JPS586471B2 - Alcohol manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing alcohol using sugars such as disaccharides and monosaccharides, mixtures thereof, or molasses containing these mixtures as a raw material and using yeast as a catalyst.

It is known to immobilize yeast to continuously produce ethanol, for example, yeast (Saccharo-myce
s cerevisiae) wrapped in calcium alginate and molded into an elongated cylinder shape is packed in a column to continuously produce ethanol from an aqueous glucose solution containing calcium salts, and
It has been reported that ethanol can be continuously produced from a Naro complete medium solution using a glucose aqueous solution containing yeast extract, minerals, and citric acid by forming a packed bed with immobilized yeast that is formed by enclosing Mycee carlsbergensis in carrageenan and forming it into granules.

It is well known that immobilized yeast is used to produce alcohol in this way, but when producing alcohol by the latter method, which involves reducing the particle size in order to increase the effectiveness coefficient and increase the reaction yield, the liquid phase Not only is the pressure loss large, but when gel-like immobilized yeast is used, it is compressed and deformed by the hydraulic pressure, increasing the contact area with each other, resulting in an increase in resistance and a decrease in reaction yield.

In addition, especially in the latter method of the above two methods, high yield alcohol production cannot be expected unless viable bacteria are present at a high level inside the immobilized material containing the yeast, and the bacteria are in a state of suspended animation. The yield becomes zero when the yeast dies or dies, and for this purpose, the liquid phase, ie, the substrate liquid, needs to be a complete medium such as yeast extract, which is an expensive nitrogen-containing substance.

It is generally considered advantageous to use inexpensive molasses for industrial production of alcohol.

Molasses contains a mixture of disaccharides and monosaccharides as well as nitrogen, phosphorus, magnesium, potassium, and vitamins, and the reaction to obtain alcohol from this is simply shown by the following equation.

As can be seen from this equation (3), equimolar carbon dioxide gas is generated as alcohol, and when a packed bed is formed with immobilized yeast as described above, bubbles of carbon dioxide gas remain in the layer and the immobilized yeast Not only does the wetting area become smaller to further increase the movement resistance of the substrate liquid, but also the alcohol concentration increases, so it is necessary to use alcoholic bacteria as the yeast.

In addition, if carbon dioxide gas remains, dead bacteria quickly lose enzyme activity, so it is necessary to use a complete medium as a liquid phase to give yeast a significant growth ability and maintain enzyme activity. Therefore, it was considered necessary to perform alcoholic fermentation using immobilized yeast in which viable bacteria were present.

In the present invention, a gas phase consisting of an inert gas, a liquid phase consisting of sugar as a raw material, and a solid phase consisting of granular immobilized yeast are mixed with each other to form a three-phase fluidized bed in which the solid phase is suspended, and carbon dioxide is generated. By carrying out the reaction while discharging and removing gases, carbon dioxide gas is discharged along with a portion of the produced alcohol together with inert gas, and therefore it flows well even when using immobilized yeast in the form of a gel with a light specific gravity. A uniformly dispersed and suspended state can be obtained over a wide flow range of gas and liquid phases, the solid-liquid mass transfer coefficient is large, and the alcohol concentration is automatically controlled. Since there is no need for growth, the lifespan of enzyme activity is extended without adding yeast extract or the like, making it possible to continuously produce alcohol at high yields.

Embodiments of the present invention will be described below with reference to the drawings.

Fig. 1 shows a vertical shape having a short cylindrical part 1 with the maximum diameter above the center, and above and below it an upper conical part 2 and a lower conical part 3 with gradually decreasing diameters, and the whole is made into a weightless shape. An example using a reaction tower 4 is shown, in which a gas distribution plate 5 made of a sintered metal plate, a plate with many small holes, etc. is provided at the lower end of the lower conical part 3.
An inert gas supply chamber 6 is provided through the gas dispersion plate 5, a solid phase outlet 7 is provided slightly above the gas distribution plate 5, and a solid phase inlet 8 and a produced alcohol outlet 9 are provided in the upper conical portion 2.

The top end of the upper conical portion 2 is connected to a cooler 11 via an exhaust pipe 10, and an inert gas pressure vessel 12 is connected to the supply chamber 6 via a pressure regulating valve 13 via a supply pipe 14.

