Heavy Aromatic Waste Upgrading Through Hydrogenation and Steam Cracking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The chemical industry faces challenges in recycling non-biodegradable polystyrene waste and heavy aromatic waste streams such as RFOs and HAS, which are underutilized and pose environmental and disposal issues, limiting the circular economy and reliance on virgin raw materials.
Innovation Solution
A process that upgrades heavy aromatic waste streams through hydrogenation and steam cracking to produce chemical feedstocks like ethylene, propylene, and ethylbenzene, utilizing commercial catalysts like NiMo, CoMo, Ni, Pd, and Pt, and separation techniques to achieve high purity products suitable for the POSM and SM processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If mechanical recycling processes are used for polystyrene waste, then the waste can be recycled, but the process is limited in achieving complete chemical circularity and results in downcycling
Solution Approach 1:
The patent applies parameter changes by transforming the chemical structure of polystyrene waste through hydrogenation (adding hydrogen to saturate aromatic rings) and steam cracking (thermal decomposition), changing the molecular parameters to convert the waste into valuable chemical feedstocks like ethylbenzene, styrene, and olefinic compounds, thereby achieving high-quality recycling rather than downcycling
Solution Approach 2:
The patent replaces mechanical recycling processes with chemical processing methods. Instead of mechanical sorting and reforming, the invention uses hydrogenation reactors and steam cracking units to chemically transform the waste polymers into monomers and chemical feedstocks, enabling true circular economy in the chemical industry
2Object-affected harmful factors
If heavy aromatic waste streams are disposed of traditionally, then disposal issues are avoided, but the waste streams are underutilized and pose environmental issues
Solution Approach 1:
The patent converts harmful heavy aromatic waste streams into beneficial chemical feedstocks. Through hydrogenation, the aromatic rings are saturated to produce cycloalkanes, which are then subjected to steam cracking to generate olefinic compounds and aromatic hydrocarbons that can be used as fuel or chemical raw materials, transforming environmental hazards into valuable resources
Solution Approach 2:
The patent changes the chemical parameters of heavy aromatic waste by controlling hydrogenation conditions (temperature, pressure, catalyst type) and steam cracking parameters to optimize the production of desired chemical products, thereby maximizing waste utilization and minimizing environmental impact
3Productivity
If reliance on virgin raw materials is maintained, then chemical production is ensured, but the sustainability of chemical processes is reduced
Solution Approach 1:
The patent applies preliminary action by capturing and processing heavy aromatic waste streams at the source rather than allowing them to be generated and disposed of. The waste streams are subjected to hydrogenation and steam cracking in advance to convert them into usable chemical feedstocks, ensuring continuous supply of raw materials while maintaining sustainability
Solution Approach 2:
The patent enables the chemical industry to serve itself by converting its own waste streams into valuable raw materials. The process creates a self-sustaining system where waste from one process becomes feedstock for another, reducing dependence on external virgin raw materials and enhancing overall process sustainability
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
Converts waste streams into valuable chemical feedstocks, reducing landfilling, enhancing sustainability, and providing feedstocks for petrochemical processes like POSM and SM, while minimizing environmental impact.
Implementation Method 1
subjecting the heavy aromatic waste stream to hydrogenation conditions in a first reaction zone to produce a first intermediate product, wherein: i) the heavy aromatic waste stream comprises olefinic and aromatic unsaturation; and ii) the first intermediate product is substantially free of olefinic unsaturation and has a reduced amount of aromatic unsaturation
Implementation Method 2
subjecting the first intermediate product to steam cracking conditions in a second reaction zone to produce a second intermediate product
Implementation Method 3
The second intermediate product is then separated to produce a third intermediate product comprising ethylene, propylene, or a combination thereof and a first residual fraction
Data Source
AI summary
Disclosed are methods for upgrading heavy aromatic waste streams, including polystyrene and other related materials, to chemical feedstocks. Process embodiments include feeding heavy aromatic waste streams to: a) hydrogenation followed by steam cracking followed by separation; and b) separation followed by: i) hydrogenation, and ii) hydrogenation followed by steam cracking followed by and separation. Each embodiment leads to production of ethylene, propylene, ethylbenzene, ethylbenzene precursors, or a combination thereof.