Methods and systems for producing cellulosic ethanol by biomass saccharification and fermentation

A method for producing cellulosic ethanol by biomass saccharification and fermentation, wherein the method is implemented by a system for producing cellulosic ethanol by biomass saccharification and fermentation, wherein

• the system comprises:
• a first reactor configured to carry out an enzymatic hydrolysis reaction of a biomass feedstock;
• a second reactor configured to carry out a fermentation reaction of the biomass feedstock;
• and a collection tank configured to collect the cellulosic ethanol produced from the fermentation reaction of the biomass feedstock, wherein the first reactor is provided with an enzymatic hydrolysis dosing pipe, the second reactor is provided with a fermentation dosing pipe, an outlet of the first reactor is connected to an inlet of the second reactor through a fermentation pipe, an outlet of the second reactor is connected to an inlet of the first reactor through a discharge pipe;
• a first discharge pipe is provided on the discharge pipe and configured to discharge material from the second reactor, the first reactor is connected to an inlet of the collection tank through an ethanol pipe, and the first reactor is provided with an insulation layer for heating and keeping the first reactor warm, and
• the method comprises:
• in a dosing step,
• adding the biomass feedstock to a citric acid buffer solution,
• adding cellulase, and
• dosing the prepared mixture to the first reactor through the enzymatic hydrolysis dosing pipe;
• in an enzymatic hydrolysis reaction step, carrying out the enzymatic hydrolysis reaction by maintaining a temperature of the first reactor at an enzymatic hydrolysis reaction temperature through the insulation layer;
• in a fermentation reaction step,
• transporting the material after the enzymatic hydrolysis reaction in the first reactor to the second reactor through the fermentation pipe,
• adding fermentation strains to the second reactor through the fermentation dosing pipe, and
• carrying out the fermentation reaction on the material after the enzymatic hydrolysis reaction by maintaining a temperature of the second reactor at a fermentation temperature;
• in a cellulosic ethanol production step, after completing the fermentation reaction, transporting the material after the fermentation reaction in the second reactor to the first reactor through the discharge pipe, wherein the cellulosic ethanol in the material after the fermentation reaction is evaporated into cellulosic ethanol vapors in the first reactor, and the cellulosic ethanol vapors flow into the collection tank through the ethanol pipe and are condensed into the cellulosic ethanol;
• and
• in repeat steps, repeating the enzymatic hydrolysis reaction step, the fermentation reaction step, and the cellulosic ethanol production step, wherein the material is respectively circulated multiple cycles in the first reactor and the second reactor, and after the circulation is completed in the second reactor, the material is discharged from the system through the first discharge pipe.

A method for producing cellulosic ethanol by biomass saccharification and fermentation, wherein the method is implemented by a system for producing cellulosic ethanol by biomass saccharification and fermentation, wherein

• the system comprises:
• a first reactor, a second reactor, a collection tank, a storage tank, a third diaphragm pump, and a second discharge pipe, wherein the first reactor is configured to carry out an enzymatic hydrolysis reaction of a biomass feedstock;
• the second reactor is configured to carry out a fermentation reaction of the biomass feedstock;
• and the collection tank configured to collect the cellulosic ethanol produced from the fermentation reaction of the biomass feedstock, wherein the first reactor is provided with an enzymatic hydrolysis dosing pipe, the second reactor is provided with a fermentation dosing pipe, an outlet of the first reactor is connected to an inlet of the second reactor through a fermentation pipe, an outlet of the second reactor is connected to an inlet of the first reactor through a discharge pipe;
• a first discharge pipe is provided on the discharge pipe and configured to discharge material from the second reactor, the first reactor is connected to an inlet of the collection tank through an ethanol pipe, the first reactor is provided with an insulation layer for heating and keeping the first reactor warm, the storage tank is provided on the discharge pipe, the storage tank is located downstream of the first discharge pipe for storing the material discharged from the second reactor, and the second discharge pipe is located downstream of the third diaphragm pump;
• and
• the method comprises:
• in a dosing step,
• adding the biomass feedstock to a citric acid buffer solution,
• adding cellulase, and
• dosing the prepared mixture to the first reactor through the enzymatic hydrolysis dosing pipe;
• in an enzymatic hydrolysis reaction step, carrying out the enzymatic hydrolysis reaction by maintaining a temperature of the first reactor at an enzymatic hydrolysis reaction temperature through the insulation layer;
• in a fermentation reaction step,
• transporting the material after the enzymatic hydrolysis reaction in the first reactor to the second reactor through the fermentation pipe,
• adding fermentation strains to the second reactor through the fermentation dosing pipe, and
• carrying out the fermentation reaction on the material after the enzymatic hydrolysis reaction by maintaining a temperature of the second reactor at a fermentation temperature;
• in a storage step, transporting the material after the fermentation reaction in the second reactor to the storage tank;
• after the material after the enzymatic hydrolysis reaction in the first reactor has been emptied, repeating the dosing step and the enzymatic hydrolysis reaction step;
• after the material after the fermentation reaction in the second reactor has been emptied, repeating the fermentation reaction step to transport the material after the enzymatic hydrolysis reaction in the first reactor to the second reactor through the fermentation pipe to carry out the fermentation reaction;
• in a cellulosic ethanol production step, after the material after the enzymatic hydrolysis reaction in the first reactor has been emptied, transporting the material after the fermentation reaction in the storage tank to the first reactor through the discharge pipe, wherein the cellulosic ethanol in the material after the fermentation reaction is evaporated into cellulosic ethanol vapors in the first reactor, and the cellulosic ethanol vapors are transported into the collection tank through the ethanol pipe and are condensed into the cellulosic ethanol;
• and
• after the material after the fermentation reaction in the storage tank has been emptied, repeating the storage step, the enzymatic hydrolysis reaction step, the fermentation reaction step, and the cellulosic ethanol production step, wherein the material is respectively circulated multiple cycles in the first reactor, the second reactor, and the storage tank, and after the circulation is completed in the second reactor, the material is discharged from the system through the first discharge pipe.