Membrane-less reactor design and process for biotransformation of carbon dioxide

Patent metadata

Field	Value
Publication number	US-2021170357-A1
Application number	US-202017084623-A
Country	US
Kind code	A1
Filing date	Oct 29, 2020
Priority date	Dec 4, 2019
Publication date	Jun 10, 2021
Grant date	—

Abstract

The present invention discloses a membrane-less reactor design for microbial electrosynthesis of alcohols from carbon dioxide (CO 2 ). The membrane-less reactor design thus facilitates higher and efficient CO 2 transformation to alcohols via single pot microbial electrosynthesis. The reactor design operates efficiently avoiding oxygen contact at working electrode without using membrane, in turn there is an increase in CO 2 solubility and its bioavailability for subsequent CO 2 conversion to alcohols at faster rate. The present invention further provides a process of operation of the reactor for biotransformation of the carbon dioxide.

First claim

1 . A membrane-less reactor for conversion of carbon dioxide to alcohols by microbial electrosynthesis, wherein the membrane-less reactor comprises:
a) a tubular gas diffusion electrode with an active layer modified with an electroactive material as a working electrode; b) a circular counter electrode; c) a porous bio-electroactive filter; d) an electrolyte; and e) samplings ports;
wherein the reactor is single chambered and can be operated in batch or continuous or semi-continuous mode in a continuous stirred tank reactor or in a sequential batch reactor.

2 . The membrane-less reactor as claimed in claim 1 , wherein the working electrode comprises a gas compartment either towards inner core or towards outside, and
wherein the active layer of the working electrode comprises:
a) an activated carbon powder with graphite in 60:40 proportion; and
b) the electroactive materials present in a concentration range of 0.4-0.6 mg/cm 2 .

3 . The membrane-less reactor as claimed in claim 1 , wherein the working electrode is treated with polymerized redox mediators dissolved in the electrolyte at a concentration of 0.4-0.6 mM;
wherein the electrolyte comprises trace metal solution along carbon dioxide as carbon source.

4 . The membrane-less reactor as claimed in claim 1 , wherein the counter electrode is a circular disc in shaped with perforated arrangement having wider holes and central cavity and is made up of titanium or nickel or mixed metal oxide (ruthenium or iridium) coated titanium, with a coating of highly active materials with a concentration range of 0.6-0.8 mg/cm 2 .

5 . The membrane-less reactor as claimed in claim 1 , wherein the working electrode and the counter electrode are positioned perpendicular to each other to avoid oxygen contact at the gas diffusion electrode and the working electrode is vertically arranged inside the reactor such that it remains completely immersed in the electrolyte with the active layer facing towards the electrolyte and gas diffusion layer facing towards inner side of cylinder without contacting the electrolyte, and wherein the counter electrode is positioned on top of the electrolyte.

6 . The membrane-less reactor as claimed in claim 1 , wherein a feedstock for the reactor is CO 2 alone or flue gas having 14% CO 2 along with other pollutant gases.

7 . The membrane-less reactor as claimed in claim 1 , further comprising a biocatalyst for the microbial electrosynthesis, wherein the biocatalyst is a microbe selected from a group consisting of EAB, chemoautotrophic bacteria, heterotrophic bacteria, homo acetogenic bacteria, wherein the microbe is grown under 3 V cell potential for 5-7 days prior to inoculation.

8 . The membrane-less reactor as claimed in claim 1 , wherein the reactor is operated at a pressure in the range of 2-10 bar, by maintaining the flow rate of gas and the potential is in range of 1-4 V or applied current in range of 50-200 A/m 2 .

9 . The membrane-less reactor as claimed in claim 1 , wherein the porous bio-electroactive filter is arranged in association with the active layer of the gas diffusion electrode to develop an electro-active-biofilm.

10 . A system for production of alcohol from carbon dioxide, said system comprising:
a carbon dioxide or flue gas supply reservoir; an electrolyte supply reservoir; a trace metal solution (TMS) for providing essential nutrients to microbial metabolism; a microbial separation column; a product separation column; and a membrane-less reactor for conversion of carbon dioxide to alcohols,
wherein the membrane-less reactor comprises the tubular gas diffusion electrode, the circular counter electrode, the, the electrolyte and the porous bio-electroactive filter,
wherein the carbon dioxide supply reservoir and the electrolyte supply reservoir are connected to the membrane-less reactor and supply carbon dioxide and electrolyte, respectively and the microbial separation column and the product separation column are sequentially connected to the membrane-less reactor through the electrolyte supply reservoir.

11 . A method for production of alcohol using carbon dioxide, the method comprising steps of:
a) supplying a feed of carbon dioxide and electrolyte to a membrane-less reactor; b) carbon dioxide is converted to alcohols in the membrane-less reactor; c) output from the membrane-less reactor passes through the microbe separation column to separate the used microbe from the product stream; and d) this product stream passes through the product separation column to obtain alcohol,
wherein electrolyte is recycled from the product separation column back to the electrolyte reservoir.

12 . The method as claimed in claim 11 , wherein the carbon dioxide teed is having 14% CO 2 along with other pollutant gases, and wherein the carbon dioxide feed is introduced into the membrane-less reactor by sparging continuously through a flow meter.

13 . The method as claimed in claim 11 , wherein the membrane-less reactor is operated at a temperature in the range of 25-32° C., at a pressure in the range of 1-10 bar and at a potential difference of 2-4 V.

14 . The method as claimed in claim 11 , further comprising biocatalyst selected from a group consisting of EAB, chemoautotrophic bacteria, heterotrophic bacteria and homo acetogenic bacteria.

Assignees

• Indian Oil Corp Ltd
• Vlaamse Instelling Voor Tech Onderzoek Nv Vito

Inventors

• Kumar Manoj
• Sandipam Srikanth
• Puri Suresh Kumar
• RAMAKUMAR Sankara Sri Venkata
• Diels Ludovicus
• Bouwman Lambertus
• Vanbroekhoven Karolien
• Pant Deepak

Classifications

• C25B9/07 Primary

  Common duct cells · CPC title

• Y02P20/141

  Feedstock · CPC title

• C12M47/10

  Separation or concentration of fermentation products (bioreactors combined with means for distillation or extraction of liquid fuel C12M43/02) · CPC title

• C12M29/18 Primary

  External loop; Means for reintroduction of fermented biomass or liquid percolate (loop type reactors for chemical or physical processes B01J19/2435) · CPC title

• C25B3/00

  Electrolytic production of organic compounds · CPC title