Method for preparing large-particle foam carbon by using corncob

Abstract

The invention discloses a method for preparing large-particle foam carbon by using a corncob. The method specifically comprises the following steps: drying the corncob, crushing into corncob powder, and then mixing with a catalyst to react for 30-40 minutes; adding an adhesive to react for 60 minutes, then cooling and dehydrating to obtain biomass base expandable slurry; adding a surfactant, a foaming agent and a curing agent to mix and then pouring in a mold, foaming and curing for 15-30 minutes, and drying and curing for 20-30 minutes to obtain charring precursor; then charring at the temperature of 150-350 DEG C for 20-60 minutes, curing for 4 hours at 500-600 DEG C, washing an activation product to be neutral, and drying to obtain the large-particle foam carbon. The agricultural and forestry biomass material corncob is used as a foam carbon matrix, so the consumption of a petroleum base chemical product is reduced, and high value of low-value agricultural waste is realized; the prepared foam carbon has high aperture ratio, large specific surface and strong adsorption capacity and can be applied to the field of environmental engineering such as purification of polluted water body in place of conventional active carbon.

Description

technical field [0001] The invention belongs to the field of foam carbon preparation, in particular to a method for preparing large particle foam carbon by using corncobs. Background technique [0002] Foam carbon is a lightweight solid carbon material with carbon atoms as the skeleton and a porous network structure formed by stacking carbon atoms with each other. It has a large specific surface area, high porosity, excellent adsorption and compressibility, and low thermal expansion. Coefficient and other excellent properties can be used in a wide range. At present, the research and application of foamed carbon materials at home and abroad mostly use resin as raw material, and obtain foamed carbon through foaming and high-temperature carbonization of curing agent. For example, Chinese patent CN101811885 discloses a method for preparing foamed carbon with furan resin. Furan resin is used as material, auxiliary materials are added, and then carbonized after foaming an...

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Problems solved by technology

For example, Chinese patent CN101811885 discloses a method for preparing foamed carbon with furan resin. Furan resin is used as material, auxiliary materials are added, and then carbonized after foaming and curing. The obtained foamed carbon material has high strength and long life, but the invention The furan ring is used in the process, which is volatile and toxic gas, and the carbonization stage takes a long time and the energy consumption of carbonization is high; Chinese patent CN104072796 discloses a method for preparing phenolic resin foam material and foam carbon material by self-foaming. Fast tool reaction, while using the Knoevenagel reaction of organic diacids and aldehydes, heating and decarboxylation to release carbon dioxide gas as a foaming agent, to achieve one-step self-foaming to prepare phenolic foam materials, but this invention uses phenol and its derivatives and formaldehyde solution or polymer Toxic raw materials such as formaldehyde, paraformaldehyde, acrolein, and glutaraldehyde are harmful to human health and the production environment; Chinese patent CN102008747 discloses a foamed carbon bioscaffold and its preparation method and application. The foamed carbon bioscaffold can target different cells Species Requirements Place the cell-planted carbon foam bioscaffold in a static or dynamic circulation culture system for cultivation, which has good biocompatibility, but the material uses phenolic resin as a precursor and cannot be biodegraded; Chinese patent CN102134068 discloses a method for preparing graphitized foamed carbon with high open porosity. The method uses organic solvent soluble components in asphalt substances as the carbon source of foamed carbon, but the organic solvent in the reaction is selected from tetrahydrofuran, pyridine , quinoline and other irritating raw materials, the template foam used is selected as non-degradable or refractory polyurethane foam or phenolic resin foam; The base material is used as the prepolymerization of thermosetting resin, the carbon foam is difficult to degrade, the porosity of the carbon foam is low, and the carbonization and curing steps are cumbersome and the preparation cost is high

[0003] Foamed carbon prepared by phenolic resin is easy to break during high-pressure degassing or high-temperature carbonization, which makes it difficult to control the overall structure of foamed carbon, especially for the preparation of large particle foamed carbon, and some chlorofluorocarbon blowing agents are used in the preparation process. It is very harmful to the environment and equipment; mesocarbon microspheres with a spherical structure are relatively well-reported reinforcing materials, which can increase the compressive strength of foamed carbon to 25 MPa, but mesocarbon microspheres due to high-temperature graphitization Heat treatment, in the process of compounding with the carbonaceous precursor, it is easy to produce more solid / liquid interfaces, resulting in lower impact strength and tensile strength of foamed carbon

Judging from the existing technical literature, the main problems of foam carbon materials are that most of them use petroleum-based raw materials as foam carbon precursors, complex processing procedures, expensive raw and auxiliary materials, high production costs, and foam carbon is difficult to degrade, causing great environmental pollution.

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