This has been used since the beginning of metallurgy, which dates back to over 8,000 years ago. It still continues to be in use, because there has been no better alternative that has come up, even after all this while.
Coconut shell Charcoal
Its ignition temperature is less than that of wood-based charcoal. It also causes lesser air pollution and smells better, making it prized for use in the moulding industry.