Hydrolysate deacidification-dehydration coupling process and byproduct recovery method

Abstract

The invention discloses a hydrolysate deacidification-dehydration coupling process and a byproduct recovery method, and belongs to the technical field of hydrolysate treatment. The method comprises the following steps: pretreating a hydrolysate raw material through two-stage filtration; adding the pretreated hydrolysate, a deacidification agent and a dehydration auxiliary agent into a coupling reaction device, and synchronously carrying out deacidification-dehydration reaction under the conditions of 60-120 DEG C and 0.1-0.5 MPa; after the reaction, separating to obtain a deacidification and dehydration product and a mixed solid phase; and dissolving and crystallizing the mixed solid phase to recover high-purity byproducts. The deacidification and dehydration synergistic interaction is achieved, the acidity reduction rate is larger than or equal to 85%, the water content is smaller than or equal to 5%, and the process time consumption is shortened by 28.6%; the byproduct purity is not less than 90%, and the recovery rate is not less than 80 A tail gas treatment system is additionally arranged to ensure that environmental protection reaches the standard. The process is suitable for biomass, polysaccharide and protein hydrolysate treatment, has the advantages of high efficiency, good resource utilization rate and the like, and provides an efficient solution for hydrolysate industrial treatment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrolysate treatment, and particularly relates to a hydrolysate deacidification-dehydration coupling process and a byproduct recovery method. BACKGROUND

[0002] Hydrolysate is an important intermediate product obtained by hydrolysis of biomass, polysaccharide, protein and other raw materials, and is widely used in the fields of biomass refining, food additive preparation, and synthesis of pharmaceutical intermediates. In the hydrolysis process, acidic substances in the raw materials or organic acids generated by the hydrolysis reaction remain in the hydrolysate, resulting in high acidity of the hydrolysate. At the same time, the hydrolysis reaction itself is a liquid-solid reaction system, and the hydrolysate usually contains 30%-40% of water content. The high acidity and water content will seriously affect the subsequent processing process, such as causing equipment corrosion, catalyst deactivation, and product purity reduction, etc. Therefore, the deacidification and dehydration treatment of the hydrolysate is a key pretreatment step for its industrial application.

[0003] At present, the deacidification and dehydration treatment of the hydrolysate in industry mostly adopts a step-by-step process of “first deacidification and then dehydration”. The deacidification process mainly generates salts by adding alkaline substances (such as sodium carbonate, sodium hydroxide, etc.) to react with acidic substances, and then removing the solid product by filtration; the dehydration process uses adsorption method (such as molecular sieve, anhydrous calcium chloride) or evaporation method to remove water in the system. However, this step-by-step process has obvious technical defects: on the one hand, the deacidification and dehydration processes are independent of each other and cannot form a synergistic effect, resulting in long process cycle and high energy consumption. For example, the heat generated by the deacidification reaction is not effectively utilized, and additional energy is consumed to maintain the dehydration temperature; and the removal of water in the dehydration process is not timely, which also reduces the mass transfer efficiency of the deacidification reaction, resulting in low overall process efficiency. According to the actual production data, the total time of the step-by-step process usually exceeds 14h, and the acidity reduction rate is usually less than 75%, and the water content is difficult to control below 5%.

[0004] On the other hand, the traditional process has a rough treatment method for the solid mixture (mainly salts and unreacted deacidification agent) generated by the deacidification reaction, which is mostly directly discarded as solid waste. This not only causes serious waste of resources, but also increases the cost of solid waste treatment for enterprises; although some processes attempt to recover byproducts, due to the lack of a targeted purification process, the purity of the recovered products is only about 70%, which cannot meet the requirements of industrial-grade raw materials, and has low economic value.

[0005] In addition, the existing process is insufficient in pretreatment of the hydrolysate raw material, and most of them only use single-stage filtration or do not filter, resulting in that large-particle impurities and small colloidal particles in the raw material directly enter the reaction system. These impurities not only adsorb the deacidifying agent and dehydration aid, reducing their effective utilization rate, but also may block the subsequent separation equipment, affecting the continuity and stability of the process, ultimately leading to high impurity content of the deacidification and dehydration product, which cannot meet the raw material quality requirements of high-end fields such as food and medicine.

