WO2010044092A1 - Process for selective hydrogenation of alkynes to alkenes over single metal supported catalysts with high activity - Google Patents

Process for selective hydrogenation of alkynes to alkenes over single metal supported catalysts with high activity Download PDF

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WO2010044092A1
WO2010044092A1 PCT/IN2009/000043 IN2009000043W WO2010044092A1 WO 2010044092 A1 WO2010044092 A1 WO 2010044092A1 IN 2009000043 W IN2009000043 W IN 2009000043W WO 2010044092 A1 WO2010044092 A1 WO 2010044092A1
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catalyst
range
butynediol
hydrogenation
catalysts
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PCT/IN2009/000043
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French (fr)
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Amod Madhukar Sathe
Bapurao Sidram Shinde
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Hindustan Organic Chemicals Limited
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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C5/00—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms
    • C07C5/02—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms by hydrogenation
    • C07C5/08—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms by hydrogenation of carbon-to-carbon triple bonds
    • C07C5/09—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms by hydrogenation of carbon-to-carbon triple bonds to carbon-to-carbon double bonds
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
    • C07C29/17—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by hydrogenation of carbon-to-carbon double or triple bonds
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
    • C07C29/36—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring increasing the number of carbon atoms by reactions with formation of hydroxy groups, which may occur via intermediates being derivatives of hydroxy, e.g. O-metal
    • C07C29/38—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring increasing the number of carbon atoms by reactions with formation of hydroxy groups, which may occur via intermediates being derivatives of hydroxy, e.g. O-metal by reaction with aldehydes or ketones
    • C07C29/42—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring increasing the number of carbon atoms by reactions with formation of hydroxy groups, which may occur via intermediates being derivatives of hydroxy, e.g. O-metal by reaction with aldehydes or ketones with compounds containing triple carbon-to-carbon bonds, e.g. with metal-alkynes
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C2521/00—Catalysts comprising the elements, oxides or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium or hafnium
    • C07C2521/02—Boron or aluminium; Oxides or hydroxides thereof
    • C07C2521/04—Alumina
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C2523/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group C07C2521/00
    • C07C2523/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group C07C2521/00 of noble metals
    • C07C2523/40—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group C07C2521/00 of noble metals of the platinum group metals
    • C07C2523/44—Palladium

Definitions

  • US Patent # 5,583,274 claims selective hydrogenation of alkynes present in alkenes streams along with sulphur containing compounds, by using Pd/Ag catalysts containing fluorides in the form of potassium fluoride on alumina supports, whereas US Patent # 6,127,310 claims the use of Pd along with Pb and alkali metal or alkali metal halide as selectivity enhancers.
  • US Patents # 7,045,670 and 7,408,091 claim liquid phase selective hydrogenation of alkynes absorbed in liquid stream on Zn promoted Pd catalyst on alumina support, with hydrogen containing more than 2000 ppm CO.
  • US Patent #6,054,409 reports selective hydrogenation of unsaturated hydrocarbons in olefins with a Pd/Ag catalyst on a low surface area (2-20 mVg) alumina carrier with pore volumes greater than 0.4 cc/g and a particular size range of the pores.
  • a Pd/Ag catalyst on a low surface area (2-20 mVg) alumina carrier with pore volumes greater than 0.4 cc/g and a particular size range of the pores.
  • As per US Patent #5,750,806 selective hydrogenation of alkynes (acetylenes) to alkenes is reported on Pd/Bi monoliths in Trickle bed, and as per US Patent # 6,365,790 B 2 for Pd/Bi and Pd/Ag monoliths on Kanthal fabric.
  • Recent US Patent # 7,288,686 reveals complete removal of acetylenic compounds from hydrocarbon streams by using Pd with Ag/Zn/Bi/K in a fixed bed reactor.
  • Palladium catalysts containing one or more additional metal are also reported in prior art for selective hydrogenation of 1,4 butynediol to 1,4 butenediol/ 1,4 butanediol: Canadian Patent # 1,090,829 mentions palladium with lead in the form of lead acetate hydrate dozing to the reactor (autoclave). US Patent # 4,438,285 mentions use of Pd/Ru in a batch process, on activated carbon as well as alumina supports. US Patent
  • Ca, Mg, Ba carbonates (US Patents# 5,714,644; 6,469,221 Bl; 2006/0094910 Al); MgO (US Patent# 5,714,644); activated carbon (US Patent# 4,438,285); apart from the monoliths or fibers (US Patents# 5, 521,139; 5,750,806; 6,365,790 B2; Ind. Eng. Chem. Res., 44, 2005, 6148-6153) etc. are also reported in prior art. Reaction parameters, types of reactors etc.
  • Alkynes in the form of gases or gases absorbed in liquids are reported in prior art.
  • 1,4 butynediol is in the form of aqueous solution up to 50% concentration, excepting in one case (Ind.Eng.Chem.Res.44, 2005, 6148-6153), wherein molten pure 1,4 butynediol (from solid state) hydrogenation is reported in prior art.
  • the hydrogen gas reported in prior art is generally pure hydrogen; however controlled carbon monoxide addition to hydrogen for better selectivity towards double bond, is also reported in US patents # 5,750,806 and 6,365,730 B 2 .
  • Catalyst activity expressed in g of alkyne (or particularly 1,4 butynediol, as the case may be) reacted per day per gram of (total) metal contents in the catalyst is calculated typically for the following cases mentioned in prior art:
  • an activity in the range of 130 to 260 g butynediol/(day-g metal) can be calculated for the ranges Ni/Mo on AI 2 O 3 catalyst.
  • an activity of 75 g butanediol per hour i.e. 108 g butynediol reacted per hour can be calculated for 20 g Raney Ni/Mo catalyst used, which works out equivalent to 13O g butynediol reacted/ (day-g metal).
  • an activity in the range of 80 to 260 g butynediol reacted/ (day-g metal) can be calculated for the 1% Pt/ CaCO3 catalyst.
