanol, which is synthesized from fossil fuels other than crude oil, is attracting attention.

またメタノールは、ナフサよりけるかに低温で水素、−
酸化炭素を含むガスに改質されるので、上記改質反応の
熱源として廃熱の適用が可能であるという優位性をもっ
ている。Also, methanol can produce hydrogen at a much lower temperature than naphtha.
Since it is reformed into a gas containing carbon oxide, it has the advantage that waste heat can be used as a heat source for the reforming reaction.

この改質反応は、次の通りである。This modification reaction is as follows.

ＣＨＩＩ　ＯＨ，ＯＯ＋２Ｈ２△Ｈ２５℃＝２１．７ｋ
ｃａｔ／ｍｏ／−ＣＨ３０Ｈ＋Ｈ２０→Ｃ０２−１−３
Ｈ２△Ｈ２５℃＝１１．８ｋｃａｔ／ｍｏｔこの反応で
生成した改質ガスは、改質反応の吸熱量（ΔＨ）相当分
だけ改質ガスの発熱量が増加するという利点と、さらに
この生成した改質ガスは高オクタン価で、高出力設計の
内燃機関に適用すると圧縮比をあげて熱効率を改善する
ことや、メタノール燃焼時アルデヒド類などの排出もな
くクリーン燃焼が可能などの利点がある。CHII OH, OO+2H2△H25℃=21.7k
cat/mo/-CH30H+H20→C02-1-3
H2△H25℃=11.8kcat/mot The reformed gas produced by this reaction has the advantage that the calorific value of the reformed gas increases by the amount equivalent to the endothermic amount (ΔH) of the reforming reaction, and Quality gas has a high octane number, and when applied to an internal combustion engine with a high-output design, it has the advantage of increasing the compression ratio and improving thermal efficiency, and enables clean combustion without emitting aldehydes when burning methanol.

例えば、内燃機関の排ガスの顕熱を利用してメタノール
の改質反応を行わせる場合、排ガス温度に周知のと、と
く室温から７００℃程度の温度まで変化するため、幅広
い温度範囲にわたって内燃機関に搭載できる種変の少量
の触媒で、かつ高温下におかれていても改質性能が劣化
しない安定した触媒が必要である。For example, when carrying out a methanol reforming reaction using the sensible heat of the exhaust gas of an internal combustion engine, the temperature of the exhaust gas varies from room temperature to about 700°C, so the internal combustion engine can react over a wide temperature range. There is a need for a stable catalyst that can be installed in a small amount of different types of catalyst and that does not deteriorate its reforming performance even when exposed to high temperatures.

従来、メタノールと水との反応により水素含有量の高い
ガスを得るための触媒として種々のものが提案されてい
る。例えば、アルミナｃ以下ＡＴＯｓと記す〕などの担
体に白金などの璽族元素を担持した触媒（燃料路会誌、
第５９巻。Conventionally, various catalysts have been proposed for obtaining a gas with a high hydrogen content through the reaction of methanol and water. For example, a catalyst (Fuel Road Society Journal,
Volume 59.

第６３３号、４０頁、１９８Ｑ年〕あるいけニッケルを
担持した触媒（特開昭５０−３５２０３号、同５１−１
２２１０２号）などが提案されているが、これらの触媒
はメタンを生成する反応が起りやすく、水素を生成する
反応の選択性が悪く、そのため耐久性に乏しいなど、現
在までのところ、多くの問題点を残している。No. 633, p. 40, 198Q] Catalyst supporting nickel (JP-A-50-35203, JP-A-51-1)
No. 22102), but these catalysts have many problems to date, such as being prone to reactions that produce methane, having poor selectivity in reactions that producing hydrogen, and therefore lacking in durability. leaving a mark.

また、上述した金属担持法による触媒調製法とは別に、
沈殿法による触媒調製法があり、後者の方法により調製
される触媒の代表例としては、亜鉛、クロムさらには銅
を含有することからなるメタノール合成用触媒、銅、亜
鉛を含有することからなる一酸化炭素転化反応用触媒が
あるが、沈殿法による触媒調製法であるため、反応に有
効に使われる触媒活性成分の割合が少なく、壕だ耐久性
に乏しいという問題がある。In addition to the catalyst preparation method using the metal supporting method described above,
There is a catalyst preparation method using the precipitation method. Typical examples of catalysts prepared by the latter method include a methanol synthesis catalyst containing zinc, chromium and even copper, and a catalyst containing copper and zinc. There are catalysts for carbon oxide conversion reactions, but since the catalysts are prepared using a precipitation method, the proportion of catalytic active components that can be effectively used in the reaction is small, and the problem is that they lack durability.

