DE102004031023B4 - Process for converting organic starting materials into oil-like products - Google Patents

Abstract

Process for converting organic starting materials into oil-like products using the process steps
a) generating a first educt stream from the organic starting materials,
b) producing a second educt stream from at least one water-soluble organic compound which comprises at most three carbon atoms, and water,
c) heating the second educt stream to a temperature between 500 ° C and 700 ° C at a pressure between 22.1 MPa and 30 MPa, whereby hydrogen is generated,
d) mixing the hydrogen from the second starting material stream with the first starting material stream at a temperature between 200 ° C. and 450 ° C. and a pressure between 22.1 MPa and 30 MPa, thereby producing an oil-like product as product stream,
e) removing the oily product from the product stream.

Description

The The invention relates to a process for the conversion of organic Edukten, in particular of biomasses or heavy oils, in oil-like products.

A possibility The energetic use of biomass is the production of liquid fuels. For dry Biomasses are often proposed multi-stage processes and occasionally also applied. Wet biomass such as sludges, fresh plants and. Ä. need to the conversion are dried, whereby the efficiency decreases. For a long time is therefore looking for opportunities worldwide sought to wet biomass into liquid oily Convert products.

Out the conversion of biomass, heavy oils and other organic Edukten in hot High-pressure water arise oil-like Products of inferior quality. Above all, organically bound oxygen and sulfur as well as heavy metals in the product deteriorate the product quality and should be removed.

In F. Goudrian, B. van de Beld, FR Boerefijn, GM Bos, JE Naber, S. van der Wal, JA Zeevalkink, Thermal efficiency, of the HTU ^© Process for Biomass Liquefaction, in Progress in Thermochemical Biomass Conversion, Blackwell Science Volume 2, pages 1312-1325, the so-called HTU ^© process is described, which takes place in water at a pressure between 10-18 MPa and a temperature between 300-360 ° C at a residence time of 5-20 minutes. Here, two fractions, one light and one heavy fraction, are formed. The light fraction needs another treatment to produce usable products. The heavy fraction can only be burned with coal. The products obtained in this process have a high viscosity and are even solid at ambient conditions.

From the EP 0 402 405 B1 The so-called CatLiq process is known, which runs at temperatures of 200 to 450 ° C and pressures of 5.1 to 35.5 MPa. This process requires a catalyst comprising a compound of Group IA and IV B elements of the Periodic Table. As a result, larger amounts of water-soluble products such as alcohols are produced and thus reduces the yield of oily compounds.

From the DE 199 55 150 A1 For example, a process for producing hydrogen in which hydrocarbons or alcohols are reacted in supercritical water is known. The DE 101 35 431 C2 discloses a method of pretreating reactors for hydrogen production wherein the hydrogen is generated from the reaction of organic compounds with supercritical water. The DE 102 10 178 C1 discloses a method of treating fluid substances in supercritical water without clogging heat exchangers and lines for the reactant stream. These pamphlets give no indication of how biomass can be converted into an oily product.

outgoing From this it is the object of the present invention to provide a method to propose that the mentioned disadvantages and limitations does not have. In particular, this method is intended to generate of oily ones Products from low-quality organic educts such as biomass or the refining of heavy oils enable.

These The object is solved by the features of claim 1. The under claims each describe advantageous embodiments of the invention.

to execution the method according to the invention In a first process step a) a first reactant stream from the organic educts, which preferably comprise biomass or heavy oil, generated. In a preferred embodiment, the first reactant stream is passed over a heat exchangers with the waste heat the product stream to a temperature between 200 ° C and 250 ° C, i. below the reaction temperature, heated.

The proposed process for the conversion of organic educts in oleaginous Products based on the provision of hydrogen at high Pressure and high temperature. For this purpose, in accordance with method step b), a first second educt stream of one or more water-soluble organic compounds that are at most include three carbon atoms, and generates water, wherein the dissolved organic Share at most 50% by weight. Therefor suitable are z. B. lower alcohols (methanol, ethanol), Aldehydes (formaldehyde or acetaldehyde), ketones (eg acetone), acids (acetic acid) or formic acid) or a mixture thereof.

According to process step c), the second educt stream is then heated to a temperature between 500 ° C and 700 ° C at a pressure between 22.1 MPa and 30 MPa and reacted with water. This produces hydrogen (H ₂ ) and other gases.

Subsequently, in method step d), the gases thus generated, which in a preferred embodiment are composed predominantly of hydrogen, from the second educt current with the first educt current at a temperature between 200 ° C and 450 ° C and a pressure between 22.1 MPa and 30 MPa mixed.

The over the second educt flow supplied amount of hydrogen is preferably 0.5 times to 4 times that of the first Educt current contained carbon (atomic ratio). Especially preferred is an atomic ratio of supplied Hydrogen to carbon in the first reactant stream of about 1: 2. Thereby becomes about twice stoichiometric Hydrogen excess achieved.

Important is the heating of the first educt stream (biomass or heavy oil) on the Adding the hot second educt stream of water, hydrogen and other gases. This will cause the formation of high-carbon unwanted by-products such as. Coke suppressed.

Of the Flow of hot second reactant stream of water, hydrogen and other gases preferably in the range from 20% to 100% of the flow rate of the educt stream.

The Reaction temperature is set to a value between 200 ° C and 450 ° C, to suppress a gasification reaction and the highest possible Yield of oleaginous To reach products. However, temperatures between 200 ° C and 360 ° C are preferred Precipitation of inorganic salts at supercritical temperatures to avoid.

