Carbonaceous Adsorbent Regeneration With Controlled Catalyst Oxidation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for regenerating catalyst-impregnated carbonaceous adsorbents, such as those used in biogas cleaning, are ineffective due to catalyst reduction and sulfur contamination, leading to uncontrolled oxidation and waste, which is both costly and environmentally harmful.
Innovation Solution
A method involving pyrolysis, steam reactivation, controlled oxidation, and rapid cooling of the carbonaceous adsorbent below 250°C, combined with controlled oxidation of reduced catalyst, to prevent hotspot formation and sulfur compound management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thermal regeneration is applied to catalyst-impregnated carbonaceous adsorbent, then adsorbed substances are removed by pyrolysis, but the catalyst is reduced in the low-oxygen atmosphere leading to uncontrolled oxidation and self-combustion
Solution Approach 1:
The patent applies preliminary action by introducing air in a controlled manner during the regeneration process before the catalyst reduction becomes problematic. Specifically, air is introduced at a controlled rate during the heating phase and then increased at a controlled rate after reaching peak temperature, preventing uncontrolled oxidation while maintaining regeneration effectiveness
Solution Approach 2:
The patent changes the oxygen concentration parameter dynamically during the regeneration process. It transitions from a low-oxygen atmosphere during initial heating to a controlled oxygen introduction phase, adjusting the oxygen level to prevent catalyst reduction while avoiding uncontrolled oxidation and self-combustion
2Ease of manufacture
If spent carbonaceous adsorbent is discarded instead of regenerated, then regeneration costs and complexity are avoided, but valuable carbon material and catalyst are wasted
Solution Approach 1:
The patent applies discarding and recovering by implementing a regeneration process that recovers both the carbonaceous adsorbent and the catalyst. The controlled oxidation process restores the catalyst activity while regenerating the carbon structure, allowing both materials to be reused rather than discarded
Solution Approach 2:
The patent applies self-service by designing a regeneration process that uses the heat generated from the controlled oxidation of the carbonaceous material itself to drive the regeneration process. The carbon oxidation provides the necessary heat for water gas shift reactions and catalyst regeneration, reducing external energy requirements
3Quantity of substance
If high sulfur loading is present on spent adsorbent, then conversion to SOx compounds occurs during pyrolysis, but current flue gas cleaning methods cannot handle the large amounts of sulfur
Solution Approach 1:
The patent changes the oxidation parameter control to manage sulfur emissions. By controlling the oxygen introduction rate and temperature profile, the process converts sulfur to SOx at a controlled pace that matches the capacity of flue gas cleaning systems, while still effectively removing sulfur from the adsorbent
Solution Approach 2:
The patent applies feedback by monitoring the regeneration process parameters (temperature, oxygen consumption, gas composition) to adjust the oxygen introduction rate. This feedback control ensures that SOx generation remains manageable while achieving complete sulfur removal from the adsorbent
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 method effectively regenerates catalyst-impregnated carbonaceous adsorbents, preventing self-combustion and enabling the recovery of valuable materials, while meeting regulatory sulfur emissions standards.
Implementation Method 1
pyrolysis of the dried carbonaceous adsorbent into volatile substances and carbon residues
Implementation Method 2
the well-known water/gas reaction in which carbon residues react at high temperatures with water to form carbon monoxide and hydrogen
Implementation Method 3
When such reduced catalyst is again exposed to air, the catalyst may oxidize in an uncontrolled way leading to release of heat and the formation of hotspots
Data Source
AI summary
A method and system are disclosed for regenerating carbonaceous adsorbent, the method comprising the steps of:a) providing a carbonaceous adsorbent comprising a catalyst and adsorbed contaminants,b) pyrolysing of the adsorbed contaminants,c) reactivating the carbonaceous adsorbent by subjecting the carbonaceous adsorbent to steam thereby obtaining a reactivated carbonaceous adsorbent,d) cooling the thus obtained reactivated carbonaceous adsorbent to a temperature of less than 250° C. ande) oxidizing catalyst that is in a reduced state following steps b) and c) comprised in the reactivated carbonaceous adsorbent.