Polyhydroxyalkanoates extraction system

Patent metadata

Field	Value
Publication number	US-2022010059-A1
Application number	US-202017026993-A
Country	US
Kind code	A1
Filing date	Sep 21, 2020
Priority date	Jul 13, 2020
Publication date	Jan 13, 2022
Grant date	—

Abstract

A polyhydroxyalkanoates extraction system comprises a pretreatment subsystem, an extraction subsystem and a recycling subsystem. The pretreatment subsystem comprises a fermentation device and an activation device so as to carry out a microorganism acclimation process. The extraction subsystem comprises a freezing device, a pretreatment device and an extraction device. The extraction subsystem is used for receiving a third sludge so that the third sludge is subjected to a freezing process, a pretreatment process, an extraction process and a purification process in the freezing device to form a polyhydroxyalkanoates mixture, and the extraction device performs a precipitation process to generate polyhydroxyalkanoates precipitate. The recycling subsystem comprises an aerobic sludge digestion device and a sequencing batch reactor activated sludge treatment device so as to carry out an aerobic sludge digestion process and a sequencing batch reactor activated sludge process.

First claim

What is claimed is:

1 . A polyhydroxyalkanoates (PHAs) extraction system comprising:
a pretreatment subsystem including:
a fermentation device, including a fermentation tank, a first sludge placed in the fermentation device and fermented in the fermentation tank to form a fermentation broth; and
an activation device, including a thermostatic water tank and an oxygen supply device, a second sludge placed in the activation device and diluted by water in the thermostatic water tank, the oxygen supply device supplying oxygen to the second sludge in the thermostatic water tank to activate the second sludge and form an activated sludge, and the activation device receiving the fermentation broth and performing a microorganism acclimation process with the activated sludge in the thermostatic water tank and to form a third sludge;
an extraction subsystem including:
a freezing device, receiving the third sludge and performing a freezing process with the third sludge in the freezing device to form a fourth sludge;
a pretreatment device, receiving the fourth sludge and performing a pretreatment process to disrupt cells of microorganism in the fourth sludge; and
an extraction device, including an extraction tank and a precipitation tank, the extraction device receiving the fourth sludge and performing an extraction process and a purification process in the extraction tank to form a polyhydroxyalkanoates mixture and a first waste, wherein the extraction process is adding an aqueous solution of sodium hypochlorite (NaClO) into the fourth sludge to lyse cell walls of microorganism and release polyhydroxyalkanoates, and wherein the purification process is removing substances other than polyhydroxyalkanoates, the precipitation tank receiving the polyhydroxyalkanoates mixture and performing a precipitation process to produce a polyhydroxyalkanoates precipitate and a second waste; and
a recycling subsystem including:
an aerobic sludge digestion device, receiving part of the first waste and/or part of the second waste and performing an aerobic sludge digestion process; and
a sequencing batch reactor activated sludge treatment device, receiving part of the first waste and/or part of the second waste and performing a sequencing batch reactor activated sludge process.

2 . The polyhydroxyalkanoates extraction system according to claim 1 , wherein the extraction tank further comprises a stirrer and a liquid level controller.

3 . The polyhydroxyalkanoates extraction system according to claim 1 , wherein the pretreatment device comprises an ultrasonic pulverizer, the pretreatment process comprises an ultrasonic treatment process to treat the fourth sludge, and wherein an ultrasonic wave is applied to the fourth sludge by the ultrasonic pulverizer.

4 . The polyhydroxyalkanoates extraction system according to claim 1 , wherein the pretreatment process comprises placing the fourth sludge in an environment at a temperature above 30° C.

5 . The polyhydroxyalkanoates extraction system according to claim 1 , wherein the pretreatment process comprises adding the aqueous solution of sodium hypochlorite into the fourth sludge.

6 . The polyhydroxyalkanoates extraction system according to claim 1 , wherein the pretreatment device comprises a high-voltage pulse generator, the pretreatment process comprises a high-voltage pulse extraction process performing on the fourth sludge, and the high-voltage pulse generator applies a high-voltage pulse electric field to the fourth sludge to disrupt microorganisms and release polyhydroxyalkanoates.

7 . The polyhydroxyalkanoates extraction system according to claim 1 , wherein the extraction process comprises adding the aqueous solution of sodium hypochlorite into the fourth sludge to prepare a sludge mixture with a liquid-solid ratio of 0.67 mg/ml 4 mg/ml, wherein the liquid-solid ratio is a ratio of a weight of a solid portion in the fourth sludge to a volume of the aqueous solution of sodium hypochlorite added.

8 . The polyhydroxyalkanoates extraction system according to claim 7 , wherein the extraction tank further comprises a centrifugation device, and the purification process comprises centrifuging the sludge mixture, washing with acetone, and centrifuging to remove materials other than polyhydroxyalkanoates.

9 . The polyhydroxyalkanoates extraction system according to claim 1 , wherein the first sludge is fermented in the fermentation tank at 40° C.-50° C. for 4-6 days to form the fermentation broth.

10 . The polyhydroxyalkanoates extraction system according to claim 1 , wherein the activation device comprises a dissolved oxygen monitor, and wherein if a saturated dissolved oxygen (DO) of the activated sludge reaches 75%-85% (6.18 mg/L-7.01 mg/L), the fermentation broth is added to synthesize polyhydroxyalkanoates, and the fermentation broth is added again if the saturated dissolved oxygen of the activated sludge drops to 65%-75% (5.36 mg/L-6.18 mg/L), then repeating 5-10 times to form the third sludge.

11 . The polyhydroxyalkanoates extraction system according to claim 1 , wherein after the pretreatment process, a surfactant solution is added to the fourth sludge, and the surfactant solution is an aqueous solution of sodium dodecyl sulfate (SDS) or sodium dodecyl sulfonate (SDS′).

Assignees

• Univ Nat Chi Nan

Inventors

• Tsai Yung-Pin
• Chen Ku-Fan
• Lu Meng-Shan
• Yang Chih-Chi
• Shiu Hao

Classifications

• Y02W10/20

  Sludge processing · CPC title

• Y02W10/10

  Biological treatment of water, waste water, or sewage · CPC title

• C12P7/625

  Polyesters of hydroxy carboxylic acids · CPC title

• C12P39/00

  Processes involving microorganisms of different genera in the same process, simultaneously · CPC title

• C02F1/36

  ultrasonic vibrations · CPC title