Agglomerated particulate low-rank coal feedstock and uses thereof

摘要

The present invention relates generally to processes for preparing agglomerated particulate low-rank coal feedstocks of a particle size suitable for reaction in a fluidized-bed reactor and certain other gasification reactors and, in particular, for coal gasification and combustion applications. The present invention also relates to an integrated coal hydromethanation process including preparing and utilizing such agglomerated particulate low-rank coal feedstocks.

主权项

1. A process for preparing a free-flowing agglomerated particulate low-rank coal feedstock of a specified particle size distribution, the process comprising the steps of:
(A) selecting a specification for the particle size distribution of the free-flowing agglomerated particulate low-rank coal feedstock, the specification comprising
(i) a target dp(50) that is a value in the range of from about 100 microns to about 1000 microns,(ii) a target upper end particle size that is a value greater than the target dp(50), and less than or equal to about 1500 microns, and(iii) a target lower end particle size that is a value less than the target dp(50), and greater than or equal to about 45 microns; (B) providing a raw particulate low-rank coal feedstock having an initial particle density; (C) grinding the raw particulate low-rank coal feedstock to a ground dp(50) of from about 2% to about 50% of the target dp(50), to generate a ground low-rank coal feedstock; (D) pelletizing the ground low-rank coal feedstock with water and a binder to generate free-flowing agglomerated low-rank coal particles having a pelletized dp(50) of from about 90% to about 110% of the target dp(50), and a particle density of at least about 5% greater than the initial particle density, wherein the binder is selected from the group consisting of a water-soluble binder, a water-dispersible binder and a mixture thereof; and (E) removing all or a portion of
(i) particles larger than the upper end particle size,(ii) particles smaller than the lower end particle size, or(iii) both (i) and (ii), from the free-flowing agglomerated low-rank coal particles to generate the free-flowing agglomerated low-rank coal feedstock.