Zhang J.,Taiyuan University of Technology |
Zhang J.,Training Base of State Key Laboratory of Coal Science and Technology Jointly Constructed |
Yan Y.,Taiyuan University of Technology |
Yan Y.,Training Base of State Key Laboratory of Coal Science and Technology Jointly Constructed |
And 4 more authors.
Fuel Processing Technology
Solid phosphoric acid catalysts have been industrially used for propene oligomerization to improve the gasoline quality. However, solid phosphoric acid catalysts will lose their mechanical strength in the presence of water which is used to hydrolyze silicon phosphates to produce free phosphoric acids for maintaining the catalytic activity. In this case, to harmonize the catalyst lifetime and activity of solid phosphoric acid catalysts, the properties of silicon phosphate were investigated to achieve the maximum catalytic performance. A solid phosphoric acid catalyst was prepared with kieselguhr and concentrated phosphoric acid. Trace water was used to promote the release of active components from silicon phosphates during the reaction. Free phosphoric acid content, as a vital property of a solid phosphoric acid catalyst, was measured by ammonia temperature-programmed desorption. The crystal phase composition of silicon phosphates in a solid phosphoric acid catalyst was analyzed by X-ray diffraction. The catalytic performance was evaluated in a fixed bed under the conditions of 210 °C and 4 MPa. A solid phosphoric acid catalyst with relative content of 51% Si5O(PO4)6 and 49% SiP2O7 showed the best performance in improving catalytic activity and lifetime, and the conversion of propene was above 99% for nearly 70 h. © 2014 Elsevier B.V. Source
Fan Y.,Taiyuan University of Technology |
Fan Y.,Training Base of State Key Laboratory of Coal Science and Technology Jointly Constructed |
Yi Q.,Taiyuan University of Technology |
Yi Q.,Training Base of State Key Laboratory of Coal Science and Technology Jointly Constructed |
And 6 more authors.
Fuel Processing Technology
A novel coproduction system of lignite pyrolysis integrated with Fischer-Tropsch synthesis and coal-tar hydrogenation to produce liquid fuels and chemicals is proposed. The moisture content of the lignite, the gasifier adopted and the choice of electricity generation are the critical factors that make a big difference in the assessment of the system. Sensitivity analysis of different moisture contents and gasifier types are investigated and comparisons are done between processes with and without electricity generation. The results showed that the system could benefit a lot from the decrease of moisture content of feedstock, and that although requiring higher financial investment, Shell-gasifier-based process would produce more liquid. Moreover, applying the electricity generation system would enhance the economic performance and make an impact on the energy efficiency. By the energy and economic assessments, nearly 40% of the low heat value and over 15% of the internal rate of return in the best case are obtained at an annual handling scale of 5 million tons of lignite. Meanwhile, over half a million tons of liquid are obtained and the CO2 emission is within the range of 7.5-9.5 t/t-oil. © 2015 Elsevier B.V. Source