System and method for co-producing high-quality xylose and premium caramel color using corn cobs

Abstract

The present invention relates to a system and method for simultaneously producing high-quality xylose and high-grade caramel color using corn cobs. The system includes a xylose production subsystem, an enzymatic hydrolysis subsystem, and a caramel color production subsystem, which are connected to each other through piping. The xylose production subsystem includes a raw material tank, a pretreatment tank, an acid hydrolysis kettle, a plate and frame filter press, a filtrate neutralization tank, a nanofiltration membrane separator, an electrodialysis separator, an evaporation concentration tank, a crystallization tank, a centrifuge, and a dryer, which are connected in sequence through piping. The enzymatic hydrolysis subsystem includes a retentate neutralization tank and an enzymatic hydrolysis reaction kettle, which are connected in sequence through piping. The caramel color production subsystem includes a sugar solution mixing tank, a browning reaction kettle, a flash tank, an ultrafiltration membrane separator, and a wiped film evaporator, which are connected in sequence through piping. The present invention not only utilizes the hexose in corn cob waste and the pentose in the xylose mother liquor as resources, but also obtains a high-value-added high-grade caramel color product, thereby improving the comprehensive utilization value of corn cobs.

Description

[Technical Field]

[0001] The present invention relates to the technical field of sugar alcohol production, and more particularly to a system and method for simultaneously producing high-quality xylose and premium caramel color using corn cobs. [Background technology]

[0002] Xylose is a white crystalline, sweet-tasting pentose with a sweetness 0.7 times that of sucrose. It is used as a sucrose substitute to reduce sugar consumption and sweetness. High-quality xylose has higher purity and better light transmittance than certified xylose. High-quality caramel color is a caramel color with more than twice the color intensity and durability of regular caramel color. Patent Publication No. CN111647694A describes a method for extracting xylose from corncobs, which involves acid hydrolysis, decolorization, ion exchange, evaporation, and crystallization separation to obtain the finished xylose product. Most of the solid corncob waste after acid hydrolysis is directly incinerated, while the crystallized xylose mother liquor is primarily sold at a low price to syrup manufacturers, resulting in a significant waste of hexose resources in the corncob waste and pentose resources in the xylose mother liquor. Summary of the Invention [Problem to be solved by the invention]

[0003] The technical problem to be solved by the present invention is to provide a system and method for simultaneously producing high-quality xylose and high-quality caramel color using corncob, which uses corncob as raw material to extract pentoses therein, produce high-quality xylose, and then use the pentoses in the mother liquor and the hexoses in the corncob residue to produce high-quality caramel color, thereby avoiding the waste of various sugar resources in corncob and converting environmentally unfriendly agricultural waste into products with high economic value, thereby promoting high-end manufacturing, environmental and ecological protection, and high-quality economic development. [Means for solving the problem]

[0004] The present invention is accomplished as follows: A system for simultaneously producing high-quality xylose and high-grade caramel color using corn cobs, comprising: The system includes a xylose production subsystem, an enzymatic hydrolysis subsystem, and a caramel color production subsystem, which are connected to each other via piping. The xylose production subsystem includes a raw material tank, a pretreatment tank, an acid hydrolysis reactor, a plate and frame filter press, a filtrate neutralization tank, a nanofiltration membrane separator, an electrodialysis separator, an evaporation concentration tank, a crystallization tank, a centrifuge, and a dryer, which are connected in series via piping. The enzymatic hydrolysis subsystem includes a retentate neutralization tank and an enzymatic hydrolysis reactor, which are connected in series via piping. The caramel color production subsystem includes a sugar solution mixing tank, a browning reactor, a flash tank, an ultrafiltration membrane separator, and a wiped film evaporator, which are connected in series via piping. the plate and frame filter press is provided with a filtrate outlet and a retentate outlet, the filtrate outlet is connected via piping to a filtrate neutralization tank, and the retentate outlet is connected via piping to a feed inlet of the retentate neutralization tank; the centrifuge is provided with a solids outlet and a liquids outlet, the solids outlet is connected via piping to a feed inlet of a dryer, and the liquids outlet is connected to one feed inlet of a sugar solution mixing tank, and another feed inlet of the sugar solution mixing tank is connected via piping to a discharge outlet of the enzymatic hydrolysis reactor; the raw material tank stores the corn cob raw material to be processed; the material discharged from the discharge outlet of the dryer is high-quality xylose, and the material finally obtained at the discharge outlet of the wiped-film evaporator is high-quality caramel color.

