UPGRADING COAL LOW QUALITY WITH DRYING PROCESS WITHOUT OXYGEN

Abstract

kcal/kg that accumulate in stockpile PT. Nusa Alam Lestari. The author
conducted a preliminary survey to determine the amount of low quality coal in
PT. Nusa Alam Lestari. In February 2017 the number of coal with a calorie value
below 5100 kcal /kg - 5500 kcal / kg on the stockpile of seam stack at 10422 tons
of stockpile.
Here are several kinds of coal upgrading process, one of them is drying
process. Coal Drying aims to remove or decrease the water content contained in
coal, so that with reduced moisture content is able to increase the calorific value
of coal.
In the process of upgrading with the drying process (Coal Drying)
obtained coal calorific value by using Furnance Carbolite to influence
temperature and reaction time that is at 400⁰C for 1 hour produce coal with
calories 5,697,94 kkal / kg. At 400⁰C for 2 hours produces coal with a calorific
value of 5,987.8 kcal kg. At 400⁰C for 3 hours produces coal with a calorific
value of 6,182.70 kcal/kg. At 500⁰C for 1 hour produce coal with a calorific value
of 6,192.44 kcal/kg. At a temperature of 500⁰C for 2 hours yields a coal calorific
value of 6,233.86 kcal / kg. At a temperature of 500⁰ for 3 hours yields a calorific
value of 6,219.24 kcal / kg. At 600⁰C for 1 hour yields a calorific value of
6,423.15 kcal/ kg. At 600⁰C for 2 hours 6,470.15 kcal/kg. At 600⁰C for 3 hours
yields a caloric value of 6,375.14 kcal/kg.
In this research, the optimum caloric value obtained at drying process is
600⁰C for 2 hours with decreasing water content 3,95%. In the drying process to
the effect of temperature and calorie reaction time rose from 5,457.99 kcal/kg to
6,470.15 kcal/kg.