“Green” integrated system: Non-grid-connected wind power and coal-to-methanol

Wind energy is a mature technology that has promising future in development and utilization of renewable energy sources, but the contribution rate of wind power on the grid is difficult to reach beyond 10% due to the high randomicity of wind. Coal-to-methanol process as the representative of the modern coal chemical industry is the important strategic alternatives of petrochemical product in application, but it will emit a considerable amount of carbon dioxide in the production process. A new integrated system which combines coal-to-methanol with wind power is proposed in this paper. In this system, wind power is used to electrolyze water for producing H₂ and O₂. The O₂ is fed to the gasifier as gasification agent. The H₂ is mixed with the CO-rich gas to adjust the H₂/CO to an appropriate ratio for methanol synthesis. In comparison with conventional coal-to-methanol system, the proposed system omits the expensive and energy-consuming Air-Separation-Unit (ASU) and greatly reduces the water gas shift process, which brings both advantages in the utilization of all raw materials and significant reduction of CO₂ emission. This system will be attractive in the regions of China with abundant wind and coal resources.