Reducing dairy effluent treatment costs and environmental impacts
The dairy sector is facing pressure to cut costs and to restrict its environmental footprint. Clearfleau's high-rate anaerobic digestion systems reduce costs and the environmental impact, by dealing more effectively with liquid effluents such as:
- Trade effluent (white water) from production
- Wash down residues and reject products
- Waste flows containing excess dairy fats
- By-products, such as whey or permeate
In 2008, Clearfleau secured an Environmental Transformation Fund (ETF) demonstration project with BV Dairy in Dorset. The anaerobic digestion plant, completed in Autumn 2010, processes the liquid dairy waste streams that were previously discharged to sewer or hauled off site. It will produce a significant proportion of BV Dairy’s energy needs (heat and power).
The plant has been built adjacent to the dairy and will treat up to 60,000m3 per year. It will cut on-site electricity bills by 60%, reducing BV Dairy’s carbon footprint by over 50%. The plant is a demonstration site for the dairy sector and food industry.
Prior to construction Clearfleau operated its mobile trial unit on the BV Dairy site as part of the final design phase. This achieved excellent biogas production and a reduction of feedstock COD from about 30,000 mg/l to less than 300 mg/l. This performance has been replicated in the operation of the full scale plant.
Liquid anaerobic digestion can be integrated with existing treatment systems. Details on the flows and loads is used to evaluate biogas and payback potential. It is also possible to assess effectiveness on your site with our mobile trials unit. Possible financial benefits include:
- Reduced costs for sewer discharge and off-site waste disposal
- Revenue from FITs and the RHI for on-site energy generation
- Reduced costs for purchase of electricity and other fossil fuels
- For some sites, tax savings from reducing the carbon footprint
Consequently anaerobic digestion plants that can be tailored to the specific feedstocks on individual sites are revenue generating. A number of UK dairy companies are considering on-site effluent treatment. They are looking to generate renewable energy and in due course reduce carbon tax obligations.
UK Integrated Pollution Prevention and Control regulations (IPPC) require companies to make continual improvements in environmental practices. ISO 14001 requires periodic environmental audits. The dairy sector is being encouraged to reduce net energy consumption and limit its overall carbon footprint. Generating energy from waste is eligible for Enhanced Capital Allowances (ECAs).
