Thermolysis Waste Plastics Apparatus with Two-Step Separation
Solution Overview
Problem
Current methods for thermolysis of plastic waste struggle with achieving efficient and repeatable production of high-quality hydrocarbon products while minimizing energy consumption and unwanted byproducts like coke, and often require catalysts or complex separation processes.
Innovation Solution
A continuous thermolysis process using an extruder to plasticize waste plastics, which are then fed into a reactor with dual high-speed propellers, operating at 390-430°C, with a two-step product separation system involving direct contact condensers and wiped film evaporators, allowing for the production of three distinct hydrocarbon fractions without catalysts and reducing coke formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If catalysts are used in thermolysis process, then hydrocarbon production efficiency is improved, but process complexity and cost increase
Solution Approach 1:
The invention extracts and removes the catalyst component from the thermolysis process. By conducting catalytic cracking without physical catalysts present in the reactor, the process eliminates catalyst handling, separation, and regeneration complexities while maintaining high hydrocarbon production efficiency through vapor-phase catalytic cracking.
Solution Approach 2:
The invention introduces a circulating fluidized bed as an intermediary system that enables catalytic cracking without direct catalyst contact in the main reactor. The circulating fluidized bed acts as a mediator that facilitates hydrocarbon production while allowing continuous catalyst circulation and regeneration outside the main reaction zone.
2Productivity
If thermolysis temperature is increased to improve hydrocarbon yield, then production efficiency increases, but energy consumption and coke formation increase
Solution Approach 1:
The invention changes the operational parameters by conducting thermolysis at moderate temperatures (300-450°C) rather than high temperatures, while maintaining high hydrocarbon yield through the introduction of catalysts and use of circulating fluidized bed technology that enhances reaction efficiency at lower energy input.
Solution Approach 2:
The circulating fluidized bed enables continuous catalyst circulation and regeneration, maintaining optimal catalytic activity throughout the process. This continuous action ensures sustained high hydrocarbon yield without requiring temperature increases that would raise energy consumption and coke formation.
3Manufacturing precision
If complex separation processes are used to purify hydrocarbon products, then product quality is improved, but process complexity and production time increase
Solution Approach 1:
The invention segments the product separation into distinct fractional distillation stages that separate hydrocarbons by boiling point ranges. This segmentation achieves high product quality through systematic fractionation while keeping each separation stage relatively simple and manageable.
Solution Approach 2:
The invention changes separation parameters by using fractional distillation based on boiling point differences rather than complex chemical separation methods. This approach achieves high product purity through physical property differences, simplifying the separation process while maintaining manufacturing precision.
4Productivity
If continuous thermolysis process is implemented, then productivity is improved, but process control complexity and equipment requirements increase
Solution Approach 1:
The invention implements continuous thermolysis through a circulating fluidized bed system that enables uninterrupted feedstock processing and product formation. The continuous circulation of catalyst and maintainance of steady-state operation ensure continuous hydrocarbon production while using relatively simple control mechanisms.
Solution Approach 2:
The circulating fluidized bed system provides self-regulating characteristics where the fluidization process automatically maintains optimal mixing and heat transfer conditions. The system self-adjusts to maintain continuous operation without requiring complex external control mechanisms, achieving high productivity with simplified process control.
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 approach enables the production of high-repeatability light oil, heavy oil, and wax products with reduced energy consumption and minimal unwanted byproducts, allowing for flexible processing and direct commercialization or further refining of products, with the gaseous product usable as fuel for process heating.
Implementation Method 1
plastic waste are continuously fed to the extruder where are plasticized
Implementation Method 2
heated up to the temperature of the reactor
Implementation Method 3
in temperature 380 - 500 °C polymeric chains' cracking and producing light hydrocarbons takes place
Implementation Method 4
polymeric chains' cracking and producing light hydrocarbons
Implementation Method 5
vapor-liquid mixture is transported to separator from which the liquid phase is returned into cracking reactor and gaseous phase is conducted to water-cooled condenser
Implementation Method 6
The liquid phase is separated on gasoline fraction conducted into tank and diesel oil conducted into tank in distillation column
Implementation Method 7
dual high-speed propellers, allowing for the production of three distinct hydrocarbon fractions
Implementation Method 8
two-step product separation system involving direct contact condensers and wiped film evaporators
Implementation Method 9
two-step product separation system involving direct contact condensers and wiped film evaporators
Data Source
Figure 1
AI summary
The subject of the invention is apparatus and method for thermolysis of waste plastics especially for receiving of hydrocarbon products. Apparatus for thermolysis of waste plastics consisting feeding system, thermolysis reactor, external circulation loop and product collecting system according to the invention is characterized in that collecting and two-step product separation system is involving condenser (6), product cooling system (3), light fraction receiver (26) with gaseous product removing system (27), crude heavy fraction receiver (21) and vacuum evaporator (7). Plastic waste thermolysis method is characterized in that product vapors are removed continuously from reactor and conducted to condenser in which condensation of vapors is carried out and product mixture separation to light oil conducted to light oil receiver from which the gaseous products are received and liquid products are conducted to light oil tank and for further processing and crude heavy which through heat exchanger and crude heavy oil receiver is pumped to vacuum evaporator in which next step of separation of crude heavy oil to and heavy oil is obtained.