  • the catalyst activity works out to 160 g butynediol reacted/ (day-g metal).
  • the object of the present invention is to provide an efficient, commercially attractive process for the preparation of alkenes, particularly 1, 4 butenediol with high selectivity and activity per unit of metal contents, by hydrogenating the corresponding alkynes, particularly pure or technical grade 1,4 butynediol, under low pressure and temperature, in the absence of any additives for improving selectivity (e.g. CO), by a commercially available suitably supported catalyst containing a single metal component, prepared in any conventional manner and achieving a longer catalyst life.
  • selectivity e.g. CO
  • the object of the present invention is achieved by a process for the hydrogenation of alkynes, particularly technical grade 1 ,4 butynediol, in a reactor, in the presence of a standard commercial catalyst prepared in any conventional manner, working under hydrogenation pressure from 1 to 20 bar, at a temperature range of 15 to 250 0 C, under hydrogen pressure from 1 to 20 bar, under space velocity ranging from: GHSV 1 to 10,00Oh '1 , and LHSV 0.001 to 1Oh "1 .
  • the process is preferably carried out using pure or technical grade 1 ,4 butynediol- synthesized by various alternate routes correspondingly , from acetylene and aqueous formaldehyde.
  • the strength of butynediol solution is 20 to 60%, preferably aqueous solution.
  • the hydrogen gas is in pure form and in particular, carbon monoxide or any other compound is not periodically added to the same for controlling the selectivity.
  • the hydrogenation reaction is carried out in a continuous single tube bubble column up flow reactor.
  • the hydrogenation catalysts are capable of hydrogenating triple to double and subsequently to single bond compounds, which may contain very low amount of a single active metal, chosen from palladium, nickel, molybdenum, copper or platinum.
  • the active metal content may vary from 0.0001 to 1%, preferably from 0.0005 to 0.01%.
  • the catalyst support can be selected from alumina, alumino silicates, silica gel or activated carbons. More efficient utilization of the active metal results in high activity per unit of metal contents , at the same time giving very high selectivity.
  • typical physical properties of the catalyst being: the surface area between 3 to 300 mVg, preferably 5 to 10 m 2 /g; the pore volume between 0.05 to 0.6 cc/g, preferably 0.15 to 0.50 cc/g; the side crushing strength between 2 to 20 kg, preferably 5 to 15 kg.
  • the most preferred catalyst being palladium supported on alumina in a wide range of palladium contents offered within the range of these physical properties. Catalysts of this type are commercially available under the various grades as follows:
  • Li another embodiment of the invention the process is carried out under hydrogen pressures from 5 to 15 bar.
  • the process is carried out at a temperature in the range of 50-150 0 C.
  • the gas hourly space velocity (GHSV) for the process is in the range of 10 to 1000 h "1 .
  • liquid hourly space velocity (LHSV) for the process is in the range of 0.01 to 1 h '1 .
  • the catalyst is run consecutively for more than 5000 hours.
  • the process is scaled up 1: 10 times in a similar single tube reactor, without adversely affecting the selectivity of alkenes.
  • Hydrogenation reactor for the present study consisted of a standard stainless steel continuous single tube reactor, with an outside jacket arrangement for heat removal. Gas & liquid were introduced at the bottom of the reactor in co-current up flow manner. At the reactor outlet from the top, the two phases were separated in a gas- liquid separator. The hydrogenation runs were carried out once through for the liquid as well as gas. In an industrial set up, gas recycle arrangement after the gas-liquid separator is easily possible.
  • the reactor was packed with PCI/AI 2 Q 3 catalysts containing Pd in various proportions from amongst the commercially available catalysts of various grades from different suppliers mentioned earlier. Pure industrial hydrogen gas as such was used. Carbon monoxide (CO) or any other components were not added at any time to the hydrogen to influence on the hydrogenation process selectivity.
  • CO Carbon monoxide
  • Example 2 The catalyst activity for various PdZAl 2 Oj catalysts is described in Example 2, as a function of LHSV for constant value of GHSV.
  • Technical grade 1,4 butynediol produced under different catalysts (typically Catalyst #1 and Catalyst #2) at Malawistan Organic Chemicals Limited, Rasayani, Maharashtra, India, was employed for the study.
  • the catalyst activity expressed per unit mass of the catalyst shows inconsistency, however the activity based on unit mass of the active metal is found to increase with lower active metal containing (typically palladium) catalysts, under all conditions. Hence this was selected as a proper basis for all further comparisons.
  • Example 3 showing the variation of GHSV with LHSV confirms that the reaction is influenced by mass transfer effects. Further study, illustrated by Examples 4 to 8 focuses on the selectivity for l,4butenediol.
  • Example 4 It can be seen from Example 4 that there is a threshold catalytic activity, beyond which the selectivity to 1,4 butenediol is adversely affected.
  • Example 5 illustrates that with lowering of active metal (palladium) contents of the catalysts, selectivity towards 1,4 butenediol (desirable) improves significantly at complete conversions of 1,4 butynediol, by suppressing the formation of 1,4 butanediol (undesirable).
  • Example 6 further reaffirms this selectivity trend, where pure 1,4 butynediol is used.
  • the process selectivity improves with lower active metal contents for 1,4 butynediol prepared by various techniques.
  • Example 7 wherein pure 1,4 butenediol product in aqueous solution was introduced as feed, hydrogenated and the outlet product showed consistency in the assay content of 1,4 butenediol, under similar hydrogenation process conditions as for 1,4 butynediol. This was further established in the 1 : 10 scaled up version of the bubble column up flow reactor by Example 8.
  • the gas hourly space velocity (GHSV) was maintained at about 31O h '1 and the liquid hourly space velocity (LHSV) kept at about 0.075 h "1 .
  • Catalyst activity obtained at full conversion of butynediol was 504 g butynediol/ (day- kg catalyst).