[0006] At the same time, during the deacidification reaction process, trace amounts of acidic tail gas may be produced, and the traditional process often lacks effective tail gas treatment measures, which is directly discharged and easy to cause air pollution, not meeting the national environmental protection requirements. For different types of hydrolysates (such as biomass hydrolysate, polysaccharide hydrolysate, and protein hydrolysate), their acidity, impurity composition, and moisture content differ, and the existing process cannot achieve efficient treatment through simple parameter adjustment, and the raw material adaptability is poor, limiting its application range.

[0007] In summary, the current hydrolysate deacidification and dehydration process has problems such as low efficiency, poor resource utilization, unstable product quality, insufficient environmental protection, and narrow raw material adaptability, and it is urgent to develop an integrated process that can realize deacidification-dehydration synergistic effect, high-value recovery of by-products, and green environmental protection, to meet the actual needs of industrial production. SUMMARY

[0008] The technical problem to be solved by the present application is the low efficiency, poor resource utilization, unstable product quality, insufficient environmental protection, and narrow raw material adaptability of the existing hydrolysate deacidification and dehydration process.

[0009] The technical solution adopted by the present application is: a hydrolysate deacidification-dehydration coupling process and by-product recovery method, comprising the following steps:

[0010] S1, conveying the hydrolysate raw material to a pretreatment unit for filtration and impurity removal to obtain pretreated hydrolysate;

[0011] S2, pumping the pretreated hydrolysate into a coupling reaction device, adding a deacidifying agent and a dehydration aid to the coupling reaction device, and performing deacidification-dehydration coupling reaction under preset temperature and pressure conditions;

[0012] S3, after the reaction is completed, conveying the reaction mixture to a separation unit for solid-liquid separation to obtain a deacidification and dehydration product and a mixed solid phase;

[0013] S4, performing by-product recovery treatment on the mixed solid phase to obtain a target by-product.

[0014] As a further scheme of the present application: the impurity removal in step S1 adopts two-stage filtration, the first-stage filtration adopts a filter screen with a pore size of d1=80-120 mesh, and the second-stage filtration adopts a microfiltration membrane with a pore size of d2=200-300 mesh; wherein d1 is the pore size of the first-stage filter screen, used for removing large-particle impurities in the hydrolysate raw material, and d2 is the pore size of the second-stage microfiltration membrane, used for further removing fine impurities; the hydrolysate raw material is at least one of biomass hydrolysate, polysaccharide hydrolysate or protein hydrolysate.

[0015] As a further scheme of the present application: the deacidifying agent in step S2 is at least one of alkaline metal oxide, carbonate or hydroxide, and the addition amount of the deacidifying agent satisfies m1=(5%-15%)×m0, wherein m1 is the mass of the deacidifying agent, and m0 is the mass of the pretreated hydrolysate, which can ensure sufficient deacidification reaction and avoid excessive waste of the deacidifying agent; the dehydration aid is at least one of molecular sieve, anhydrous calcium chloride or silica gel, and the addition amount of the dehydration aid satisfies m2=(3%-8%)×m0, wherein m2 is the mass of the dehydration aid, used for efficiently adsorbing water in the reaction system.

[0016] As a further scheme of the present application: the preset temperature in step S2 is T=60-120℃, the preset pressure is P=0.1-0.5 MPa, and the coupling reaction time is t=2-6 h; wherein T is the reaction temperature, affecting the deacidification-dehydration reaction rate, P is the reaction pressure, guaranteeing the stability of the reaction system, and t is the reaction time, ensuring the reaction to reach equilibrium; a stirring device is used for stirring during the reaction, and the stirring speed is n=150-300 r / min, n being the stirring speed, used for promoting the uniform mixing of materials.

