This feasibility study
evaluates the technical and engineering viability of constructing and operating
a plastic-to-fuel (PTF) pyrolysis plant with a daily processing capacity of 10
metric tons (TPD) of mixed plastic waste. The plant converts non-recyclable
plastics into liquid fuel, non-condensable gases, and solid char using a
controlled thermal pyrolysis process.
๐งช 2. Applicable Science and
Engineering Principles
- Thermal
Decomposition:
Pyrolysis is governed by thermochemical decomposition of polymers at 300โ500ยฐC in an oxygen-free environment, breaking long-chain hydrocarbons into smaller molecules. - Heat
Transfer Mechanism:
Critical to the process is efficient conduction and convection heat transfer within the reactor walls and feedstock bed. - Reaction
Kinetics:
First-order kinetics dominates for HDPE and LDPE, with rate constants influenced by temperature, pressure, and catalyst selection. - Catalysis
(Optional):
Use of zeolites (e.g., ZSM-5) or alumina/silica-based catalysts can enhance oil quality and reduce gas yield.
๐๏ธ
3. Main Components and Process Units
- Feedstock Preparation Unit:
- Shredders and dryers for
plastic conditioning (size < 20 mm).
- Magnetic and density separators
to remove metals and debris.
- Pyrolysis Reactor (Batch or
Semi-Continuous):
- Material: SS316/310S for
corrosion and heat resistance.
- Heating: External furnace
(diesel/gas/electric).
- Operating temp: 350โ450ยฐC.
- Pressure: Slightly above
atmospheric (~1โ1.2 bar).
- Condensation System:
- Series of shell-and-tube or
air-cooled condensers.
- Oil tank for liquid fuel
collection.
- Demister for tar removal.
- Gas Handling Unit:
- Non-condensable gases
redirected to burner for process heat.
- Scrubber with NaOH/activated
carbon for emission control.
- Char Removal & Handling:
- Manual or screw discharge.
- Bagging for sale/use as fuel or
filler.
- Control & Instrumentation:
- PLC/SCADA with I/O for
temperature, pressure, level, gas detection.
- Emergency shut-down interlocks.
๐งฑ 4.
Material of Construction (MoC)
Component |
Recommended
MoC |
Standards |
Reactor Shell |
SS310 / Inconel |
ASME Sec VIII |
Condensers |
SS304 / CS with FRP |
API 660 |
Feedstock Conveyors |
Mild Steel (Painted) |
IS 2062 |
Piping |
CS/SS |
ASTM A106/A312 |
Control Panels |
IP55 Enclosure |
IEC 60529 |
๐งพ 5.
Process Inputs & Outputs
Stream |
Input/Output |
Quantity
(Daily) |
Plastic Waste |
Input |
10,000 kg |
Liquid Fuel |
Output |
~6,000โ6,500
L |
Non-condensable Gas |
Output |
~1,500โ2,000
mยณ |
Solid Char |
Output |
~1,000โ1,200
kg |
๐ก๏ธ
6. Safety and Environmental Systems
- Fire & Gas Detection: LEL detectors, flameproof
junction boxes, foam extinguishers.
- Pressure Relief System: Rupture discs and spring-loaded
relief valves.
- Gas Scrubber: Caustic scrubber to neutralize
acidic gases (HCl, SOx).
- Effluent Handling: Zero-liquid discharge (ZLD)
design with condensate recycle.
- Noise and Heat Shielding: Acoustic panels and refractory
insulation.
๐
7. Engineering Standards and Codes
Discipline |
Standard/Code |
Pressure Vessels |
ASME Boiler &
Pressure Vessel Code |
Electrical Design |
IEC 60364, NEC |
Safety |
NFPA 86, OSHA, API
RP 500 |
Environmental |
ISO 14001, IFC
Guidelines |
๐งฎ 8. Plant
Sizing and Space Requirement
- Plot Size: Minimum 500 mยฒ
- Utilities Required:
- Power: ~60โ75 kW
- Water: 2โ4 mยณ/day (non-potable)
- Air: ~6 bar for instrument use
- Building Height: 6โ8 m for reactor installation
- Foundation: RCC with vibration-proof mounts
for heavy units
๐
9. Flexibility and Modularity
- Modular design allows scaling to
20โ50 TPD by parallel reactor trains.
- Retrofit options for
co-processing rubber, biomass, or multilayer plastics.
โ
Conclusion
The proposed 10 TPD
Plastic to Fuel Plant is technically and operationally feasible
under standard engineering practices. The process utilizes mature pyrolysis
technology, relies on widely available components, and adheres to international
engineering codes. With proper design, the plant ensures reliable performance,
environmental compliance, and scalability for future expansion.
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