Low Temperature Activated Carbon Plant: Front-End Engineering Design (FEED)

 

The project aims to develop a Low Temperature Activated Carbon (LTAC) production facility with an initial capacity of 5,000 metric tons per annum (TPA).

Front-End Engineering Design (FEED)

Part 1: Project Overview & Design Basis


1.1 Project Description

The project aims to develop a Low Temperature Activated Carbon (LTAC) production facility with an initial capacity of 5,000 metric tons per annum (TPA). The facility is designed to be modular and scalable, enabling expansion up to 30,000 TPA in phases. The plant will process biomass-based feedstocks (such as coconut shells, wood chips, palm kernel shells) through drying, pyrolysis, low-temperature steam activation, and final finishing to produce high-quality activated carbon.


1.2 Project Objectives

  • Develop a sustainable and modular activated carbon production facility.
  • Use low-temperature activation technology to reduce energy consumption and emissions.
  • Ensure high quality of the final product, compliant with international standards.
  • Allow for future expansion without major infrastructure overhaul.

1.3 Plant Location and Site Considerations

  • Location Type: Semi-rural/peri-urban zone with access to plantation/agro-waste sources.
  • Site Area Requirement (Initial 5,000 TPA): ~6,000–8,000 m².
  • Site Area (Full 30,000 TPA): ~30,000 m².
  • Nearby Resources: Biomass plantations, water supply, and power grid.
  • Climate Considerations: Tropical/humid, average ambient temperature 25–35°C, rainfall 2,000 mm/year.

1.4 Plant Capacity

Phase

Installed Capacity

Expansion Capability

Operation Mode

Phase 1

5,000 TPA

Modular block-based

Single shift

Final Phase

30,000 TPA

6 x 5,000 TPA lines

Continuous (24/7)


1.5 Feedstock and Input Requirements

Parameter

Value

Biomass Type

Coconut Shells, Palm Kernel Shells, Wood Chips

Feedstock Requirement

~15,000 tons/year for 5,000 TPA output

Moisture Content

≤ 12% (after drying)

Transport Mode

Truck delivery from plantations


1.6 Product Specifications

Parameter

Target Value

Iodine Number

≥ 900 mg/g

Moisture

≤ 5%

Ash Content

≤ 8%

Hardness

≥ 95%

Particle Size

As per application (mesh 8x30, 12x40, etc.)


1.7 Utility Requirements (Initial 5,000 TPA)

Utility

Estimated Load/Consumption

Source

Electrical Power

~250 kW connected load

Local grid or diesel genset backup

Steam

~1,200 kg/hr

Biomass-fired steam boiler

Cooling Water

~5 m³/hr

Recycled loop (cooling tower)

Compressed Air

6 bar, 30 Nm³/hr

Screw compressor

Fuel (Startup)

Diesel for burner startup only

Local supplier


1.8 Design Life and Operation Philosophy

  • Design Life: 20 years (with regular maintenance)
  • Operation Mode: Semi-continuous with potential shift-based operation
  • Manpower Requirement (5,000 TPA): ~20–25 persons (operators, engineers, maintenance, logistics)

1.9 Environmental and Regulatory Basis

  • Compliance with:
    • ISO 14001 (Environmental Management)
    • ISO 45001 (Occupational Health & Safety)
    • National environmental emissions and effluent standards
  • EIA/AMDAL required for >10,000 TPA capacity
  • Dust control and gas scrubbing system required

1.10 Key Assumptions

  • Feedstock is available within a 100 km radius
  • Grid power is stable or reliable diesel backup is provided
  • Land is owned or long-leased with no legal conflict
  • Steam boiler license and emission permits can be secured
  • Final product is packed and sold in bulk (bagged or super sack)

1.11 Deliverables from FEED – Part 1

  • Design Basis Document (this file)
  • Site Layout (to be included in Part 3)
  • Initial Utility Load List
  • Equipment List (in next part)
  • Process Description (next part)

Part 2: Process Design


2.1 Process Flow Description

The Low Temperature Activated Carbon (LTAC) production process comprises the following major steps:

  1. Biomass Reception & Preprocessing
    • Biomass (e.g., coconut shells) is received, sorted, and crushed.
    • Oversized or contaminated materials are removed.
    • Crushed material is stored in covered bunkers.
  2. Drying
    • Moisture reduction to <12% using rotary dryer or belt dryer.
    • Heat source: biomass hot gas generator or steam heat exchanger.
  3. Pyrolysis (Carbonization)
    • Biomass is carbonized at 400–500°C in a rotary kiln or multi-hearth furnace.
    • Oxygen is restricted to prevent combustion.
    • Volatile gases are collected and used as fuel or flared.
  4. Low-Temperature Activation
    • Carbonized char is exposed to steam at ~700°C.
    • Activation increases surface area and porosity.
    • Residence time: 30–60 minutes depending on product grade.
  5. Cooling
    • Activated carbon is cooled in inert or air-cooled screw coolers to below 50°C.
  6. Screening and Grinding
    • The product is sized (e.g., 8x30 mesh, 12x40) or ground to powder.
  7. Packing and Storage
    • Packed in 25–50 kg bags or jumbo bags.
    • Stored in moisture-controlled warehouse.