[0017] As a further scheme of the present application: the separation unit in step S3 includes a centrifugal separator and a filter, the reaction mixture is first subjected to centrifugal separation, the centrifugal speed is n c =3000-5000 r / min, and the centrifugal time is t c =10-20 min, wherein n c is the centrifugal speed, t c is the centrifugal time, both of which jointly determine the centrifugal separation effect, obtaining a preliminary separation liquid and a preliminary solid phase; then the preliminary separation liquid is filtered through the filter, the filtering precision is d f =0.1-0.5 μm, d f is the filtering precision, used for intercepting micro solid-phase particles, obtaining the deacidification-dehydrated product.

[0018] As a further scheme of the present application: the by-product recovery treatment in step S4 includes the following steps: S41, adding the mixed solid phase to a dissolving tank, adding a solvent for dissolving, the stirring temperature is T s =40-80℃, and the stirring time is ts =1~3h, where T s The stirring temperature affects the solvent dissolution efficiency. s S42. Stirring time is used to ensure that the mixed solid phase is fully dissolved; S43. The dissolved mixture is filtered to obtain filtrate and filter residue; S444. The filtrate is evaporated, concentrated, cooled and crystallized to obtain the target by-product.

[0019] As a further aspect of the present invention: the solvent in step S41 is one of water, an aqueous ethanol solution, or an aqueous acetone solution, and the mass ratio of the solvent to the mixed solid phase satisfies m s :m sp =5:1 to 10:1, where m s For solvent mass, m sp The ratio of the mixed solid phase mass ensures complete dissolution of the mixed solid phase while avoiding solvent waste; the evaporation and concentration temperature in step S43 is T. e =70~90℃, vacuum degree is P v = -0.08 to -0.05 MPa, V concentrated to the original volume c =After 1 / 3 to 1 / 5, cooling and crystallization are carried out, where T e P is the evaporation temperature. v V represents the vacuum level. c The volume percentage after concentration is determined by these three factors, which work together to control the evaporation and concentration effect; the cooling temperature is T. c =0~10℃, crystallization time is t c r = 8–12 h, T c For cooling temperature, t c r represents the crystallization time, used to promote the crystallization and precipitation of the target byproduct.

[0020] As a further embodiment of the present invention: the coupled reaction device includes a reaction vessel body, a jacketed heating device, a pressure control system, a stirring device, and a feed and discharge port; a temperature sensor and a pressure sensor are installed inside the reaction vessel body, which are respectively connected to the temperature control system and the pressure control system, and can monitor and control the temperature T and pressure P in the reaction system in real time, wherein the definitions of T and P are the same as in claim 4.

[0021] As a further aspect of the present invention, it also includes an exhaust gas treatment step, in which the exhaust gas generated during the coupling reaction is transported to the exhaust gas treatment tower through an exhaust gas collection pipeline and treated by a spray absorption method. The absorbent is an acidic solution with a mass fraction w of 10% to 20%, where w is the mass fraction of the absorbent, which is used to ensure the exhaust gas absorption efficiency and the exhaust gas meets the emission standards after treatment.

[0022] As a further aspect of the present invention: the acidity reduction rate of the product after deacidification and dehydration satisfies η a ≥85%, moisture content meets ww ≤5%; the purity of the target by-product satisfies p p ≥90%, the recovery rate satisfies η r ≥80%; wherein, η a is the acidity reduction rate, reflecting the deacidification effect, w w is the moisture content, reflecting the dehydration effect, p p is the by-product purity, η r is the by-product recovery rate, collectively reflecting the comprehensive performance of the process.

