Glass-fused-to-steel tanks adopting the CSTR biogas digester have recently been put into operation at a livestock farm in Morocco

Recently, complete-set GFS (Glass-Fused-to-Steel) bolted tank equipment made in China has been successfully applied to a large-scale livestock farm project in Morocco. Adopting the CSTR (Continuous Stirred-Tank Reactor) process, the whole system is specially designed to treat high-strength organic wastewater mainly composed of livestock manure.

The large-scale livestock breeding industry in North Africa’s Morocco continues to expand. Breeding operations generate substantial volumes of high-strength agricultural organic wastewater, including manure and washing effluent. Discharge without effective treatment will trigger environmental problems such as water pollution and soil salinization. Local authorities are actively promoting the resource utilization of agricultural waste and encouraging the adoption of anaerobic digestion technology to convert livestock waste into biogas energy and organic fertilizer.

The project adopts GFS bolted enamel tanks as the main reactor for CSTR anaerobic digestion. Steel plates of the tank are coated with enamel glaze through high-temperature sintering, which resists corrosion by organic acids and hydrogen sulfide generated during anaerobic digestion. Featuring a modular bolted assembly structure, the tanks adapt to local construction conditions in North Africa and shorten on-site installation time.

The system is equipped with pretreatment units, agitators and double-membrane gas holders. After pretreatment, manure-laden wastewater flows into the CSTR reactor. Thorough mixing enables full contact between microorganisms and wastewater feedstock, degrading COD in the water and achieving pollutant reduction.

Biogas produced from fermentation can supply internal heating for the livestock farm. Digested sludge and digestate liquor after fermentation can be processed into organic fertilizer for field application, realizing the integration of “pollution treatment, energy recovery and circular agriculture”.

North Africa presents distinctive operational challenges: large diurnal temperature variations, intense ultraviolet radiation, and salt-spray corrosion in some areas. These impose stringent requirements on the weather resistance of the enamel glaze of GFS tanks and the anti-aging performance of sealing gaskets. During the project design phase, anti-corrosion and sealing configurations were optimized to adapt to local climatic conditions. Meanwhile, air-tightness control of the biogas system was strengthened to comply with overseas safety and environmental regulations.

Industry sources indicate that the market for livestock manure resource utilization in North Africa is gradually expanding. Demand for similar agricultural organic wastewater and biogas projects keeps rising in Algeria, Tunisia and other countries. Chinese-manufactured GFS bolted enamel tanks combined with the CSTR anaerobic process enjoy broad market prospects in Africa’s agricultural environmental-protection sector.