In Figure 2 the block flow diagram of the process is reported with preliminary mass and energy balance. The last step is the liquefaction of the synthetic gas obtaining LNG and a boil-off stream that is then recycled to the process. A final TSA polishing unit brings the concentration of CO 2 to the required specification. Subsequently, carbon dioxide is separated by using a membrane gas separation system, and the permeate (rich in carbon dioxide and hydrogen) is recycled to the methanation unit.
Therefore, the first operation after the methanation reactor is cooling the outlet stream to near-ambient temperature to remove most of the water content, then followed by a temperature swing adsorption (TSA) that further dries the stream.
Steam and carbon dioxide must be below a certain concentration to avoid freezing in the condenser during the liquefaction process. After the methanation step, the stream is mainly made of water, methane, hydrogen, and carbon dioxide. Because the methanation reaction is highly exothermic, the reactor must have adequate cooling to maintain as much isothermal operation as possible. The reagents are mixed with the recycle stream, and the H 2-to-CO 2 ratio is maintained equal to the stoichiometric value of 4. The produced hydrogen is then mixed with carbon dioxide captured from air. Hydrogen is produced through a water electrolyzer using renewable electricity. The process modeling results also evidenced that the impact of the gas pretreatment and liquefaction process on the plant energetics is 4% of the total power input. A process efficiency up to 46.3% (electric to chemical) resulted from the study. The heat produced by the electrolyzer and methanation unit is greater than the thermal energy requirement by the CO 2 capturing unit during desorption. Finally, the thermal integration was performed to minimize the external heat requirement. Hence, the minimum work required for the liquefaction resulted in being 0.57 kWh el/kg LNG. Subsequently the liquefaction unit was developed, optimizing the SMR composition and pressures to minimize the total work required. After a screening of different polyimide-type membranes, a two-stage layout was selected and dimensioned. The gas separation system was designed using a combination of temperature swing adsorption techniques (stream dehumidification) and membrane separation (CO 2 separation). A thermodynamic analysis excluded the possibility of carbon deposition formation in the methanation reactor due to methane recirculation. The gas separation unit produces an exhaust stream, rich in not only hydrogen and carbon dioxide but also methane, that is recycled to the methanation unit inlet.
The proposed concept is based on water electrolysis to produce hydrogen, CO 2 capture from air using solid adsorption materials, catalytic CO 2 methanation, gas separation, and a single mixed refrigerant (SMR) liquefaction process. In this work, an innovative power to liquefied methane concept was developed, and process simulations for a 200 kW el demonstration plant were carried out. Multidisciplinary and mission-driven by nature, TAE is leveraging proprietary science and engineering to create a bright future for us all.The continuous increase in electricity production from renewable energy sources (RESs) introduces the intrinsic fluctuating characteristic of RESs in the electric power grid, causing nontrivial grid management issues (e.g., grid congestion). TAE is based in California and maintains international offices in the UK and Switzerland. The company’s revolutionary technologies have produced a robust portfolio of commercial innovations in other large adjacent markets such as power management, energy storage, transmission, electric mobility, life sciences, and more. With over 1100 issued patents, more than $880 million in private capital, six generations of National Laboratory-scale devices, and an experienced team of over 250 employees, TAE is now on the cusp of delivering this transformational energy source capable of sustaining the planet for centuries. TAE Technologies (pronounced T-A-E) was founded in 1998 to develop commercial fusion power with the cleanest environmental profile and represents the fastest, most practical, and economically competitive solution to bring abundant energy to the grid.
0 kommentar(er)
