| Autor: |
Pinkard BR; Mechanical Engineering Department, University of Washington, Seattle, WA 98195, USA., Gorman DJ; Mechanical Engineering Department, University of Washington, Seattle, WA 98195, USA., Tiwari K; Mechanical Engineering Department, University of Washington, Seattle, WA 98195, USA., Rasmussen EG; Mechanical Engineering Department, University of Washington, Seattle, WA 98195, USA., Kramlich JC; Mechanical Engineering Department, University of Washington, Seattle, WA 98195, USA., Reinhall PG; Mechanical Engineering Department, University of Washington, Seattle, WA 98195, USA., Novosselov IV; Mechanical Engineering Department, University of Washington, Seattle, WA 98195, USA. |
| Abstrakt: |
Optimizing an industrial-scale supercritical water gasification process requires detailed knowledge of chemical reaction pathways, rates, and product yields. Laboratory-scale reactors are employed to develop this knowledge base. The rationale behind designs and component selection of continuous flow, laboratory-scale supercritical water gasification reactors is analyzed. Some design challenges have standard solutions, such as pressurization and preheating, but issues with solid precipitation and feedstock pretreatment still present open questions. Strategies for reactant mixing must be evaluated on a system-by-system basis, depending on feedstock and experimental goals, as mixing can affect product yields, char formation, and reaction pathways. In-situ Raman spectroscopic monitoring of reaction chemistry promises to further fundamental knowledge of gasification and decrease experimentation time. High-temperature, high-pressure spectroscopy in supercritical water conditions is performed, however, long-term operation flow cell operation is challenging. Comparison of Raman spectra for decomposition of formic acid in the supercritical region and cold section of the reactor demonstrates the difficulty in performing quantitative spectroscopy in the hot zone. Future designs and optimization of continuous supercritical water gasification reactors should consider well-established solutions for pressurization, heating, and process monitoring, and effective strategies for mixing and solids handling for long-term reactor operation and data collection. |