[0005] Furthermore, the filtrate discharged from the filtrate outlet of the plate and frame filter press is a corn cob hydrolyzed liquid, and the retentate discharged from the retentate outlet of the plate and frame filter press is a corn cob waste product.

[0006] Furthermore, the liquid sent from the liquid outlet of the centrifuge is a xylose mother liquor.

[0007] Furthermore, the liquid discharged from the outlet of the enzymatic hydrolysis reaction vessel is an enzymatic hydrolysis liquid.

[0008] The present invention is accomplished as follows: A method for simultaneously producing high-quality xylose and premium caramel color using corn cobs, comprising the steps of: The method uses a system for simultaneously producing high-quality xylose and high-grade caramel color using corn cobs according to any one of the above, Step 1: The corn cob powder stored in the raw material tank is sent to a pre-treatment tank through a pipe to be washed with water and pickled to obtain corn cob liquid, and then the corn cob liquid is sent to an acid hydrolysis kettle through a pipe to be acid hydrolyzed; Step 2: obtaining a feed solution for a plate and frame filter press by acid hydrolysis, and sending the feed solution for the plate and frame filter press through a pipe to the plate and frame filter press for filtering; Step 3: filtering the feed solution to the plate and frame filter press through the plate and frame filter press to obtain a liquid portion of the corn cob hydrolyzate and a solid portion of the corn cob waste, respectively; Step 4: neutralizing the corncob hydrolyzed liquid in a filtrate neutralization tank, decolorizing it in a nanofiltration membrane separator, desalination in an electrodialysis separator, concentrating it in an evaporation concentration tank, crystallizing it in a crystallization tank, and separating it into solid and liquid using a centrifuge, to obtain crystalline xylose and xylose mother liquor, respectively; drying the crystalline xylose in a dryer to obtain high-quality xylose crystals with a purity of >99% and a light transmittance of >98%, and sending the xylose mother liquor to a sugar liquid mixing tank via a pipe; The method further includes step 5 of sending the corn cob waste to a residue neutralization tank for neutralization, then sending it to an enzymatic hydrolysis reactor for enzymatic hydrolysis to obtain an enzymatic hydrolyzed liquid, sending the enzymatic hydrolyzed liquid to a sugar solution mixing tank via a pipe to mix with a xylose mother liquor, and further performing a browning reaction in a browning reactor, evaporation in a flash tank, separation in an ultrafiltration membrane separator, and wiped film evaporation in a wiped film evaporator to obtain a high-quality caramel color product with a color ratio as high as 50,000 EBC. [Effects of the Invention]

[0009] Compared with the prior art, the system and method for simultaneously producing high-quality xylose and premium caramel color using corncobs of the present invention has the following features:

[0010] 1. By mixing corncob waste with the pentoses and hexoses in xylose mother liquor to produce high-grade caramel color, the utilization rate of the sugar resources in corncob reaches over 90%. This invention not only improves the utilization rate of corncob resources, but also produces high-end caramel color products with a color rate of 50,000 EBC, greatly improving the comprehensive utilization value of corncob.

[0011] 2. By improving the entire process system and optimizing the caramel color production process, high-grade caramel color can be produced from the hexose in corncob waste and the pentose in xylose mother liquor, improving the quality of the caramel and converting 1,000 yuan / ton of xylose mother liquor and corncob waste into 5,000 yuan / ton of high-grade caramel color, increasing the economic benefit by more than five times.

[0012] 3. The incineration and large-scale accumulation of corncob waste occupies environmental resources and affects the construction of ecological civilization, while the comprehensive utilization of corncob waste contributes to sustainable development and the construction of green ecological civilization. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic diagram showing the principle of a preferred embodiment of a system for simultaneously producing high-quality xylose and premium caramel color using corn cobs according to the present invention. [Figure 2] 1 is a schematic diagram of the flow direction of each material in the method for simultaneously producing high-quality xylose and a high-grade caramel color using corn cobs according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] In order to clarify the technical problems, technical solutions and advantageous effects of the present invention, the present invention will be described in more detail below with reference to examples. It should be understood that the specific examples described herein are only used to illustrate the present invention and are not intended to limit the present invention.

