Furfural residue and sodium percarbonate mother liquor combined treatment process

Abstract

The present application provides a kind of combined processing technology of furfural residue and sodium percarbonate mother liquor, sodium percarbonate mother liquor is mixed with furfural residue and stirred uniformly, the mixture obtained is gravity settled, then filtration, filter pressing are carried out, to obtain filter residue and filtrate, the filtrate is reused for the production of sodium percarbonate.The process comprehensively utilizes the alkali, flocculants, agglomerants and anti-caking agents in the mother liquor to treat the acid in the furfural residue, sodium metasilicate and magnesium sulfate can agglomerate the furfural residue, solving the problem of furfural residue flying.At the same time, the initial ignition point of furfural residue is reduced, the oxygen content is increased, and the calorific value is increased, which can be further separated and processed, such as fermentation, graphene, compound fertilizer, production of 5-hydroxymethyl furfural, wood-plastic filler and other various purposes.The above process is simple, realizes the comprehensive utilization of waste, saves the operation cost, and at the same time does not produce secondary pollution, has very high popularization and application value.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of furfural residue treatment, and particularly relates to a combined treatment process of furfural residue and sodium percarbonate mother liquor. BACKGROUND

[0002] Furfural residue is a waste residue containing 1-2 wt% acid, 30-60 wt% water, 10-20 wt% cellulose and 35-60 wt% hemicellulose after the decomposition of hemicellulose in corn cob into furfural under high-temperature and high-pressure acidic conditions, and has a strong sour smell and is easy to scatter after drying. At present, the methods for utilizing the waste residue include direct combustion, activated carbon production, 5-hydroxymethyl furfural production, gasification and graphene production, but all have defects.

[0003] Sodium percarbonate mother liquor is the liquid remaining after the removal of sodium percarbonate solids by centrifugation, and the main components are saturated sodium chloride, saturated sodium percarbonate, a small amount of flocculant sodium polyacrylate, hydrogen peroxide stabilizer metasilicate sodium, sodium tripolyphosphate and magnesium sulfate. If these waste waters are treated separately, the effective component sodium chloride needs to be filtered, resin adsorbed and recrystallized, which is high in cost. At present, there is no good treatment method.

[0004] Therefore, it is an urgent need in the industry to develop a process capable of simultaneously treating furfural residue and sodium percarbonate mother liquor. SUMMARY

[0005] The present application provides a combined treatment process of furfural residue and sodium percarbonate mother liquor to solve the problems in the prior art that furfural residue has a strong sour smell and is easy to scatter after drying, and the treatment and recycling procedures of sodium percarbonate mother liquor are complex and high in cost. The alkali of sodium percarbonate mother liquor is used to neutralize the acid of furfural residue, the flocculant sodium polyacrylate is used to flocculate furfural residue, sodium percarbonate is used to bleach furfural residue, and part of cellulose and lignin is oxidized to play a sterilization role on furfural residue.

[0006] Metasilicate sodium and magnesium sulfate can agglomerate furfural residue to solve the problem of furfural residue scattering, facilitate subsequent treatment, and reduce the initial combustion point and improve the calorific value of the treated furfural residue, so that the furfural residue can be further separated and processed, such as fermentation, graphene production, compound fertilizer production, 5-hydroxymethyl furfural production, wood-plastic filler production and other various purposes, realizing the comprehensive utilization of waste and saving operation cost without secondary pollution.

[0007] To achieve the above technical purposes, the present application adopts the following technical solutions:

[0008] A combined treatment process of furfural residue and sodium percarbonate mother liquor, characterized in that the process comprises the following steps:

[0009] (1) mixing the sodium percarbonate mother liquor with the furfural residue, continuously stirring to obtain a mixture;

[0010] (2) gravity settling the mixture obtained in step (1);

[0011] (3) using a vacuum filter press to filter the settled material obtained in step (2);

[0012] (4) after the filtration is completed, pressure filtration is performed;

[0013] (5) pressure filtration to obtain a furfural residue filter cake and a filtrate, and the filtrate is reused for the production of sodium percarbonate.

[0014] In the present application, the furfural residue is a residue generated in the production of furfural, containing 1-2wt% of acid, 30-60wt% of water, 10-20wt% of cellulose, and 35-60wt% of hemicellulose.

[0015] In the present application, the sodium percarbonate mother liquor is a liquid generated after centrifugal separation of sodium percarbonate in the production of sodium percarbonate, containing 5-15wt% of sodium carbonate, 15-20wt% of sodium chloride, a small amount of flocculant sodium polyacrylate, hydrogen peroxide stabilizer metasilicate sodium, sodium tripolyphosphate, and magnesium sulfate.

[0016] In the present application, in step (1), the sodium percarbonate mother liquor and the furfural residue are mixed in a ratio of (4-5):(1-1.2), and the continuous stirring time is 1-1.1h.

[0017] In the present application, preferably, in step (2), the settling time is 25-30min.

[0018] In the present application, in step (3), the pressure in the vacuum filter press is 0.05-0.07MPa.

