Device for extracting gaseous and liquid products from a reaction fluid

Abstract

It is provided a device and method for extracting gaseous and liquid products from a reaction fluid, in particular from an electrochemical reaction systems.

Claims

1. A device for extracting gaseous reaction products and liquid reaction products from a reaction fluid, from an electrochemical reaction system, the device comprising: at least one inlet feeding for reaction fluid into the device; at least one outlet for exiting a fluid depleted of said gaseous reaction products and liquid reaction products out of the device; a first compartment comprising a first membrane supported on a first porous material and configured to separate the gaseous reaction products from the reaction fluid using the first membrane; and a second compartment comprising a second membrane supported on a second material and configured to separate the liquid reaction products from the reaction fluid using the second membrane; a capillary tube system configured to guide the reaction fluid from the inlet and into the first compartment whereby the reaction fluid contacts the first membrane and the gaseous reaction products separate from the reaction fluid and to subsequently guide the reaction fluid into the second compartment whereby the reaction fluid contacts the second compartment and the liquid reaction products separates from the reaction fluid; wherein the capillary tube system fluidly connects the first compartment to the second compartment; a first negative pressure source connected to the first compartment and configured to apply, in operation, a first sub-atmospheric pressure to the first membrane whereby the gaseous reaction products transfer through the first membrane; and a second negative pressure source connected to the second compartment and configured to apply, in operation, a second sub-atmospheric pressure to the second membrane whereby the liquid reaction products transfer through the second membrane.

2. The device according to claim 1, wherein the first compartment and second compartment are aligned along an axis.

3. The device according to claim 1, wherein the first compartment and second compartment are arranged inversely or back-to-front along the axis.

4. The device according to claim 1, wherein the first compartment comprises a first ring and a second ring, the first ring comprising a first opening and the second ring comprising a second opening and wherein the second compartment comprises a third ring and a fourth ring, the third ring comprising a third opening and the fourth ring comprising a fourth opening, wherein the first opening comprises a round piece or disc including the capillary tube system and the second opening comprises the first porous material.

5. The device according to claim 4, wherein the first membrane is disposes with the first ring and the second membrane is disposed with the second ring.

6. The device according to claim 4, wherein the second ring comprises a connection connected to the second negative pressure source.

7. The device according to claim 1, wherein at least one flow inlet and at least one flow outlet comprise a disk arranged between the first ring of the first compartment and the second ring of the second compartment.

8. The device according to claim 1, wherein the first membrane comprises polytetrafluoroethylene PTFE, polyetheretherketone PEEK, polyvinylidene fluoride PVDF, or silicone; or a film directly deposited on the first porous material or a thin layer directly deposited on the first porous material and the second membrane comprises polytetrafluoroethylene PTFE, polyetheretherketone PEEK, polyvinylidene fluoride PVDF, or silicone; or a film directly deposited on the second porous material or a thin layer directly deposited on the second porous material.

9. The device according to claim 1, wherein the first membrane in the first compartment has a porosity between 10 and 30 nm, and a thickness between 100 and 200 m and the first porous material is a first frit having a porosity between 0.3 and 0.8 m, and a thickness between 2 and 6 mm.

10. The device according to claim 1, wherein the second membrane in the second compartment has a porosity between 30 and 80 nm, and a thickness between 100 and 200 m and the second porous material is a second frit having porosity between 5 and 15 m, and a thickness between 2 and 6 mm.

11. A method of extracting gaseous reaction products and liquid reaction products from a reaction fluid using the device according to claim 1, the method comprising: feeding a reaction fluid comprising gaseous reaction products and liquid reaction products into the device through the at least one inlet into the first compartment such that the gaseous reaction products are first separated from the reaction fluid in the first compartment via the first membrane under the first sub-atmospheric pressure provided by the first negative pressure source, and the liquid reaction products are subsequently separated through evaporation from the reaction fluid in the second compartment a via the second membrane under the second sub-atmospheric pressure provided by the second negative pressure source, wherein the first sub-atmospheric pressure is lower than the second sub-atmospheric pressure and the gaseous reaction products transfer through the first membrane and the liquid reaction products transfer through the second membrane for analysis, and a fluid depleted of said gaseous reaction products and of said liquid reaction products exit out of the device through the at least one outlet.

12. The method according to claim 11, wherein the first sub-atmospheric pressure in the first compartment is between 5 and 15 mbar and the second sub-atmospheric pressure in the second compartment is between 50 and 150 mbar.

13. The method according to claim 11, wherein the first sub-atmospheric pressure is between 10.sup.2 and 10.sup.3 mbar.

14. The method according to claim 11, further comprising analyzing the gaseous reaction products separated from the reaction fluid and analyzing the liquid reaction products separated from the reaction fluid suing a mass spectrometer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The proposed solution is described in the following in more detail with reference to the figures.