[0023] Advantages of the present application:

[0024] 1. Realize deacidification-dehydration synergistic effect, greatly improve process efficiency

[0025] The present application breaks through the limitation of traditional "first deacidification and then dehydration" step-by-step process, and adds deacidification agent and dehydration aid into the same coupling reaction device, and synchronously carries out deacidification-dehydration reaction under the condition of preset temperature T = 60-120℃, pressure P = 0.1-0.5MPa. The trace heat generated by the deacidification reaction can promote the adsorption rate of the dehydration aid to the moisture, and the dehydration process reduces the moisture content of the system, which can improve the mass transfer efficiency of the deacidification reaction, and the two form a synergistic effect. As can be seen from the comparison of Example 1 and Comparative Example 1, the total time of the coupling process (10h) is shortened by 28.6% compared with the step-by-step process (14h), and the acidity reduction rate η a is increased from 75% to 88%, the moisture content w w is reduced from 7.8% to 4.2%, realizing the double improvement of efficiency and effect, and significantly reducing the production energy consumption and time cost.

[0026] 2. High-value recovery of by-products, improving resource utilization and economic value

[0027] In view of the problem that the solid mixture generated by the deacidification reaction in the traditional process is directly discarded, the present application designs a "dissolution-filtration-crystallization" by-product recovery process. By controlling the mass ratio m s :m sp = 5:1-10:1, evaporation concentration temperature T e = 70-90℃ and cooling crystallization condition T c = 0-10℃, the target by-product (such as sodium carbonate crystal) with purity p p ≥90%, recovery rate η r ≥80% can be efficiently recovered from the mixed solid phase. The by-product purity of Examples 1-3 is all more than 90%, while the purity of Comparative Example 1 is only 72% due to the absence of purification step, and Comparative Example 2 directly discards, resulting in resource waste. This scheme converts the original waste into high-purity industrial raw materials, not only improves the resource utilization, but also increases the additional economic benefits for enterprises, in line with the concept of circular economy development.

[0028] 3. Pretreatment-separation integrated design to ensure product quality stability

[0029] The present application sets two-stage filtration pretreatment at the front end of the process, the first stage filter screen aperture d1 = 80-120 mesh removes large particle impurities, and the second stage microfiltration membrane aperture d2 = 200-300 mesh traps small colloidal particles, ensuring that the impurity content of the pretreated hydrolysate is ≤0.5%. Effective removal of impurities avoids their adsorption interference with the deacidifying agent and dehydration aid, and prevents the subsequent separation unit from being blocked. Compared with Comparative Example 1 and Comparative Example 3 (without pretreatment), the acidity reduction rate of the process without pretreatment is only 62%, the moisture content is as high as 9.5%, and the byproduct purity is only 68%, while the deacidified and dehydrated product of the present scheme has stable quality, low impurity content, and can directly meet the raw material requirements of subsequent deep processing (such as food and pharmaceutical fields), reducing the cost investment of subsequent purification steps.

[0030] 4. Green and environmentally friendly process, reducing environmental pollution risk

[0031] The present application adds a tail gas treatment step, which transports the trace amount of acidic tail gas possibly generated in the coupling reaction to the tail gas treatment tower through the tail gas collection pipeline, and sprays and absorbs it with an acidic solution with a mass fraction w = 10%-20%, so that the treated tail gas meets the emission standard, avoiding the pollution of direct tail gas emission to the atmospheric environment. At the same time, the recovery of byproducts reduces the amount of solid waste emissions, and the solvent can be recycled by distillation for recycling, further reducing the waste liquid treatment pressure. The entire process flow does not produce harmful pollutants, meets the national environmental protection standards, and reduces the environmental governance cost and compliance risk of enterprises.

[0032] 5. Wide adaptability of raw materials, diversified application scenarios

[0033] The present application process has good adaptability to different types of hydrolysate raw materials, whether it is biomass hydrolysate, polysaccharide hydrolysate or protein hydrolysate, as long as the process parameters (such as deacidifying agent addition amount m1 = (5%-15%) x m0, stirring speed n = 150-300 r / min, etc.) are adjusted according to the characteristics of the raw materials, efficient deacidification and dehydration and byproduct recovery can be achieved. Examples 1-3 use three different raw materials, all of which can achieve an acidity reduction rate ≥85% and a moisture content ≤5%, proving that the present scheme can be widely applied in biomass refining, food processing, pharmaceutical intermediate preparation and other fields, and has strong universality and market promotion value.

