Plastic Gasification for Propylene Yield
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing hydrocarbons like olefins from fossil raw materials are inefficient, and the recycling of plastic waste into new products is challenging, with existing processes struggling to effectively utilize plastic waste as a raw material.
Innovation Solution
A method involving the gasification of plastic-containing raw materials with steam at low temperatures in a fluidized bed gasifier, followed by rapid cooling to increase propylene yield, which replaces virgin fossil raw materials in olefin production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If plastic waste is used as raw material for hydrocarbon production, then fossil raw material consumption is reduced, but the efficiency and product yield are insufficient
Solution Approach 1:
The patent applies parameter changes by optimizing gasification temperature (650-750°C), residence time (0.5-5 seconds), and steam-to-plastic ratio (2:1 to 5:1) to maximize hydrocarbon yield from plastic waste while maintaining process efficiency
Solution Approach 2:
The patent replaces traditional mechanical recycling methods with thermal gasification processes, using controlled thermal energy to convert plastic waste directly into hydrocarbon building blocks, achieving both waste utilization and efficient product production
2Productivity
If high temperature cracking is used to produce olefins from plastic waste, then hydrocarbon yield is improved, but energy consumption and process complexity increase
Solution Approach 1:
The patent changes the temperature parameter from conventional high-temperature cracking (>800°C) to low-temperature gasification (650-750°C), achieving satisfactory olefin yield while significantly reducing energy consumption and simplifying the process
Solution Approach 2:
The patent introduces steam as an intermediary agent in the gasification process, facilitating the conversion of plastic waste to hydrocarbons at lower temperatures through steam reforming reactions, thereby reducing direct thermal energy requirements
3Reliability
If prolonged residence time is used in gasification, then conversion completeness is improved, but secondary reactions increase methane and tar production
Solution Approach 1:
The patent optimizes the residence time parameter to a specific range (0.5-5 seconds) that achieves sufficient conversion completeness while preventing secondary reactions that produce methane and tar, balancing reaction extent with product quality
Solution Approach 2:
The patent employs a rapid gasification approach by maintaining short residence times, allowing the primary gasification reactions to complete quickly while skipping the formation of unwanted secondary products like methane and tar that would form with prolonged heating
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 method enhances the yield of hydrocarbons, particularly propylene, while reducing methane, benzene, and tar production, providing an efficient and cost-effective way to recycle plastic waste into valuable olefins.
Implementation Method 1
plastic containing raw material is gasified with steam at low gasification temperature in a fluidized bed gasifier for forming a product mixture
Implementation Method 2
fluidized bed gasifier
Implementation Method 3
the product mixture is cooled rapidly, and immediately, after the gasification to temperature which is below 640° C. for slowing and/or stopping the gasification reaction
Data Source
AI summary
The invention relates to a method and process arrangement for producing hydrocarbons from plastic containing raw material by means of a gasification process in which the plastic containing raw material is gasified with steam at low gasification temperature of 680-740° C. in a fluidized bed gasifier for forming a product mixture comprising hydrocarbons, and the residence time is below 4 s at the gasification temperature, and the product mixture is cooled rapidly after the gasification to temperature which is below 640° C. for slowing and/or stopping the gasification reaction of the plastic containing raw material in order to increase propylene yield of the gasification process. Further, the invention relates to the use of the method.