(2) FIG. 1 shows a view of the separating device according to the solution.

(3) FIG. 2 shows a view of one separation layer of the device according to the solution.

(4) FIG. 3 shows a view of the flow through the capillary system of the device according to the solution.

(5) FIG. 4 shows mass fragments for m/z 2 recorded during the hydrogen evolution reaction using the device according to the solution.

(6) FIG. 5 shows mass spectrum of products obtained during Electroreduction of CO.sub.2 on Oxide derived copper electrode.

(7) FIG. 6 shows simultaneously recorded cyclic voltammograms and mass fragments.

(8) FIG. 7 shows mass spectrum of products obtained during Electro-oxidation of HCO.sub.3.sup. species on Gold and/or Nickel deposited electrode.

DETAILED DESCRIPTION

(9) FIG. 1 is an explosion view of the two-layer compartment separator of gas and liquid products from incoming reaction fluid according to the solution. As illustrated in FIG. 1 a first compartment (or chamber) is configured for separating or extracting the gaseous products from the reaction fluid and a second compartment (or chamber) is configured for separating or extracting the liquid products from the reaction fluid. Each comparment comprises a set of membrane and frit porous material. Each compartment is in communication with a vacuum side. In the right corner of FIG. 1 the assembled collector is illustrated.

(10) In FIG. 2 one separation layer or compartment is presented in detail showing the components of one of the sides of the evaporator. FIG. 3 illustrates the flow of the reaction fluid through the capillary system of the device according to the solution.

(11) As illustrated in FIGS. 1 and 2 each of the two compartments comprise a first ring with an opening and a second ring with an opening. The diameters of the first and second ring are approx. the same.

(12) The opening of the first ring houses a round piece or disc type piece with an inserted or incorporated capillary tube system is arranged (capillary tube system is worked into the material of the round piece or disc)

(13) The opening of second ring houses a frit porous material. The first or second membrane is placed between the first and the second ring. Thus, thus the membrane is sandwiched or interposed between the first and second ring. The membranes may be made of PTFE, PEEK or PVDF. The first membrane of the first compartment has porosity of 20 nm and thickness of 200 to 100 micrometers and frit with thickness of 4 mm and porosity of 0.5 micrometers. For second side, the membrane layer and frit is composed by a membrane with porosity of 50 nm thickness of 200 to 100 micrometers and frit with thickness of 4 mm and porosity of 10 micrometers.

(14) A further disc (having approximately the same diameter as the first and second ring) is arranged between the first ring of the first compartment and the second ring of the second compartment. Said disc comprises a flow inlet and a flow outlet. The Inlet and outlet capillaries are incorporated or worked into the disc material. Inlet and outlet capillaries of the disc are in communication with the capillary system of the round piece/disc inserted into the opening of the first ring of each compartment.

(15) The first and second compartments are aligned back-to-front along the same axis. The second ring of each compartment is provided with a connection to the vacuum source.

(16) The compartments including the rings, discs and membranes with frit porous material are enclosed by an insulation cover. The insulation cover may comprise a sleeve that houses the compartments and two plates (with openings for the connection to the vacuum sources) that are closely attached to sleeve ends. The Insulation cover is made of PMMA material and two plates made of stainless steel.

(17) The extended capillary system is now further described in more detail (FIGS. 2 and 3). The inlet capillary distributes the incoming flow of the reaction fluid to two horizontal capillaries. Each of the two horizontal capillary (i.e. parallel to the membrane) is connected in turn to two vertical capillaries (i.e. vertical to the membrane) with openings at the membrane corners. The membrane is connected with capillary tubes. Thus, the incoming flow is distributed to four capillaries that are in communication with the membrane, in particular four corners of a membrane. The four vertical capillaries promoting turbulent flow over the interface of the membranes. The incoming reaction fluid flows from the membrane corners over the membrane surface to the center of the membrane. While the reaction fluid flows over the first membrane the gaseous reaction product is separated through the membrane into the vacuum system. In the center of the (first) membrane is another capillary to guide the fluid depleted from gaseous products from the first compartment to the second compartment. In the second compartment the arrangement of the capillary system is basically the same as in the first compartment (mirror image). In the second compartment the reaction fluid (now depleted from the gaseous products) is guided through the inlet capillary, two horizontal capillaries and four vertical capillaries over the second membrane, and the liquid reaction products are separated or evaporated from the reaction fluid into the vacuum system. The reaction fluid now depleted of the gaseous and liquid reaction products flows through the outlet out of the device.

Example 1

(18) Detection time is crucial for studying the electrochemical reaction. The gas collector is able to detect H.sub.2 gas, at differential periods of around 100 millisecond range, as presented in FIG. 4. Such highly sensitive measurement allows to evaluate the reaction kinetics, despite the undesired liquid media interface at MS. The intensity of MS signal results from the applied electrochemical charge. Short period of reaction also represents low intensity signals. Nevertheless, the catalytic reaction has limited detection possibility at time range within 50 ms, where signals are at noise level of detection.

(19) FIG. 4 shows mass fragments for m/z 2 recorded during the hydrogen evolution reaction resulting from step of potential with a defined duration of steps, during electro-reduction process of instantaneous hydrogen evolution at the Pt catalyst (metal disk) 5 mm Electrolyte: 0.05 M H.sub.2SO.sub.4.

Example 2

(20) High signal intensity and multiple products detection when CO.sub.2 is used as reactant during electrochemical reduction process for direct conversion to hydrocarbon molecules. In FIG. 5 are presented the main gas products, such as methane, ethylene and CO or liquid products like ethanol, acetaldehyde, acetone and allyl alcohol. The extractor system was able to separate the gas and liquid products from the electrolyte solution at high speed to clearly differentiate the potential of starting product evolution.

(21) FIG. 5 shows the electroreduction of CO.sub.2 on Oxide derived copper electrode, electrochemical current-IF (red line); mass spectrum current for gas products with hydrogen (grey line), carbon monoxide (green line), ethylene (violet line) and methane (blue line); mass spectrum current for liquid products with ethanol (orange line), acetaldehyde (orange line), acetone (green line) and allyl alcohol (red line). Conditions: 5 mV.Math.s.sup.1 in 0.1 M KHCO.sub.3. Saturation of electrolyte flowing at speed 12 L.Math.s.sup.1. Ion source set in neg with ion source standard calibration pre-measurements. SEM voltage was set at 1050V and every mass was recorded simultaneously with Dwell time 100 a.u., resolution 50 and pause time 1. Capillary flow 2 L.Math.s.sup.1.

Example 3

(22) The most important achievement is represented by the detection of liquid products, which is done at significant time resolution. The evaporation of liquid products into the vacuum system is achieved in part due to the flexibility of the combination of the hydrophobic PTFE membrane and the frit porous material for membrane support. The other important achievement is high MS signal intensity due to high flow of analysis gas into the MS, by combining two differential pumping stages, one dedicated to the gas and liquid collector and the second for MS analysis. Two pumping stages make it possible to allow many combinations of hydrophobic membrane porosity. Due to the high volatility of methanol, analysis of MS during a methanol oxidation reaction as in FIG. 6A is only possible by combining the right set of membrane and frit porous material. Also, in FIG. 6B is presented the CO.sub.2 formation during the oscillatory electro-oxidation of methanol on platinum. Such reaction conditions are only attained in stable reaction conditions at reactor cell, in part achieved using the seamless design of the capillary tube.

(23) FIG. 6A shows simultaneously recorded cyclic voltammograms and mass fragments for carbon dioxide m/z 44, methyl formate at m/z 60, carbon monoxide at m/z 28 and methane at m/z 15, during electro-oxidation of methanol on 20 wt % platinum-nanoparticle catalyst supported on Vulcan drop coated in 5 mm glassy carbon. Conditions: 10 mV.Math.s.sup.1. FIG. 6B shows Period-one potential time series (red line) during electro-oxidation of methanol at 0.5 M H.sub.2SO.sub.4 and 1 M of methanol accompanied by mass fragments of carbon dioxide at m/z 44 (green line) in 20 wt % platinum-nanoparticle catalyst supported on Vulcan drop coated in 5 mm glassy carbon.

Example 4

(24) The high vacuum regime under the membrane allows for fast extraction of converted unstable chemicals in solution, this is important to extract substances with low chemical stability or substances with no vapor pressure. A membrane coated with a catalytic active material such as Gold and Nickel is submitted to a high oxidative potential promoting an oxidation reaction to volatile MS detectable compounds. The reaction of non-detectable MS species like ionic dissolved compounds such as bicarbonate. The coated membrane is submitted to an oxidative potential using a power supply or a potentiostat instrument, which converts the ionic compounds to gaseous or volatile species such as CO.sub.2. The cathode is an immersed platinum wire with thickness 0.5 mm placed at the outflow of liquid.

(25) FIG. 7 shows mass spectrum signals of resulted m/z 44 CO.sub.2 (orange line) and m/z 32 O.sub.2 (purple line) products during electro-oxidation of 0.1M KHCO.sub.3 solution on Gold and on Gold-Nickel deposited membrane electrodes. The CO.sub.2 formation results from the bicarbonate oxidation, while O.sub.2 evolution results from the expected OER process of water splitting.