Ensure compliance and avoid environmental penalties and charges with the right waste oil recovery system, says Robert Brocklesby.
06 January 2020 | Robert Brocklesby
Removing used unwanted cooking fats, oil and greases (FOGs) from the manufacturing process can get messy - practically, environmentally and financially.
Industrial contamination of wastewater with used FOGs is a significant problem. While collection tanks can take away most FOGs, they still seep into drains at many sites, contaminating the waterways - a big environmental no-no for the water companies and it can be bad for your business, corporate social responsibility (CSR) and the environment.
Penalties will follow
When contamination occurs owing to the accumulation of FOGs in drains, waterways get blocked. When wastewater is unable to flow freely through the sewer network to make it to the wastewater treatment works, it can overflow and back up through storm drains, into streets and even into homes.
In England and Wales, it is an offence to cause or knowingly permit a water discharge activity unless you are complying with an environmental permit or exemption.
An environmental permit issued by the Environment Agency provides a consent level for the quantity of FOGs allowed to go through the drains.
Companies must comply with the permit and all the conditions. Breaching the consent levels can result in heavy fines and, in some cases, imprisonment.
While FOGs in a wastewater system are a big problem, there are methods available to trap and recover them.
FOG recovery systems
The collection of unwanted FOGs at the source can contribute significantly to their collection and impact on the wastewater system. It is also the most cost-effective option for FOGs recovery.
Oil recovery systems and specialist equipment installed on site can trap FOGs.
The equipment and systems each site needs for effective collection must be appropriate, not only for the location of the problem but also for the types of products that are being manufactured and the different FOGs being used in their cooking process. FOGs for frying crisps needs to be trapped and collected by a different system from FOGs used in bacon production.
Every FOGs recovery system is tailored to each manufacturing and processing site. This is necessary to make sure that the right recovery system is installed and located right at the source of the issue to guarantee the removal of FOGs, reassuring the customer that it is compliant and meeting its required consent levels.
Oil recovery systems work differently, depending on the action required:
- Just to recover liquid oils;
- Remove oils and fats with some solids; and
- Removing harder fats.
The weather can also have a big impact, as FOGs tend to harden during the winter. Recovery systems are designed to work in extremes of hot and cold and are engineered to recover FOGs through all environments.
Each recovery system is engineered to be long-lasting and low-maintenance, demanding minimal power while providing a low-cost solution. They all work differently, but in principle each system will remove unwanted FOGs from wastewater and reduce the risk of contamination.
Installation and collection
Depending on client needs and site-specific problems, a bespoke system will need to be installed, ranging from skimmers to large-scale oil recovery systems. The equipment is installed with appropriate oil collection tanks provided on site.
A skimmer is a special material on a rope or belt that is placed into the recovery point such as a tank or drain. The skimmer attracts FOGs at the top while rejecting the water. The FOGs are then scraped off and deposited into a collection vessel for recovery.
FOGs recovered in the tanks are monitored and once the tanks are full, all material recovered is recycled and blended into feedstock for biofuel, creating a sustainable solution for waste.
Each litre of biofuel produced from waste saves about 2.8kg of carbon. These systems enable manufacturing processes to be more sustainable, reduce operating costs and landfill use, keep sites and waterways clear and improve a company's CSR.
Robert Brocklesby is managing director at Brocklesby Ltd