Biogas Residue Fertilizer

OFEC provides complete equipment and process solutions for the resource utilization of biogas residue, transforming it into marketable organic fertilizer. With capacities ranging from 0.5 to 30 tons per hour, our solutions are scalable to suit everything from small pilot plants to large-scale industrial production.

As biogas projects expand worldwide, the treatment and resource utilization of biogas residue have become a key industry focus. Converting biogas residue – a by‑product of anaerobic digestion – into commercial organic fertilizer not only solves the disposal challenge but also creates a new revenue stream for biogas plant operators.

Industry Overview

Biogas residue fertilizer is the solid remnant left after biogas fermentation. It is rich in organic matter, humic acid, nitrogen, phosphorus, potassium, and a wide range of micronutrients. Typically, biogas residue contains 30%–50% organic matter, 10%–20% humic acid, 0.8%–2.0% total nitrogen, 0.4%–1.2% total phosphorus, and 0–2.0% total potassium. In addition, it provides essential trace elements such as zinc, selenium, magnesium, various amino acids, vitamins, auxins, and multiple active enzymes – all of which are readily absorbed by plants.
Moreover, biogas residue harbors beneficial microorganisms including indoleacetic acid producers, lactic acid bacteria, Bacillus spp., and gibberellin‑producing strains. These microbes promote plant growth, suppress pathogens, and eliminate pest eggs, making biogas residue both a fertilizer and a biological pesticide.

Biogas residue organic fertilizer is a full‑nutrient fertilizer, rich in organic matter, N‑P‑K, secondary and micronutrients, organic compounds, and beneficial microbes. It offers both rapid and sustained nutrient release, making it superior to chemical fertilizers in multiple ways.

Typical Process Flow

Industrial biogas residue fertilizer production typically follows this standard process:

Raw Material Collection → Dewatering Pre‑treatment → Crushing → Batching & Mixing → Granulation → Drying & Cooling → Screening → Coating (Optional) → Packaging & Storage

Process Stage Breakdown:

Stage	Core Task	Key Equipment
Raw Material Collection	Collection, dewatering, and storage of biogas residue	Conveying systems, storage bins
Dewatering Pre‑treatment	Reducing moisture content to suitable processing range	Solid‑liquid separator, dewatering unit
Crushing	Reducing lumps to optimal particle size	Semi-wet material crusher
Batching & Mixing	Adding auxiliary materials based on residue characteristics, thorough blending	Batching system, twin‑shaft mixer
Granulation	Forming powder materials into uniform pellets	Drum / disc granulator
Drying & Cooling	Reducing pellet moisture content to safe storage levels	Rotary dryer, cooler
Screening	Separating finished pellets from returns	Trommel screener
Coating	Anti-caking or functional coating treatment (optional)	Coating machine
Packaging & Storage	Automatic weighing, bagging, and palletizing	Automatic packaging machine, palletizing system

Stage

Core Task

Key Equipment

Raw Material Collection

Collection, dewatering, and storage of biogas residue

Conveying systems, storage bins

Dewatering Pre‑treatment

Reducing moisture content to suitable processing range

Solid‑liquid separator, dewatering unit

Crushing

Reducing lumps to optimal particle size

Semi-wet material crusher

Batching & Mixing

Adding auxiliary materials based on residue characteristics, thorough blending

Batching system, twin‑shaft mixer

Granulation

Forming powder materials into uniform pellets

Drum / disc granulator

Drying & Cooling

Reducing pellet moisture content to safe storage levels

Rotary dryer, cooler

Screening

Separating finished pellets from returns

Trommel screener

Coating

Anti-caking or functional coating treatment (optional)

Coating machine

Packaging & Storage

Automatic weighing, bagging, and palletizing

Automatic packaging machine, palletizing system

OFEC Production Line Solutions

OFEC offers two mainstream granulation lines with complete equipment and process solutions for biogas residue fertilizer production, covering all core processes from raw material handling to finished product packaging. For smaller-scale investors, we also provide the E1 Fertilizer Production Station – a compact, combined granulation line.