Chemical Conversion of Carbon Dioxide and Gaseous Hydrocarbons to Solvents

Abstract

Catalytic chemical conversion of carbon dioxide gas combined with a hydrocarbon gas, comprising natural gas, methane, ethane, propane, butane or pentane, over a transition metal oxide, produces organic solvent products. The process converts oxidized carbon compounds to valued organic products and can reduce or eliminate the carbon footprint of industrial electric power generation industry. Catalytic processes are taught for chemical conversion of oxides of carbon, principally carbon dioxide (formed by combustion of hydrocarbons), to solvent compounds comprising acetone, butanol, pentane and related organic products. The catalysts are transition metal oxides, selected from the group comprising manganese, iron and cobalt or combinations thereof.

Claims

1. A chemical process for reacting carbon dioxide with a gaseous hydrocarbon, comprising natural gas, methane, ethane, propane, butane or pentane, in the presence of a transition metal oxide catalyst, selected from the group comprising manganese oxide, iron oxide or cobalt oxide, forming solvents comprising acetone, butanol, pentane, pentanone, heptanol and nonane.

2. A chemical process for reacting carbon dioxide with a gaseous hydrocarbon, comprising natural gas, methane, ethane, propane, butane or pentane, in the presence of a transition metal oxide catalyst, selected from the group comprising manganese oxide, iron oxide or cobalt oxide, at temperatures of 200° C. to 460° C. and pressures of 1 atmosphere to 7 atmospheres forming solvents comprising acetone, butanol, pentane, pentanone, heptanol and nonane.

3. A chemical process for reacting carbon dioxide with a gaseous hydrocarbon, comprising natural gas, methane, ethane, propane, butane or pentane, in the presence of a transition metal oxide catalyst, selected from the group comprising manganese oxide, iron oxide or cobalt oxide, at temperatures of 200° C. to 500° C. and pressures of 1 atmosphere to 10 atmospheres forming solvents comprising acetone, butanol, pentane, pentanone, heptanol and nonane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0017] A process is disclosed for catalytic chemical conversion of carbon dioxide mixed with gaseous hydrocarbon compounds, comprising natural gas, methane, ethane, propane, butane or pentane, to solvents using selected members of a family of transition metal catalysts, comprising manganese oxide, iron oxide, cobalt oxide or combinations thereof. Solvent products were formed from carbon dioxide and gaseous hydrocarbons using two different chemical conversion processes to prove product formation. Solvents formed from a pressure reactor were isolated for testing and products produced in a flow through reactor were confirmed by Fourier Transform Infrared spectroscopy (FTIR) as disclosed in the Chemical Conversions that follow.

[0018] The process for catalytic reaction of carbon dioxide with gaseous hydrocarbons comprising natural gas, methane, ethane, propane, butane or pentane is demonstrated in production of solvents comprising acetone, butanone, pentanone, hexanone, heptanone, octanone, nonanone, decanone and undecanone, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonadecane, icosane and heneicosane. The chemistry reveals a reaction of one of the oxygen atoms of carbon dioxide with a hydrogen atom donated by each of two hydrocarbon molecules to form, for example, acetone solvent and the byproduct water. It also reveals carbon dioxide reacting with each of three hydrocarbon molecules to form, for example, butanol and carbon dioxide reacting with each of four hydrocarbon molecules to form, for example, pentane and the byproduct water.

[0019] The process is based on transition metal oxide catalysis to facilitate conversion of carbon dioxide mixed with gaseous hydrocarbon compounds at temperatures, in the range of 200° C. to 500° C. and reaction pressures in the range of 1 atmosphere to 10 atmospheres, to produce solvents.

Chemical Conversions

[0020] A first set of catalytic chemical conversions was conducted using a 300 mL high-pressure reactor. Products were identified by physical properties and boiling point. The reactor was fit with two valves to facilitate gas flow in and gas flow out. It was closed and sealed by means of a bolt assembly. Approximately 5 grams of anhydrous magnesium chloride (included to assure residual water was absorbed) was combined with 7.5 grams of ⅛″ long cylindrical silica-alumina support coated with 2 percent by weight cobalt oxide. The reactor was heated to 310° C. and flushed with bone dry carbon dioxide gas. It was cooled, pressurized with 5 psig bone dry carbon dioxide and the pressure increased to 47 psig with dried natural gas (95% methane). The reactor was heated to 450° C. for an hour and fifteen minutes as the pressure declined. The reactor was cooled to ambient temperature and opened. Solvent liquid, 0.815 gram, was isolated from the remaining solid by filtration. The solvent had a pungent odor and a boiling point of 56° C. identified as acetone.

[0021] A second reaction was conducted by loading 5 grams of anhydrous magnesium chloride was combined with 7.5 grams of ⅛″ long cylindrical silica-alumina support coated with 2 percent by weight manganese oxide. The reactor was heated to 310° C. and flushed with bone dry carbon dioxide gas. It was cooled, pressurized with 23.5 psig bone dry carbon dioxide and the pressure increased to 100 psig with dried propane. The reactor was heated to 450° C. for an hour and one half as the pressure declined. The reactor was cooled to ambient temperature and opened. Solvent liquid, 0.865 gram, was isolated from the remaining solid by filtration. The solvent had a light odor of bananas and a boiling point of 151° C. identified as heptanone.

