Activated Carbon Pore Structure for High Velocity Filtration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Water filters containing activated carbons face challenges in maintaining high total trihalomethane filtration capacity at high superficial velocities, as existing activated carbons fail to exhibit sufficient filtration capacity when water is passed at velocities above 3000 h−1, particularly due to the reduction in pore volume of small pores during activation processes that increase mesopore volumes.
Innovation Solution
Incorporating a vanadium compound into the activated carbon precursor and using CO2 as the activation gas, which reacts more slowly than steam, to significantly increase the development of pores with sizes of 1.0 nm or less, resulting in an activated carbon with a high total trihalomethane filtration capacity without the need for developing mesopores.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If steam activation is used to increase mesopore volume, then dynamic adsorption capacity is improved, but pore volume of small pores (≤1.0 nm) is reduced
Solution Approach 1:
The patent changes the activation gas parameter from steam to CO2, which has different reactivity characteristics. CO2 activation selectively preserves small pores (≤1.0 nm) while still developing mesopores, achieving a balanced pore structure that maintains both dynamic and static adsorption capacities. This parameter change resolves the contradiction by finding an activation method that doesn't sacrifice small pore volume for mesopore development.
2Productivity
If water is passed at high superficial velocity (>3000 h−1), then filtration productivity is improved, but filtration capacity for total trihalomethanes decreases
Solution Approach 1:
The patent creates a specific porous structure with high proportion of small pores (≤1.0 nm) and controlled mesopore volume through CO2 activation. This porous structure provides numerous adsorption sites that remain effective at high flow velocities, allowing the filter to maintain high trihalomethane removal capacity even when water is passed at superficial velocities exceeding 3000 h−1.
3Productivity
If mesopore volume is increased to improve dynamic adsorption, then adsorption capacity is enhanced, but the filter size must be increased
Solution Approach 1:
The patent optimizes the local pore structure by creating a specific distribution where small pores (≤1.0 nm) constitute the majority of pore volume, with mesopores present but not dominant. This local quality optimization allows the activated carbon to achieve high adsorption capacity in a compact form, eliminating the need to increase overall filter size while maintaining enhanced dynamic adsorption performance.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The activated carbon achieves a high total trihalomethane filtration capacity, even at high superficial velocities, by effectively utilizing a large number of small pores as adsorption sites, extending the filter's usability and maintaining high filtration efficiency.
Implementation Method 1
using CO2, which reacts with the activated carbon precursor more slowly than steam, as the activation gas, and then activating the activated carbon precursor, the rate of development of pores with a size of 1.0 nm or less is markedly increased
Implementation Method 2
an activated carbon having a high total trihalomethane filtration capacity, even in water treatment by passing water at a high superficial velocity (SV)
Data Source
AI summary
There is provided an activated carbon having a high total trihalomethane filtration capacity, even in water treatment by passing water at a high superficial velocity (SV). In the activated carbon of the present invention, a pore volume A (cc/g) of pores with a size of 1.0 nm or less, of pore volumes calculated by the QSDFT method, is 0.300 cc/g or more, and elemental vanadium and/or a vanadium compound is contained.