[0015] As shown in Figures 1 and 2, a preferred embodiment of the system for simultaneously producing high-quality xylose and premium caramel color using corncobs of the present invention includes a xylose production subsystem I, an enzymatic hydrolysis subsystem II, and a caramel color production subsystem III, which are connected to each other via piping. The arrows in the figures indicate the direction of material flow within the system.

[0016] The xylose production subsystem I includes a raw material tank 1, a pretreatment tank 2, an acid hydrolysis reactor 3, a plate-and-frame filter press 4, a filtrate neutralization tank 5, a nanofiltration membrane separator 6, an electrodialysis separator 7, an evaporation concentration tank 8, a crystallization tank 9, a centrifuge 10, and a dryer 11, all connected via pipes. The enzymatic hydrolysis subsystem II includes a filtrate neutralization tank 12 and an enzymatic hydrolysis reactor 13, all connected via pipes. The caramel color production subsystem III includes a sugar solution mixing tank 14, a browning reactor 15, a flash tank 16, an ultrafiltration membrane separator 17, and a wiped-film evaporator 18, all connected via pipes. The raw material tank 1 stores corn cob A, which is the raw material to be processed. The material discharged from the outlet of the dryer 11 is high-quality xylose B, and the final material obtained from the outlet of the wiped-film evaporator 18 is high-quality caramel color C.

[0017] Each of the plate & frame filter presses 4 is provided with a filtrate outlet and a retentate outlet, the filtrate outlet communicates with a filtrate neutralization tank 5 via piping, and the retentate outlet communicates with a supply port of a retentate neutralization tank 12 via piping. The filtrate discharged from the filtrate outlet of the plate & frame filter press 4 is corn cob hydrolyzed liquid D, and the retentate discharged from the retentate outlet of the plate & frame filter press 4 is corn cob waste E.

[0018] The centrifuge 10 is provided with a solid outlet and a liquid outlet, and the solid outlet is connected to a supply port of the dryer 11 via a pipe, and the liquid outlet is connected to one supply port of a sugar solution mixing tank 14, and another supply port of the sugar solution mixing tank 14 and a discharge port of the enzymatic hydrolysis reaction vessel 13 are connected to each other via a pipe.

[0019] The liquid sent from the liquid outlet of the centrifuge 10 is a xylose mother liquor F. The liquid discharged from the outlet of the enzymatic hydrolysis reaction vessel 13 is an enzymatic hydrolyzed liquid G.

[0020] The pretreatment tank 2 removes impurities from the corncob A by washing with clean water or dilute acid. The acid hydrolysis tank 3 hydrolyzes the hemicellulose in the corncob A. The plate-and-frame filter press 4 separates the corncob hydrolyzate D from the corncob waste E. The filtrate neutralization tank 5 neutralizes the pH of the corncob hydrolyzate D. The nanofiltration membrane separator 6 decolorizes the corncob hydrolyzate D. The blocking solution decolorized by the nanofiltration membrane separator 6 is a pigment solution, and the permeate is a decolorized solution. The electrodialysis membrane separator 7 desalinates the decolorized solution. The blocking solution desalted by the electrodialysis membrane separator 7 is a concentrated salt solution, and the permeate is a desalted solution. The evaporation concentration tank 8 and crystallization tank 9 are used for evaporation concentration and xylose crystallization. The centrifuge 10 separates the crystalline xylose from the xylose mother liquor F. The dryer 11 dries the high-quality xylose B crystals.

[0021] The residue neutralization tank 12 neutralizes the pH of the corncob waste E, and the enzymatic hydrolysis reactor 13 enzymatically hydrolyzes the cellulose in the corncob waste E to produce glucose. The sugar solution mixing tank 14 mixes the xylose mother liquor F and the enzymatic hydrolysis solution G. The browning reactor 15 browns the mixed sugar solution to produce a high-quality caramel color crude product. The flash tank 16 removes amino compounds and sulfites, which are impurities in the caramel color. The ultrafiltration membrane separator 17 removes 4-methylimidazole, which is an impurity in the caramel color. The wiped-film evaporator 18 concentrates the caramel color at low temperature to produce a high-quality caramel color C.