[0034] 6. Simple and controllable process operation, easy to industrialize

[0035] The coupling reaction device, separation unit and by-product recovery equipment of the application all adopt mature industrial-grade components, and each process parameter (such as temperature, pressure, time and material ratio) is monitored and regulated in real time by a sensor and a control system, so that the operation is simple and the stability is high. In the process of scaling up from laboratory test to industrial production, the adjustment range of the process parameters is clear, and complex equipment modification is not required. The 1000 kg level raw material processing scale adopted in the embodiment is close to the industrial production level, the product performance is stable, and it is proved that the scheme has good industrial application prospect and can realize technical transformation quickly.

[0036] In summary, the application has the advantages of higher efficiency, better resource utilization, better environmental protection and better adaptability than the prior art through the innovative design of process coupling, by-product recovery and process optimization, and provides an efficient, economical and environmentally friendly integrated solution for the deacidification and dehydration treatment of hydrolysate, which has important technical innovation significance and practical application value. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 The flow chart of the hydrolysate deacidification-dehydration coupling process and by-product recovery method of the application. DETAILED DESCRIPTION

[0038] The application will be further described in detail below in combination with specific examples and comparative examples, but the protection scope of the application is not limited to the following examples, and any technology realized based on the above content of the application belongs to the protection scope of the application.

[0039] Example 1: Biomass hydrolysate as raw material

[0040] In this embodiment, biomass hydrolysate (acidity 5.2 g / L, moisture content 35%) is used as raw material, and the specific steps are as follows:

[0041] S1, impurity removal by pretreatment unit

[0042] The biomass hydrolysate is transported to the pretreatment unit, and two-stage filtration is used to remove impurities. The first-stage filtration selects a filter screen with a pore size of d1=100 mesh (d1 is the pore size of the first-stage filter screen, and large-particle biomass residues are removed); the second-stage filtration selects a microfiltration membrane with a pore size of d2=250 mesh (d2 is the pore size of the second-stage microfiltration membrane, and colloidal particles are removed), to obtain pretreated hydrolysate with impurity content ≤0.5%.

[0043] S2, deacidification-dehydration coupling reaction

[0044] The pretreated hydrolysate (m0 = 1000 kg, where m0 is the mass of the pretreated hydrolysate) was pumped into the coupled reaction apparatus, and a deacidifying agent (sodium carbonate) and a dehydrating aid (4A molecular sieve) were added. The amount of deacidifying agent added met the following requirements: m1 = 10% × m0 = 100 kg (m1 is the mass of the deacidifying agent); the amount of dehydrating aid added met the following requirements: m2 = 5% × m0 = 50 kg (m2 is the mass of the dehydrating aid). The reaction temperature was set to T = 90℃ (T is the reaction temperature), the pressure to P = 0.3 MPa (P is the reaction pressure), the stirring speed to n = 200 r / min (n is the stirring speed), and the reaction time to t = 4 h (t is the reaction time).

[0045] S3, Solid-Liquid Separation

[0046] The reaction mixture is fed into the separation unit: first through a centrifuge (n c =4000r / min,t c =15min; n c The centrifugal speed is t. c (centrifugation time) to obtain a preliminary separated liquid and solid phase; then filtered by a filter (filtration accuracy d) f =0.3μm, d f (To achieve filtration precision) the deacidification and dehydration products and a mixed solid phase are obtained.

[0047] S4. By-product recycling and treatment

[0048] Mixed solid phase (m sp =140kg, m sp (For mixed solid phase quality) processing steps:

[0049] S41 Dissolution: Add 80% ethanol aqueous solution (m s :m sp =8:1, m s =1120kg; m s (for solvent mass), T s =60℃(T) s (t is the stirring temperature) s =2h(t) s (This refers to the stirring time);

[0050] S42 filtration: Removes filter residue to obtain filtrate;

[0051] S43 crystallization: The filtrate is concentrated by evaporation (T) e =80℃, P v = -0.06MPa, concentrated to V c =1 / 4; T e P is the evaporation temperature. v V represents the vacuum level. c After concentration (by volume percentage), cooling crystallization (T) c =5℃, tc r = 10 h; T c t is the cooling temperature, c r is the crystallization time), to obtain sodium carbonate crystal by-product.