Sugar as a raw material, such as molasses, is fed to the bottom of the reaction tower 4 from a raw material supply port 15 provided slightly above the gas distribution plate 5 to form a liquid phase b having a liquid level slightly above the produced alcohol outlet 9. The granular immobilized yeast is introduced from the solid phase inlet 8 to form the solid phase c, and inert gases such as nitrogen, hydrogen, and helium pass through the gas distribution plate 5 and become bubbles to the center of the reaction tower 4. is introduced to form a gas phase a.

The gas phase a rising from the bottom to the center of the reaction tower 4 entrains the liquid phase b and the solid phase c to generate an upward flow, and when it reaches near the liquid level, the liquid phase b and the solid phase c are reversed and move up the reaction tower. It becomes a downward flow along the wall of 4 and goes to the bottom, and at that time, part of the gas phase a goes to the bottom together with the downward flow, but the rest escapes above the liquid level, and the carbon dioxide gas produced by the reaction and the The alcohol is sent to the cooler 11 through the exhaust pipe 10, where it is cooled by cooling water, and the condensed alcohol passes through the conduit 16 and is stored in a sealed alcohol container 17.

The mixture of carbon dioxide and inert gas is sent to the carbon dioxide absorber 19 through an exhaust gas pipe 18 branched from the conduit 16, and the remaining inert gas is sucked by a blower 20 and stored in a container 21, from which it is sent to a blower 22. It is taken out and sent to the supply chamber 6 for circulation, and at that time, it is replenished from the pressure vessel 12 as appropriate.

The discharged liquid is continuously taken out from the produced alcohol outlet 9, and the alcohol subjected to simple distillation in the flash evaporator 33 passes through the condenser 34 and is collected in the receiver 35, and the residual liquid is sent from the bottom of the evaporator 33 to the next reaction column. or returned to the raw material supply port 15 described above.

The same applies even if the reaction tower 4 is spherical instead of bouncy.

FIG. 2 shows an example using a cylindrical vertical reaction tower 31, in which an inert gas supply chamber 6 is provided at the center of the bottom via a gas distribution plate 5 similar to the above. Reaction tower 31
A solid phase outlet 7, a solid phase inlet 8, a produced alcohol outlet 9, and a raw material supply inlet 15 are provided at the same positions as in FIG. 32 are built in and fixed concentrically so that the bubbles from the gas distribution plate 5 are sent only into the inside of this duct 32, which includes a cooler 11, an inert gas pressure container 12, an alcohol container 17, The carbon dioxide absorber 19, container 21, and blowers 20, 22 are arranged in the same manner as in the embodiment shown in FIG.

The raw sugar forms a liquid phase b having a liquid level above the upper edge of the duct 32, and the air bubbles introduced only into the duct 32 form a gas phase a, which flows from the lower edge of the duct to liquid phases b and The solid phase c is sucked in and these three phases rise in a mixed state, and when it exits the upper end of the duct 32, a part of the gas phase a is inverted together with the liquid phase b and the solid phase c and flows outside the duct 32. The remaining alcohol descends or escapes above the liquid level and is sent to the cooler 11 through the exhaust pipe 10 along with a portion of the produced alcohol and carbon dioxide gas.

In the two embodiments described above, continuous operation is performed by appropriately replenishing the raw material sugar as the produced alcohol is recovered, and by replacing the immobilized yeast as appropriate.

As described above, in the present invention, a liquid phase consisting of sugar as a raw material and a solid phase consisting of granular immobilized yeast are placed in a reaction column, and a gas phase is introduced from the bottom of the column by inert gas bubbles. As the temperature rises, an upward flow entraining the liquid phase and the solid phase is generated, which becomes a mixed flow and mixes with each other to form a three-phase fluidized bed in which the solid phase is suspended.

When using a bollard-shaped or spherical reaction tower as shown in Figure 1, the direction and velocity of the liquid phase change between the upward flow at the center and the downward flow, and a vortex is generated. The phase and solid phase are stirred in a complicated manner, and when using a reaction tower with a built-in duct as shown in Figure 2, a downward extrusion flow is formed outside the duct, and in either case, three phases are mixed inside the reaction tower. It forms a fluidized bed and circulates up and down.

