AT528164A1 - Process for the preparation of gamma-valerolactone from furfuryl alcohol - Google Patents

Abstract

The invention relates to a process for the production of gamma-valerolactone, in which furfuryl alcohol reacts in acidic, alcoholic solution to form levulinic acid and is converted by simultaneous esterification to alkyl levulinate, which is converted in a hydrogenation to gamma-valerolactone, while the alcohol is again recovered and circulated.

Description

Gamma Valerglactone (GVL) is a solvent with properties similar to acetone, but is suitable for more advanced applications due to its human and environmental compatibility, as well as its much higher boiling point.

The production is currently only known from renewable raw materials. For example, the production from hexases, especially fractoses, is known. However, the yield is low and more or less difficult to separate by-products are formed, also called humins. For example, if one needs to produce one kilogram of GVL from fructose, three kilograms of fructose are used and two kilograms of mumine and amelisenic acid are produced.

US 3,752,848 describes an acid hydrolysis of furfuryl alcohol with hydrochloric acid as catalyst and aliphatic ketone as solvent. Furfuryl alcohol is usually produced by hydrogenation of furfurate and this is obtained by hydrolysis of fenfuran.

US 5,175,257 describes a process in which levulinic acid is used as a solvent in the hydrolysis,

US 9,376,411 Describes a process in which zeflulose and hemizefiulose are hydrolyzed and the resulting levulinic acid is extracted with GVL and then the mixture of levulinic acid and GVL is hydrolyzed,

US 2023/0322885 describes a process in which furfuryl alcohol is reacted with alcohols at temperatures of 125 = 180°C using sulfonic acid as catalyst to form levulinic acid ester. A yield of SO — 20% is achieved.

WO 2023/0845811 also describes a process for the preparation of levulinic acid esters from furfuryl alcohol and aliphatic alcohols, in particular butanol, at 105 - 160°C with inorganic acids, preferably sulfuric acid as catalyst,

In these processes, humins are formed during hydrolysis, which regularly form extremely sticky deposits in the technically required additives, which are difficult to remove and reduce the yield of the process. The higher the reaction temperature, the faster degradation products and by-products of the reaction are formed. These humins, which are loaded with sulfur components in a sticky state, are difficult to treat or integrate into an orderly combustion.

The invention is therefore based on the object of finding a process in which the formation of humins is minimal, the yield is high and the formed humins do not lead to sticky deposits,

The aim of the invention is also to find a process by which the by-products and residues can be easily removed and a complete separation of the bicarbonated ester from the humins is possible.

It was therefore surprising that when using 0.1 - 2 wt. M HCl as catalyst acid and relatively low temperatures between 50 and 50°C, the reaction rate for complete conversion of furfundalkaline in ethanol solution is between 4 and 6 hours and the formed hemines are not sticky, compared to the deposits that occur when using sulfuric acid and sulfanic acids at temperatures above 100°C.

According to the invention, the SWVL mixture is dissolved by adding 30 to 30 wt% furfuryl alcohol to an alcohol containing 0.1 to 2 wt% NOL, heating this mixture to 60 - 0°C and esterifying it in one or more reactors to alkyl levulinate, neutralizing the catalyst acid, separating the excess alcohol from the reaction mixture with the added water, separating the formed alkyl levulinate from the formed salts and by-products (e.g., methyl groups), hydrating the alkyl levulinate with hydrogen and a nickel-based catalyst at 5 bar at partial pressure and 100 - 200°C in a reactor, and distilling the hydrogen from the prepared alcohol, water and By-products are separated, while the recovered alkaloid is freed from the introduced water and returned to the

semittel and reaction agarner is used for esterification, semittet and reaction agarner is used for esterification

& sr

ders Samıma- Velerafa

Since the cumin formation from paralioreactions and subsequent reactions occurs simultaneously with the main action

takes place, it has proven advantageous to start the furfuralkahel content of the reaction mixture with ca. SO a/l and to carry out the further supply of raw material continuously until the uptimale supply between 150 and Z80 @A Furfurslalkoahaf in the reaction mixture is reached,

m

With regard to the distillative separation of the methane stream from the asactar, consisting of levulinic acid ester, alcohol, water, SCL and MHurns, it is advantageous to use ethanol as a reaction partner

& an raiatie have vapor pressure compared to 8. Butyl levulinate, $

to become customer service

n, it has proven to be important niche after the reactor to Deulra Since the humic

inat should be burned, Is the Neutralisatjon with Anımanlak

In order to prevent the development of by-products and mining products, the HOLin of the Keakti proved to be advantageous in separating EtRyÄävı.

Since humins absorb or contain certain amounts of ethyl levulinate, it is advantageous to condense the humins in liquid sulfur in an agitator dryer at >200°C in the feed stream. This produces a fine-grained powder that can easily be used as fuel or blown directly into a sulfur chamber, while >90% of the ethyl levulinate is absorbed by the humins. 8 MOL of the humins bound in the humins is removed during combustion.

released and washed as dry and can be used again IN di s.