  • the hydrogenation reactor containing 0.1% Pd/ AUC ⁇ catalyst as described in part (a) was used for this study.
  • Zinc 60- to 500 ppm was introduced in the form of zinc acetate dihydrate by addition to the technical grade 35% butynediol solution , as described in part (a).
  • Example 2 The same continuous single tube bubble column up flow reactor as referred to in Example 1, was used for hydrogenation studies of technical grade aqueous butynediol solutions prepared from aqueous formaldehyde and acetylene under two different catalysts (Catalysts #1 and #2 respectively) of butynediol synthesis at Malawistan Organic Chemicals Limited, Rasayani, Maharashtra, India, under the same pressure and temperature conditions as mentioned in Example 1, except that the hydrogenation reactor was packed with standard industrial PdZAl 2 Q 3 catalysts containing palladium contents in varying amounts. The runs were carried out under varying liquid hourly space velocities (LHSV), keeping Gas hourly space velocity (GHSV) constant The results are tabulated in Table 2.
  • LHSV liquid hourly space velocities
  • GHSV Gas hourly space velocity
  • the catalyst activity in part (A) is expressed as grams of butynediol reacted per day- per kilogram of the catalyst. However, to get a better comparison of the activity, the same is also expressed in terms of grams of palladium contents in the catalyst in part (B).
  • Example 2 The same continuous single tube bubble column up flow reactor as referred to in Example 1 was used for hydrogenation of various technical grade aqueous butynediol solutions with standard industrial Pd/Al 2 Qj catalysts containing palladium contents in varying amounts, as referred to in Example 2 and was operated at the same temperature and pressure conditions as mentioned in Example 1, except that the runs were carried out under varying GHSVs, at constant LHSVs.
  • the results are tabulated in Table 3.
  • the catalyst activity is expressed here as grams of butynediol reacted per day- per gram of palladium contents in the catalyst.
  • Example 2 The same continuous single tube bubble column up flow reactor as referred to in Example 1 was used for hydrogenation of various technical grade aqueous butynediol solutions with standard industrial Pd/Al 2 C>3 catalysts containing palladium contents in varying amounts, under the same range of GHSV and LHSV as referred to in example 2 and 3, and was operated at the same temperature and pressure conditions as mentioned in Example 1.
  • the results are tabulated in Table 4.
  • the catalyst activity, as in Example 3 is expressed as grams of butynediol reacted per day- per gram of palladium contents in the catalyst.
  • Example 2 The same continuous single tube bubble column up flow reactor as referred to in Example 1 was used for hydrogenation of various technical grade aqueous butynediol solutions with standard industrial Pd/AfeOs catalysts containing palladium contents in varying amounts, under the same range of GHSV and LHSV as referred to in example 2 and 3, and was operated at the same temperature and pressure conditions as mentioned in Example 1. Hydrogenation in tins case, was carried out such that complete conversion of 1,4 butynediol is achieved. Selectivities for the desired product (1,4 butenediol) and the undesired product (1,4 butanediol) are expressed. The results are tabulated in Table 5.
  • Example 2 The same continuous single tube bubble column up flow reactor as referred to in Example 1 was used for hydrogenation studies of pure Butynediol ('Aldrich * make) dissolved in demineralized water to make a 35% solution and was operated at the same temperature and pressure conditions as mentioned in Example 1.
  • the hydrogenation reactor was packed with standard industrial Pd/AkQj catalysts containing 0.002% Pd contents, and was operated under the same range of GHSV and LHSV as mentioned in Examples 2 and 3. Hydrogenation was carried out just near complete conversion of butynediol.
  • the catalyst activity achieved was 13,100 of butynediol/day-g palladium. Selectivities for the desired product (1,4 butenediol) and the undesired product (1,4 butanediol) are expressed. The results are tabulated in Table 6.
  • Example 7 The same continuous single tube bubble column up flow reactor as referred to in Example 1 was used for hydrogenation studies of industrially available pure 1,4 butenediol, dissolved in demineralized water to make a 35% solution and was operated at the same temperature and pressure conditions as mentioned in Example 1.
  • the hydrogenation reactor was packed with standard industrial PdVAfeQj catalysts containing 0.002% Pd contents (as in example 6), and was operated under the same range of GHSV and LHSV as mentioned in Examples 2 and 3. The results are tabulated in Table 7.
  • Example 7 Hydrogenation study for over hydrogenation of pure butenediol, as illustrated in Example 7, was repeated in a 1:10 scaled up version of the continuous single tube bubble column up flow reactor, as described in Example 1, and maintained at the same temperature and pressure conditions in Example 1 and operated under the same range of GHSV and LHSV as mentioned in Examples 2 and 3.
  • the hydrogenation reactor was packed with standard industrial PdZAl 2 O 3 catalysts containing 0.002% Pd contents (as in Examples 6 and 7). The results are tabulated in Table 8.
  • the process can utilize 1,4 butynediol right from highly pure grade to any technical grade, which may be synthesized by various alternative processes using different catalysts, from the reaction of formaldehyde and acetylene.
  • the influence of mass transfer on the present process can be advantageously used for achieving high activity, by choosing a right combination of GHSV and LHSV, which will result in more throughputs.

Abstract

The present invention relates to a process for selectively hydrogenating alkynes to alkenes over suitably supported single metal catalysts with high activity per unit of metal contents. It further elaborates selective hydrogenation of technical grades of 2-Butyne-1,4 diol produced from Reppe synthesis to 2-Butene-1,4 diol, with substantially lower Pd containing catalyst, amongst various commercially available Pd/ Al2Q3 catalysts, under lower hydrogen pressures ranging from 1 to 20 bar, at lower temperatures between 15 to 250 °C, with GHSV 1 to 10,000 h 1 and LHSV 0.001 to 10 h-1, which can be scaled up more than 10 times in a continuous single tube or multi tubular reactor.