[0052] S5, tail gas treatment

[0053] The coupling reaction tail gas is treated in a tail gas treatment tower and is sprayed and absorbed with a mass fraction w = 15% of sulfuric acid solution (w is the mass fraction of the absorption liquid) to meet the standard for discharge.

[0054] Example 2: using polysaccharide hydrolysate as raw material

[0055] The raw material of this example is polysaccharide hydrolysate (acidity 4.8 g / L, moisture content 32%), and the steps are basically the same as those of Example 1, with the following parameters adjusted:

[0056] S1: d1 = 80 mesh, d2 = 200 mesh;

[0057] S2: m1 = 5% x m0, m2 = 3% x m0, T = 60°C, P = 0.1 MPa, n = 150 r / min, t = 6 h;

[0058] S3: n c = 3000 r / min, t c = 20 min, d f = 0.1 μm;

[0059] S4: m s : m sp = 5:1, T s = 40°C, t s = 3 h, T e = 70°C, P v = -0.08 MPa, V c = 1 / 5, T c = 0°C, t c r = 12 h;

[0060] S5: w = 10%.

[0061] Example 3: using protein hydrolysate as raw material

[0062] The raw material of this example is protein hydrolysate (acidity 5.5 g / L, moisture content 38%), and the steps are basically the same as those of Example 1, with the following parameters adjusted:

[0063] S1: d1 = 120 mesh, d2 = 300 mesh;

[0064] S2: m1 = 15% x m0, m2 = 8% x m0, T = 120°C, P = 0.5 MPa, n = 300 r / min, t = 2 h;

[0065] S3: n c = 5000 r / min, t c = 10 min, d f = 0.5 pm;

[0066] S4: m s : m sp = 10:1, T s = 80°C, t s = 1 h, T e = 90°C, P v = -0.05 MPa, V c = 1 / 3, T c = 10°C, t c r = 8 h;

[0067] S5: w = 20%.

[0068] Comparative Example 1: Separate deacidification + separate dehydration process

[0069] The same biomass hydrolysate raw material as in Example 1 was used, and a "deacidification first and then dehydration" step-by-step process was used, with the following differences:

[0070] There was no coupling reaction device, and the same amount of deacidification agent (m1 = 100 kg) was first added at T = 90°C and P = 0.1 MPa for 3 h of reaction, and after filtration, a deacidification liquid was obtained;

[0071] The same amount of dehydration aid (m2 = 50 kg) was added to the deacidification liquid at T = 70°C for 4 h of adsorption dehydration, and then the product was obtained after filtration;

[0072] The by-product recovery was only through simple filtration, without dissolution-crystallization purification.

[0073] Comparative Example 2: No by-product recovery process

[0074] The same raw material and coupling process as in Example 1 were used, but the mixed solid phase was directly discarded, and the by-product recovery step of S4 was not performed.

[0075] Comparative Example 3: No pretreatment filtration process

[0076] The same raw material and coupling process as in Example 1 were used, but the two-stage filtration step of S1 was omitted, and the biomass hydrolysate was directly pumped into the coupling reaction device.

[0077] Performance comparison analysis of examples and comparative examples

[0078] The product performance and process indicators of each example and comparative example were detected, and the results are shown in the following table:

[0079]

[0080]

[0081] Key conclusion analysis:

[0082] 1. Coupling process advantage: η of examples 1-3 (coupling process) a (85%-90%) and water content (3.5%-4.8%) are better than η of comparative example 1 (step-by-step process) a = 75% and w w = 7.8%, and the total time is shorter (8-12h vs 14h), proving that the deacidification-dehydration coupling reaction can synergistically improve efficiency and shorten the process cycle.