[0022] The present invention also discloses a method for simultaneously producing high-quality xylose and a premium caramel color using corn cobs, the method using any of the systems for simultaneously producing high-quality xylose and a premium caramel color using corn cobs described above, the method comprising the following steps:

[0023] Step 1: Corn cob A powder stored in raw material tank 1 is sent to pre-treatment tank 2 via piping to be washed with water and pickled to obtain corn cob liquid, which is then sent to acid hydrolysis tank 3 via piping for acid hydrolysis.

[0024] Step 2: The corn cob liquid is acid hydrolyzed in the acid hydrolysis kettle to obtain the feed liquid H for the plate & frame filter press, and the feed liquid H for the plate & frame filter press is sent to the plate & frame filter press 4 through a pipe and filtered.

[0025] Step 3: The feed liquid H to the plate and frame filter press is filtered through the plate and frame filter press 4 to obtain a liquid portion and a solid portion, respectively. The liquid portion is the corncob hydrolyzate liquid D, and the solid portion is the corncob waste E.

[0026] Step 4: The corncob hydrolyzed liquid D is neutralized in filtrate neutralization tank 5, decolorized in nanofiltration membrane separator 6, desalted in electrodialysis separator 7, concentrated in evaporation concentration tank 8, crystallized in crystallization tank 9, and solid-liquid separated in centrifuge 10 to obtain crystalline xylose and xylose mother liquor. The crystalline xylose is dried in dryer 11 to obtain high-quality xylose B crystals, and the xylose mother liquor F is sent via piping to sugar solution mixing tank 14. The high-quality xylose A crystals have a purity of >99% and a light transmittance of >98%.

[0027] Step 5: The corn cob waste E is sent to the residue neutralization tank 12 for neutralization, then sent to the enzymatic hydrolysis reactor 13 for enzymatic hydrolysis to obtain an enzymatic hydrolyzed solution G, which is sent to the sugar solution mixing tank 14 via a pipe to be mixed with the xylose mother liquor F, and further subjected to browning reaction in the browning reactor 15, evaporation in the flash tank 16, separation in the ultrafiltration membrane separator 17, and wiped film evaporation in the wiped film evaporator 18 to obtain a high-quality caramel color C product with a high color ratio of 50,000 EBC.

[0028] Specifically, in step 1, the mass percentage concentration of the sugar resource dry matter in corn cob A is 60-70 wt%, and the sugar resource dry matter contains 50-55 wt% hexose and 45-50 wt% pentose, and a 0.20-0.30 wt% sulfuric acid solution with a liquid-solid ratio of 3:1 is used for the pickling treatment.

[0029] Specifically, in step 2, in the acid hydrolysis, the corncob material / liquid ratio is 1:5, the amount of sulfuric acid added is 1.2-1.5%, the temperature is 120-125°C, and the time is 100-140 min.

[0030] Specifically, in step 4, in the decolorization treatment using the nanofiltration membrane separator 6, the nanofiltration membrane separator 6 has an operating temperature of 40 to 60°C and an operating pressure of 15 to 35 bar, and in the desalination treatment using the electrodialysis separator 7, the electrodialysis membrane separator 7 has an operating current of 60 to 120 A, a voltage of 200 to 250 V, and an operating pressure of 15 to 35 bar.

[0031] Specifically, in step 5, the pH is adjusted to 5.5 to 6.5 in the enzymatic hydrolysis, 2 to 4 mass% of a commercially available cellulose complex enzyme is used as a catalyst, the temperature of the enzymatic hydrolysis reaction is controlled to 40 to 60°C, the time of the enzymatic hydrolysis reaction is 72 to 96 hours, and in the browning reaction in the browning reaction vessel 15, a mixture of ammonia water or ammonium carbonate, ammonium bicarbonate and urea in a ratio of 6:2:2 to 4:4:2 is used as a reaction aid. In adjusting the reaction, the pH is first adjusted to 7.0 to 9.0. The temperature is then raised to 80-90°C and reacted for 30-50 minutes, then raised to 160-180°C and reacted for 3-5 hours, then the pH is adjusted to 2-4, and then the temperature is lowered to 130-150°C and reacted for 0.5-1 hour. In the separation by the ultrafiltration membrane separator 17, the ultrafiltration membrane separator 17 has an operating temperature of 40-60°C and an operating pressure of 5-7 bar, and in the wiped film evaporation by the wiped film evaporator 18, the evaporation pressure is 4-5 bar and the vacuum degree is 80-90 kPa.