Description

Process for Selective Hydrogenation of Alkynes to Alkenes over Single Metal Supported Catalysts with High Activity
Prior Art
Selective hydrogenation of alkynes to alkenes in general, and particularly that of 2-Butyne-l,4 diol (Butynediol) to 2-Butene-l,4 diol (Butenediol) as well as 2-Butene- 1,4 diol Butanediol), have been extensively studied and reported in the prior art.
Palladium catalysts containing one or more additional metal containing catalysts
Palladium based catalysts, invariably with one or more additional metal contents on various catalyst supports have been reported for hydrogenation of alkynes to alkenes/ alkanes:
US Patent # 5,583,274 claims selective hydrogenation of alkynes present in alkenes streams along with sulphur containing compounds, by using Pd/Ag catalysts containing fluorides in the form of potassium fluoride on alumina supports, whereas US Patent # 6,127,310 claims the use of Pd along with Pb and alkali metal or alkali metal halide as selectivity enhancers. US Patents # 7,045,670 and 7,408,091 claim liquid phase selective hydrogenation of alkynes absorbed in liquid stream on Zn promoted Pd catalyst on alumina support, with hydrogen containing more than 2000 ppm CO. US Patent #6,054,409 reports selective hydrogenation of unsaturated hydrocarbons in olefins with a Pd/Ag catalyst on a low surface area (2-20 mVg) alumina carrier with pore volumes greater than 0.4 cc/g and a particular size range of the pores. As per US Patent #5,750,806 selective hydrogenation of alkynes (acetylenes) to alkenes is reported on Pd/Bi monoliths in Trickle bed, and as per US Patent # 6,365,790 B2 for Pd/Bi and Pd/Ag monoliths on Kanthal fabric. Recent US Patent # 7,288,686 reveals complete removal of acetylenic compounds from hydrocarbon streams by using Pd with Ag/Zn/Bi/K in a fixed bed reactor.
Palladium catalysts containing one or more additional metal are also reported in prior art for selective hydrogenation of 1,4 butynediol to 1,4 butenediol/ 1,4 butanediol: Canadian Patent # 1,090,829 mentions palladium with lead in the form of lead acetate hydrate dozing to the reactor (autoclave). US Patent # 4,438,285 mentions use of Pd/Ru in a batch process, on activated carbon as well as alumina supports. US Patent
# 5,714,644 mentions use of Pd with Cu, Zn, Cd, Ag in a batch process, US Patent
# 6,528,689 reports Pd or Pd/Ni catalysts, whereas a latest US patent # US 2006/0094910 Al reports Ni in combination with Pd. Palladium catalysts in the form of monoliths have also been reported: US Patent # 5,521,139 reports Pb as additional metal (element) to Pd in monolith gauges in a Trickle bed reactor for 1,4 butenediol product from 1,4 butynediol; Ihd. Eng. Chem. Res. 44, 2005, 6148-6153 reports palladium in activated carbon filters as catalyst in an autoclave for hydrogenation of molten pure (otherwise solid) 1,4 butynediol to 1,4 butenediol.
Catalysts other than Palladium
Catalysts other than Pd, have also been reported for 1,4 butynediol hydrogenation in prior art. US Patent # 6,469,221 Bl reports a platinum based catalyst in a trickle bed reactor. US Patent # 6,528,689 Bl also reports a platinum as well as ZSM-5 based catalyst in an autoclave, whereas US Patent # 2006/0094910 reports Pt along with Pd/Ni for a batch process. US Patent # 6262,317 Bi reports NiMo catalyst in a continuous bubble column up flow reactor. Catalysis Today, 93-95 (2004), 439-443 mentions about the same in supercritical CO1 with stainless steel wall of Ae autoclave, promoting the reaction.
Catalysts supports
Out of the various catalysts referred to in the previous discussions, majority are with alumina supports (Canadian Patent# 1,090,829; US Patents # 5,583,274; 5,714,644; 6,054,409; 6,127,310; 6,262,317 Bl; 7,045,670; 7,408,091; 7,288,686). Other supports e.g. Ca, Mg, Ba carbonates (US Patents# 5,714,644; 6,469,221 Bl; 2006/0094910 Al); MgO (US Patent# 5,714,644); activated carbon (US Patent# 4,438,285); apart from the monoliths or fibers (US Patents# 5, 521,139; 5,750,806; 6,365,790 B2; Ind. Eng. Chem. Res., 44, 2005, 6148-6153) etc. are also reported in prior art. Reaction parameters, types of reactors etc.
The prior art studies referred previously are carried out between a pressure range of 1.5 to 60 bar (excepting in the supercritical CO2 case, Catalysis Today, 93-95 (2004) 439-443, it is 160 bar) and a temperature of 50 tol50°C.
The studies have been reported both in batch rectors (autoclave type) or continuous gas liquid type trickle bed or bubble column up flow reactors. US Patent # 6,262,317 Bi describes a multi tubular reactor with 15 numbers of tubes for the hydrogenation study. For the continuous reactors, the gas hourly space velocities (GHSV) are reported from 250 to 12,000 h'1 and the liquid hourly space velocities (LHSV) from 0.05 to 20,00O h"1.
Alkynes in the form of gases or gases absorbed in liquids are reported in prior art.
1,4 butynediol is in the form of aqueous solution up to 50% concentration, excepting in one case (Ind.Eng.Chem.Res.44, 2005, 6148-6153), wherein molten pure 1,4 butynediol (from solid state) hydrogenation is reported in prior art.
The hydrogen gas reported in prior art is generally pure hydrogen; however controlled carbon monoxide addition to hydrogen for better selectivity towards double bond, is also reported in US patents # 5,750,806 and 6,365,730 B2.
Catalyst activity
Catalyst activity, expressed in g of alkyne (or particularly 1,4 butynediol, as the case may be) reacted per day per gram of (total) metal contents in the catalyst is calculated typically for the following cases mentioned in prior art:
- For US Patent # 7,288,686 Bl, in Example 2, WHSV values of 4, 3, 4, 6.1 g hydrocarbon/ (hour-g catalyst) are mentioned. For the catalyst composition of 0.2% Pd, 0.11% Ag, 0.27% Zn and 1.42% Bi, the total metal content of the catalyst is 2%, the balance being alumina. Hence catalyst activity values of 200, 150, 200, 305 g hydrocarbon/ (hour- g metal content), can be calculated for 36 g total catalyst used, which works out equivalent to 4800, 3600, 4800, 7320 g hydrocarbon reacted/(day-g metal).
- For Canadian Patent # 1,090,829 in Example 1, an activity of 3962 g butynediol reacted/(day-g metal), can be calculated for the Pd/A.Og catalyst with Pb (as lead acetate), continuous addition in an autoclave.
- For US Patent # 6,262,317 Bl, an activity in the range of 130 to 260 g butynediol/(day-g metal) can be calculated for the ranges Ni/Mo on AI2O3 catalyst. Particularly for Example 5 in a tube reactor, an activity of 75 g butanediol per hour i.e. 108 g butynediol reacted per hour, can be calculated for 20 g Raney Ni/Mo catalyst used, which works out equivalent to 13O g butynediol reacted/ (day-g metal).
- For US Patent # 6,469,221 Bi , an activity in the range of 80 to 260 g butynediol reacted/ (day-g metal) can be calculated for the 1% Pt/ CaCO3 catalyst. Particularly for example 15 in a single tube reactor for 10 cc/h of 20% butynediol solution hydrogenated with 30 g of 1% Pt/CaCθ3 catalyst, the catalyst activity works out to 160 g butynediol reacted/ (day-g metal).
Object of the Invention
The object of the present invention is to provide an efficient, commercially attractive process for the preparation of alkenes, particularly 1, 4 butenediol with high selectivity and activity per unit of metal contents, by hydrogenating the corresponding alkynes, particularly pure or technical grade 1,4 butynediol, under low pressure and temperature, in the absence of any additives for improving selectivity (e.g. CO), by a commercially available suitably supported catalyst containing a single metal component, prepared in any conventional manner and achieving a longer catalyst life. Summary of the Invention
The object of the present invention is achieved by a process for the hydrogenation of alkynes, particularly technical grade 1 ,4 butynediol, in a reactor, in the presence of a standard commercial catalyst prepared in any conventional manner, working under hydrogenation pressure from 1 to 20 bar, at a temperature range of 15 to 2500C, under hydrogen pressure from 1 to 20 bar, under space velocity ranging from: GHSV 1 to 10,00Oh'1, and LHSV 0.001 to 1Oh"1.
In one embodiment of the present invention, the process is preferably carried out using pure or technical grade 1 ,4 butynediol- synthesized by various alternate routes correspondingly , from acetylene and aqueous formaldehyde. The strength of butynediol solution is 20 to 60%, preferably aqueous solution.
In another embodiment of the invention, the hydrogen gas is in pure form and in particular, carbon monoxide or any other compound is not periodically added to the same for controlling the selectivity.
In a preferred embodiment of the invention, the hydrogenation reaction is carried out in a continuous single tube bubble column up flow reactor.
In another embodiment of the invention, the hydrogenation catalysts are capable of hydrogenating triple to double and subsequently to single bond compounds, which may contain very low amount of a single active metal, chosen from palladium, nickel, molybdenum, copper or platinum. The active metal content may vary from 0.0001 to 1%, preferably from 0.0005 to 0.01%. The catalyst support can be selected from alumina, alumino silicates, silica gel or activated carbons. More efficient utilization of the active metal results in high activity per unit of metal contents , at the same time giving very high selectivity. In another embodiment of the invention, typical physical properties of the catalyst being: the surface area between 3 to 300 mVg, preferably 5 to 10 m2/g; the pore volume between 0.05 to 0.6 cc/g, preferably 0.15 to 0.50 cc/g; the side crushing strength between 2 to 20 kg, preferably 5 to 15 kg. The most preferred catalyst being palladium supported on alumina in a wide range of palladium contents offered within the range of these physical properties. Catalysts of this type are commercially available under the various grades as follows:
MJs Arora Matthey, India: 50 B; Degussa, Japan: E/221, E/252; Johnson Matthey, UK: R-48, JM 308/1; Met-Pro, USA; Sud Chemie AG, Germany: G-68.G-68C, G83, G-83C; UCI, USA (now Sud Chemie, USA): G68E; UCIL, India (now Sud Chemie, India): 995X, 996X, 1021-X.WN-333.
Li another embodiment of the invention, the process is carried out under hydrogen pressures from 5 to 15 bar.
In another embodiment of the invention, the process is carried out at a temperature in the range of 50-1500C.
In another embodiment of the invention, the gas hourly space velocity (GHSV) for the process is in the range of 10 to 1000 h"1.
In another embodiment of Ae invention, the liquid hourly space velocity (LHSV) for the process is in the range of 0.01 to 1 h'1.
In further embodiment of this invention, no special activation method is required for the catalyst before hand.
In another embodiment of the invention, the catalyst is run consecutively for more than 5000 hours.
In another embodiment of the invention, the process is scaled up 1: 10 times in a similar single tube reactor, without adversely affecting the selectivity of alkenes.
Detailed Description
Hydrogenation reactor for the present study consisted of a standard stainless steel continuous single tube reactor, with an outside jacket arrangement for heat removal. Gas & liquid were introduced at the bottom of the reactor in co-current up flow manner. At the reactor outlet from the top, the two phases were separated in a gas- liquid separator. The hydrogenation runs were carried out once through for the liquid as well as gas. In an industrial set up, gas recycle arrangement after the gas-liquid separator is easily possible. The reactor was packed with PCI/AI2Q3 catalysts containing Pd in various proportions from amongst the commercially available catalysts of various grades from different suppliers mentioned earlier. Pure industrial hydrogen gas as such was used. Carbon monoxide (CO) or any other components were not added at any time to the hydrogen to influence on the hydrogenation process selectivity. Pure 1,4 butynediol 'Aldrich' make was used. Technical grade 1,4 butynediol was obtained by synthesizing acetylene and aqueous formaldehyde under different catalysts/different conditions at Hindustan Organic Chemicals Ltd., Rasayani, Maharashtra, India. Analyses of the reactant as well as products were carried out by gas chromatography.
