Biogas plants mostly operate with Internal Combustion Engines (ICE) to convert heat of biogas to electricity. In average, this conversion is done with a thermal efficiency in the order of 30%, while the rest represents thermal losses, with flue gases and cooling water being the predominant waste heat carriers. Recovery of high-temperature flue gases, involves technical interventions to aspiration process of the ICE engines that could affect the engine’s operation and performance, and thus are avoided. On the other hand, cooling water is available at low temperature (~80-90 oC) resulting to low heat to power conversion efficiency. Currently, Organic Rankine Cycle (ORC) technology is the most efficient technique to recover heat from low temperature heat sources and fits perfectly the conditions set by the cooling system of ICE engines. As a result several ORC products are already available in the market for this purpose, mostly of medium/large-scale.
The IE-E product is based on ORC technology. However, it is equipped with a beyond the state of the art expander experiencing higher efficiency compared to ORC market available products. A first prototype has been designed, manufactured and tested, revealing the potential of this technology. Further work is required to validate and improve this concept and up-scale the expander to the commercial size of 20 kW rated power, so that to meet the decentralized biogas ICE market. The identified markets for initial uptake of the new product are Greece, Italy and Germany due to favourable biogas electricity prices.
The new product will increase energy efficiency of biogas process. As that it directly contributes to the reduction of greenhouse gas emissions and efficient exploitation of a low grade heat source. However, the IE-E product establishes a new expander design, and by developing different models a wide range of industrial waste heat recovery activities can be covered. Apart from that, the development and commercialization of this product contributes to the creation of new jobs (mostly technicians, engineers, and supportive staff for sales and promotion).
The overall objective is to develop a high-performing heat-to-power engine with a superior performance and affordable cost, bringing a short payback period (even 3 years depending on incentives) that can bring multiple benefits to society, the environment, and can ensure a high growth and profits to PSYCTO.
