• Home
• Engineering
• Production
• Materials
• News Room
• Contact

DP Seals puts the
bubbles back into
anaerobic digestion

Anaerobic digestion is the natural breakdown of organic materials into methane, carbon dioxide gas and fertiliser. As part of an integrated waste management system, it reduces landfill gas emission into the atmosphere and, because it produces a biogas rich in methane and carbon dioxide, offers a renewable energy source to replace fossil fuels.

A typical anaerobic digester is a sealed vessel, or series of vessels, in which bacteria act without oxygen on organic feedstock that needs to be fully mixed and warmed, usually to blood temperature. Systems are either batch or continuous; regardless of type, most rely on mechanical stirring to promote digestion. British engineer Christopher Maltin and his team at Organic Power in Somerset developed a new process offering significant advantages over previous technologies for treating organic wastes.

The GALAD™ System is based on the Maltin® System, which has specially shaped, low energy tanks that have no moving parts, thus ensuring more complete digestion with lower running and maintenance costs. Using tanks in series allows a continuous process, ensuring all feedstock is properly digested, producing maximum energy, and eliminating pathogens from the output.

Patented tank shape
The Maltin System’s patented tank shape promotes thorough and continuous mixing with minimum use of energy whilst ensuring all organic material is available for digestion all the time. The shape creates an inverted V along the centre of the tank where a curtain of gas bubbles provides stirring, ensuring any moving parts are external to the tank for easy maintenance. Heating only needs to be applied at points where it increases circulation within the tank.

Utilising a series of tanks facilitates different families of bacteria establishing themselves more quickly whilst the fluid dynamics within each tank ensure plug flow through the system so that each stage of the process, with different bacteria, has time to be completed.

The tanks and pipes are usually made of recycled high-density polyethylene - which is also fully recyclable. These materials completely eliminate corrosion caused by the hydrogen sulphide generated during anaerobic digestion.

Applications C & C Green Energy’s GALAD System can be used to:
	Treat a very wide range of organic wastes: solid or liquid domestic and industrial organic wastes – even abattoir waste – food processing residues, agricultural slurries and for cleaning process water
	Convert specially grown energy crops into biogas
	Generate and upgrade biogas to biomethane for vehicle fuel
	Create clean fertiliser and soil conditioner
	Create food quality or solvent quality renewable carbon dioxide gas
	Create renewable materials, such as wood substitutes that are better than MDF