Anaerobic Co-Digestion System

At the heart of Dar Eco Circular’s Integrated Waste Facility (IWF) lies the
Anaerobic Co-Digestion (ACoD) System—a fusion of advanced Mechanical-Biological Treatment (MBT)
and BTA® anaerobic digestion technology. This system turns organic waste and faecal sludge into
clean energy, fertilizers, and industrial inputs, transforming Dar es Salaam’s waste crisis into
a launchpad for climate resilience, green industry, and food security.

🌍 Introduction to Integrated Biological Systems

Dar es Salaam faces overloaded landfills, untreated sludge, and minimal recycling.
The ACoD System introduces Urban MBT + Co-Digestion Hubs, powered by proven German technology,
designed for modularity and scalability across Africa.

🚫 Diverts 80–90% of organics away from landfills
🌱 Avoids 3.5 million+ tCO₂e annually by capturing methane
⚡ Generates renewable biogas, RDF, and fertilizers
🏘️ Frees up 130+ acres of urban land at Pugu for housing & greenspace
🌍 Positions Dar es Salaam as an African leader in circular infrastructure

♻️ Mechanical-Biological Treatment (MBT)

Technology Partner: Eggersmann Group (Germany)

Eggersmann’s FUEL® and CONVAERO® systems stabilize organic waste, recover recyclables, and produce
Refuse-Derived Fuel (RDF) for industries like cement and WtE.

System Workflow

Pre-shredding & volume reduction
Aerobic drying in CONVAERO® tunnels
Optical & magnetic sorting for recyclables
RDF production for industry
Stabilized compost feedstock for co-digestion

✅ Enables fossil fuel substitution, ✅ reduces landfill emissions by 90%,
✅ reclaims sites like Pugu Landfill for housing.

⚡ Anaerobic Co-Digestion (ACoD)

Technology Partner: BTA International GmbH (Germany)

Using wet digestion + Thermal Hydrolysis (THP), BTA’s technology co-digests food waste, sludge,
and effluents to deliver high biogas yields and pathogen-free biosolids.

System Workflow

Wet Pre-treatment: grit removal & homogenization
Anaerobic Digestion: sealed digesters capture biogas
Biogas Use: CHP, CBG for buses, grid injection
Digestate Use: fertilizer, soil conditioners, green bricks

🌱 Value: Turns sludge into fertilizer, supports food resilience, reduces fuel imports, and
strengthens sanitation in flood-prone zones.

🔬 The BTA® Anaerobic Co-Digestion Process

The BTA® Process is at the heart of Dar Eco Circular’s Anaerobic Co-Digestion System, representing one of the most advanced biological waste treatment solutions globally.

At its core, the process consists of two essential stages:

Hydro-mechanical pre-treatment → Separates contaminants (plastics, metals, inerts) and homogenizes organic waste into a clean suspension suitable for digestion.
Wet Anaerobic Digestion → The pre-treated suspension is fed into sealed digesters where biogas is generated under controlled mesophilic or thermophilic conditions.

Yet, a full-scale BTA® Plant incorporates further critical processes to maximize efficiency, stability, and sustainability:

Solid–Liquid Separation → Digestate is separated into a nutrient-rich liquid fraction (for fertilizer and irrigation) and a stabilized solid fraction (usable as compost, soil conditioner, or construction input).
Process Water Management → Internal water recycling minimizes fresh water demand, reduces effluent discharge, and ensures closed-loop resource use.

📊 See Fig. 1 for schematic representation of the BTA® Process.

🎥 Watch the BTA® Process in Action

Together, these steps enable the conversion of complex waste streams—including food waste, faecal sludge, and high-COD industrial effluents—into renewable energy, fertilizers, and safe biosolids, while ensuring high environmental performance and alignment with IFC and AfDB sustainability standards.

🏗️ Deployment Model: Circular Infrastructure Anchors

Facility	Municipal Zone	Core Tech	Functions
Pugu Kinyamwezi	Ilala/Temeke	MBT	Landfill reclamation, RDF, compost
Vingunguti	Ilala/CBD	ACoD	Septage digestion, mini-grid biogas
Pemba Mnazi (SEZ)	Kigamboni	MBT + ACoD + WtE	Industrial RDF, THP, fertilizer hub

⚡ Modular, scalable, and aligned with SEZ & Smart City plans.

🌐 Global Benchmarking & Local Innovation

Global Inspiration

🇫🇮 Lohja, Finland → ACoD of MSW & sludge → inspires Pugu landfill reclamation
🇸🇪 Skövde, Sweden → Biogas + WtE district heating → informs Vingunguti hub
🇮🇶 Ecocem, Iraq → RDF via Eggersmann MBT → guides Pemba Mnazi industrial feed

Dar’s Local Innovations

📦 Containerized ACoD modules for dense zones
⚡ Mini-grid integration with surplus biogas
🌱 Urban biofertilizer loop → supporting urban farms & agroforestry

🌟 Strategic Benefits

Climate: 3.5M+ tCO₂e avoided annually; carbon credit ready
Energy: Biogas & CBG offset LPG/diesel imports
Food Security: 20,000+ tonnes/year of local fertilizer
Urban Resilience: Land reclaimed for housing & greenspace
Industry: RDF replaces coal, biosolids → bricks
Jobs: 1,000+ green jobs & SME opportunities

🚀 From Crisis to Catalyst

The Anaerobic Co-Digestion System is more than waste treatment—it’s a
visionary leap for Dar es Salaam. By combining MBT, ACoD, and WtE, the city will: