US-12623199-B2 - Plasma conversion reactor of C02 with C1 to C4 hydrocarbon to C1 to C5 oxygenate and method thereof

Abstract

An apparatus for forming a C1 to C5 oxygenate from carbon dioxide and a C1 to C4 hydrocarbon is described. The apparatus comprises: a dielectric barrier discharge, DBD, device arranged to generate a plasma; and a passageway having an inlet for the carbon dioxide and the C1 to C4 hydrocarbon and an outlet for the oxygenates. In one example the passageway includes therein a catalyst. The passageway extends, at least in part, through the DBD device wherein, in use, the carbon dioxide in reacted with the C1 to C4 hydrocarbon in the generated plasma, thereby forming the oxygenates from at least some of the carbon dioxide and the C1 to C4 hydrocarbon. The DBD device comprises a conducting liquid as a ground electrode. A method and a use are also described.

Inventors

• Xin Tu
• Yaolin Wang

Assignees

• THE UNIVERSITY OF LIVERPOOL

Dates

Publication Date

20260512

Application Date

20210615

Priority Date

20200615

Claims (14)

1. 1 . An apparatus for forming a C1 to C5 oxygenate from carbon dioxide and a C1 to C4 hydrocarbon, the apparatus comprising: a dielectric barrier discharge, DBD, device arranged to generate a plasma; and a passageway including an inlet for the carbon dioxide and the C1 to C4 hydrocarbon and an outlet for the oxygenates, wherein the passageway extends, at least in part, through the DBD device wherein, in use, the carbon dioxide and the C1 to C4 hydrocarbon are reacted in the generated plasma, thereby forming the C1 to C5 oxygenate from at least some of the carbon dioxide and the C1 to C4 hydrocarbon and wherein the DBD device comprises a conducting liquid electrode: wherein the DBD device comprises a transition metal oxide catalyst; and wherein the transition metal oxide catalyst is iron oxide.
2. 2 . The apparatus according to claim 1 , wherein the C1 to C4 hydrocarbon is selected from methane, ethane, propane and mixtures thereof.
3. 3 . The apparatus according to claim 1 , wherein the liquid electrode is a water electrode or a sodium chloride electrode.
4. 4 . The apparatus according to claim 1 , wherein the transition metal catalyst is held on a support selected from the group consisting of SiO 2 , TiO 2 , Al 2 O 3 , CeO 2 , ZrO 2 , ZnO, Cr 2 O 3 , carbon nanotubes, Ga 2 O 3 , In 2 O 3 and zeolite.
5. 5 . The apparatus according to claim 1 , wherein the apparatus comprises a catalyst selected from the group consisting of TiO 2 , CeO 2 , SiO 2 , Al 2 O 3 , ZrO 3 , ZSM-5 and SAPO.
6. 6 . A method of forming a C1 to C5 oxygenate from carbon dioxide and a C1 to C4 hydrocarbon, the method comprising: generating a plasma using a dielectric barrier discharge, DBD, device; and reacting the carbon dioxide and the C1 to C4 hydrocarbon in the generated plasma, thereby forming the C1 to C5 oxygenate from at least some of the carbon dioxide and the C1 to C4 hydrocarbon; wherein the DBD device comprises a liquid electrode; wherein the DBD device comprises a transition metal oxide catalyst; and wherein the transition metal oxide catalyst is iron oxide.
7. 7 . The method according to claim 6 , wherein reacting the carbon dioxide and the C1 to C4 hydrocarbon comprises reacting the carbon dioxide and the C1 to C4 hydrocarbon at approximately ambient temperature.
8. 8 . The method according to claim 6 , wherein generating the plasma using the DBD device comprises generating a stable plasma in a time in a range of from 1 to 60 minutes.
9. 9 . The method according to claim 6 , wherein the conversion of carbon dioxide and/or conversion of C1 to C4 hydrocarbon is in a range from 10 to 50%.
10. 10 . The method according to claim 6 , wherein the selectivity of methanol is in a range from 20 to 70%.
11. 11 . The method according to claim 6 , wherein the molar ratio of carbon dioxide to C1 to C4 hydrocarbon is in a range from 1:3 to 3:1.
12. 12 . The method according to claim 6 , wherein the method comprises supplying a specific energy input in a range of 15 to 60 kJ/L.
13. 13 . The apparatus of claim 1 , wherein the C1 to C4 hydrocarbon is methane.
14. 14 . The apparatus of claim 1 , wherein the liquid electrode is a water electrode.