本発明者らは、上記の問題を解決すべく、研究を重ねた
結果、銅、亜鉛さらにはクロムの酸化物を組合せた触媒
がメタノールの分解反応およびメタノールと水との反応
に高活性であること、またこれらの酸化物は担体に担持
した方が比表面積が大きく触媒効率が高いことに注目し
、更に鋭意実験検討を重ねた結果、銅、亜鉛の酸化物あ
るいは銅、亜鉛、クロムの酸化物を担体に担持した触媒
が、メタノールと水とから水素富化ガスを得る反応に対
し、高活性でかつ選択性に非常に優れていることを見出
し、本発明を完成するに至った。In order to solve the above problems, the present inventors have conducted repeated research and found that a catalyst that combines oxides of copper, zinc, and even chromium has high activity in the decomposition reaction of methanol and the reaction between methanol and water. In addition, we focused on the fact that these oxides have a larger specific surface area and higher catalytic efficiency when supported on a carrier, and as a result of further intensive experimental studies, we found that copper, zinc oxides, or copper, zinc, and chromium oxides. The present inventors have discovered that a catalyst in which a substance is supported on a carrier has high activity and excellent selectivity for the reaction of producing hydrogen-enriched gas from methanol and water, leading to the completion of the present invention.

触媒の選択性は、特に、メタノールから水素のみを製造
しようとする場合に重要となる。メタノールからできる
だけ多くの水素を得るためには、第１段階として触媒を
利用し、 ＣＨ３０Ｈ十Ｈ２０＝　ＣＯ２４５Ｈ９なる反応により
炭酸ガスと水素に分解し、第２段階として炭酸ガスを吸
収液等で除去することにより水素を製造する方法が最も
有望である。The selectivity of the catalyst is particularly important when it is intended to produce only hydrogen from methanol. In order to obtain as much hydrogen as possible from methanol, the first step is to use a catalyst to decompose it into carbon dioxide and hydrogen through the reaction CH30H+H20=CO245H9, and the second step is to remove carbon dioxide with an absorbent, etc. The most promising method is to produce hydrogen by

この場合、第１段階の反応において水素と炭酸ガスへの
選択性が悪く、これら以外の物質が生成すると、第２段
階の分離工程が複雑になり、ひいては製造コストの上昇
につながることから、第１段階に使用する触媒の選択性
が非常に重要となる。In this case, the selectivity to hydrogen and carbon dioxide gas is poor in the first stage reaction, and if substances other than these are produced, the second stage separation process will be complicated, and this will lead to an increase in production costs. The selectivity of the catalyst used in the first stage is very important.

本発明は、メタノールと水との反応により水素富化ガス
を得るための触媒として、銅、亜鉛の酸化物あるいは銅
、亜鉛、クロムの酸化物を担体に担持した触媒を提供す
るものである。The present invention provides a catalyst in which an oxide of copper or zinc or an oxide of copper, zinc, or chromium is supported on a carrier as a catalyst for obtaining hydrogen-enriched gas by the reaction of methanol and water.

本発明における担体は特に限定されるものではないが、
例えばアルミナ担体、アルミナをチタニアやジルコニア
で被覆した担体、チタニア担体等が有効である。The carrier in the present invention is not particularly limited, but
For example, an alumina carrier, a carrier made of alumina coated with titania or zirconia, a titania carrier, etc. are effective.

上記担体に、銅、亜鉛又は銅、亜鉛、クロムの活性金属
の酸化物を担持させる方法は、従来から用いられている
方法でよく、例えば上記活性金属の硝酸塩水溶液等に担
体を浸漬後、乾燥、焼成すれば、上記活性金属の酸化物
が担持された触媒が得られる。The method for supporting copper, zinc, or oxides of active metals such as copper, zinc, and chromium on the above-mentioned carrier may be any conventional method. For example, the carrier is immersed in an aqueous nitrate solution of the above-mentioned active metal, and then dried. By calcination, a catalyst on which the active metal oxide is supported can be obtained.

銅、亜鉛の酸化物を担持させる場合のそれぞれの酸化物
の担持量Ｆｉ１〜５０重量％が好１しく・また銅、亜鉛
、クロムの酸化物を担持させる場合のそれぞれの酸化物
の相持量も１〜５０重量％が好ましい。When supporting oxides of copper and zinc, the amount of each oxide supported is preferably Fi 1 to 50% by weight. Also, when supporting oxides of copper, zinc, and chromium, the amount of each oxide supported is also 1 to 50% by weight is preferred.