2.2 Simplified Process Flow Diagram (PFD)

 



2.3 Mass and Energy Balance (5,000 TPA Basis)

Input Materials:

  • Biomass Feedstock: ~15,000 tons/year (dry basis)
  • Water (for cooling & steam): ~10,000 m³/year
  • Electricity: ~500,000 kWh/year
  • Biomass fuel for dryer/boiler: ~1,000 tons/year

Output:

  • Activated Carbon: 5,000 tons/year
  • By-products: Ash, Char dust (100–300 tons/year)
  • Flue Gases: To scrubbing unit

Energy Use:

  • Thermal: ~2.5–3.5 GJ/ton of product
  • Electrical: ~100 kWh/ton of product

2.4 Process Equipment Summary (Main Units)

Equipment

Type

Quantity

Crusher

Hammer Mill

1

Dryer

Rotary/Belt

1

Carbonization Kiln

Rotary or Multi-Hearth

1

Activation Reactor

Rotary with steam inlet

1

Cooling Screw

Jacketed / water-cooled

1

Screening Machine

Vibratory

1–2

Packing Machine

Semi-auto bagging

1


2.5 Process Control Philosophy (To be detailed in Part 4)

  • Local PLC with SCADA interface
  • Temperature and flow monitoring in each stage
  • Gas analyzer for flue control
  • Manual override and alarm system

2.6 P&ID (Summary Functional Description)

P&ID to be developed in Part 3

  • All units will be equipped with:
    • Temperature sensors (RTD or thermocouple)
    • Flow sensors for steam, air, biomass
    • Pressure indicators on steam lines
    • Interlock system to prevent unsafe operations

2.7 Process Safety Features

  • Emergency vent for kiln and reactor
  • Flame arrestors on gas outlets
  • Fire suppression in dryer and carbon storage
  • Temperature interlocks and shutdown systems

2.8 Compliance and Standards

  • NFPA 86 (Ovens and Furnaces)
  • ISO 9001 for product quality
  • ISO 14001 for emissions
  • EN 746-2 for thermal processing safety

Part 3: Mechanical & Equipment Design


3.1 Major Process Equipment List

Equipment

Description

Qty

Material of Construction (MOC)

Biomass Crusher

Hammer or knife mill

1

Mild Steel (MS) with SS liners

Rotary Dryer

Direct-fired or steam indirect

1

Carbon Steel with refractory lining

Carbonization Kiln

Low-temperature rotary kiln

1

Alloy Steel, refracted

Steam Activation Reactor

Insulated rotary type

1

Stainless Steel 310/316

Cooling Conveyor

Water-jacketed screw conveyor

1

SS contact parts + MS outer shell

Screening Machine

Vibrating screen

1

SS304 in contact areas

Pulverizer / Grinder

Impact or hammer mill

1

SS304

Bagging Machine

Semi-automatic with scale

1

MS frame, SS hopper


3.2 Equipment Datasheet Summary (Example)

Equipment Name: Rotary Kiln

  • Type: Horizontal rotary, direct heating
  • Capacity: ~1 TPH char production
  • Length x Diameter: 10 m x 1.5 m
  • Rotation Speed: 0.5–1 rpm
  • MOC (Shell): Carbon Steel with 3-layer refractory lining
  • Drive System: Gear reducer with VFD
  • Temperature Range: 400–600°C
  • Insulation: Ceramic fiber + castable refractory

3.3 Equipment Layout Principles

  • Linear Process Flow: From raw material to product, minimizing cross-traffic.
  • Modular Blocks: Each 5,000 TPA line occupies ~1,200 m²
  • Isolation Zone: Thermal equipment (kiln, dryer) in separated fire-safe zone
  • Green Belt Buffer: 10% of site area for emission barrier and natural cooling

