Cogeneration of power and methanol based on a conventional power plant in Germany

摘要

The global increase in electricity production by wind and photovoltaic plants poses challenges for local electricity grids as well as for electricity markets. These renewable energy sources rely heavily on current weather conditions, by that producing electricity in a fluctuating manner. This results in temporary electricity surpluses causing temporarily low or even negative electricity prices. Additionally, a stable operation of the electricity grid must be maintained even locally.To solve these problems, the intelligent coupling of the electricity, gas and heat sectors could be a promising approach. So called “Power-To-X” concepts such as Power-to-Heat (P2H) or Power-to-Fuel (P2F) cover technologies that aim to convert electrical energy into material energy storages, synthetic fuels and energy-intensive chemical raw products. For conventional power plants, the production of methanol is currently the most discussed option in Germany.In this paper a techno-economic analysis of the implementation of a Power-to-Methanol plant (P2MeOH) into a conventional power plant is presented. This study is based on real power generation data of the real hard coal-fired power plant “Westphalia E” in Germany in 2017. It takes into account parameters such as P2MeOH invest costs, costs for carbon dioxide emission as well as electricity, methanol and oxygen market prices. The required mass and energy flows for the techno-economic analysis are calculated by a custom implemented thermodynamic model.This study shows that an additional revenue could be generated under current market situations and that this possible revenue sums up to 5.2 million € per year. In ecological regards, around 150,000 tons CO2could be saved per year. The calculated P2MeOH invest costs amount to 137.5 million €. Additionally, it could be obtained that by far most costs are caused by the electrolyser. As further technical progress in that field is expected, this could lead to higher economic benefits in the future.