Phurnacite Smokeless Coal - 25kg bag Phurnacite is highly regarded as the number one smokeless fuel for cookers, room heaters, & stoves. Phurnacite is over fifty years old, & remains the country's first choice of high performance smokeless fuel. The hard, clean phurnacite briquette provides long lasting, consistent, & controllable heat. In the right conditions, Phurnacite will slumber for over 18 hours.