Slow Pyrolysis

The Gold Standard Method for Producing High-Carbon, High-Quality Biochar

Slow pyrolysis is the most effective and scientifically recognized method for creating premium-grade biochar. Unlike fast pyrolysis which is designed to maximize bio-oil slow pyrolysis focuses on producing stable carbon, consistent structure, and deep pore formation. These characteristics make slow-pyrolysis biochar ideal for soil health, water filtration, aquaculture, and long-term carbon sequestration.

At Chitosan Global, all our biochar products Powder, Small, Medium, Chip, and 8″ Biochar Socks come from controlled slow pyrolysis to ensure maximum purity, stability, and performance.

What Is Pyrolysis?

Pyrolysis is a thermal process in which biomass (such as wood, plant material, or agricultural residues) is heated in an oxygen-deprived environment. Without oxygen, the material does not burn. Instead, it breaks down into:

• Biochar (solid carbon)

• Bio-oil (liquid condensate)

• Syngas (combustible gas)

The ratio of these outputs depends entirely on temperature, heating rate, and retention time.

What Makes Slow Pyrolysis Different?

Slow pyrolysis involves gradual heating at moderate temperatures, allowing the biomass to convert into dense, stable carbon.

Typical Temperature Range:

350°C – 700°C (662°F – 1292°F)

Heating Rate:

Slow and controlled (not rapid)

Retention Time:

Longer holding time ensures complete carbonization

Primary Product:

High-quality biochar with a consistent pore structure

Because the process is gradual, the carbon remains intact and develops deeper, more complex pores — ideal for nutrient retention, microbial colonization, and filtration.

Slow vs Fast Pyrolysis (Clear Comparison)

Slow pyrolysis produces superior biochar purer, more porous, and more stable.

Why Slow Pyrolysis Biochar Is Better

1. Higher Carbon Content

Slow pyrolysis retains more carbon, which increases biochar performance in soil and water.

2. More Porous Structure

Longer heating creates microscopic tunnels that store nutrients, beneficial bacteria, and water.

3. Greater Stability (100+ Years)

Biochar from slow pyrolysis does not break down quickly, making it ideal for long-term carbon sequestration.

4. Lower Volatile Compounds

Reduces smoke, odor, and unnecessary contaminants.

5. Better for Soil & Water Applications

Because of its consistency and purity.

How Slow Pyrolysis Works (Step-by-Step)

Step 1: Biomass Selection

Hardwood, agricultural waste, or plant residue is chosen for its moisture level and density.

Step 2: Drying Phase

Material is heated to remove moisture without burning.

Step 3: Torrefaction Begins

Biomass begins decomposing at low temperature, releasing vapors.

Step 4: Carbonization Phase (350–700°C)

Temperature increases slowly in an oxygen-limited chamber.
This is where stable carbon forms.

Step 5: Pore Formation

Internal structures expand and become porous the key benefit for soil and water health.

Step 6: Cooling in a Controlled Environment

Biochar must cool without oxygen exposure to prevent accidental ignition.

Step 7: Screening & Grading

Biochar is processed into multiple grades:

• Powder (“Baking Flour” Grade)

• Small (Grain of Sand)

• Medium (Grain of Rice)

• Chip (1″ size)

• Biochar Socks for algae treatment

Environmental Benefits of Slow Pyrolysis

Carbon Sequestration

Slow pyrolysis locks carbon into a stable form for hundreds to thousands of years, helping reduce CO₂ in the atmosphere.

Low Emissions

Because oxygen is limited, emissions are significantly reduced compared to burning.

Waste Reduction

Transforms agricultural waste into a valuable environmental tool.

Improved Sustainability

A clean, circular process that supports regenerative farming and ecological restoration.

Why We Use Slow Pyrolysis at Chitosan Global

We choose slow pyrolysis because it produces the highest-quality biochar for all applications, including:

• Soil restoration

• Garden and farm productivity

• Water filtration

• Aquaculture

• Pond and lake clarity

• Algae reduction

• Heavy metal absorption

• Environmental cleanup & remediation

Every batch is monitored for:

• Carbon percentage

• Pore consistency

• Moisture level

• Ash content

• Stability

• Purity

This guarantees professional, dependable biochar no matter the grade you purchase.

Products Made Using Slow Pyrolysis

Below are the biochar types we produce from slow pyrolysis:

Biochar Powder – Baking Flour Grade

Ideal for composting, seed mixes, gardens, and soil microbe activation.

Small Biochar – Grain of Sand Size

Best for raised beds, gardens, vineyards, and soil health improvement.

Medium Biochar – Grain of Rice Size

Used widely on farms, orchards, landscaping, and large fields.

Biochar Chip – 1″ Size

Perfect for filtration, ponds, water treatment, and drainage.

8″ Diameter Biochar Socks – Algae Treatment

Designed to remove phosphorus, nitrogen, toxins, and suspended solids.

Slow pyrolysis is the highest-quality, most reliable method for producing premium biochar. Through gradual heating and controlled carbonization, it creates a clean, stable, porous carbon structure that delivers unmatched performance in both soil and water environments.

For agriculture, aquaculture, ponds, restoration, or large-scale environmental projects slow-pyrolysis biochar is the superior choice.