Search

CN-121990635-A - Biochar-based hydrogel evaporator, preparation method and application

CN121990635ACN 121990635 ACN121990635 ACN 121990635ACN-121990635-A

Abstract

The invention belongs to the technical field of solar seawater desalination, and particularly relates to a biochar-based hydrogel evaporator, a preparation method and application thereof. Compared with the prior art, the invention prepares the biochar-based hydrogel evaporator for solar sea water desalination (SSD) by using a simple mixing method, wherein the biochar-based hydrogel evaporator is prepared by calcining Siberian iris waste at a high temperature, and the evaporation heat is reduced and the evaporation rate is improved by carbonizing the Siberian iris. Meanwhile, the addition of PEG destroys the original network structure of SGG, which results in the formation of a new pore structure, facilitating the faster movement of water molecules. Under the same reaction parameters, the evaporation rate is obviously improved by 0.21 kg.m ‑2 ·h ‑1 compared with the evaporator without PEG, and the photo-thermal conversion efficiency is improved by 11.3%.

Inventors

  • WANG XIAOSHU
  • WANG LEI
  • LI SHAOFENG
  • WANG YANGYANG
  • LI JUNMIN
  • LIU JIN
  • WANG JINSHENG

Assignees

  • 深圳职业技术大学

Dates

Publication Date
20260508
Application Date
20251105
Priority Date
20241105

Claims (10)

  1. 1. A biochar-based hydrogel evaporator is characterized by comprising gellan gum, siberian iris and polyethylene glycol.
  2. 2. The biochar-based hydrogel evaporator of claim 1, wherein the gellan gum is 2-10 parts by weight, iris sibirica is 1-5 parts by weight, and polyethylene glycol is 2-5 parts by weight.
  3. 3. The biochar-based hydrogel evaporator of claim 2, wherein the gellan gum is 4 parts, iris sibirica is 1 part, and polyethylene glycol is 3 parts by weight.
  4. 4. The preparation method of the biochar-based hydrogel evaporator is characterized by comprising the following steps of: s100, cleaning Siberian iris, drying, crushing, and sieving the crushed materials to obtain biomass powder with uniform granularity; S200, calcining the screened biomass powder, mixing the calcined carbonized biomass powder with deionized water, stirring and ultrasonically oscillating to obtain Siberian iris biochar suspension; s300, heating the Siberian iris biochar suspension, adding gellan gum, continuously stirring, adding polyethylene glycol after stirring, and continuously stirring; S400, adding CaCl 2 again, continuously stirring until cooling, and introducing the cooled mixed solution into a die for cooling and molding to obtain a primary sample; S500, immersing the primary sample into liquid nitrogen for a plurality of times, and then sequentially freezing, drying and freezing to finally obtain the biochar-based hydrogel evaporator.
  5. 5. The method for preparing a biochar-based hydrogel evaporator according to claim 4, wherein in step S100: the crushing times of Siberian iris are twice, and the crushed materials are sieved by a 100-mesh sieve.
  6. 6. The method for preparing a biochar-based hydrogel evaporator as set forth in claim 5, wherein in step S200: Calcining the screened biomass powder specifically comprises respectively heating to 900 ℃ in a nitrogen environment for 2h; The time of stirring and ultrasonic shaking was 2 hours.
  7. 7. The method for preparing a biochar-based hydrogel evaporator according to claim 6, wherein in the step S300: Heating Siberian iris charcoal suspension to 90deg.C, adding gellan gum, stirring for 1 hr, and adding polyethylene glycol, stirring for 20min.
  8. 8. The method for preparing a biochar-based hydrogel evaporator as set forth in claim 7, wherein in said step S400: Stirring was continued for 10min after the addition of CaCl 2 again, and the mixture was stirred until it cooled to 50 ℃.
  9. 9. The method for preparing a biochar-based hydrogel evaporator according to claim 8, wherein in step S500: the primary sample was immersed in liquid nitrogen for 15s, then frozen at-18 ℃ for 6h, repeated 3 times, and finally frozen in a freeze dryer for 36h to obtain the biochar-based hydrogel evaporator.
  10. 10. Use of a biochar-based hydrogel evaporator according to claims 1-3 and a method for the production of a biochar-based hydrogel evaporator according to claims 4-9 for solar desalination of sea water.

