| 摘要 |
<p>An integrated process for producing desulfurized hydroprocessed products from Fischer-Tropsch synthesis is disclosed. The process involves isolating and dsulfurizing a methane-rich stream from a natural gas source in a first separation zone and a desulfurization zone. The methane-rich stream is converted to syngas and subjected to a hydrocarbon synthesis step, for example, a Fischer-Tropsch synthesis step. The products from the hydrocarbon synthesis step typically include a C4- fraction, a C5-20 fraction, and a C20+ wax fraction. These fractions are isolated in a second separation zone, typically via fractional distillation. The C4- fraction can be recycled through the first separation zone to provide a second methane-rich fraction for conversion to synthesis gas. The C4- fraction can optionally be treated, for example, with hydrotreatment or hydroisomerization catalysts and conditions before or after passage through the first separation zone. The hydrocarbons in the C5-20 and C20+ wax fractions are subjected to additional process steps, for example, hydrotreatment, hydroisomerization, hydrocracking (particularly in the case of the wax fraction), preferably in the presence of sulfur containing compounds. The products of the additional process steps are sent to a third separation zone, and yield one or more fractions useful, for example, in fuel-related products (preferably C5-20 hydrocarbons) as well as an additional C4- fraction. The additional C4- fraction, which can include sulfur impurities resulting from the hydroconversion reaction, can also be desulfurized in the desulfurization zone along with the natural gas. This eliminates the need for a second desulfurization zone. The desulfurization zone can be scaled up from its normal size, if desired, to accommodate the additional sulfur removal resulting from the hydroconversion.</p> |