3.4 Materials of Construction (MOC)

Service Area

MOC Recommendation

Reason

Wet Biomass Handling

MS with epoxy or SS304 liners

Corrosion resistance

High Temp Kiln

Alloy Steel, Refractory Lined

Thermal and mechanical strength

Steam Lines

SS304 or Carbon Steel SCH 40

Pressure and corrosion resistance

Product Contact Area

SS304

Prevent contamination

Exhaust Ducts

Carbon Steel + paint

Non-corrosive flue gas


3.5 Civil/Structural Load Data (Preliminary)

Equipment

Operating Weight (ton)

Foundation Type

Rotary Kiln

~15 tons

RCC with vibration pads

Dryer

~10 tons

RCC slab

Steam Boiler

~20 tons

Deep RCC footing

Bagging Machine

~2 tons

Steel pedestal


3.6 Mechanical Safety Features

  • Explosion vents on drying and pyrolysis units
  • Emergency Stop Buttons at all operator points
  • Insulated and guarded rotating parts
  • Temperature interlocks on all combustion and heating systems
  • Smoke/CO detectors near pyrolysis chamber

3.7 Codes and Standards Applied

Component

Standard Applied

Pressure Vessels

ASME Sec VIII Div 1

Structural Steel

AISC / ASTM A36

Refractory Materials

API 936

Lifting Equipment

OSHA 1910, ISO 9927

General Fabrication

ISO 9001, ISO 3834 (Welding)


Part 4: Instrumentation, Electrical & Automation


4.1 Electrical Power Demand & Distribution

4.1.1 Power Load Estimation (5000 TPA Capacity)

Equipment

Rated Power (kW)

Qty

Total (kW)

Biomass Crusher

30

1

30

Dryer Blower & Drive

45

1

45

Rotary Kiln Drive

15

1

15

Activation Reactor Drive

22

1

22

Cooling Screw Drive

15

1

15

Screening + Pulverizer

30

1

30

Bagging System

5

1

5

Lighting & Auxiliaries

20

Total Installed Load (Approx.)

182 kW

4.1.2 Electrical System Architecture

  • Main Power Source: 415V, 3-phase, 50Hz (or site-specific)
  • Backup Power: Diesel Genset 250 kVA
  • Distribution: MCCs located in control room; underground armored cables
  • Protection: MCBs, MCCBs, Earth leakage detection, Surge protection

4.2 Instrumentation Architecture

4.2.1 Key Instruments by Area

Area

Instruments

Purpose

Dryer

Temp sensor, flow switch, RTD

Moisture control, safety shutdown

Kiln

Thermocouple, gas analyzer (CO, CH4)

Process monitoring, safety

Activation Reactor

Steam flowmeter, pressure switch

Process control, interlock

Cooling

Temp sensor, motor current relay

Cooling confirmation

Product Area

Weighing sensor, level switch

Packing control

General

Smoke & fire detector, emergency push

Safety

4.2.2 Instrument Specification Sample

Instrument Type: Thermocouple

  • Type: K Type, sheathed
  • Range: 0–1000°C
  • Mounting: Flanged or threaded
  • Signal Output: 4–20 mA via transmitter
  • Protection: IP65, SS304 sheath

4.3 Automation Philosophy

4.3.1 Control System Overview

  • Architecture:
    • Local PLC-based system (Siemens S7-1200 or Allen Bradley CompactLogix)
    • SCADA HMI interface (optional remote monitoring via web dashboard)
    • Hardwired ESD loop for critical interlocks
  • Control Mode:
    • Semi-automatic with operator setpoints
    • Auto-purge & startup sequences for kiln & dryer
    • Alarm management (visual + audible)

4.3.2 Sample PLC I/O List

I/O Type

Description

Qty

AI (Analog In)

Temperature, Flow, Pressure

20

AO (Analog Out)

Control valves (steam, air)

5

DI (Digital In)

Limit switches, emergency stop

30

DO (Digital Out)

Motor start, alarm indicators

30


4.4 Safety Interlocks and System Integration

4.4.1 Interlock Matrix (Sample)

Condition

Action

Dryer temp > 180°C

Dryer shutdown, alarm

Kiln gas leak detected

Fuel cutoff, ventilation on

Steam pressure drop in reactor

Reactor shutdown

Emergency stop pressed

All motors off, vents open

Fire detected in control room

Power cut to non-essential

4.4.2 Fire & Gas Safety

  • CO/CH4 detection in activation area
  • Flameproof junction boxes near hot zones
  • Fire alarm panel + smoke detector network
  • Integration to plant-wide alarm horn/siren

4.5 Relevant Standards and Codes

Category

Applicable Standards

Instrumentation

ISA S5.1, IEC 61508, IEC 61131-3

Electrical Panels

IEC 61439-1, IEC 60204-1

Automation

IEC 61131, Modbus/Profibus standards

Safety Systems

NFPA 70E, ISO 13849, IEC 61511


Part 5: Health, Safety, and Environment (HSE) & Risk Mitigation


5.1 HSE Philosophy

The HSE strategy focuses on proactive prevention of incidents through:

  • Inherently safe plant design
  • Environmental compliance with national and international regulations
  • Occupational health protection
  • Continuous risk assessment and mitigation
  • Emergency preparedness

5.2 Occupational Health & Process Safety Hazards

Hazard Area

Potential Risk

Mitigation Measures

High Temperature Units

Burns, fires, explosion

Thermal insulation, explosion vents, PPE

Steam System

Scalding, pipe bursts

Pressure relief valves, leak detection

Dust from Charcoal

Respiratory hazards, dust explosion

Dust collectors, ATEX-rated motors

Noise from Crushers

Hearing damage

Ear protection, acoustic enclosure

Slippery Floors

Falls/slips

Anti-slip coating, proper drainage

Handling Chemicals

Skin, eye irritation

SDS availability, PPE, eyewash stations


5.3 Fire and Explosion Prevention

Fire Sources

  • Biomass dust
  • Volatile gases from pyrolysis
  • Hot surfaces

Preventive Measures

  • Grounding and bonding of equipment
  • Flame arrestors and gas vents
  • Automatic fire detection system with smoke and CO sensors
  • Fire extinguishers (ABC, CO₂) located every 15 meters
  • Fire hydrant and sprinkler system in storage areas

5.4 Environmental Impact Assessment (EIA)

5.4.1 Air Emission Sources

  • Kiln flue gas (CO₂, CO, VOCs)
  • Dust from grinding and screening

Control Systems:

  • Multi-cyclone and bag filter systems
  • Scrubber for VOC neutralization
  • Chimney stack height ≥12 meters for dispersion

5.4.2 Water & Wastewater

  • No process water consumption (closed steam loop)
  • Only sanitary wastewater (treated via STP or septic)
  • No liquid effluents from production line

5.4.3 Solid Waste

Type

Source

Disposal/Reuse Method

Ash

From dryer combustion

Used as soil amendment

Reject Carbon

Oversized or under-burnt

Recycled to kiln feed

Filter Dust

Baghouse unit

Compacted and landfilled


5.5 Green Design Integration

  • Green Belt: 10–15% of site area for buffer and carbon sequestration
  • Rainwater Harvesting: For utility use and firewater storage
  • Natural Lighting and Ventilation: Reduces energy footprint
  • Low-NOx Burner Selection: For reduced air pollution

5.6 Risk Assessment (HAZOP Summary)

Node

Deviation

Consequence

Safeguards

Kiln Temperature

High Temp

Fire, equipment damage

Temp Interlock, Alarm

Steam Pressure

Low Pressure

Incomplete activation

Pressure switch, backup line

Dust Collector

Blockage

Explosion risk

DP Switch, Auto-shaking

Conveyor Motor

Overcurrent

Fire risk, shutdown

OLR, MCC trip

CO Level

Above threshold

Toxic inhalation

Gas Detector + Ventilation


5.7 Compliance Standards and References

Regulation / Standard

Area Covered

OSHA 29 CFR 1910

General workplace safety

NFPA 654, 68, 69

Dust explosion prevention

ISO 14001

Environmental management

ISO 45001

Occupational health & safety

IFC / World Bank EHS Guidelines

Air emissions, wastewater


5.8 Emergency Preparedness

  • Assembly Point: Clearly marked zones with route signage
  • Mock Drills: Quarterly simulations of fire, chemical spill, and blackout
  • Trained Response Team: Fire marshals, first aid officers
  • Emergency Shutdown Procedure: PLC logic + manual override


Part 6: Existing Reference Plants & Performance Benchmarks


6.1 Objective

This section presents validated reference plants that have successfully operated using low-temperature activation technology for biomass-based activated carbon. The aim is to benchmark operational feasibility, product quality, scalability, and sustainability.


6.2 Reference Plant #1 – EcoCarb Pvt Ltd (India)

  • Location: Gujarat, India
  • Capacity: 6,000 TPA
  • Feedstock: Coconut shell, wood chips
  • Technology: Indirect rotary kiln at 450–550°C with steam activation
  • Operation Since: 2016
  • Key Highlights:
    • Modular expansion achieved in 2021 to 12,000 TPA
    • Achieved Iodine Number: 900–1100 mg/g
    • Ash Content: <5%
    • Utilized baghouse and scrubber for emissions control
    • Carbonization and activation in same continuous unit