Runs were carried out starting with 0.1% Pd/AfeQj catalyst (a). To get a comparison of the selectivity improvement, zinc as the additional metal component was used in two ways. Firstly (b), impregnation with zinc and reduction of the 0.1% Pd/AUQj catalyst were done 'in-situ'. Ih second method (c), continuous addition of zinc was made to butynediol solution in a similar manner as described by Hort for lead acetate addition (Canadian Patent # 1,090,829). This is illustrated by Example 1. It shows that marginal improvement in selectivity is achieved by additional component, that too when it is present in the feed solution and not on the catalyst surface, as compared to the base case when additional metal is not introduced.
Further investigations were carried out without any additional metal, other than the palladium already present in the available Pd/A-203 catalyst. These are described from Example 2 onwards.
The catalyst activity for various PdZAl2Oj catalysts is described in Example 2, as a function of LHSV for constant value of GHSV. Technical grade 1,4 butynediol produced under different catalysts (typically Catalyst #1 and Catalyst #2) at Hindustan Organic Chemicals Limited, Rasayani, Maharashtra, India, was employed for the study. The catalyst activity expressed per unit mass of the catalyst shows inconsistency, however the activity based on unit mass of the active metal is found to increase with lower active metal containing (typically palladium) catalysts, under all conditions. Hence this was selected as a proper basis for all further comparisons. Example 3 showing the variation of GHSV with LHSV confirms that the reaction is influenced by mass transfer effects. Further study, illustrated by Examples 4 to 8 focuses on the selectivity for l,4butenediol.
It can be seen from Example 4 that there is a threshold catalytic activity, beyond which the selectivity to 1,4 butenediol is adversely affected. The lower the active metal (palladium) contents of the catalyst, the higher the threshold catalytic activity. Ih other words, the lower active metal contents can 'tolerate higher activity better' for the process, while retaining its selectivity towards 1 ,4 butenediol.
As per the specifications / requirements of pure 1,4 butenediol finished product, unreacted 1,4 butynediol has to be negligible in the same. This means that the hydrogenation process must proceed towards complete conversion of 1,4 butynediol. It also requires 1,4 butanediol to be as low as possible (1-2%). Example 5 illustrates that with lowering of active metal (palladium) contents of the catalysts, selectivity towards 1,4 butenediol (desirable) improves significantly at complete conversions of 1,4 butynediol, by suppressing the formation of 1,4 butanediol (undesirable). Example 6 further reaffirms this selectivity trend, where pure 1,4 butynediol is used. Thus the process selectivity improves with lower active metal contents for 1,4 butynediol prepared by various techniques.
It is also industrially required that the process should not only give good selectivity at complete conversions, but under over hydrogenation conditions, wherein the amount of 1,4 butynediol is absent. This is verified by Example 7 wherein pure 1,4 butenediol product in aqueous solution was introduced as feed, hydrogenated and the outlet product showed consistency in the assay content of 1,4 butenediol, under similar hydrogenation process conditions as for 1,4 butynediol. This was further established in the 1 : 10 scaled up version of the bubble column up flow reactor by Example 8.
The present invention is described below by way of examples. However, the following examples are illustrative and should not be construed as limiting the scope of the invention. All the concentrations are expressed in percentage by weight, unless otherwise stated. Example 1
(Comparative Example)
(a) Continuous hydrogenation with palladium on alumina (PaVAhOs) catalyst
The continuous single tube bubble column reactor described earlier, was packed with 0.1% of Pd/ AfeQj catalyst. Continuous Hydrogenation using the above catalyst for technical grade 35% butynediol solution (prepared from aqueous formaldehyde and acetylene under different catalysts of butynediol synthesis at Hindustan Organic Chemicals Limited, Rasayani, Maharashtra, India) was carried out in the same, under the following experimental conditions/parameters:
Pressure = 10 bar
Temperature = HO0C
The gas hourly space velocity (GHSV) was maintained at about 31O h'1 and the liquid hourly space velocity (LHSV) kept at about 0.075 h"1.
Catalyst activity obtained at full conversion of butynediol was 504 g butynediol/ (day- kg catalyst).
(b) Zinc surface treatment 'in situ 'for ike Pd/ AI2O3 catalyά
About 1300 cc DM water containing 10 to 20% zinc acetate was charged to the feed tank. This was introduced into the hydrogenation reactor described in part (a), containing 0.1% Pd/ AUQj catalyst under 12 bar hydrogen pressure and at ambient (3O0C) temperature. A liquid hourly space velocity (LHSV) of 0.15 h"1 was maintained for 24 hrs. The liquid feed was then stopped. The reactor was kept at ambient temperature and 12 bar H2 pressure, subsequently for 65 hrs. Gas was then introduced at a gas hourly space velocity (GHSV) of 310 h"\ maintained by hydrogen bubbling for 24 hrs at 1070C to reduce the zinc acetate to zinc. The outlet gas was vented through a water seal. Afterwards DM water wash was given under the same conditions as above so that total reactor holdup was displaced once. The catalyst was then ready for reaction. Continuous Hydrogenation using the above pre-treated catalyst for technical grade 35% butynediol solution, as described and under the same experimental conditions/parameters as mentioned in part (a) was carried out in the reactor.