Therefore, since the gas phase and the solid phase are evenly mixed with the liquid phase and raised, the flow coefficient between these three phases can be increased, and the solid phase is uniform over a wide flow range of the gas and liquid phases. Not only can a state of dispersion and suspension be obtained, but also the reversed downward flow is suctioned by the gas phase at the bottom, so even if it contains solid phases of small diameter or light specific gravity, it descends smoothly. In this way, a reaction system with a large solid-liquid mass transfer coefficient and a large gas-liquid mass transfer coefficient is formed, and since it is a three-phase fluidized bed, the pressure loss of the liquid phase increases and the reaction This does not cause any inconvenience such as a decrease in yield.

Furthermore, according to the present invention, since an inert gas is used in the gas phase, not only can viable bacteria be present at a high level in the solid phase and high-yield alcohol production can be expected, but also the carbon dioxide gas generated during the reaction can be quickly removed. Since a part of the produced alcohol and the inert gas are discharged and removed at the same time, the reaction shown in equation (3) above proceeds in the right direction, and the alcohol production reaction is carried out advantageously. In addition, the high concentration of alcohol in the liquid phase is automatically controlled and adjusted, so there is no need to use alcohol-resistant bacteria as the yeast.

Furthermore, according to the present invention, since the reaction is carried out while removing carbon dioxide gas, the active life of each enzyme in the immobilized yeast is extended, and not only does it not matter even if the yeast is in suspended animation or dead, it also eliminates the need for a medium containing expensive nitrogen compounds. It has various excellent effects such as being able to produce alcohol at low cost without using it.

Next, test results of the present invention will be described.

Wet yeast (Saccharomyces cerevi)
siae) 2 g of acrylamide monomer per 10 g, N,
N'-methylenebisacrylamide 0.5g, 2.5w
4 cc of t% potassium persulfate solution and 4 cc of 5 wt% dimethylaminopropionitrile were added and polymerized into a round rod shape with a diameter of 1 mm, which was then cut into 1.5 mm lengths to prepare immobilized yeast.

[Test 1] 104 cc of immobilized yeast and molasses (disaccharide 0.47 mol/l, monosaccharide 0.96 mol/l) were placed in a spindle-shaped reaction tower with a volume of 2 liters.
l) 940 cc is introduced, and nitrogen gas is supplied at a rate of 23 cc/sec through the gas distribution plate at the bottom.

The liquid has a temperature of 30°C, a pH of 5.05, and a flow rate of 1cc/m.
It was supplied at a rate of in.

After reaching steady state, the delivery liquid was 8% alcohol (W/V),
Disaccharide 0.1 mol/l, glucose 0.3 mol/l
, containing 0.6 mol/l fructose, from which 2C
A condensed alcohol of 13% (w/v) in C/h was obtained.

Furthermore, the molar ratio of CO2/N2 in the exhaust gas is 0.03, 5.
There was no change in the activity of the immobilized yeast after continuous operation for several days.

[Test 2] The same amounts of immobilized yeast, molasses, and nitrogen gas as in Test 1 were placed in the apparatus shown in Figure 2, and liquid batch operation was performed, and the changes over time are shown in the table below.

[Test 3] 220 cc of yeast immobilized in a spindle-shaped reaction tower and 0.9 sucrose
gmol/l, MgSO42g/l, KH2PO427
g/l, stock solution 2 with a proportion of Na2HPO40.02 g/l
1, and keep the liquid temperature at 30℃ and supply nitrogen gas at 5Ncc/se.
Supply at a rate of c.

The feeding and delivery speeds of the liquid were 2 cc/min, and after reaching a steady state, condensed alcohol of 16 parts (W/V) and 100 cc/h was obtained from the delivered liquid.

[Brief explanation of the drawing]

1 and 2 are partially cutaway explanatory diagrams showing different embodiments of the present invention. 4... Reaction tower, 5... Gas distribution plate, 7
...Solid phase extraction port, 8...Solid phase inlet,
9... Produced alcohol outlet, 11...
・Cooler, 12... Pressure vessel, 15...
・Raw material supply port, 17...Alcohol container, 19
...carbon dioxide absorber, 31 ... reaction tower, 32 ... duct.

Claims (1)

[Claims] 1. A liquid phase consisting of raw material sugar and a solid phase consisting of granular immobilized yeast are placed in a reaction column, and a gas phase consisting of inert gas bubbles is introduced from the bottom of the column to create an upward flow and a reverse flow. A downward flow is generated to mix the three phases with each other to form a three-way fluidized bed in which the solid phase is suspended, and the generated carbon dioxide is sent to the reaction tower together with a part of the produced alcohol and an inert gas. A method for producing alcohol, which comprises discharging and removing alcohol from