[0032] The following specific examples further illustrate the system and method of the present invention for co-producing high quality xylose and premium caramel color using corn cobs. Example 1

[0033] In a first embodiment of the system and method for simultaneously producing high-quality xylose and a high-grade caramel color using corncobs according to the present invention, corncobs are used as raw materials and refined to obtain high-quality crystalline xylose, which is then enzymatically hydrolyzed. The enzymatic hydrolyzate is then mixed with the xylose mother liquor obtained after centrifugation to produce a high-grade caramel color. The method includes the following steps:

[0034] Step 1: The corn cob powder in the raw material tank 1 is sent to the pre-treatment tank 2 through a pipe to be washed with water and pickled. The pickling is carried out using a 0.20 wt% sulfuric acid solution with a liquid-solid ratio of 3:1, and then sent to the acid hydrolysis tank 3 for hydrolysis.

[0035] Step 2: The corncob washing liquid from the pretreatment tank 2 is sent to the acid hydrolysis tank 3 via a pipe, where it is hydrolyzed at a corncob liquid-to-solid ratio of 5:1, with 1.2% sulfuric acid added, at 125°C, for 140 minutes, and then sent to the plate and frame filter press 4 for filtration.

[0036] Step 3: The hydrolysis material is separated into two parts using a plate and frame filter press 4, the liquid part being corncob hydrolyzate D and the solid part being corncob waste E.

[0037] Step 4: The corncob hydrolyzed solution D is neutralized in filtrate neutralization tank 5, decolorized in nanofiltration membrane separator 6, desalted in electrodialysis separator 7, concentrated in evaporation concentration tank 8, crystallized in crystallization tank 9, and separated into solid and liquid forms in centrifuge 10 to obtain crystalline xylose and xylose mother liquor F. The crystalline xylose is dried in dryer 11 to obtain high-quality xylose B crystals. Xylose mother liquor F is then sent to sugar solution mixing tank 14 via a pipe. The high-quality xylose crystals have a purity of >99% and a light transmittance of >98%. Nanofiltration membrane separator 6 operates at a temperature of 60°C and a pressure of 20 bar. Electrodialysis membrane separator 7 operates at a current of 100 A, a voltage of 250 V, and a pressure of 20 bar.

[0038] Step 5: The corncob waste is neutralized in the residue neutralization tank 12 and then enzymatically hydrolyzed in the enzymatic hydrolysis reactor 13 to obtain enzymatic hydrolysis solution G. This enzymatic hydrolysis solution G is then mixed with the xylose mother liquor F in the sugar solution mixing tank 14 via a pipe. The enzymatic hydrolysis solution G is then browned in the browning reactor 15, evaporated in the flash tank 16, separated in the ultrafiltration membrane separator 17, and evaporated in the wiped film evaporator 18 to obtain a high-quality caramel color product C with a high color rate of 50,000 EBC, all other indicators meeting national standards, and a high sugar resource utilization rate of 90%. During the enzymatic hydrolysis, the pH is adjusted to 5.5, 2% by weight of a commercially available cellulose complex enzyme is added as a catalyst, and the enzymatic hydrolysis temperature is controlled at 50°C. The enzymatic hydrolysis time is 72 hours. The browning reaction in the browning reactor 15 uses a 6:2:2 mixture of ammonium carbonate, ammonium bicarbonate, and urea as the reaction aid. The reaction is controlled by first adjusting the pH to 9.0, then raising the temperature to 90°C and reacting for 30 minutes, then raising the temperature to 170°C and reacting for 3 hours, then adjusting the pH to 3.0, and then lowering the temperature to 130°C and reacting for 1 hour. The ultrafiltration membrane separator 17 operates at a temperature of 60°C and a pressure of 5 bar. The wiped film evaporator 18 operates at a pressure of 4 bar and a vacuum of 90 kPa. Comparative Example 1