(c) Continuous zinc addition to butynediol solution with Pd/AlzOj catalyst
The hydrogenation reactor containing 0.1% Pd/ AUC^ catalyst as described in part (a) was used for this study. Zinc (60- to 500 ppm) was introduced in the form of zinc acetate dihydrate by addition to the technical grade 35% butynediol solution , as described in part (a).
Continuous Hydrogenation using the zdnc containing 1,4 butynediol solution was carried out in the reactor, under the same experimental conditions/parameters as described in part (a).
The selectivities for the three cases viz.(a) catalyst as such, (b) surface treatment on the catalyst with zinc and (c) zinc introduced in the liquid feed itself, are tabulated in Table 1.
Table 1
Figure imgf000011_0001
Example 2
The same continuous single tube bubble column up flow reactor as referred to in Example 1, was used for hydrogenation studies of technical grade aqueous butynediol solutions prepared from aqueous formaldehyde and acetylene under two different catalysts (Catalysts #1 and #2 respectively) of butynediol synthesis at Hindustan Organic Chemicals Limited, Rasayani, Maharashtra, India, under the same pressure and temperature conditions as mentioned in Example 1, except that the hydrogenation reactor was packed with standard industrial PdZAl2Q3 catalysts containing palladium contents in varying amounts. The runs were carried out under varying liquid hourly space velocities (LHSV), keeping Gas hourly space velocity (GHSV) constant The results are tabulated in Table 2. The catalyst activity in part (A) is expressed as grams of butynediol reacted per day- per kilogram of the catalyst. However, to get a better comparison of the activity, the same is also expressed in terms of grams of palladium contents in the catalyst in part (B).
Table 2 (i) Runs with Butynediol Synthesized under Catalyst #1
(A)
Figure imgf000012_0001
(B)
Figure imgf000013_0001
(ii) Runs with Butynediol Synthesized under Catalyst #2
(A)
Figure imgf000013_0002
(B)
Figure imgf000014_0001
Example 3
The same continuous single tube bubble column up flow reactor as referred to in Example 1 was used for hydrogenation of various technical grade aqueous butynediol solutions with standard industrial Pd/Al2Qj catalysts containing palladium contents in varying amounts, as referred to in Example 2 and was operated at the same temperature and pressure conditions as mentioned in Example 1, except that the runs were carried out under varying GHSVs, at constant LHSVs. The results are tabulated in Table 3. The catalyst activity is expressed here as grams of butynediol reacted per day- per gram of palladium contents in the catalyst.
Table 3
Figure imgf000014_0002
Example 4
The same continuous single tube bubble column up flow reactor as referred to in Example 1 was used for hydrogenation of various technical grade aqueous butynediol solutions with standard industrial Pd/Al2C>3 catalysts containing palladium contents in varying amounts, under the same range of GHSV and LHSV as referred to in example 2 and 3, and was operated at the same temperature and pressure conditions as mentioned in Example 1. The results are tabulated in Table 4. The catalyst activity, as in Example 3, is expressed as grams of butynediol reacted per day- per gram of palladium contents in the catalyst.
Table 4 (i) Runs with Butynediol Synthesized under Catalyst #1
Figure imgf000015_0001
Threshold catalyst activity. (ii) Runs with Butynediol Synthesized under Catalyst #2
Figure imgf000016_0001
• Threshold catalyst activity. @ Threshold catalyst activity still higher than this activity range. Example 5
The same continuous single tube bubble column up flow reactor as referred to in Example 1 was used for hydrogenation of various technical grade aqueous butynediol solutions with standard industrial Pd/AfeOs catalysts containing palladium contents in varying amounts, under the same range of GHSV and LHSV as referred to in example 2 and 3, and was operated at the same temperature and pressure conditions as mentioned in Example 1. Hydrogenation in tins case, was carried out such that complete conversion of 1,4 butynediol is achieved. Selectivities for the desired product (1,4 butenediol) and the undesired product (1,4 butanediol) are expressed. The results are tabulated in Table 5.
Table 5
(i) Runs with Butynediol Synthesized under Catalyst #1
Figure imgf000017_0001
(ii) Runs with Butynediol Synthesized under Catalyst #2
Figure imgf000017_0002
Example 6
The same continuous single tube bubble column up flow reactor as referred to in Example 1 was used for hydrogenation studies of pure Butynediol ('Aldrich* make) dissolved in demineralized water to make a 35% solution and was operated at the same temperature and pressure conditions as mentioned in Example 1. The hydrogenation reactor was packed with standard industrial Pd/AkQj catalysts containing 0.002% Pd contents, and was operated under the same range of GHSV and LHSV as mentioned in Examples 2 and 3. Hydrogenation was carried out just near complete conversion of butynediol. The catalyst activity achieved was 13,100 of butynediol/day-g palladium. Selectivities for the desired product (1,4 butenediol) and the undesired product (1,4 butanediol) are expressed. The results are tabulated in Table 6.
Table 6
Figure imgf000018_0001
Various runs on the 0.002% Pd/Al2Qj catalyst as illustrated by Examples 2,3,4,5 and 6 were carried out for a total duration of more than 5000 hours. The catalyst activity showed consistency during this period. Example 7
The same continuous single tube bubble column up flow reactor as referred to in Example 1 was used for hydrogenation studies of industrially available pure 1,4 butenediol, dissolved in demineralized water to make a 35% solution and was operated at the same temperature and pressure conditions as mentioned in Example 1. The hydrogenation reactor was packed with standard industrial PdVAfeQj catalysts containing 0.002% Pd contents (as in example 6), and was operated under the same range of GHSV and LHSV as mentioned in Examples 2 and 3. The results are tabulated in Table 7.
Table 7
Figure imgf000019_0001
Example 8
Hydrogenation study for over hydrogenation of pure butenediol, as illustrated in Example 7, was repeated in a 1:10 scaled up version of the continuous single tube bubble column up flow reactor, as described in Example 1, and maintained at the same temperature and pressure conditions in Example 1 and operated under the same range of GHSV and LHSV as mentioned in Examples 2 and 3. The hydrogenation reactor was packed with standard industrial PdZAl2O3 catalysts containing 0.002% Pd contents (as in Examples 6 and 7). The results are tabulated in Table 8.
Table 8
Figure imgf000019_0002
Advantages of the Invention
1. The process, which uses very low palladium contents and no other additional metal and which does not require any additional compound along with hydrogen for achieving selectivity of alkynes to alkenes, as illustrated for 1,4 butynediol to 1,4 butenediol hydrogenation.
2. The process can utilize 1,4 butynediol right from highly pure grade to any technical grade, which may be synthesized by various alternative processes using different catalysts, from the reaction of formaldehyde and acetylene.
3. Very high selectivity of 1, 4 butenediol is obtained even with the complete conversion of 1, 4 butynediol by the present process and its good over- hydrogenation capability, with reproducible results even at higher scale up ratios.
4. The influence of mass transfer on the present process can be advantageously used for achieving high activity, by choosing a right combination of GHSV and LHSV, which will result in more throughputs.
All the above aspects make the process commercially very attractive, as well as easier for operation at higher scale up ratios.

Claims

We claim :
1. An improved process for the selective hydrogenation of alkynes to alkenes, using substantially lower content of a single metal suitably supported catalyst, under lower hydrogen pressure: from 1 to 20 bar, at a lower temperature: between 15 to 250° C, with GHSV in the range of 1 to 10, 000 h"\ LHSV in the range of 0.001 to 10 h"\ exhibiting high catalyst activity per unit of metal content and longer catalyst life.
2. The process as claimed in claim 1, which is further, carried out in continuous single tube bubble column up flow reactors, with pure hydrogen, without any selectivity enhancers.
3. The process as claimed in claims 1 and 2, wherein said selective hydrogenation of alkynes to alkenes further comprises of selective hydrogenation of 1,4 butynediol to 1,4 butenediol .
4. The process as claimed in claim 3, wherein said 1,4 butynediol further comprises of pure 1,4 butynediol or technical grade 1,4 butynediol synthesized from aqueous formaldehyde and acetylene, using different catalysts by any suitable route.
5. The process as claimed in claims 1 and 2, wherein said single metal suitably supported catalyst contains a single metal in the range of 0.0001 to 1%.
6. The process as claimed in claim 5, wherein said catalyst further comprises of palladium metal on alumina support in the range of 0.0005 to 0.01%.
7. The process as claimed in claims 1 to 5, wherein said catalyst surface area is in the range of 3 to 300 m2 /g, preferably 5 to 10 m2 /g.
8. The process as claimed in claims 1 to 5, wherein said catalyst pore volume is in the range of 0.05 to 0.60 cc/g, preferably 0.15 to 0.50 cc/g.
. The process as claimed in claim 1 to 5, wherein the side crushing strength of said catalyst varies from 2 to 20 kg, preferably 5 to 50 kg.
10. The process as claimed in claims 1 and 2, wherein the hydrogen pressure is preferably in the range of 5 to 15 bar.
11. The process as claimed in claims 1 and 2, wherein the temperature is preferably in the range of 50 to 150° C.
12. The process as claimed in claims 1 and 2, wherein the GHSV is preferably in the range of 10 to 1,000 h"1.
13. The process as claimed in claims 1 and 2, wherein the LHSV is preferably in the range of 0.01 to 1 h'1.
14. The process as claimed in claims 1 to 13, wherein said catalyst activity is in the range of 10 to 10,00,000 g alkyne reacted/ (day-g of metal contents in the catalyst).
15. The process as claimed in claims 1 to 14, wherein said catalyst is run for a long duration exceeding 5,000 hrs.
16. The process as claimed in claims 1 to 15, wherein the over hydrogenation of alkenes to alkanes is negligible.
17. The process as claimed in claims 1 to 16, which can be scaled up to a higher scale by at least a scale up ratio of 1:10 with the help of commercially available catalysts, in continuous single tube or multi-tubular reactor (s), without adversely affecting the selectivity towards alkenes substantially as herein described with reference to Examples 1 to 8 in the specification.
PCT/IN2009/000043 2008-10-15 2009-01-13 Process for selective hydrogenation of alkynes to alkenes over single metal supported catalysts with high activity WO2010044092A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115739077A (en) * 2022-10-13 2023-03-07 厦门大学 High-selectivity palladium-based catalyst and application thereof

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4831200A (en) * 1986-12-30 1989-05-16 Labofina, S.A. Process for the selective hydrogenation of alkynes
US6262317B1 (en) * 1996-10-10 2001-07-17 Basf Aktiengesellschaft Process for preparing 1,4-butanediol by catalytic hydrogenation of 1,4-butinediol
US6469221B1 (en) * 2000-11-20 2002-10-22 Council Of Scientific And Industrial Research Process for the conversion of 1, 4 butynediol to 1, 4 butanediol, or a mixture of 1, 4 butenediol and 1,4 butanediol
US7045670B2 (en) * 2003-09-03 2006-05-16 Synfuels International, Inc. Process for liquid phase hydrogenation

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4831200A (en) * 1986-12-30 1989-05-16 Labofina, S.A. Process for the selective hydrogenation of alkynes
US6262317B1 (en) * 1996-10-10 2001-07-17 Basf Aktiengesellschaft Process for preparing 1,4-butanediol by catalytic hydrogenation of 1,4-butinediol
US6469221B1 (en) * 2000-11-20 2002-10-22 Council Of Scientific And Industrial Research Process for the conversion of 1, 4 butynediol to 1, 4 butanediol, or a mixture of 1, 4 butenediol and 1,4 butanediol
US7045670B2 (en) * 2003-09-03 2006-05-16 Synfuels International, Inc. Process for liquid phase hydrogenation

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115739077A (en) * 2022-10-13 2023-03-07 厦门大学 High-selectivity palladium-based catalyst and application thereof

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