Catalytic Pyrolysis of Plastic Waste Using Mild Acid Catalysts
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pyrolysis processes for producing hydrocarbon products from plastic-containing materials result in low yields of desired oil or wax products and are contaminated with impurities like chlorine and bromine, requiring additional cleaning steps.
Innovation Solution
A method and apparatus utilizing a catalytic pyrolysis process with a mildly acidic catalyst comprising aluminium oxide, aluminium silicate, zirconium oxide, or their combinations, in the presence of steam, to convert plastic-containing materials into hydrocarbon products, specifically wax, while tolerating impurities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If acidic catalysts (zeolites) are used for catalytic pyrolysis, then the pyrolysis process can proceed, but soot production increases and yield of desired oil or wax products decreases
Solution Approach 1:
The patent changes the key parameter of catalyst acidity from strong (zeolites) to mild (alumina, silica-alumina, zirconia). This parameter change fundamentally alters the reaction pathway, reducing carbon deposition and soot formation while maintaining acceptable pyrolysis conversion and improving selectivity toward desired liquid and wax products.
Solution Approach 2:
The patent employs a catalyst system that replicates the essential function of acidic catalysts (promoting bond cleavage and rearrangement) but uses materials with different chemical properties (metal oxides instead of zeolites). This 'copying' approach achieves similar pyrolysis activation without the harmful side effects of strong acidity.
2Productivity
If plastic containing chlorine or bromine is subjected to pyrolysis, then hydrocarbon products are produced, but the products become contaminated with these impurities requiring additional cleaning steps
Solution Approach 1:
The patent converts the harmful effect of halogen-containing plastics into a beneficial outcome by using mild catalysts that do not promote severe dehydrochlorination or polymerization reactions. The mild catalytic environment allows the halogen to be released as simple HCl or HBr that can be easily removed, while the hydrocarbon backbone remains intact and convertible to useful products without severe contamination.
3Ease of manufacture
If traditional catalytic pyrolysis is used, then plastic can be converted to hydrocarbon products, but additional cleaning steps are required to remove impurities
Solution Approach 1:
The patent extracts and removes the problematic strong acidic catalyst component from the system, replacing it with mild metal oxide catalysts. This extraction eliminates the source of severe product contamination and soot formation, thereby removing the need for complex additional cleaning steps while maintaining the core pyrolysis function.
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 process achieves a higher yield and improved quality of wax hydrocarbon products, effectively handling contaminated plastic waste and reducing the need for additional cleaning steps, thus enhancing waste plastic recycling and utilization.
Implementation Method 1
pyrolyzing the plastic containing material in the presence of the steam by using a catalytic pyrolysis with a mildly acidic catalyst comprising at least aluminium oxide, aluminium silicate, zirconium oxide or their combinations
Implementation Method 2
pyrolyzing the plastic containing material in the presence of the steam by using a catalytic pyrolysis
Data Source
AI summary
The invention relates to a method and an apparatus for producing a hydrocarbons product from plastic containing material, wherein the plastic containing material is subjected into a pyrolysis reactor, steam is fed into the pyrolysis reactor, and the plastic containing material is pyrolyzed in the presence of the steam by using a catalytic pyrolysis with a mildly acidic catalyst comprising at least aluminium oxide, aluminium silicate, zirconium oxide or their combinations to convert the plastic containing material to the hydrocarbon product comprising wax. Further, the invention relates to the use of the product obtained by the method.