Role of rheology on the hydraulic transportation of lignite coal and coal ash slurries in the pipeline

The transportation of Lignite coal and Coal ash in slurry form through pipelines is economically and environmentally more viable than the other conventional modes of transportation. The main focus of the present work is to demonstrate the effect of particle concentration and size on the rheological properties of slurries and to further investigate the head loss, energy consumption, energy cost, and transport capacity during slurry transport through pipes. The rheology data indicate the shear thinning flow behavior for all particle concentrations and sizes examined in the shear rate ((Formula presented.)) range of 10–500 s⁻¹. The high viscosity of slurry containing fine particles can be reduced by introducing an optimum concentration of coarse particles, which subsequently results in lower head loss, energy consumption, and cost. A Power-law model is fitted to rheological flow curves in order to obtain flow behavior index (n) and consistency coefficient (k), which are then used to calculate specific energy consumption and head loss. The energy cost in USD per ton per 100 km is calculated from the specific energy consumption and is found to be substantially cheaper than the existing rail and road transportation costs in India.