High Solids Anaerobic Digestion and Composting of Food Waste: Turning Earth’s Aikan Technology


Turning Earth uses Aikan™ High Solids Anaerobic Digestion (HSAD) Technology to convert organics into renewable energy. Anaerobic digestion is a biological process that occurs in the absence of oxygen. Anaerobic microbes consume organic matter, eventually converting what they consume into a methane rich biogas.

Aikan’s unique three step integrated HSAD and in-vessel composting (IVC) technology allows for batch processing of waste, producing biogas and compost, without moving the solid waste fraction.  Aikan technology provides the most elegant, flexible and integrated solution to converting organic waste into high quality biogas and compost.  Here is how it works.

An Aikan system is laid out in such a way that it physically separates hydrolysis (“leaching out”) and methane generation, the two main processes that constitute what is generally known as high solids anaerobic digestion.

The performance of an Aikan system relies on the following 3 steps:

Hydrolysis: Inside the process module fresh waste is sprayed with degasified percolatedrawn from the biogasreactor. This induces bacterial hydrolysis, leaching out fatty acids. Percolate is drained from the bottom of the process module, effectively separating the waste into dry and wet fractions.
Methane Generation: The wet fraction (the percolate), with its content of fatty acids, is pumped back to the gas reactor where methane generation takes place, physically separated from the solid waste fraction. Steps 1 and 2 are continued as long as the percolate has potential for biogas production.
Composting: When the potential for biogas production has decreased, the process module switches to forced ventilation (negative aeration) of  the remaining solid waste. Aeration rapidly initiates a highly effective composting process. Heat from the composting ensures complete sanitization and evaporation of excess humidity.
During all 3 steps, the process module remains closed. No solid waste is moved, with only fluids and air circulating between the process module and the gas reactor in a closed system. The system design ensures that the processes of hydrolysis, percolation, methane generation and composting are separate and occur rapidly and extremely efficiently. There is no need for inoculation using earlier processed material to start fresh batches. This insures full traceability. The process is self-sustaining and there is no need for heating to start the process.

Aikan Technology optimizes transformation processes that occur naturally in the decomposition of biological waste and makes sure that the outputs can be captured, upgraded and turned into valuable resources that can be recycled. We invite you to learn more about the Aikan Advantage at Aikan Technology.

The biogas produced from this process can be used in a variety of ways as a renewable energy source

Electricity and Heat: Combined Heat and Power (“CHP”) units can convert the biogas into heat and electricity which can be used on-site or sold into the electric grid.  The heat can be used for industrial processes, space heating and refrigeration or space cooling through an absorption chiller
Renewable Natural Gas (“RNG”): The biogas can be refined into pipeline quality natural gas and used on-site or sold into natural gas pipelines.
Compressed Natural Gas (“CNG”): The biogas can be refined and compressed in CNG and used as a transportation fuel
Other: Methane from the biogas can be separated and used as a feedstock for a variety of other uses.  For example, research is being conducted by NASA on methane’s potential as a rocket fuel.  Methane is also a key feedstock for the production of hydrogen