Microporous Carbon Catalyst Deoxygenation of Pyrolysis Vapors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pyrolysis products from lignocellulosic biomass have high oxygen content, leading to irreversible polymerizations and making subsequent treatment difficult, and existing deoxygenation methods using non-carbon-based catalysts produce unsaturated hydrocarbons and are prone to poisoning.
Innovation Solution
The method involves using meso- and/or microporous carbon-based catalysts to deoxygenate pyrolysis vapors in a separate reactor before condensation, with temperatures between 350°C to 500°C, and the catalysts can be made from pyrolysis coke, ensuring high carbon content and resistance to poisoning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If non-carbon-based catalysts are used for deoxygenation, then deoxygenation efficiency is improved, but the catalyst is prone to poisoning and produces unsaturated hydrocarbons
Solution Approach 1:
The patent employs microporous carbon-based catalysts (activated carbon, activated coke, carbon nanotubes, carbon molecular sieves) with specific pore structures to achieve deoxygenation. The porous structure provides high surface area and active sites for catalytic reactions while being resistant to poisoning, directly resolving the contradiction between deoxygenation efficiency and catalyst reliability.
Solution Approach 2:
The patent changes the fundamental parameter of catalyst material composition from non-carbon-based to carbon-based materials. This parameter change fundamentally alters the catalyst's resistance to poisoning while maintaining deoxygenation capability, and the microporous structure parameters (pore size, surface area) are optimized to enhance catalytic performance.
2Stability of the object's composition
If deoxygenation is carried out before condensation, then irreversible polymerization is prevented, but the process complexity increases
Solution Approach 1:
The patent combines the deoxygenation reactor and condensation unit into an integrated system where deoxygenation occurs in the vapor phase before condensation. The condensed liquid product is automatically separated into aqueous and organic phases, merging multiple functions (deoxygenation, condensation, separation) into a streamlined process that prevents polymerization without excessive complexity.
3Ease of manufacture
If charcoal is used as catalyst, then cost-effectiveness is improved, but decarboxylation and decarbonylation effects are limited due to lack of micropores
Solution Approach 1:
The patent specifically selects microporous carbon-based materials (activated carbon, activated coke, carbon nanotubes, carbon molecular sieves) that possess both cost-effectiveness and microporous structures. These materials provide high surface area and active sites for decarboxylation and decarbonylation reactions, resolving the contradiction between cost and deoxygenation efficiency that plagues non-porous charcoal.
4Object-generated harmful factors
If pyrolysis temperature is increased above 700°C, then tar destruction is improved, but energy consumption increases
Solution Approach 1:
The patent introduces a microporous carbon-based catalyst as an intermediary substance that facilitates tar destruction at lower temperatures (350-500°C). The catalyst provides alternative reaction pathways with lower activation energy, enabling effective tar removal without the high energy consumption required by thermal cracking alone, thus resolving the contradiction between tar destruction and energy consumption.
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
This process effectively deacidifies and chain shortens hydrocarbons, producing saturated hydrocarbons suitable for gas engines and turbines, with increased calorific value and yield, and the carbon-based catalysts are insensitive to poisons and can be reactivated.
Implementation Method 1
the pyrolysis vapors are brought into contact with a meso- and/or microporous, in particular a microporous, catalyst prior to condensation, wherein the catalyst is carbon-based
Implementation Method 2
The liquid and gaseous products of technical pyrolysis processes, especially rapid pyrolysis, have an excessively high oxygen content in their molecules
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method is described for producing pyrolysis gas and pyrolysis oil from biogenic starting materials. First, a biogenic starting material, selected from ligncocellulosic biomass and lignocellulosic residual substances, and a carbon-based catalyst are provided. The starting material is then thermally treated in a pyrolysis reactor at a temperature T1 to effect pyrolysis of the starting material to liquid, vaporous or gaseous pyrolysis products. These pyrolysis products are then brought into contact with the carbon-based catalyst at a temperature T2 so that deoxygenation of the pyrolysis products to at least partially deoxygenated pyrolysis products occurs. These products are then collected in a separation device in which product separation takes place. In addition to liquid or gaseous pyrolysis products, catalysts that can be used for deoxygenation are also described which can be produced from the solid material that was separated following pyrolysis.