Description

FIELD The present invention relates to apparatus and methods, for example apparatus and methods for use in carbon dioxide hydrogenation processes. Particularly, the present invention relates to an apparatus and method for use in carbon dioxide reforming of a C1 to C4 hydrocarbon to a C1 to C5 oxygenate using a non-thermal plasma generated by dielectric barrier discharge (DBD). BACKGROUND TO THE INVENTION The conversion and utilization of CO2, an increasingly attractive C1 building block, not only contributes to alleviating global climate changes induced by the increasing CO2 emissions but also opens up new sustainable routes for synthesizing useful feedstock chemicals and fuels. Direct transformation of hydrocarbons (especially methane) into value-added chemicals is a “holy grail” in chemistry. It is particularly challenging to perform selective conversion of hydrocarbons (especially methane) to oxygenates under mild conditions. As CO2 and hydrocarbons are thermodynamically stable molecules, considerable efforts have been devoted to activating the C═O, C—C and C—H bonds and converting to more valuable products efficiently over the past decades. The catalytic reforming of hydrocarbons (e.g. a C1 to C4 hydrocarbon) with CO2, however, remains challenging, primarily because of the chemical inertness of these molecules. Therefore, high temperature and/or high pressure is usually required to overcome the activation barrier during conventional catalytic conversions. Direct transformation of a C1 to C4 hydrocarbon with CO2 to oxygenates is very challenging and almost impossible under milder conditions, thus this process remains a well-known ‘holy grail’ in chemistry. Thermal catalytic CO2 reforming with a C1 to C4 hydrocarbon to oxygenates using an indirect route often proceeds through two steps: i) CO2 reforming of hydrocarbons to produce syngas at high temperatures due to thermodynamic barrier of this reaction; 2) conversion of syngas to oxygenates at high pressure and relatively high temperature. The first step for syngas production is highly endothermic and requires high temperatures and energy input. It is almost impossible to directly convert hydrocarbons with CO2 to oxygenates in a single step bypassing the generation of syngas. Non-thermal plasmas have been employed as a highly promising approach for converting a wide range of stable C-containing molecules to syngas, alcohols and oxygenates in a single step under low temperature and ambient pressure. The energetic electrons can activate molecules via excitation, dissociation and ionization. The reactive species (i.e. radicals, ions, excited species) generated in the plasma contribute to both the gas phase reactions and surface reactions, initiating new reaction pathways at low temperatures and ambient pressure. The use of a catalyst in the plasma process has great potential to enhance the selectivity towards target products. Plasma catalysis provides a promising and alternative for the single step selective production of a C1 to C5 oxygenate via CO2 reforming of a C1 to C4 hydrocarbon at near room temperature and ambient pressure. SUMMARY OF THE INVENTION It is one aim of the present invention, amongst others, to provide an apparatus and method for converting carbon dioxide and a C1 to C4 hydrocarbon into a C1 to C5 oxygenate, which at least partially obviates or mitigates at least some of the disadvantages of the prior art, whether identified herein or elsewhere. For instance, it is an aim of embodiments of the invention to provide an apparatus to provide plasma-activated synthesis of a C1 to C5 oxygenate from carbon dioxide and a C1 to C4 hydrocarbon, with a high conversion of reactants, high selectivity and/or yield of oxygenates and/or high energy efficiency. For instance, it is an aim of embodiments of the invention to provide a method of synthesising a C1 to C5 oxygenate from carbon dioxide and a C1 to C4 hydrocarbon at low temperature or room temperature and atmospheric pressure using plasma. For instance, it is an aim of embodiments of the invention to provide an apparatus for and/or a method of carbon dioxide reforming or oxidative coupling of hydrocarbons using soft oxidant CO2 that does not require additional heating and can be conducted at ambient pressure. For instance, it is an aim of embodiments of the invention to provide an apparatus for and/or a method of carbon dioxide reforming that may be integrated with renewable energy sources (e.g. wind and solar power), especially the use of intermittent renewable energy during peak load for localised or distributed energy storage. DETAILED DESCRIPTION OF THE INVENTION According to the present invention there is provided an apparatus, as set forth in the appended claims. Also provided is a method and a use. Other features of the invention will be apparent from the dependent claims, and the description that follows. Apparatus A first aspect provides an apparatus for forming a C1 to C5 oxygenate from