Hello Miria, with small ...

Hello Miria,

with small scale, it will be beneficial to have energy recovery from sewage sludge.  A

You may want to think on Anaerobic Digestion (AD) for small scale. AD will produce methane gas that can be used for energy recovery. There are examples of portable units for organic waste.

here is an example of technology developed int he UK that use AD on a small scale unit for food waste

http://seabenergy.com/products/anaerobic-digesters/  

Regarding how much energy can be recovered from a tonne of sewage sludge, that will depend on many factors including the process, water content and technology used.  Most of the Water companies int he UK use AD and CHP units for treating the sewage sludge and energy recovery. for example, In a typical AD process, each tonne of dry matter fed will produce 350m3 of biogas (65% methane) which generates up to 820kWh of electrical energy. In a typical Advanced AD-Thermal Hydrolysis Plant (AHP)process, each tonne of dry matter fed will produce 450m3 of biogas which would generate up to 1,100kWh of electrical energy. However, THP demands an input high-grade heat and additional electrical energy, when compared with conventional AD.

Have a look at the attached file, which will give you an overview of the current practice of AD in the UK.