6.3 Reference Plant #2 – GreenCarbon Ltd (Thailand)

  • Location: Surat Thani, Thailand
  • Capacity: 10,000 TPA
  • Feedstock: Palm kernel shell (PKS)
  • Technology: Rotary reactor with low-O₂ atmosphere and steam injection
  • Operation Since: 2017
  • Key Features:
    • Integrated biomass drying using waste heat
    • Digital SCADA system controlling temperature zones
    • Product used in water filtration and gold recovery
    • Reduced CO₂ emissions by 30% using biomass-fueled boiler

6.4 Reference Plant #3 – EnviroCarb USA

  • Location: Louisiana, USA
  • Capacity: 5,000 TPA
  • Feedstock: Hardwood sawdust
  • Technology: Low-temperature microwave-assisted activation
  • Operation Since: 2018
  • Highlights:
    • Batch-based operation
    • Focus on ultra-low ash activated carbon
    • Fully automated with Modbus integration
    • Compliant with EPA emission norms

6.5 Key Performance Benchmarks

Parameter

Industry Range

Reference Target (Project)

Iodine Number

800–1200 mg/g

950–1100 mg/g

BET Surface Area

600–1200 m²/g

>1000 m²/g

Ash Content

<8%

<5%

Bulk Density

350–600 kg/m³

400–500 kg/m³

Moisture Content

<10%

<7%

VOC Emissions

<50 mg/Nm³

<30 mg/Nm³

Plant Availability

>90%

Target 92–95%

Specific Energy Use

0.7–1.2 kWh/kg

~0.95 kWh/kg


6.6 Lessons Learned from Operational Plants

  • Steam quality significantly impacts activation consistency; use of saturated steam >4 bar is optimal.
  • Modular design (multi-kiln) supports easier maintenance and staggered production.
  • Dust control and fugitive emissions require rigorous filter maintenance.
  • Automation reduces labor costs and enhances product repeatability.
  • Use of waste heat recovery improves thermal efficiency and plant economics.

6.7 Takeaways for FEED Development

  • Proven technology with more than 5 years of operation in tropical and industrial settings
  • Viability of multiple biomass types as feedstock
  • Effective scalability from 5,000 to 30,000 TPA via parallel line expansion
  • Compliance with environmental and product quality standards achievable with current systems

If desired, a field visit or virtual benchmarking with these plants can be arranged as part of the detailed engineering phase or investor due diligence.


7.1 Reference Standards Utilized

Standard Organization

Standard Name / Number

Scope of Application

ASTM International

ASTM D2866, D4607, D1762-84

Moisture, Iodine Number, Activation Specs

ISO

ISO 14001, 45001

Environmental & Occupational Safety Mgmt.

ASME

ASME B31.3

Process Piping

API

API 650, 661

Storage Tanks, Heat Exchangers

NFPA

NFPA 68, 69

Dust Explosion Prevention

IEC

IEC 61511

Safety Instrumented Systems (SIS)

IFC / World Bank

EHS Guidelines

Emission, Effluent, and Worker Safety


7.2 Scientific Literature and Engineering Data

  1. Activated Carbon: Production, Properties and Applications
    • Marsh, H., & Rodriguez-Reinoso, F. (Elsevier Science)
    • Technical foundation of carbon microstructure and pore development.
  2. Biomass-Based Activated Carbon: A Review
  3. Design Considerations for Steam Activation Process
    • International Journal of Chemical Reactor Engineering
    • Thermodynamics of low-temp activation and steam reactivity.
  4. Charcoal & Carbonization Handbook (FAO Document)
    • FAO.org
    • Guidelines on biomass selection and conversion techniques.

7.3 Engineering Tools & Software Used

Tool

Purpose

Aspen Plus

Process simulation and material balance

AutoCAD & Plant 3D

2D/3D layout and P&ID development

Microsoft Excel

Heat & mass balance calculations

HAZOP Manager

Safety and operability studies

COMSOL Multiphysics

Heat transfer simulation (Kiln zone)

SketchUp & Photoshop

Plant visualization and cover rendering


7.4 Industrial Supplier and Technology Benchmark Sources

  1. Jacobi Carbons (Sweden)
  2. Carbon Activated Corp (USA)
  3. ECOMAX Carbon (India)
  4. EnviroSorb Technologies (USA)

7.5 Government Regulations Consulted

  • Indonesia Ministry of Environment & Forestry (KLHK)
    • Regulation No. P.12/Menlhk/Setjen/Kum.1/4/2019 – Emission standards
    • Regulation No. 56/M-IND/PER/11/2006 – Industrial Safety and Health
  • EPA USA
    • Title 40 – Protection of Environment
  • ILO & WHO
    • Industrial hygiene and chemical exposure guidelines

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