[0019] In the present application, the alkali in the mother liquor neutralizes the acid in the furfural residue, the flocculant sodium polyacrylate flocculates the furfural residue, the sodium percarbonate bleaches the furfural residue, and oxidizes part of the cellulose and lignin, and also sterilizes the furfural residue, facilitating subsequent processing.

[0020] In the present application, metasilicate sodium and magnesium sulfate can agglomerate the furfural residue during filtration and pressure filtration, and the furfural residue no longer scatters, and because of the dispersing effect of sodium tripolyphosphate, the agglomeration of the furfural residue is not too hard, and it is easy to be crushed into small pieces, or directly dried and granulated by a boiling bed.

[0021] In the present application, the treated furfural residue has high density and no acid, and after oxidation, it is convenient for subsequent processing, such as can be used as fuel, and compared with before treatment, the initial ignition point of the furfural residue is reduced, the calorific value is improved, and at the same time, the oxygen content in the furfural residue is increased during the treatment process, and no additional combustion-supporting agent and oxygen-increasing agent is needed to ignite.

[0022] The process comprehensively utilizes the alkali, flocculants, caking agents and anti-caking agents in the mother liquor to treat the acid in the furfural residue, and the sodium metasilicate and magnesium sulfate can caking the furfural residue, so as to solve the problem of furfural residue flying. The furfural residue particles after bleaching, oxidation and sterilization have reduced initial combustion point, increased oxygen content and increased calorific value, so that the furfural residue can be further separated and deeply processed, such as fermentation, graphene, compound fertilizer, production of 5-hydroxymethyl furfural, wood-plastic filler and various purposes; the comprehensive utilization of waste is realized, the operation cost is saved, and secondary pollution is not caused at the same time. The above process is simple, and mature equipment for filtering, washing and drying can be directly used, so that the application value is extremely high. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The flowchart of the process is shown. DETAILED DESCRIPTION

[0024] In order to make the technical purpose, technical scheme and beneficial effects of the present application clearer, specific embodiments will be described below in combination with the drawings and specific

[0025] The embodiments further illustrate the technical scheme of the present application.

[0026] Embodiment 1

[0027] A furfural residue and sodium percarbonate mother liquor combined treatment process, as shown in Figure 1 The sodium percarbonate mother liquor 40 kg produced after centrifugal separation of sodium percarbonate in the production process of sodium percarbonate and the furfural residue 10 kg produced in the production process of furfural are mixed, and the mixture is continuously stirred for 1 hour; after stirring is completed, the mixture is gravity settled for 25 min, then the pressure in the vacuum filter is set to 0.05 MPa, and the vacuum filter is used for filtration; after vacuum filtration is completed, pressure filtration is performed, 31 kg of filtrate and 4 kg of filter residue are obtained, the obtained filtrate is reused for the production of sodium percarbonate, and the filter residue is detected for the ignition point and the calorific value.

[0028] Embodiment 2

[0029] A furfural residue and sodium percarbonate mother liquor combined treatment process, as shown in Figure 1 The sodium percarbonate mother liquor 40 kg produced after centrifugal separation of sodium percarbonate in the production process of sodium percarbonate and the furfural residue 10 kg produced in the production process of furfural are mixed, and the mixture is continuously stirred for 1 hour; after stirring is completed, the mixture is gravity settled for 25 min, then the pressure in the vacuum filter is set to 0.05 MPa, and the vacuum filter is used for filtration; after vacuum filtration is completed, pressure filtration is performed, 31 kg of filtrate and 4 kg of filter residue are obtained, the obtained filtrate is reused for the production of sodium percarbonate, and the filter residue is detected for the ignition point and the calorific value.

[0030] Example 3

[0031] A combined treatment process of furfural residue and sodium percarbonate mother liquor, as shown in Figure 1 , 40 kg of sodium percarbonate mother liquor generated after centrifugal separation of sodium percarbonate in the production process of sodium percarbonate and 12 kg of furfural residue generated in the production process of furfural are mixed, and the mixture is continuously stirred for 1 hour; after stirring is completed, the mixture is gravity settled for 25 min, then the pressure in the vacuum filter is set to 0.05 MPa, and vacuum filtration is performed using a vacuum filter; after vacuum filtration is completed, pressure filtration is performed, 31.6 kg of filtrate and 4.3 kg of filter residue are obtained, the obtained filtrate is reused for the production of sodium percarbonate, and the filter residue is detected for ignition point and calorific value.

[0032] Example 4

[0033] A combined treatment process of furfural residue and sodium percarbonate mother liquor, as shown in Figure 1 , 40 kg of sodium percarbonate mother liquor generated after centrifugal separation of sodium percarbonate in the production process of sodium percarbonate and 10 kg of furfural residue generated in the production process of furfural are mixed, and the mixture is continuously stirred for 1.1 hours; after stirring is completed, the mixture is gravity settled for 25 min, then the pressure in the vacuum filter is set to 0.05 MPa, and vacuum filtration is performed using a vacuum filter; after vacuum filtration is completed, pressure filtration is performed, 33 kg of filtrate and 3.5 kg of filter residue are obtained, the obtained filtrate is reused for the production of sodium percarbonate, and the filter residue is detected for ignition point and calorific value.

