$13.$ Describe the environmental considerations associated with the storage and handling of coal. What measures can be taken to mitigate these impacts?

$14.$ Discuss the role of coal carbonisation in the production of synthetic natural gas $($SNG$).$ How does this process contribute to energy security?

$15.$ Explain the significance of the Lurgi and Winkler processes in the context of integrated gasification combined cycle $($IGCC$)$ systems.

$16.$ Compare the Winkler and KopperTotzek coal gasification processes in terms of throughput, efficiency, and suitability for different types of coal.