[0083] 2. By-product recovery value: the purity of by-products of examples 1-3 is ≥ 90%, and the recovery rate is ≥ 80%, while the purity of comparative example 1 is only 72% due to the absence of a purification step, and comparative example 2 results in resource waste due to the absence of recovery, indicating that the by-product recovery process of the present application can significantly improve resource utilization and economic value.

[0084] 3. Pretreatment necessity: η of comparative example 3 (without filtration pretreatment) a = 62%, w w = 9.5%, which is much lower than example 1, because impurities will adsorb deacidifying agents and dehydration aids, reducing reaction efficiency, proving that two-stage filtration pretreatment is a key step to ensure process effectiveness.

[0085] 4. Raw material adaptability: examples 1-3 use biomass, polysaccharides, and protein hydrolysates, all of which meet the performance requirements, indicating that the process of the present application has good adaptability to different types of hydrolysates.

[0086] In summary, the present application realizes efficient deacidification and dehydration of hydrolysate and high-value recovery of by-products through an integrated process of "pretreatment-coupling reaction-separation-by-product recovery", with the significant advantages of simple process, high efficiency, and high resource utilization.

[0087] The above examples are used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can modify the technical solutions described in the foregoing examples, or make equivalent substitutions for part of the technical features; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the present application.

Claims

1. A coupled process for deacidification and dehydration of hydrolysate and a method for recovering by-products, characterized in that, Including the following steps: S1. The hydrolysate raw material is transported to the pretreatment unit for filtration and impurity removal to obtain pretreated hydrolysate; S2. Pump the pretreated hydrolysate into the coupling reaction device, add a deacidifying agent and a dehydrating aid to the coupling reaction device, and carry out the deacidification-dehydration coupling reaction under preset temperature and pressure conditions. S3. After the reaction is completed, the reaction mixture is sent to the separation unit for solid-liquid separation to obtain the deacidified and dehydrated product and the mixed solid phase. S4. Perform by-product recovery treatment on the mixed solid phase to obtain the target by-product.

2. The hydrolysate deacidification-dehydration coupled process and by-product recovery method according to claim 1, characterized in that, The filtration and impurity removal in step S1 employs a two-stage filtration process. The first-stage filtration uses a filter screen with a pore size of d1 = 80-120 mesh, and the second-stage filtration uses a microfiltration membrane with a pore size of d2 = 200-300 mesh. Here, d1 is the pore size of the first-stage filter screen, used to remove large particulate impurities from the hydrolysate raw material, and d2 is the pore size of the second-stage microfiltration membrane, used to further remove fine impurities. The hydrolysate raw material is at least one of biomass hydrolysate, polysaccharide hydrolysate, or protein hydrolysate.

3. The hydrolysate deacidification-dehydration coupled process and by-product recovery method according to claim 1, characterized in that, The deacidifying agent in step S2 is at least one of alkaline metal oxides, carbonates, or hydroxides. The amount of the deacidifying agent added satisfies m1 = (5% to 15%) × m0, where m1 is the mass of the deacidifying agent and m0 is the mass of the pretreated hydrolysate. This ratio ensures a sufficient deacidification reaction and avoids excessive waste of the deacidifying agent. The dehydrating aid is at least one of molecular sieves, anhydrous calcium chloride, or silica gel. Its amount added satisfies m2 = (3% to 8%) × m0, where m2 is the mass of the dehydrating aid, and it is used to efficiently adsorb water in the reaction system.

4. The hydrolysate deacidification-dehydration coupled process and by-product recovery method according to claim 1, characterized in that, The preset temperature in step S2 is T = 60-120℃, the preset pressure is P = 0.1-0.5MPa, and the coupling reaction time is t = 2-6h; where T is the reaction temperature, which affects the deacidification-dehydration reaction rate, P is the reaction pressure, which ensures the stability of the reaction system, and t is the reaction time, which ensures that the reaction reaches equilibrium; during the reaction, a stirring device is used for stirring, and the stirring speed is n = 150-300r / min, where n is the stirring speed, which is used to promote uniform mixing of materials.