[0034] Example 5

[0035] A combined treatment process of furfural residue and sodium percarbonate mother liquor, as shown in Figure 1 , 40 kg of sodium percarbonate mother liquor generated after centrifugal separation of sodium percarbonate in the production process of sodium percarbonate and 10 kg of furfural residue generated in the production process of furfural are mixed, and the mixture is continuously stirred for 1 hour; after stirring is completed, the mixture is gravity settled for 30 min, then the pressure in the vacuum filter is set to 0.05 MPa, and vacuum filtration is performed using a vacuum filter; after vacuum filtration is completed, pressure filtration is performed, 33.8 kg of filtrate and 3.4 kg of filter residue are obtained, the obtained filtrate is reused for the production of sodium percarbonate, and the filter residue is detected for ignition point and calorific value.

[0036] Example 6

[0037] A combined treatment process of furfural residue and sodium percarbonate mother liquor, as shown in Figure 1As shown, 40 kg of sodium percarbonate mother liquor produced after centrifugal separation of sodium percarbonate in the production process of sodium percarbonate and 10 kg of furfural residue produced in the production process of furfural are mixed, and the mixture is continuously stirred for 1 hour; after stirring is completed, the mixture is gravity settled for 25 min, then the pressure in the vacuum filter is set to 0.06 MPa, and the vacuum filter is used for filtration; after vacuum filtration is completed, pressure filtration is carried out, 34.5 kg of filtrate and 3.1 kg of filter residue are obtained, the obtained filtrate is reused for the production of sodium percarbonate, and the filter residue is detected for ignition point and calorific value.

[0038] Example 7

[0039] A furfural residue and sodium percarbonate mother liquor combined treatment process, as shown in Figure 1 As shown, 40 kg of sodium percarbonate mother liquor produced after centrifugal separation of sodium percarbonate in the production process of sodium percarbonate and 10 kg of furfural residue produced in the production process of furfural are mixed, and the mixture is continuously stirred for 1 hour; after stirring is completed, the mixture is gravity settled for 25 min, then the pressure in the vacuum filter is set to 0.06 MPa, and the vacuum filter is used for filtration; after vacuum filtration is completed, pressure filtration is carried out, 34.5 kg of filtrate and 3.1 kg of filter residue are obtained, the obtained filtrate is reused for the production of sodium percarbonate, and the filter residue is detected for ignition point and calorific value.

[0040] The ignition point of the furfural residue with a water content of 50% and the examples 1-7 was detected by a thermogravimetric analyzer, and the calorific value of the furfural residue with a water content of 50% and the examples 1-7 was detected by an intelligent full-automatic heat calorimeter, and the results are as follows:

[0041]

[0042] From the above table, it can be seen that the ignition point of the treated furfural residue is relatively reduced, the main reason is that the water content of the treated furfural residue is greatly reduced, so that the furfural residue is more easily burned, the greater the vacuum degree of the vacuum filter, the more water is filtered out, the less the water content of the furfural residue, the lower the ignition point. The calorific value of the treated furfural residue increases obviously, from examples 1-3, it can be seen that when the ratio of sodium percarbonate mother liquor to furfural residue is different, the calorific value of the obtained furfural residue is not much different, from examples 1 and 4, it can be seen that with the increase of stirring time, the calorific value of the obtained furfural residue increases, because the longer the stirring time, the more sufficient the contact and mixing of the mother liquor and the furfural residue, and then the better the acid-base neutralization, and the furfural residue can also be fully oxidized; from examples 1 and 5, it can be seen that with the increase of gravity sedimentation time, the calorific value of the obtained furfural residue increases, because with the increase of sedimentation time, water is more easily filtered out, and the density of furfural residue will increase; from examples 1 and 6-7, it can be seen that with the increase of vacuum degree of the vacuum filter, the calorific value of the obtained furfural residue increases, because with the increase of vacuum degree, more water is filtered out, and the density of furfural residue will increase.

Claims

1. A combined treatment process for furfural residue and sodium percarbonate mother liquor, characterized in that, The process includes the following steps: (1) Mix sodium percarbonate mother liquor with furfural residue and stir continuously until homogeneous to obtain a mixture; (2) The mixture obtained in step (1) is subjected to gravity sedimentation; (3) The sediment obtained in step (2) is filtered using a vacuum filter. (4) After vacuum filtration is completed, pressure filtration is performed; (5) The furfural residue filter cake and filtrate are obtained by pressure filtration. The filtrate is reused in the production of sodium percarbonate.

2. The process according to claim 1, characterized in that, The furfural residue is the residue produced during the furfural production process. Sodium percarbonate mother liquor is the liquid produced after centrifugation of sodium percarbonate during the production of sodium percarbonate.

3. The process according to claim 1, characterized in that, In step (1), the sodium percarbonate mother liquor and furfural residue are mixed in a mass ratio of (4~5):(1~1.2) and stirred continuously for 1~1.1 h.

4. The process according to claim 1, characterized in that, The settling time in step (2) is 25-30 min.

5. The process according to claim 1, characterized in that, In step (3), the pressure inside the vacuum filter is 0.05~0.07 MPa.

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