Device and method for enhancing hydrophilicity of biochar

BACKGROUND OF THE INVENTION The present invention relates to a device and method for increasing the hydrophilicity of lignocellulosic bio-carbon, in particular vacuum devices, for creating pressure changes between bio-carbon particles and increasing fluid infiltration and exfiltration of bio-carbon pores. This increases the ability of bio-carbon to retain water and chemicals. Such modified bio-carbon can be used in a variety of environmental technologies such as biofiltration systems by increasing the moisture retention time in bio-carbon, increasing chemical retention in bio-carbon, reducing water use in environmental technology systems, increasing the efficiency of organic pollutant degradation at lower water consumption.

TECHNICAL LEVEL

The device and method for increasing the hydrophilicity of a bio-carbon can be applied to improve the physicochemical properties of bio-carbon derived from any starting lignocellulosic feedstock in relation to increasing the hydrophilicity of the bio-carbon. Vacuum technology is superior to conventional aqueous carbon saturation, which usually only affects the outer surface and a small portion of the inner surface of the carbon. Bio-carbon is produced by biomass pyrolysis. The resulting bio-carbon is subsequently exposed to vacuum and a surfactant (PAM) solution. The effect of bio-carbon after pyrolysis is required to increase the internal pore volume and surface area of ​​the bio-carbon. Exposure of bio-carbon to steam after pyrolysis of rhamnolipid solution aims to increase the internal pore volume and surface area of ​​the bio-carbon, remove harmful condensed compounds from the bio-carbon pore, and incorporate biological compounds into the bio-carbon structure, best achieved by modifying the chemical and physical properties of . The vacuum effect causes the solution to infiltrate into and exfiltrate from the pores of the bio-carbon, thereby accelerating the removal of the resin condensed compounds from the pores of the bio-carbon. The solution effect is used for three reasons: 1) to increase the porous structure surface of the bio-carbon; 2) neutralize the pH of the bio-carbon; 3) to remove the resin compounds from the pores of the bio-carbon.

U.S. Pat. US9809502. The technology described in the present invention involves placing the bio-carbon in a vacuum container. A humidifying agent is added thereto and a vacuum is created using a vacuum pump connected to a vacuum hose having a valve. When the valve in the container is closed, the pressure in the container drops from 99.99 kPa to 1.33 kPa. The bio-carbon can be stored in a vacuum for a few seconds to 100 minutes. The wetting enhancer enters the vacuum container through the hose, opening the valve. When the valve is opened, the exposure solution is used to modify the surface of the pore of the bio-carbon. A vacuum can be created either after the solution has been applied to the carbon or when the solution enters the container. The container holds the bio-carbon in a blender. Thereafter, bio-carbon saturated with rhamnolipid solution may be exposed to a stream of air to remove excess water from the bio-carbon. The modified bio-carbon can thus be impregnated with additives due to the development of additional pore surface properties.

A disadvantage of the prototype is the proposed modification of the bio-carbon with a solution. Unlike vapor, the liquid phase of the reagent affects only the outer surface area of ​​the pores of the bio-carbon and only a small part of the inner surface area. Another disadvantage is that it is proposed to prepare the modifying solution from chemical surfactants which are toxic. Modification uses up to 10-100 times more chemicals compared to surfactants of biological origin.

THE SUBSTANCE OF THE INVENTION

The object of the present invention is to increase the hydrophilicity of bio-carbon to improve the moisture content of the bio-carbon by increasing the internal surface area of ​​the bio-carbon. Mixing of bio-carbon with vapor saturation of rhamnolipid fluid and creation of pressure changes between bio-carbon particles under vacuum conditions are used. The vaporization solution used to increase the hydrophilicity of the bio-carbon is made from deionized water and rhamnolipid surfactant due to the latter's high capacity to hydrate hydrophobic surfaces.

Ramnolipids are surfactant glycolipids belonging to biologically derived surfactants and are composed of a hydrophilic group formed by one or two molecules of rhamnose and a hydrophobic group consisting of one or two saturated acid chains. Ramnolipid materials are produced from renewable raw materials and a wide variety of microorganisms, but mainly from

Pseudomonas aeruginosa. Compared to their synthetic analogues, rhamnolipid substances are less toxic, more active in the wetting capacity and more stable at the extreme temperatures, pH, and salinity conditions. The moisture content of hydrophobic low temperature bio-carbon can be increased by using a solution of rhamnolipid material in a concentration of 30-40 mg / l, due to the reduction of the surface tension of water from 72 mN / m to 30-35 mN / m.

Steam activation of bio-carbon can increase the hydrophilicity of bio-carbon for several reasons. First, steam activation increases the surface area of ​​bio-carbon by releasing condensed compounds that clog pores of the bio-carbon. The amount of water adsorbed on the bio-carbon is directly dependent on the large surface area of ​​the bio-carbon, which may cause these types of bio-carbon to adsorb large amounts of water. Second, vapor activation increases microporousity due to small pores merging and increasing internal voids. Third, vapor activation oxidizes the surface of bio-carbon pores, resulting in the formation of surface acidic oxygen-containing functional groups (e.g., carboxyl, carbonyl, ether, and phenolic hydroxyl groups) that increase the hydrophilicity of bio-carbon due to hydrogen bonding with water molecules. Fourth, vapor activation promotes the removal of condensed compounds (monoaromatic and polycyclic aromatic hydrocarbons, benzonitrile, benzofurans) from the pores of the bio-carbon, which impede water access to the bio-carbon. The pore clogging effect reduces the hydrophilicity of the bio carbon. It is important to emphasize the physical role of vapor in increasing the hydrophilicity of bio-carbon. Because water vapor has a lower density (0.59 kg / m³at 99.63 ° C boiling point) and viscosity (0.000012 kg / ms at 99.63 ° C boiling point) compared to the liquid water phase (997.996 kg / m respectively).³ and 0.000978 kg / ms at 21 ° C water), their molecules may more readily penetrate the porous internal structure of the bio-carbon and its capillaries during vapor activation of the bio-carbon, resulting in a better vapor effect on said bio-carbon properties.

