Microbial Electrochemical Systems and Technologies: It Is Time To Report the Capital Costs

摘要

Microbial electrochemical systems and technologies (METs) that can convert chemical energy stored in organic or inorganic matter into energy and/or to valuable chemicals have been studied extensively in the past decade. Generally, a MET reactor is composed of anodes and cathodes separated by membranes. Electrons are released from the microbial oxidation of substrate in the anode and are subsequently accepted by the cathode to complete a reduction reaction. After extensive fundamental studies to understand the electron transfer mechanisms, microbiology, reactor architecture and materials involved, METs are becoming a versatile technology platform for various applications such as wastewater treatment, bioremediation, environmental monitoring, and sustainable production of bioenergy and valuable chemicals. As examination of the technical viability continues, the economic feasibility and assessment aspects are being studied extensively, especially for METs that have come closer to being used in practical applications. The capital costs are one of the decisive economic factors for scale-up and commercialization of METs. Therefore, the reduction of material and construction costs has frequently been cited as the main objective in recent studies. However, the question remains as to whether the capital costs have been accurately reported for the METs that have been developed. Less than 10 out of several thousand publications have provided this information; thus, the answer is obvious.