以上のようにして得られた触媒は、メタノールと水とか
ら水素富化ガスを生成する反応に対し、２５０℃という
低温で高活性を示し、さらに生成ガスの組成が水素７５
％、炭酸ガス２５％のほぼ理論量になるという非常属選
択性に優れた触媒活性を示すものである。The catalyst obtained as described above exhibits high activity at a low temperature of 250°C for the reaction of producing hydrogen-enriched gas from methanol and water, and furthermore, the composition of the produced gas is hydrogen 75%.
% and carbon dioxide gas, which is approximately the theoretical amount of 25%, showing excellent catalytic activity in non-metallic selectivity.

なお、上記のように担体へ触媒活性成分を担持させた触
媒は、第３成分である担体に触媒活性成分が良好に分散
され、触媒活性成分の結晶化のない触媒であるため、沈
殿法で調製された触媒よりも耐久性に優れている。In addition, the catalyst in which the catalytically active component is supported on the carrier as described above is a catalyst in which the catalytically active component is well dispersed in the carrier as the third component, and the catalytically active component does not crystallize. It is more durable than prepared catalysts.

以下、実施例により本発明を具体的に説明する。Hereinafter, the present invention will be specifically explained with reference to Examples.

実施例１ 粒径２〜４　ｍｍ　のγ−Ａ４ｇｏ］から力るペレット
を硝酸銅、硝ｌｖ岨鉛水溶液に浸漬し、酸化銅、酸化亜
鉛で各５重量％づつ含有するように担持した触媒１を調
製した。Example 1 A catalyst 1 in which pellets made from γ-A4go with a particle size of 2 to 4 mm were immersed in an aqueous solution of copper nitrate and nitrate, and supported with copper oxide and zinc oxide in an amount of 5% by weight each. was prepared.

触媒１の活性評価を大気圧下でり、　Ｈ，Ｓ、　Ｖ、　
（液空間速度）　６　ｈ”　、反応原料メタノール−水
の等モル混合液なる条件で行い、結果を表１に示す。The activity of catalyst 1 was evaluated under atmospheric pressure, H, S, V,
(liquid hourly space velocity) 6 h", and an equimolar mixture of reaction raw material methanol and water. The results are shown in Table 1.

表　　１ なお、得られたガス中の水素の割合は、全て７０％以上
であった。Table 1 Note that the proportion of hydrogen in the obtained gases was all 70% or more.

実施例２ 実施例１と同じ方法で、酸化銅、酸化亜鉛、酸化クロム
を各５重量％づつ含有するように担持した触媒２を調製
し、実姉Ｎ１と同じ条件で活性評価を行い、結果を表２
に示す。Example 2 Catalyst 2 containing 5% by weight each of copper oxide, zinc oxide, and chromium oxide was prepared in the same manner as in Example 1, and its activity was evaluated under the same conditions as its older sister N1. Table 2
Shown below.

なお、得られたガス中の水素の割合は、全て７０％以上
であった。Note that the proportion of hydrogen in the obtained gases was all 70% or more.

実施例３ 担体としてチタニア担体、アルミナ・チタニア担体、ア
ルミナ・ジルコニア担体をそれぞれ用いる以外は実施列
１と全く同様にして酸化銅、酸化亜鉛を各５重量％づつ
含有するように担持した触媒３，４．５を調製し、反応
温度を３５０℃の一定にする以外は実施例１と同じ条件
で活性評価を行い、結果を表３に示す。Example 3 Catalyst 3 was prepared in exactly the same manner as in Example 1 except that a titania support, an alumina/titania support, and an alumina/zirconia support were used as supports, respectively, to contain copper oxide and zinc oxide in an amount of 5% by weight each. 4.5 was prepared and the activity was evaluated under the same conditions as in Example 1 except that the reaction temperature was kept constant at 350°C. The results are shown in Table 3.

表　　３ なお、得られたガス中の水素の割合は全て７０％以上で
あった。Table 3 Note that the proportion of hydrogen in the obtained gases was all 70% or more.