5. The hydrolysate deacidification-dehydration coupled process and by-product recovery method according to claim 1, characterized in that, The separation unit in step S3 includes a centrifuge and a filter. The reaction mixture is first centrifuged at a speed of n. c =3000~5000r / min, centrifugation time is t c =10~20min, where n c The centrifugal speed is t. c The centrifugation time and the centrifugation time together determine the centrifugation separation effect, resulting in a preliminary separated liquid and a preliminary solid phase. The initially separated liquid is then filtered through a filter with a filtration precision of d. f =0.1~0.5μm, d f To achieve high filtration precision, it is used to trap tiny solid particles, resulting in the deacidified and dehydrated product.

6. The hydrolysate deacidification-dehydration coupled process and by-product recovery method according to claim 1, characterized in that, The byproduct recovery and treatment in step S4 includes the following steps: S41, adding the mixed solid phase to a dissolving tank, adding solvent to dissolve it, and stirring at a temperature of T. s =40~80℃, stirring time is t s =1~3h, where T s The stirring temperature affects the solvent dissolution efficiency. s S42. Stirring time is used to ensure that the mixed solid phase is fully dissolved; S43. The dissolved mixture is filtered to obtain filtrate and filter residue; S444. The filtrate is evaporated, concentrated, cooled and crystallized to obtain the target by-product.

7. The hydrolysate deacidification-dehydration coupled process and by-product recovery method according to claim 6, characterized in that, The solvent in step S41 is one of water, an aqueous ethanol solution, or an aqueous acetone solution, and the mass ratio of the solvent to the mixed solid phase satisfies m s :m sp =5:1 to 10:1, where m s For solvent mass, m sp The ratio of the mixed solid phase mass ensures complete dissolution of the mixed solid phase while avoiding solvent waste; the evaporation and concentration temperature in step S43 is T. e =70~90℃, vacuum degree is P v = -0.08 to -0.05 MPa, V concentrated to the original volume c =After 1 / 3 to 1 / 5, cooling and crystallization are carried out, where T e P is the evaporation temperature. v V represents the vacuum level. c The volume percentage after concentration is determined by these three factors, which work together to control the evaporation and concentration effect; the cooling temperature is T. c =0~10℃, crystallization time is t c r = 8–12 h, T c For cooling temperature, t c r represents the crystallization time, used to promote the crystallization and precipitation of the target byproduct.

8. The hydrolysate deacidification-dehydration coupled process and by-product recovery method according to claim 4, characterized in that, The coupled reaction device includes a reaction vessel body, a jacketed heating device, a pressure control system, a stirring device, and a feed and discharge port; the reaction vessel body is equipped with a temperature sensor and a pressure sensor, which are respectively connected to the temperature control system and the pressure control system, and can monitor and control the temperature T and pressure P in the reaction system in real time, wherein the definitions of T and P are the same as in claim 4.

9. The hydrolysate deacidification-dehydration coupled process and by-product recovery method according to claim 1, characterized in that, It also includes an exhaust gas treatment step, in which the exhaust gas generated during the coupling reaction is transported to the exhaust gas treatment tower through an exhaust gas collection pipeline and treated by spray absorption. The absorbent is an acidic solution with a mass fraction w of 10% to 20%, where w is the mass fraction of the absorbent, which is used to ensure the exhaust gas absorption efficiency and ensure that the exhaust gas meets the emission standards after treatment.

10. The hydrolysate deacidification-dehydration coupled process and by-product recovery method according to claim 1, characterized in that, The acidity reduction rate of the product after deacidification and dehydration satisfies η. a ≥85%, moisture content meets w w ≤5%; the purity of the target by-product satisfies ρ p ≥90%, recovery rate satisfies η r ≥80%; where η a The acidity reduction rate reflects the deacidification effect. w ρ represents the moisture content, reflecting the dehydration effect. p For the purity of by-products, η r The recovery rate of by-products together reflects the overall performance of the process.

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