A tanker for liquid methane, built for the Octan company by Llwynwgril Space Systems. You read about the source of the methane in the description on Flickr or MOCpages.
Octan 24 by David Roberts, on Flickr
Octan 24 by David Roberts, on Flickr
Octan 24 by David Roberts, on Flickr
Octan 24 Cockpit Details by David Roberts, on Flickr