Efficient solutions for turning liquid waste into energy with anaerobic digestion

Wastewater treatment plants, dairy farms, abattoirs and food processing plants have considerable liquid waste streams, often with a significant organic proportion. These businesses can considerably cut down on their electricity and heating costs by turning this waste into power.

Modern technology and equipment achieve better results than ever before. Hurll Nu-Way offers efficient solutions for turning liquid waste (sludge) into electricity by anaerobic digestion.

Thickened sludge is heated either with a heat exchanger or directly in the anaerobic digester. With the help of a sludge pump, the sludge is kept circulating for maintaining the optimum temperature. Sludge is renewed either constantly at small rates or in a batch process; then, after a specified retention time, the digestate goes into the storage.

Sliding vane compressors are used in the best-practice mixing methods for continuous unconfined gas mixing of the sludge. In these methods, the gas produced by the heated sludge is compressed by the sliding-vane compressor skid and feeds the biogas at high pressure to the gas diffusing system, placed on the bottom of the digester. The gas creates a large-scale mixing pattern in the digester, providing homogenous mixing to the sludge.

Unlike with Lance styles of gas injection, no dead spots within the tank are present, resulting in no sedimentation build-up and no pipe blockage. This method is said to offer the most reliable and efficient mixing, warranting high yields of biogas and pacification of volatile organic compounds.

Generated biogas is transferred to the storage, which is kept pressurised with help of air blowers. Typically, the excess gas can be flared. A better solution is to utilise it for heat and power generation. In this scenario, biogas is sent to a combined heat and power unit (CHP) via the gas boosters.

The CHP engine converts gas into heat and electricity, which can be used on-site to cover the company’s demand or even sold to the grid, depending on the size of the unit and the quantity of biogas produced. An integrated boiler/burner system is typically supplied as an auxiliary heating system for backup purposes.

Hurll Nu-Way offers quality equipment (with reference sites utilising this equipment throughout the world), allowing the turning of waste into power and reducing emissions of landfill gas into atmosphere, all with fast return on investment