Su DE TE

HE Pros anne {10} of the humins for the most part! it is combined and fed to the hydrogenation, a ethanol and water vapor in the destication cauldron

The levulinic acid is separated in the distillation column and mixed with the car, while the castilated solution (15) is introduced, where it is distilled from ethanol and water via Kapfaas areatrop, while

in the Sumaef the water is drained.

is advantageous in an iktor hai 10 30 bar © Reaktignstemmerafur mt SO a4 Ranney Nickel Dzw.

of 85-100 X achieved and afrın yield van >95

The Hyaı \assarstoft pressure and 150 - 3 dopings of molybdenum, thereby a conversion of SowM, . The further aiting takes place via a further distillation column (48) in which overhead ethanol impurities are distilled, while from the

x aden impurities In a

x

A

Bottom product the valerolactan from the high boiling:

SS

further distillation column: 3 a bgetran The purity of the obtained gamma valerolactone

is >09 wt.

An ethanol stream of 100 ke/h (2} is mixed in a mixer (4} with 3 ke/h of 32 wt.% hydrochloric acid {3} and 5 ke/h of furfuryl alcohol, heated to 80 °C in the heat exchanger (5) and fed into a reactor {6}. The tubular reactor {6} has a diameter of 350 mm and a height of 5000 mm and is made of GRP with a PFA inliner. A further 5 kg/h of furfuryl alcohol is added at each quarter of the reactor height. At the reactor outlet, the conversion is 990.5% and 26.7 ke/h of ethyl levulinate and 2 ke/h of humins are recovered in the product stream {7}. To neutralize the product stream, 3.5 ke/h of 20 wt.% ammonia solution are added in the mixer {9}. and this is fed to the distillation column {10}, in which ethyl levulinate is drawn off as a side stream (13) and water and ethanol are drawn off at the top of the column, while in the sump a mixture of 5.7 kg/h of ethyl levulinate and 2 ke/h of humins are drawn off and fed to a spray tracker (24), in which a further 6 ke/h of ethyl levulinate is evaporated and condensed with a 230°C nitrogen stream. The humins are obtained as a powder with an average diameter of 40 micrometers and can be sprayed into a combustion chamber in dust form.

The condensed ethyl levulinate is hydrogenated in an amount of 26 keg/h in the hydration autoclaves (38) and {39} and 6.8 keg/h of ethanol are recovered and recycled in the distillation (46) and in the distillation {55} 17 keg/h of gamma valerofactone with »59% purity are recovered via Kapf (61).

In total, the yield is 33% based on the amount of furfuryl alcohol used,

i. A process for the preparation of gamma valerolactones from furuncohol by esterification with an aliphatic alcohol and subsequent esterification of the resulting alkyl levulinate, characterized in that 8a 10 to 30 wt. of alkyl levulinate are dissolved in an alcohol and 0.1 to 2 wt. X MO are added to the solution, this mixture is heated to 60°C and hyrolyzed in one or more reactors to alkyl levulinate, the catalyst acid is neutralized

& is and the surplus Alkahal with the added water from the reaction mixture away

WINd, care formed alkyl glycinate from the oiled salts

and Nehesnpracukten (Humnen} are separated, Alkyl ; Jeldrack and 100 to 200°C water to Neberare ır recovered alcohol from

Kninet with hydrogen and a nickel-based catalyst and the cleaved gamma-valerolactone is released by distillation from the alkali, while water is used as a solvent and reaction partner for the reaction.

A res EXT.

2, Method according to claim 1, characterized in that sat as Alkılalkahol $

of ethano is used for ashification.

3. Verf 2, Chnaf,

N

that the addition of the surfurylaikahol into the reactor is added continuously throughout the entire reaction process,

years according to claim 1 or characterized by

1 Ins A SE 8 AA ne 1. Dis 3, characterized,

ı continuously operated pipe reactor Ist,

4, Method according to claim

that the hydrophobic reactor eleven

Claims 1. to 4., thereby &

Katalvsatarskure after the Res

Fr SE vyı A &. Procedure nac}

that the neuter

A AO INNE TOÄAFTHYTMN

NT Bear AS

MAR

6. Process according to efrasm rüche 3, to 5, characterized ® that the humins in a dryer, preferably Sari

Alk Hävalinat Bitrefl ws

hirackner from after contained

&

Claims (1)

3. A process for the preparation of gamma valerolactan from furfuryl alcohol by esterification with an aliphatic alcohol and subsequent hydrogenation of the resulting alkyl levulinate, characterized in that 10 to 30 wt.% of furfuryl alcohol are dissolved in an alcohol and 0.1 to 2 wt. % HCl are added to the solution, this mixture is heated to 80 - 100°C and hydrolyzed in one or more reactors to alkyl levulinate, the catalyst acid is neutralized with ammonia and the excess alcohol is separated from the reaction mixture with added water, and the alkyl levulinate formed is separated from the salts and by-products formed (muminins) in a spray reactor, alkyl levulinate is hydrogenated with hydrogen and a nickel-based catalyst at >12 bar hydrogen pressure and 100 to 300°C, preferably 150°C and the gamma-valerolactone formed is separated by distillation from the released alcohol, water and by-products, while the recovered alcohol is freed from the introduced water and is used again as solvent and reactant for the esterification. 2. Process according to claim 1, characterized in that ethanol is used as the alkyl alcohol for the esterification. 3. Process according to claim 1 or 2, characterized in that the furfuryl alcohol is added to the reactor continuously over the entire reaction process. 4. Process according to claims 1 to 3, characterized in that the hydrolysis reactor is a continuously operated tubular reactor. MOST RECENT CLAIMS