The fruity aroma of success

• French fruit wholesaler and marketer turns its 1 800 tonne-a-year headache into an efficient biogas energy and heat plant
• Energy independence, co-generation potential, fertiliser for farms, partnerships with neighbouring companies, and more

Boyer SAS is fresh fruit giant, marketing melons, plums, grapes, cherries and exotic fruits. With an output of around 20 000 tonnes per year, it is one of the main French operators in the melon sector, which it markets under the Philibon brand. With such high volumes, damage and waste are a constant challenge. 

During packing operations, Boyer SAS was forced to discard nearly 1 800 tonnes a year of non-compliant fruits; too small, too big, deformed or rotten. In 2008, the company started looking into building an anaerobic 'digestion unit' on-site to treat fruit waste. After carrying out a feasibility study, the unit was built and put into service at the end of 2011.

Of the roughly 2 700 tonnes of fruit waste going into the unit annualy, two-thirds comes from the Boyer plant (1 800 tonnes) and one-third is supplied by neighbouring fruit stations (900 tonnes). The waste is pitted, crushed and then treated in a 400 m3 liquefier before being transferred to a 55 m3 digester, where the material is heated and further broken down, producing biogas.

Key benefits

The biogas generated from the waste material fires a 100 kWe co-generation engine that produces electricity (about 1.7 MWh per year sold to EDF and fed back into the grid) and heat (about 1.6 MWh per year). In addition to biogas, the unit also produces organic matter that can be reused as fertiliser; 300 tonnes is produced a year which is re-used as fertiliser by local fruit farms. This recovery process produces enough heat to keep the digester at a optimal temperature and supplies hot water for washing the equipment.

Anaerobic digestion has several advantages for farms and agri-food industries: revenues from the sale of electricity and coverage of own-energy needs to offset volatile energy prices. Fruit and vegetable packing sites have certain advantages (variety and quantity of supply) that make them attractive targets for installing units such as Boyer's.