The bio-carbon hydrophilic enhancer has a solution reservoir of rhamnolipid material with a solution inlet, from which a solution of rhamnolipid material flows into the underside of the vacuum treatment tank of the bio-carbon by means of an outlet hose. The heating element is used to create a vapor of a solution of rhamnolipid material, which is used to oxidize the bio-carbon particles and to purify the resins. A temperature sensor and an automatic control unit are used to record the vapor temperature of a solution of ramnolipid material in the range of 100-105 ° C. The lower part of the vacuum treatment tank for bio-carbon is separated from the upper by a perforated baffle, which is used to separate the bio-carbon filler from the solution of rhamnolipid material and to remove the modified bio-carbon at the end of the modification process. Flange connection with gasket to remove perforated septum before removal of modified bio-carbon. The agitator, consisting of an electric motor, shaft and rod-shaped blades, performs the function of mixing the filler of the bio-carbon and therefore promotes the vapor exchange of the solution with the internal structure of the bio-carbon. Continuous operation of the mixer is regulated by an automatic control unit. A biocarbon filler of 2-4 mm fraction passes through the opening of the bio-carbon in the upper part of the tank and is exposed to steam of a solution of rhamnolipid material for 2.5 to 3 hours. The vapor pressure of the solution reduces the pressure in the tank from 99 900 Pa to 1333 Pa due to the creation of a pseudomembrane layer of bio-carbon particles.

DESCRIPTION OF THE DRAWINGS FIG. a schematic longitudinal view of a device for steam and vacuum solution of a ramnolipid material for the modification of a bio-carbon.

DETAILED DESCRIPTION OF THE INVENTION

The device for increasing the hydrophilicity of the bio-carbon consists of a solution tank 1 of rhamnolipid material filled with a solution of rhamnolipid material 2 through a solution filling opening 3, a valve 4 connecting a 8, filled with solution of rhamnolipid material 9, temperature sensor 10, automatic control unit 11, flanged connection with gasket 12, perforated baffle 13, upper vacuum treatment vessel 6 14, electric motor 15, shaft 16, agitator blades 17, bio-carbon feed port 18, nozzle 19 connecting vacuum treatment vessel 6 through valve 20 to vacuum pump 21 for creating vacuum in upper vacuum treatment vessel in a portion 14 of a container 6 filled with a vapor 23 of a solution of a ramnolipid material 2 in both a capillary of bio-carbon 22 and a bio-carbon 22.

PRINCIPLE OF OPERATION OF THE INSTALLATION

The container 1 is filled with a solution of ramnolipid material 2 fed through an opening 3. When the valve 4 is opened, the solution 2 of ramnolipid material 2 passes through the hose 5 from the container 1 into the lower part of the vacuum treatment vessel 6. , the solution of rhamnolipid material 9 contained therein is heated to boiling point to obtain maximum (up to 100%) vapor saturated air. Upon reaching the vapor temperature of 100105 ° C, which is measured by a temperature sensor 10 connected to the automatic control unit 11, the heating element 7 is automatically switched off. When the vapor temperature drops below 100 ° C, the automatic control unit 11 activates the reheating of the solution of ramnolipid material 9. The automatic control unit 11 also regulates the continuous operation of the mixer consisting of an electric motor 15, a shaft 16 and a rod-shaped blade 17. During the process of modification of bio-carbon 22, the condensed compounds are liberated from the internal and external structure of the bio-carbon and thus the solution exchange of rhamnolipid material with the internal structure of bio-carbon 22 is promoted. The perforated baffle 13 with flange connection and gasket 12 is intended to prevent the particles of bio-carbon 22 from entering the solution of the rhamnolipid material 9 and, at the end of the modification process, to remove the modified bio-carbon 22. The perforated baffle 13 also contributes to a more even distribution of the vapor 23 in the upper vacuum treatment vessel 6 14 in the bio-carbon 22. The 1 kg bio-carbon 22 having a fraction of 2-4 mm is fed through the opening 18 to the upper vacuum treatment vessel 6 14. The bio-carbon is exposed steam solution of rhamnolipid substance 23 2.5-3 hours. Bio-carbon 22, saturated with solution vapor 23, has been shown to lose its initial hydrophobicity after 7 days. This is associated with the filling of the pore space and the oxidation of the pore surface. When bio-carbon 22 is saturated with steam solution of ramnolipid material 23, a vacuum of 99 990 Pa - 1333 Pa is created in the upper part of the vacuum treatment vessel 14 using a vacuum pump 21 so that the bio carbon particles 22 22 and steam 23. When the valve 20 of the unit is opened, the pressure in the tank is reduced by applying a vacuum pump 21 from 99 990 Pa to 1333 Pa . The bio-carbon is stored under vacuum for up to 2.5-3 hours. Vacuum accelerates fluid infiltration into and exfiltration from pores of bio-carbon. Due to the effect of the particles of bio-carbon, the purging and purification of bio-carbon capillaries is improved. The liquid fill level in the lower part of the vacuum treatment volume 6 8 is 20% of the volume of the vacuum treatment volume 6, and the bio-carbon level in the upper part 6 of the vacuum treatment volume 14 is 60%.