Digestion of bread left-overs in an Amsterdam neighbourhood (Kolenkitbuurt)

In the Amsterdam neighbourhood of Kolenkit a large part of the population is Muslim. Due to cultural and religious reasons these people are not considering their bread left-overs as waste. Instead there is a strong wish to value to bread left-overs in some way. In their words “the bread should be given back to the earth”. In reality this resulted in feeding of pigeons which attracted also seagulls and rats to the neighbourhood.[expand]

The community of Amsterdam decided to collect left-over bread in special “bread containers”. However, no useful and commonly accepted use of the bread left-overs was found. So after collection, it was still processed together with the “normal garbage”. An artists collective, the Pink Pony Express,  started working on this problem. They collected left-over bread and used these in an exhibition in the Kolenkit neighbourhood in 2012/2013 (left picture). Using a demonstration reactor of Enki Energy, the Pink Pony Express showed the conversion of bread into biogas is the best use for bread left-overs. The biogas produced during the exhibition was used for cooking and roasting marshmallows.

The exhibition was a huge success. Therefore, it was decided to continue the cooperation with the inhabitants, Pink Pony Express, Cascoland (artists collective) en Amsterdam Energie (local energy cooperation) and to place a pilot reactor in a house in Amsterdam Kolenkitbuurt (mid-left picture). The use of the house was provided by Rochdale, a housing association. This initiative, with the name Gascoland, has officially been opened in March 2014 (mid-right picture). The gas produced by the reactor has been used for cooking in a community kitchen (right picture).[/expand]

broodvergister[1]Vergister AmsterdamLocatie broodvergister AmsterdamBroodvergister keuken

Hotel-restaurant Van der Valk, Cuijk (Hotel Cuijk)

During the preparation of food Swillgasser enkiin kitchens of restaurants, a considerable amount of food waste remains. This waste, together with the leftovers of the meals, is called swill. Enki Energy has performed research and development on swill digestion for over three years and optimized the digestion process of swill. [expand]

The R&D activities have resulted in a very specific, active, culture of micro-organisms, which is able to process swill in a very fast way and generating biogas with a high percentage of methane. Besides a watery fraction is generated, which can be flushed to the drainage. A patented process technology is developed to digest the swill. In cooperation with Huisman Etech Experts (Druten, the Netherlands) this process technology has been introduced in a compact digester, called the Swillgasser . The first Swillgasser has been operational for over 6 years now at Hotel Cuijk and has produced a large volume of biogas.

Sustainable entrepreneurship is an important business objective of Hotel Cuijk. The control of the environmental impact of the hotel plays the main role. The management and all employees are responsible for this. To implement this business objective follows the guidelines of the Green Key Hotel Cuijck, an European recognized certification of the quality mark Foundation for environment, safety and quality. (website Hotel Cuijk) [/expand]


Palm Oil Mill Effluent

Palm oil is an edible vegetable oil. Palm oil and palm kernel oil based ingredients are present in approx. 50% of products on the shelves in supermarkets. These include both food and non-food products.  During extraction of the oil, huge amounts of water are used. In the end this results in large amounts of waste water. This waste water is an environmental hazard. [expand]

Palm Oil Mill Effluent(POME), the watery waste stream from palm oil mills contains high amounts of organic material (COD: 50,000-100,000 mg/l). Currently POME is kept in large basins (lagoons) where it is slowly concerted in methane and CO2 through microbial activity (left picture). The CO2 and methane escape into the atmosphere and especially methane contributes largely to global warming. Besides their detrimental effects on the climate, the lagoons are also take up lots of space.

Enki Energy developed a tank reactor concept (right picture) to treat the POME fast and completely. The products of the process are water and biogas. The energy of the biogas can be used for production of electricity and heat. Atmospheric emission of methane is no longer the case.

The first test reactor is placed at a Palm Oil Mill in Colombia.[/expand]

Vervuilde basin ColombiaEnki reactor vergister








 Unox & HydroBusiness

Unox, a brand of Unilever which produces soups and sausages, is always looking for improvements in their production process. Reduction of the waste(water) stream can be one aspect of improvement.[expand] Enki Energy studied the possibilities for anaerobic biological treatment of Unox’ wastewater, which contains considerable amounts of lipids. Experiments by Enki Energy  showed that the degree of pollution could be decreased significantly by anaerobic digestion. Anaerobic digestion yields biogas, which can be used as a sustainable fuel. Anaerobic biological treatment can thus make the production process more sustainable and reduce costs for energy supply. [/expand]


Van Raaij Biological Chicory

In the cultivation of chicory (witlof), the roots remain as a waste product. These chicory roots turn out to be digestible anaerobically very well by bacteria that were grown for this purpose by Enki Energy. [expand] After a orientating study and a follow-up yielding positive results, currently a digester has been designed. Special attention is paid to local reuse of all leftovers after anaerobic digestion. The generated biogas, process water and digestate will all be reused locally.[/expand]

WWTP Nijmegen

Wastewater treatment plants receive a lot of floating fatty material, delivered by the wastewater. The water board “Rivierenland” asked Enki Energy to study the possibilities to treat this material biologically under anaerobic circumstances. [expand] Enki Energy cultivated a microbial population in the lab that is very well suitable to treat the greasy material. This process yields biogas and raw materials that can be used in other wastewater treatment processes. Using the bacteria grown enables the water board to optimise the treatment process.[/expand]