比較例１ 硝酸銅（３水塩）７６ｇ、硝酸亜鉛（６水塩）８５、３
　、、硝酸クロム（９水塩）　６５．８　ｇを水２ｔに
溶解し、これにａ　５　ｍｏｌ／ｌの炭酸ソーダ水溶液
をｐｉ（７まで良く攪拌しながら加え、沈殿を生成させ
、この沈殿物を濾過、洗浄し、粒径２〜４　ｍｍ　のペ
レットにして、１００℃で乾燥後、３Ｆ４０℃で３時間
焼成して酸化鋼４０％、酸化亜鉛４０％、酸化クロム２
０％を含有する触媒を得た。Comparative Example 1 Copper nitrate (trihydrate) 76g, zinc nitrate (hexahydrate) 85.3
,,Dissolve 65.8 g of chromium nitrate (nase hydrate) in 2 tons of water, add a 5 mol/l aqueous solution of sodium carbonate to it with good stirring until pi (7), form a precipitate, and dissolve this precipitate. The pellets were filtered and washed, made into pellets with a particle size of 2 to 4 mm, dried at 100°C, and then fired at 3F and 40°C for 3 hours to produce 40% steel oxide, 40% zinc oxide, and 2 chromium oxide.
A catalyst containing 0% was obtained.

この触媒の活性評価を実施例１と同じ条件で行ったとこ
ろ、表４の結果を得た。When the activity of this catalyst was evaluated under the same conditions as in Example 1, the results shown in Table 4 were obtained.

表　　４ なお、得ら浄だガス中の水素の割合は全て７０％以上で
あった。Table 4 Note that the proportion of hydrogen in the obtained purified gases was all 70% or more.

比較例２ 比較例１の硝酸クロムを添加しない以外は比較例１と同
様の方法で操作し、酸化銅５０％、酸化亜鉛５０％から
なる触媒を調製した。この触媒の活性評価を実施例１と
同じ条件で試験したところ表５の結果を得た。Comparative Example 2 A catalyst consisting of 50% copper oxide and 50% zinc oxide was prepared in the same manner as in Comparative Example 1 except that chromium nitrate was not added. When the activity of this catalyst was tested under the same conditions as in Example 1, the results shown in Table 5 were obtained.

表　　５ なお、得られたガス中の水素の割合は、全ての温度で７
０％以上であった。Table 5 The proportion of hydrogen in the obtained gas was 7 at all temperatures.
It was 0% or more.

しかし、比較例１．２の沈殿法で調製した触媒は、活性
金属の含有濃度が高く、高価であるわりには、本発明触
媒以上の性能は得られなかった。However, although the catalyst prepared by the precipitation method of Comparative Example 1.2 contained a high active metal concentration and was expensive, it did not provide better performance than the catalyst of the present invention.

実施例４ 実施例２で調製した触媒２と実施例３で調製した触媒４
．５及び比較例１で調製した触媒について大気圧下でり
、　Ｈ，Ｓ、　Ｖ、　６　ｈ−１、反応原料がメタノー
ル−水の等モル混合液という条件で反応温度を５５０℃
に一定にして５０時間連続運転を行った。この結果、表
６に示すように、比較例１で調製した触媒が約１割の活
性低下を示したのに対し、本発明触媒は殆んど低下せず
耐久性にお−て優れて−ることが判った。Example 4 Catalyst 2 prepared in Example 2 and Catalyst 4 prepared in Example 3
．． The catalysts prepared in No. 5 and Comparative Example 1 were subjected to the following conditions: H, S, V, 6 h-1, and the reaction temperature was 550° C. under the conditions that the reaction raw material was an equimolar mixture of methanol and water.
Continuous operation was carried out for 50 hours at a constant temperature. As a result, as shown in Table 6, while the catalyst prepared in Comparative Example 1 showed a decrease in activity of about 10%, the catalyst of the present invention showed almost no decrease in activity and was excellent in durability. It turns out that

表　　６ なお、実施例におりｚ−ｃｔｊ粒状触媒について記述し
であるが、触媒の形状は特に限定するものでなく、ハニ
カム状、板状などの触媒形状を用φてもＪＩＬ−ことは
言うまでもない。Table 6 Although Z-CTJ granular catalysts are described in the examples, the shape of the catalyst is not particularly limited, and it goes without saying that catalyst shapes such as honeycomb shape and plate shape can also be used. stomach.

以上、実施例に示したように本発明における触媒は、メ
タノールと水を反応させて水素富化ガスを得る反応に対
し低温で、高活性、高選択性、かつ長痔命の触媒である
ことが明らかである。As shown in the examples above, the catalyst of the present invention is a catalyst with high activity, high selectivity, and long life at low temperature for the reaction of methanol and water to obtain hydrogen-enriched gas. is clear.

２０６206

Claims (1)

【特許請求の範囲】[Claims] 担体に銅、亜鉛の酸化物又は銅、亜鉛、クロムの酸化物
を担持させたことを特徴とする水素富化ガス製造用触媒
。A catalyst for producing hydrogen-enriched gas, characterized in that a carrier supports an oxide of copper or zinc or an oxide of copper, zinc or chromium.