Abstract
This invention is to provide an apparatus for continuous production of ethanol wherein the product inhibition in butanol fermentation is overcome by continuously removing butanol in-situ by gas stripping and to provide an apparatus for continuous production of ethanol wherein the butanol production is increased by continuous in-situ gas stripping and scrubbing with equal volumes of inert liquid with high boiling point and high affinity for Acetone, Butanol and Ethanol.
Specification
FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
PROVISIONAL SPECIFICATION (Section 10 and rule 13)
TITLE
AN APPARATUS AND A PROCESS FOR CONTINUOUS PRODUCTION OF BUTANOL
APPLICANT
PRAJ INDUSTRIES LIMITED of Praj House, Bavdhan, Pune - 411021, India, an Indian company
The following specification describes the invention
Field of Invention
This invention relates to an apparatus and a process for continuous production of Butanol.
Prior Art
The fermentation of carbohydrates to acetone, butanol and ethanol by solventogenic microorganisms including Clostridia is known. The problem associated with the acetone, Butanol and ethanol fermentation by Clostridia species is Butanol toxicity to the culture. This toxicity requires continuous removal of the toxic products during the process for maximum production of the solvents. Various butanol removal systems have been reported. Howeverl, there is need of an improved process for the production of solvents using solventogenic microorganisms.
Objects of Present Invention
An object of this invention is to provide an apparatus for continuous production of ethanol wherein the product inhibition in butanol fermentation is overcome by continuously removing butanol in-situ by gas stripping.
Another object of this invention is to provide an apparatus for continuous production of ethanol wherein the butanol production is increased by continuous in-situ gas stripping and scrubbing with equal volumes of inert liquid with high boiling point and high affinity for Acetone, Butanol and Ethanol.
Still another object of the present invention is to provide an apparatus and a process for continuous production of ethanol, which provide sustainable butanol production for at least 30 days by continuous in- situ gas stripping.
Further object of the present invention is to provide an apparatus and a process for continuous production of ethanol, which increase the butanol productivity to at least lg/L/hr.
Description of the Invention
According to this invention, there is provided an apparatus and a process for continuous production of ethanol which enhance butanol productivity by continuous stripping by gas and simultaneous scrubbing in inert liquid with high boiling point and high affinity for acetone, butanol and ethanol (ABE) such as Polypropylene Glycol (PPG), Oleyl alcohol, Octadecanol, Methylated ester of palm oil or palm oil. The said continuous stripping with simultaneous scrubbing in the acetone/butanol/ethanol (ABE) production uses a solventogenic microorganism. The microorganisms are inoculated in Liquefied Starch, Corn Steep Liquor (CSL) or yeast based media which is further supplemented with dextrose as a carbon source and calcium carbonate as a buffering agent. The microorganism used in the present invention is Clostridium beijerinckiirNCIM 8052..
The process of the present invention is particularly adapted for continuous butanol production beyond its toxicity limits. The continuous butanol production is facilitated by introducing the culture in the fermentation vessel, wherein the said culture comprises solventogenic microorganism and culture medium comprising CSL or Yeast extract 60 g/l, dextrose 40 g/l, butyric acid 4 g/l, CaC03 3g/l.
The apparatus for continuous butanol production and simultaneous stripping, comprises a modified glass reactor fitted with sparger(s), feed pipes, pumps and an exhaust. The exhaust is connected serially to plurality of scrubbers filled with equal volumes of inert liquid with high boiling point and high affinity for c such as Polypropylene Glycol (PPG), Oleyl alcohol, Octadecanol, Methylated ester of palm oil or palm oil.
In operation, the fermentation media and solventogenic microorganism is introduced into the fermentation vessel where it undergoes fermentation according to the conventional technique. The fermentation is carried out at 30-40 deg C for 12-24 hrs without mixing. After fermentation for 12-24 hrs, stripping gas such as nitrogen, carbon dioxide and hydrogen together or carbon dioxide or any combination thereof is sparged through fermentation media at the rate of 0.5 - 5.0 volume of gas/volume of media/minutes (wm) through the sparger. An inert antifoam agent was used to control foaming during fermentation. Sterile water and dextrose solution is fed continuously / intermittently to maintain sugar level at 20 gpl and the volume constant respectively. The source of stripping gas is a pressurised cylinder or the compressed exhausted gas collected in such cylinder or sparged in directly through a sterile filter into the fermentor.
The solvent rich gas from fermentor is allowed to pass through plurality of scrubbers connected serially, filled with inert liquid of high boiling point and high affinity for acetone, butanol and ethanol (ABE) such as Polypropylene Glycol (PPG), Oleyl alcohol, Octadecanol, Methylated ester of palm oil or palm oil. In the said scrubbers the rich gas containing vapours of acetone, butanol and ethanol will condense or get extracted in the inert liquid of high boiling point and high affinity for acetone, butanol and ethanol (ABE). The exhausted gas from the said scrubbers is re-compressed using a pump and sparged back in the fermentor after filter sterilization. The fermentor is
sampled at a regular interval of 24 hrs for analyzing the residual sugars, cell mass, acids, solvents and pH. Residual sugar is analysed using GLUCOSE OXIDASE KIT using spectrophotometer. Solvents & acids produced are analysed by Gas Chromatography. The cell mass is analysed by measuring the Optical Density at 600 nm using the spectrophotometer.