[0039] The specific steps for directly extracting xylose from corncobs (A) are as follows: Corncob raw material (1) is piped to pretreatment tank (2) for cleaning, then sent to acid hydrolysis reactor (3), where 1.5% sulfuric acid is added. The hydrolyzed liquid is then neutralized with alkali, decolorized with activated carbon, and desalted with ion exchange in plate-and-frame filter press (4). It is then evaporated, concentrated, crystallized, and centrifuged to obtain crystalline xylose. The corncob waste (E) from the plate-and-frame filter press is dried and incinerated or subjected to solid waste treatment. The xylose mother liquor (F) obtained after centrifugation is sold commercially for syrup production. The actual utilization rate of sugar resources is only 30%. Comparative Example 2

[0040] The steps for directly producing caramel color from xylose mother liquor F as a raw material specifically include the following: After centrifugation, xylose mother liquor F is directly sent via a pipe to browning reactor 15, where the pH is adjusted to 9.0, 10 wt% ammonium carbonate is added as a reaction aid, and the reaction temperature is 170°C for 3 hours. After filtration, a finished caramel color product with a color rate of 30,000 EBC and other indicators meeting national standards is obtained.

[0041] As described above, in the system and method for simultaneously producing high-quality xylose and high-grade caramel color using corncobs of the present invention, the utilization rate of the sugar resources in corncob A increases from 30% to 90%, and the color rate of caramel color increases from 30,000 EBC to 50,000 EBC, improving the overall utilization value of corncobs and enhancing the product quality of caramel color.

[0042] The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A system for simultaneously producing high-quality xylose and premium caramel color using corn cobs, comprising: The system includes a xylose production subsystem, an enzymatic hydrolysis subsystem, and a caramel color production subsystem, which are connected to each other via piping. The xylose production subsystem includes a raw material tank, a pretreatment tank, an acid hydrolysis reactor, a plate and frame filter press, a filtrate neutralization tank, a nanofiltration membrane separator, an electrodialysis separator, an evaporation concentration tank, a crystallization tank, a centrifuge, and a dryer, which are connected in series via piping. The enzymatic hydrolysis subsystem includes a retentate neutralization tank and an enzymatic hydrolysis reactor, which are connected in series via piping. The caramel color production subsystem includes a sugar solution mixing tank, a browning reactor, a flash tank, an ultrafiltration membrane separator, and a wiped film evaporator, which are connected in series via piping. The plate and frame filter press is provided with a filtrate outlet and a retentate outlet, respectively. the liquid outlet is connected via piping to a filtrate neutralization tank, and the retentate outlet is connected via piping to a feed inlet of the retentate neutralization tank; the centrifuge is provided with a solid outlet and a liquid outlet, the solid outlet is connected via piping to a feed inlet of a dryer, the liquid outlet is connected to one feed inlet of a sugar solution mixing tank, and another feed inlet of the sugar solution mixing tank is connected via piping to a discharge outlet of the enzymatic hydrolysis reactor; the raw material tank stores corn cob raw material to be processed, the mass percentage concentration of dry matter sugar resource in the corn cob is 60 to 70 wt%, and the dry matter sugar resource contains 50 to 55 wt% hexose and 45 to 50 wt% pentose; the material discharged from the discharge outlet of the dryer is high-quality xylose; and the material finally obtained at the discharge outlet of the wiped-film evaporator is high-quality caramel color.

2. 2. The system for simultaneously producing high-quality xylose and a high-grade caramel color using corn cobs according to claim 1, wherein the filtrate discharged from the filtrate outlet of the plate and frame filter press is a corn cob hydrolyzate, and the residue discharged from the residue outlet of the plate and frame filter press is corn cob waste.

3. 2. The system for simultaneously producing high-quality xylose and high-grade caramel color using corn cobs according to claim 1, wherein the liquid sent from the liquid outlet of the centrifuge is xylose mother liquor.

4. 2. The system for simultaneously producing high-quality xylose and high-grade caramel color using corn cobs according to claim 1, wherein the liquid discharged from the outlet of the enzymatic hydrolysis reactor is an enzymatic hydrolysis liquid.