Of the Process pressure becomes higher as the vapor saturation pressure set at process temperature. However, preferred are process pressures of 25 to 30 MPa to enough Reserve at pressure fluctuations and other process faults too to have.

The Residence time in the reaction space is preferably in the range 0.5 to Set for 10 minutes. Values around the 2 minutes are especially preferred.

When Product flow creates an oily Product according to process step e) is taken from the plant.

The waste heat the product stream is in a preferred embodiment via a heat exchangers transferred to the first and the second reactant stream. This will be the for the Process required energy consumption is reduced. The important thing is that here the temperature of the first reactant stream is not the reaction temperature achieved in process step d).

In addition, in this method in step d) known or new catalysts be used.

By the use of a second reactant stream and the subsequent mixture this stream without interim cooling with the first reactant stream at higher Temperatures will be the quality of the product significantly improved. The hydrogen content of the Product is increased; This reduces the oxygen and sulfur content of the product. The product quality is significantly improved in particular in terms of their viscosity.

The Invention will be described below with reference to embodiments and the figure explained in more detail, the schematically shows the flow of the proposed method.

A reactant stream 1 from waste biomass such. B. industrial sewage sludge is adjusted to about 20 wt.% Dry substance. In order to improve pumpability and reactivity, the mass is optionally comminuted to a particle size of about 0.3 mm. The first educt current 1 is with the pump 3a conveyed, brought to a pressure of 25 MPa (250 bar) and heated to up to 250 ° C. In the laboratory, this is achieved via an electric heater, but preferably via a heat exchanger 4 taking advantage of the waste heat of the product stream.

A second Eduktförderstrang is according to the aforementioned DE 101 35 431 C2 prepared. For this purpose, the reactor inner surface is oxidized with 3 wt.% Hydrogen peroxide at a pressure of 25 MPa (250 bar) and a temperature of 600 ° C. After operating for about 40 hours, the line is cleaned with water.

This pre-oxidation of the reactor is followed by normal process operation. For this purpose, the second reactant stream 2 from a solution of 50 wt.% methanol in water with the pump 3b promoted, in the heat exchanger 5 preheated by utilizing the waste heat of the product stream and then in the externally heated first reactor 6 brought to a pressure of 25 MPa (250 bar) and heated up to 600 ° C. During a residence time of 10 seconds in the high-temperature part of the reactor, a gas is formed which consists of about 65% by volume of hydrogen (H ₂ ), 15% by volume of carbon dioxide (CO ₂ ), 15% by volume of carbon monoxide (CO) and 5 vol. % Methane (CH ₄ ). From 1 mole of methanol 2 moles of hydrogen are generated under these conditions.

The flow ratio of the two educt streams 1 . 2 becomes after an input analysis of the first educt current 1 adjusted so that, based on the molar ratio of about the same amount of hydrogen as carbon is supplied. This means that the amount of methanol (1 mol of methanol = 32 g), which is fed to the process, in moles corresponds approximately to the amount of carbon in the educt. In rough anna There is half of the organic material in the first educt current 1 made of carbon. Thus, the process per gram of dry matter educt 0.65 g of methanol are fed. At a concentration of 20% by weight of educt dry substance and a feed rate of 1 t / h, a 50% by weight methanol solution with a delivery rate of 0.26 t / h is used.

In the second reactor 7 will be in the first reactor 6 produced gases, in particular hydrogen, with the first reactant stream 1 mixed at a temperature between 200 ° C and 450 ° C and a pressure between 25 MPa and 30 MPa, wherein an oil-like product 9 arises, the phase separator 8th is removed.

1

first Feedstock stream: biomass, heavy oil, etc.

2

second Feed stream: Aqueous solution with a dissolved organic proportion of at most 50% by weight

3a, 3b

pump

4

heat exchangers Part 1 (for the first reactant stream)

5

heat exchangers Part 2 (for the second educt stream)

6

first reactor

7

second reactor

8th

phase separator

9

product

Claims (9)

Process for the conversion of organic educts in oleaginous Products with the process steps a) generating a first Educt current from the organic educts, b) generating a second educt stream of at least one water-soluble organic compound, the at the most comprises three carbon atoms, and water, c) heating the second reactant stream to a temperature between 500 ° C and 700 ° C at a Pressure between 22.1 MPa and 30 MPa, which generates hydrogen becomes, d) mixing the hydrogen from the second educt stream with the first reactant stream at a temperature between 200 ° C and 450 ° C and a Pressure between 22.1 MPa and 30 MPa, whereby as product stream an oil-like Product is created, e) removing the oily product from the product stream. Method according to claim 1, characterized in that the first educt stream comprises biomass or heavy oil. Method according to claim 1 or 2, characterized that the second educt stream methanol, ethanol, formic acid, acetic acid, formaldehyde, Acetaldehyde or acetone as a water-soluble organic compound includes. Method according to one of claims 1 to 3, characterized that the second reactant stream heated to a temperature between 550 ° C and 650 ° C. becomes. Method according to one of claims 1 to 4, characterized that the mixing of the two reactant streams between 300 ° C and 360 ° C. Method according to one of claims 1 to 5, characterized that the mixing of the two educt streams during a period between 0.5 minutes and 10 minutes. Method according to one of claims 1 to 6, characterized the flow rate of the second reactant stream is between 20% and 120 % of the flow of the first reactant stream. Process according to one of Claims 1 to 7, characterized in that the number of hydrogen atoms in the form of H ₂ fed in with the second educt stream is between 0.5 and 4 times the number of carbon atoms contained in the first educt stream. Method according to one of claims 1 to 8, characterized that the waste heat of the product stream over a heat exchanger the two educt streams supplied becomes.