[0022] A second set of catalytic chemical conversions was conducted using ½ inch diameter stainless steel tube flow through reactor configured in sections. The front end consisted of a carbon dioxide flow control valve, a hydrocarbon gas flow control valve and an inlet for admission of gaseous reactants. Next section was a 3 inch drier mixing tube filled with molecular sieves 4 A. The final section of the reactor was terminated by a right angle reducer to a ¼ inch diameter tube connected to a 10 mL condensing finger immersed in a cold bath (either dry ice/acetone or ice/water baths were employed) and flow gases were exhausted. Each section was heated using electrical heating tape connected to temperature controllers with section (zone) temperatures monitored using thermal couples. Resulting products were recovered from a cold trap and identified by means of FTIR spectral band absorptions.

Example A—Acetone

[0023] The reactor zone was heated to 280° C. as carbon dioxide and natural gas were supplied at 1.4 atmospheres (20 pounds per square inch) pressure with a total flow rate of 214 mL/minute. Carbon dioxide was set to 70 mL/minute while natural gas was set to 144 mL/minute. Gases were allowed to flow for 30 minutes. A colorless liquid, weight was 6.64 grams, was collected in the cold trap immersed in an ice water bath.

[0024] The liquid was dried over anhydrous sodium sulfate then filtered to collect 4.8 grams of liquid product. An FTIR spectrum of the liquid produced useful spectral information. Relatively intense absorption bands were observed at 2966, 2937 and 2875 wave numbers with weaker bands at 1467, 1379, 1276, 905, 886, 798 and 754 wave numbers. In addition, a relatively intense band was observed at 1715 wave numbers identified with ketones with a weak band at 1199 wave numbers indicating the presence of an alcohol. This was identified as acetone, as produced in the previous section, and a lesser amount of butyl alcohol.

Example B—Butanol

[0025] The reactor zone was heated to 282° C. as carbon dioxide and natural gas were supplied at 1.4 atmospheres (20 pounds per square inch) pressure with a total flow rate of 215 mL/minute. Carbon dioxide was set to 65 mL/minute while natural gas was set to 201 mL/minute. Gases were allowed to flow for 30 minutes. A colorless liquid, weight was 6.67 grams, was collected in the cold trap immersed in an ice water bath.

[0026] The liquid was dried over anhydrous sodium sulfate then filtered to collect 5.1 grams of liquid product. An FTIR spectrum of the liquid produced useful spectral information. Relatively intense absorption bands were observed at 2964, 2936 and 2873 wave numbers with relatively weaker bands at 1466, 1378, 1275, 904, 885, 798 and 753 wave numbers. In addition, a weak band was observed at 1712 wave numbers identified with ketones with an intense band at 1198 wave numbers indicating the presence of a branched alcohol. This was identified as a minor amount of acetone, as produced in the previous section, and a majority of butyl alcohol.

Example C—Pentane

[0027] The reactor zone was heated to 280° C. as carbon dioxide and natural gas were supplied at 1.7 atmospheres (25 pounds per square inch) pressure with a total flow rate of 257 mL/minute. Carbon dioxide was set to 50 mL/minute while natural gas was set to 207 mL/minute. Gases were allowed to flow for 30 minutes. A colorless liquid, weight was 8.33 grams, was collected in the cold trap immersed in a dry ice acetone bath.

[0028] The liquid was dried over anhydrous sodium sulfate then filtered to collect 5.7 grams of cold liquid product. An FTIR spectrum of the liquid produced useful spectral information. Relatively intense absorption bands were observed at 2966, 2937 and 2875 wave numbers with relatively weaker bands at 1467, 1379, 1276, 905, 886, 798 and 754 wave numbers demonstrating a hydrocarbon liquid. In addition, a weak band at 1191 wave numbers indicating the presence of a trace of alcohol. This was identified as a low boiling hydrocarbon, pentane, and a small amount of butyl alcohol.

Example D—Tridecane

[0029] The reactor zone was heated to 286° C. as carbon dioxide and propane gas were supplied at 1.4 atmospheres (20 pounds per square inch) pressure with a total flow rate of 257 mL/minute. Carbon dioxide was set to 50 mL/minute while propane gas was set to 210 mL/minute. Gases were allowed to flow for 30 minutes. A colorless mixed liquid, weight was 11.29 grams, was collected in the cold trap immersed in an ice water bath.

[0030] The liquid was dried over anhydrous sodium sulfate then filtered to collect 8.9 grams of an oily liquid product. An FTIR spectrum of the liquid produced useful spectral information. Relatively intense absorption bands were observed at 2966, 2937 and 2875 wave numbers with relatively weaker bands at 1467, 1379, 1276, 905, 886, 798, 754 and 720 wave numbers demonstrating a hydrocarbon liquid. In addition, a weak band at 1188 wave numbers indicating the presence of a trace of alcohol. This was identified as the liquid hydrocarbons tridecane, boiling range 230° C. to 240° C., and a trace amount of butyl alcohol.