Description

Biochar-based hydrogel evaporator, preparation method and application Technical Field The invention belongs to the technical field of solar seawater desalination, and particularly relates to a biochar-based hydrogel evaporator, a preparation method and application thereof. Background With the continuous improvement of living standard and development requirements of people, the problem of water resource shortage in the future is likely to be more serious. At present, the cleaning water which can be directly used is very limited. Only 3% of the water on the earth is fresh water, and the rest 97% of the water is trapped in the ocean and is not suitable for drinking. Solar desalination is an environmentally friendly, economical and sustainable technology, providing a promising approach to clean water from seawater without relying on electricity or complex infrastructure. However, a significant challenge in solar desalination is salt accumulation on or in the solar evaporator, which reduces solar evaporation efficiency and may lead to evaporator failure. More and more research is focused on developing new structural materials to improve the efficiency of solar desalination (SSD). Heretofore, SSD applications have explored a variety of materials including polymer-based materials, semiconductors, ceramic-based materials, plasmonic metals, and carbon dots. However, its wide practical application is hampered by expensive raw materials, complicated preparation processes, and lack of biodegradability. Previous studies have found that biomass can be used as a starting material to produce carbon materials with a variety of morphologies and porous structures by carbonization, which can be used as an ideal carbon-based photothermal material. Earlier researches show that the water evaporation rates of biochar prepared from corn stalks and the like are respectively 1.65, 1.7 and 1.57 kg.m -2·h-1, the photo-thermal conversion efficiency is as high as 87.26 percent, and the water evaporation rates are respectively 76 percent and 85.9 percent under one-time solar irradiation, so that the water evaporation rates are higher than that of the traditional materials, and various plants on the soil of China have regions for large-scale growth and utilization to a certain extent. During the growth and utilization process of the plants, a large amount of biomass waste is generated, and the waste is often randomly disposed in a burning or burying mode, so that the waste of biomass energy and the damage of ecological environment are caused, and even the risk of facing air pollution and soil degradation of human beings is increased. However, if the waste biomass is converted into biochar through pyrolysis, the biochar is used for solar sea water desalination to promote the development of land plant waste biomass resources to the recycling direction. In view of this, the present invention has been made. Disclosure of Invention The invention aims to provide a biochar-based hydrogel evaporator, a preparation method and application thereof, so as to solve the technical problems mentioned in the background art. In order to achieve one of the above objects, the present invention provides the following technical solutions: A biochar-based hydrogel evaporator comprises gellan gum, iris sibirica and polyethylene glycol. Preferably, the weight portions of the gellan gum are 2-10, siberian iris, and polyethylene glycol are 2-5. Preferably, the weight portions of the components are 4 parts of gellan gum, 1 part of Siberian iris and 3 parts of polyethylene glycol. In order to achieve the second purpose, the invention provides the following technical scheme: the preparation method of the biochar-based hydrogel evaporator comprises the following steps: s100, cleaning Siberian iris, drying, crushing, and sieving the crushed materials to obtain biomass powder with uniform granularity; S200, calcining the screened biomass powder, mixing the calcined carbonized biomass powder with deionized water, stirring and ultrasonically oscillating to obtain Siberian iris biochar suspension; s300, heating the Siberian iris biochar suspension, adding gellan gum, continuously stirring, adding polyethylene glycol after stirring, and continuously stirring; S400, adding CaCl 2 again, continuously stirring until cooling, and introducing the cooled mixed solution into a die for cooling and molding to obtain a primary sample; S500, immersing the primary sample into liquid nitrogen for a plurality of times, and then sequentially freezing, drying and freezing to finally obtain the biochar-based hydrogel evaporator. Preferably, in said step S100: the crushing times of Siberian iris are twice, and the crushed materials are sieved by a 100-mesh sieve. Preferably, in said step S200: Calcining the screened biomass powder specifically comprises respectively heating to 900 ℃ in a nitrogen environment for 2h; The time of stirring and ultrasonic shaking was 2 hours. Preferably, in said s