Process for converting cellulosic material into liquid hydrocarbons

• US 20020035291A1
• Filed: 03/06/2001
• Published: 03/21/2002
• Est. Priority Date: 03/06/2000
• Status: Active Grant

• Current Assignee: Woodland Biofuels, Inc.
• Original Assignee: Woodland Chemical Systems Inc.
• Inventors: Melnichuk, Larry Jack, Kelly, Karen Venita
• Granted Patent: US 6,747,067 B2
• Time in Patent Office: Days
• US Class Current: 562/519
• CPC Class Codes: C07C 1/0485 Set-up of reactors or accessories; Multi-step processes
• CPC Class Codes: C07C 29/1518 one step being the formation of initial mixture of carbon oxides and hydrogen for synthesis
• CPC Class Codes: C07C 31/04 Methanol
• CPC Class Codes: C07C 51/12 on an oxygen-containing group in organic compounds, e.g. alcohols
• CPC Class Codes: C07C 53/08 Acetic acid pyroligneous acid C10C; preparation of vinegar C12J
• CPC Class Codes: C10J 2300/092 Wood, cellulose
• CPC Class Codes: C10J 2300/0976 as steam
• CPC Class Codes: C10J 2300/1223 by burners
• CPC Class Codes: C10J 2300/1656 Conversion of synthesis gas to chemicals
• CPC Class Codes: C10J 2300/1665 to alcohols, e.g. methanol or ethanol preparation of alcohols in general C07C29/00
• CPC Class Codes: C10J 2300/1807 Recycle loops, e.g. gas, solids, heating medium, water
• CPC Class Codes: C10J 3/00 Production of combustible gases containing carbon monoxide from solid carbonaceous fuels destructive distillation processes C10B
• CPC Class Codes: C10J 3/721 Multistage gasification, e.g. plural parallel or serial gasification stages
• CPC Class Codes: C10K 1/026 by centrifugal forces cyclones B04C
• CPC Class Codes: C10K 1/20 by treating with solids; Regenerating spent purifying masses separation by adsorption B01D53/02; separation by chemical reaction B01D53/34; refining of hydrocarbon oils with acids C10G17/02, C10G27/02, C10G29/12
• CPC Class Codes: C10K 3/04 reducing the carbon monoxide content , e.g. water-gas shift [WGS]
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

A process for the production of oxygenated C₂ hydrocarbons from cellulose is disclosed. The input cellulose waste is gasified using steam in the absence of air and the primary gaseous products of carbon monoxide and hydrogen are subjected to heat, pressure, and catalysts to form methyl alcohol. Carbon monoxide is added to the methyl alcohol and further subjected to heat, pressure and catalysts to form acetic acid. The acetic acid is purified using a distillation tower, and removed for sale. Output production is increased by adding further carbon monoxide and hydrogen from burners used to heat the gasifiers. Further carbon monoxide and hydrogen are also produced by steam gasification of the carbon residue to promote a water/gas shift. These gases are fed into the gas stream produced by the gasification of cellulose, and provide more feedstock for the reactions. The three input gas streams arising from: 1) the steam gasification of cellulose; 2) the water/gas shift in the carbon reactor; and 3) the sub-stoichiometic oxygen burning of input burner gas to heat both retorts, maximize the output chemical production while reducing the consumption of energy needed for processing the cellulose and the carbon.

Claims

1. A process for producing acetic acid from cellulosic material comprising the steps of:

heating the cellulosic material and introducing steam to crack the material at a temperature of between 650 and 900°

C. thereby producing a gas stream;

cleaning the gas stream to remove fly ash and carbon thereby producing a cleaned gas stream;

separating the gases in the cleaned gas stream to remove the carbon monoxide and hydrogen gases therefrom;

metering each of the hydrogen and the carbon monoxide in a predetermined ratio into a heated pressure vessel with a catalyst to form a methanol;

liquefying the methanol and passing it into a second heated pressure vessel with a catalyst and carbon monoxide to form acetic acid; and

liquefying the acetic acid and other material present and removing the acetic acid from the any water, other hydrocarbons and purifying the stream;

2. A process for producing acetic acid from cellulosic material as claimed in claim 1 wherein the predetermined ratio of hydrogen to carbon monoxide is 2:

1.

3. A process for producing acetic acid from cellulosic material as claimed in claim 2 wherein the heating temperature is 675°

C.

7. A process for producing acetic acid from cellulosic material according to the process steps claimed in claim 1 whereby the gasifiers used are fluid bed retorts.

8. A process for producing acetic acid from cellulosic material according to the process steps claimed in claim 1 in which the method of separating gases to remove mixed hydrocarbons from the gases emerging from the cellulose gasifier is a molecular sieve.

4. A process for producing acetic acid from cellulosic material comprising the further enhancement of;

heating the carbon and fly ash removed from the gasification of the cellulosic material in the presence of steam to produce gases;

equalizing the pressure of the gases emerging from the carbon gasification using a pressure equalizer;

directing the gases to a molecular sieve to separate the carbon monoxide from the hydrogen so they can be mixed in the correct ratios to form an alcohol in the first pressure.

5. A process for producing acetic acid from cellulosic material comprising the further enhancement of;

providing oxygen to both burners which supply indirect heating to the gasifiers using molecular sieves to remove nitrogen.

6. A process for producing acetic acid from cellulosic material comprising the further enhancement of:

Utilising the cooled gases comprised of carbon monoxide and hydrogen which are produced in the burners used to indirectly heat the gasifiers to increase the input of gases into the first pressure vessel to make an alcohol.

9. A process for producing liquid hydrocarbon from cellulosic material comprising the steps of:

heating the cellulosic material and introducing steam to crack the material at a temperature of between 650 and 900°

C. thereby producing a gas stream;

cleaning the gas stream to remove fly ash and carbon thereby producing a cleaned gas stream;

separating the gases in the cleaned gas stream to remove the carbon monoxide and hydrogen gases therefrom;

metering each of the hydrogen and the carbon monoxide in a predetermined ratio into a heated pressure vessel with a catalyst to form a liquid hydrocarbon.

10. A process for producing liquid hydrocarbon from cellulosic material as claimed in claim 9 wherein the liquid hydrocarbon is methanol and the catalyst is copper zinc oxide on an aluminium base.

11. A process for producing liquid hydrocarbon from cellulosic material as claimed in claim 10 further including the steps introducing a second catalyst to the methanol to produce a second hydrocarbon.

12. A process for producing liquid hydrocarbon from cellulosic material as claimed in claim 11 wherein the liquid hydrocarbon is formaldehyde and the second catalyst is silver.

13. A process for producing liquid hydrocarbon from cellulosic material as claimed in claim 12 and further including the steps of the introducing nitrogen, ammonia, water to the formaldehyde to produce urea-formaldehyde.

14. A process for producing liquid hydrocarbon from cellulosic material as claimed in claim 11 wherein the second liquid hydrocarbon is acetic acid and the second catalyst is chosen from the group consisting of a combination of rhodium, phosphine and iodine.