5. 1. A method for simultaneously producing high quality xylose and premium caramel color using corn cobs, comprising: A system for simultaneously producing high-quality xylose and a high-grade caramel color using the corn cob according to any one of claims 1 to 4 is used, Step 1: The corn cob powder stored in the raw material tank is sent to a pre-treatment tank through a pipe to be washed with water and pickled to obtain corn cob liquid, and then the corn cob liquid is sent to an acid hydrolysis reactor through a pipe to be acid hydrolyzed; Step 2: obtaining a feed solution for a plate and frame filter press by acid hydrolysis, and sending the feed solution for the plate and frame filter press through a pipe to the plate and frame filter press for filtering; Step 3: filtering the feed solution to the plate and frame filter press through the plate and frame filter press to obtain a liquid portion of corn cob hydrolyzate and a solid portion of corn cob waste, respectively; Step 4: neutralizing the corncob hydrolyzed liquid in a filtrate neutralization tank, decolorizing it in a nanofiltration membrane separator, desalination in an electrodialysis separator, concentrating it in an evaporation concentration tank, crystallizing it in a crystallization tank, and separating it into solid and liquid using a centrifuge, to obtain crystalline xylose and xylose mother liquor, respectively; drying the crystalline xylose in a dryer to obtain high-quality xylose crystals with a purity of >99% and a light transmittance of >98%, and sending the xylose mother liquor to a sugar liquid mixing tank via a pipe; and step 5, wherein the corn cob waste is sent to a residue neutralization tank for neutralization, then sent to an enzymatic hydrolysis reactor for enzymatic hydrolysis to obtain an enzymatic hydrolyzed liquid, the enzymatic hydrolyzed liquid is sent to a sugar solution mixing tank via a pipe to be mixed with a xylose mother liquor, and further subjected to a browning reaction in a browning reactor, evaporation in a flash tank, separation in an ultrafiltration membrane separator, and wiped film evaporation in a wiped film evaporator to obtain a high-quality caramel color product with a high color ratio of 50,000 EBC.

6. 6. The method for simultaneously producing high-quality xylose and a high-grade caramel color using corn cobs according to claim 5, wherein in step 1, a 0.20-0.30 wt % sulfuric acid solution with a liquid-to-solid ratio of 3:1 is used for the pickling treatment.

7. 6. The method for simultaneously producing high-quality xylose and a high-grade caramel color using corn cob according to claim 5, wherein in step 2, the material / liquid ratio of the corn cob is 1:5, the amount of sulfuric acid added is 1.2-1.5%, the temperature is 120-125°C, and the time is 100-140 minutes during the acid hydrolysis.

8. 6. The method for simultaneously producing high-quality xylose and a high-grade caramel color using corncobs according to claim 5, wherein in step 4, in the decolorization using a nanofiltration membrane separator, the nanofiltration membrane separator has an operating temperature of 40-60°C and an operating pressure of 15-35 bar, and in the desalination using an electrodialysis separator, the electrodialysis membrane separator has an operating current of 60-120 A, a voltage of 200-250 V, and an operating pressure of 15-35 bar.

9. In step 5, in the enzymatic hydrolysis, the pH is adjusted to 5.5-6.5, 2-4% by mass of a commercially available cellulose complex enzyme is added as a catalyst, the temperature of the enzymatic hydrolysis reaction is controlled to 40-60°C, and the enzymatic hydrolysis reaction time is 72-96 hours. In the browning reaction in the browning reactor, a reaction aid is used in which ammonia water or ammonium carbonate, ammonium bicarbonate and urea are mixed in a ratio of 6:2:2 to 4:4:

2. In the reaction adjustment, the pH is first adjusted to 7.0-9.0, and then the temperature is raised to 80-90°C and the reaction is continued for 30-50 minutes.

6. The method for simultaneously producing high-quality xylose and a high-grade caramel color using corncobs according to claim 5, wherein the reaction mixture is heated to 160-180°C and reacted for 3-5 hours, then the pH is adjusted to 2-4, and then the temperature is lowered to 130-150°C and reacted for 0.5-1 hour; the separation using an ultrafiltration membrane separator has an operating temperature of 40-60°C and an operating pressure of 5-7 bar; and the wiped film evaporation using a wiped film evaporator has an evaporation pressure of 4-5 bar and a vacuum degree of 80-90 kPa.

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