What is honeycomb ceramic and what material is it made of

Honeycomb ceramics have various shapes composed of countless equal pores, with a pore count of 120-140 per square centimeter, a density of 0.3-0.6 grams per cubic centimeter, and a water absorption rate of over 20%. Due to the characteristics of porous and thin-walled materials, the geometric surface area of the carrier has been greatly increased and the thermal shock resistance has been improved. The products produced are mainly composed of triangular and tetragonal mesh pores, which have much better load-bearing capacity and a larger number of pores. This is particularly important as a catalytic carrier. As the number of pores per unit area increases and the thickness of the carrier pore wall decreases, the trend of thermal shock resistance of ceramic carriers increases, and the temperature of thermal shock damage also increases. Therefore, honeycomb ceramics must reduce the expansion coefficient and increase the number of pores per unit area. The coefficient of thermal expansion is the main performance indicator, and the current foreign level is α 25-800 ℃ ≤ 1.0 × 10-6 ℃ -1, there is a certain gap compared to China, but the gap is getting smaller and smaller. The raw materials for early production of honeycomb ceramics are mainly kaolin, talc, aluminum powder, clay, etc., especially the application of diatomaceous earth, zeolite, expansive soil, and refractory materials. The application of honeycomb ceramics is becoming increasingly widespread, and their performance is getting better and better.

In addition to honeycomb ceramics used for sintering molding, non sintered honeycomb ceramics have also emerged, greatly improving the catalytic activity. Not only did the appearance size evolve from small spherical ring shapes to large-sized columns and square and circular shapes. According to different mold designs; Honeycomb ceramics with different sizes, shapes, and structures can be made. For example, molecular sieve catalysts used in the petrochemical industry for air adsorption and drying in oil refining, with a square size of up to 0.8m and a width of 0.25m, and a pore count of 25 per square centimeter, have undergone significant changes in raw materials, processes, and mechanical manufacturing. Especially the production process has been greatly improved. As a catalyst, honeycomb ceramics require no cracking during manufacturing and molding, organic components must be released thoroughly, and in addition to wear resistance, they also require a certain degree of mechanical strength, which can be regenerated and reused multiple times.

Honeycomb ceramics can be made from various materials. The main materials include: cordierite, mullite, aluminum titanate, activated carbon, silicon carbide, activated alumina, zirconia, silicon nitride, and composite matrices such as cordierite mullite and cordierite aluminum titanate.

After activated carbon powder or particles are made into honeycomb ceramic shapes, the purification and wastewater treatment capabilities of water treatment are greatly improved, especially in the pharmaceutical industry, where antibiotics, hormones, vitamins, nucleic acid injections, and various injections, drugs, etc. are dehydrated, decolorized, and impurities are removed.

Honeycomb ceramics can be divided into four categories based on their use: heat storage materials, fillers, catalyst carriers, and filter materials.

The honeycomb ceramic thermal storage body has a heat capacity of over 1000kJ/kg, and the product has a high usage temperature of ≥ 1700 ℃. It can save over 40% of fuel in furnaces such as heating furnaces, ovens, soaking pits, and cracking furnaces, increase production by over 15%, and discharge flue gas temperatures below 150 ℃.

Honeycomb ceramic fillers have advantages such as larger specific surface area and better strength compared to other shapes of fillers, which can make the vapor liquid distribution more uniform, reduce bed resistance, and have better effects. They can also extend their service life and have good filling effects in the petrochemical, pharmaceutical, and fine chemical industries.

Honeycomb ceramics have more advantages in catalysts. Using honeycomb shaped ceramic materials as carriers and unique coating materials, prepared from precious metals, rare earth metals, and transition metals, it has high catalytic activity, good thermal stability, long service life, high strength, and other advantages.

Honeycomb ceramics used for catalytic cracking are replacing existing products. Catalytic cracking uses heavy distillate oil between 200 and 500 ℃ as raw materials (including vacuum fraction, straight run light diesel oil, coking gas oil, etc.), and silicoaluminate as catalyst. The reaction temperature ranges from 450 to 550 ℃ (depending on the type of reactor). It has a large production capacity (with each large catalytic cracking unit cracking over one million tons of oil annually) and high technical requirements (for example, the catalyst needs to be regenerated every few minutes or even seconds of contact with the oil, and the flow rate of fluidized bed catalyst reaches 10 tons or more per minute). With the increase of catalytic activity, in order to accelerate the regeneration speed, more stringent regeneration conditions are required. For example, at temperatures ranging from 600 to 650 ℃, or even 700 ℃, the catalyst consumption is high, with 0.3 to 0.6kg of catalyst consumed per ton of feed oil. If the mechanical strength of the catalyst is poor, the consumption is much higher. This requires a slight improvement in catalyst activity, selectivity, and stability, which will have significant implications for production practice. Because of this, honeycomb ceramic catalysts are constantly innovating, and the market demand is also increasing. These catalysts for catalytic cracking have been replaced by honeycomb ceramic catalysts, and honeycomb ceramic catalysts with large pore numbers have emerged and have a strong development momentum.

Honeycomb ceramics have the following advantages as filter materials: good chemical stability, resistance to acid, alkali, and organic solvents; Excellent resistance to rapid heating and cooling, with a working temperature of up to 1000 ℃; Good antibacterial performance, not easily degraded by bacteria, not easily blocked and easy to regenerate; Strong structural stability, narrow pore size distribution, and high permeability; Non toxic, especially suitable for the handling of food and drugs.

It is mainly applied in the metallurgical industry. The honeycomb ceramic body has a large specific surface area, which improves the ability of the filter to adsorb and capture small impurities, and has better filtration effect than traditional porous ceramics, with stable metal liquid flow.