... international NGOs such as GTZ and SNV; and local NGOs such as Centre for Environment, Energy and Sustainable Development (CEESD) and Kumasi Institute of Technology, Energy and Environment (KITE); ... of tandem digesters as used by biogas service providers as opposed to the recommended layout. Figure 13. (A) Tandem digester layout used by BTWAL, BCEL, and BCL, and (B) Appropriate and ... difficult to engineer, construct and operate [23, 24 and 25]. In Ghana, Tandem plants have been constructed to treat sewage by BTWAL, BCEL, IIR, and BCL. Most common tandem digesters found in Ghana...