Fossil Energy Research (United States)

The methane hydrate formation rate and storage capacity seriously restrict hydrate storage and transportation technology development. In this study, the methane hydrate formation process in a 0.30 wt % sodium dodecyl sulfate (SDS) and mixed systems of 0.30 wt % SDS with saturated sodium sulfate (Na2SO4) was investigated. The effects of SDS concentration and initial pressure in the mixed systems on the methane hydrate formation rate and amount were studied. It was found that the methane hydrate formation process can be divided into four stages: the first rapid formation stage, the nucleation aggregation stage, the second rapid formation stage, and the hydrate stable stage. The precipitated Na2SO4 crystals provided seeds for methane hydrate formation, which can improve the hydrate formation rate and storage capacity. The Na2SO4 crystals mainly affect the first rapid formation stage and the nucleation aggregation stage. The methane hydrate formation rate in the first stage under the synergistic effect of 0.30 wt % SDS+Na2SO4 is 1.2 times higher than that of SDS alone. When increasing the formation pressure from 6 to 10 MPa, the hydrate formation rate under the synergistic effect of 0.30 wt % SDS+Na2SO4 in the first stage increased by 8 times. In the SDS+saturated Na2SO4 system, the methane hydrate formation rate and storage capacity increase with the increase of SDS concentration. SDS concentration mainly affects the first rapid formation stage. This paper is helpful to propose a new method for the methane hydrate rapid formation and is crucial for the development of hydrate storage and transportation technology.

A large operational envelope is a key requirement for modern gas turbines. Fuel staging is used here to improve the part load performance of an enhanced FLOX® type combustor. A swirl-stabilized pilot stage is integrated in the FLOX® burner and the results of high pressure lab-scale experiments at system relevant conditions are presented. The operational envelope of the piloted system could be extended by approximately 10%. Pressure scaling and variations of air preheat temperature and jet velocity describe fundamental characteristics of the piloted system. OH* chemiluminescence imaging is used to investigate flame shapes and the effect of the interacting flames. Emissions and pressure pulsations define limits, and optimum operation conditions of the combustor and show the influence of part load relevant parameters.

No contexto da Primeira Revolução Industrial tem início o Paradigma Energético-Ambiental dos Combustíveis Fósseis. No princípio, o combustível fóssil base de toda a matriz energético-tecnológico-produtiva era o carvão, que passa a ser deslocado pelo petróleo, e já bem mais tarde passa-se a valer do gás natural. O Paradigma dos Combustíveis Fósseis começa a entrar em crise na década de 1970, com a ocorrência dos choques petrolíferos de 1973 e 1979. Começam então a surgir os sinais da emergência de um novo paradigma, a saber: o Paradigma das Fontes Renováveis de Energia. Entretanto, decorridas mais de três décadas, o novo paradigma mostra-se ainda longe de se apresentar como hegemônico. O que acontece é que vive-se, de fato, um período de transição paradigmática do Paradigma dos Combustíveis Fósseis para o Paradigma das Fontes Renováveis de Energia, o qual deverá durar ainda várias décadas, representando uma fase de transformações técnico-produtivas, de incorporações de inovações a nível da tecnologia, de novas configurações energo-tecnológicas e da interação entre energéticos dominantes e fontes não convencionais de energia, buscando-se averiguar, neste contexto, a questão das mudanças climáticas.

Selective noncatalytic reduction (SNCR) is a postcombustion technique for reducing NOx emissions from power generation facilities. The optimization of the SNCR system involves maximizing NOx reduction while minimizing NH3 slip. This requires optimization of both the SNCR system as well as the combustion, as their performances are interrelated. This work discusses the results of an optimization study of SNCR systems on a wood-fired boiler. This included measurements of NH3, which was measured with a tunable diode laser, as well as temperature, O2, CO, and NOx. The results clearly showed the interrelationship between the SNCR process and combustion. Marked improvement in SNCR performance was possible on this boiler due in part to the availability of instrumentation that allowed the operators to optimize combustion and maintain these conditions once they were defined.

Roadmap to identify key challenges and priority R&D needs associated with various hydrogen fuel production technologies.