Asphalt+or+tar

These sources includes [|sugar], [|molasses] and [|rice] , [|corn] and [|potato] [|starches] , natural tree and gum resins, natural latex rubber and vegetable oils, [|lignin] , [|cellulose] , palm oil waste, coconut waste, peanut oil waste, canola oil waste, potato starch, dried [|sewerage] effluent and so on. Wikipaedia
 * Bioasphalt** is an [|asphalt] alternative made from non-petroleum based [|renewable resources].

In [|Northern Europe], the word "tar" refers primarily to a substance that is [|derived] from the wood and roots of [|pine]. In earlier times it was often used as a water repellent coating for boats, ships, and roofs. It is still used as an additive in the flavoring of candy, alcohol and other foods. Wood tar is [|microbicidal] and has a pleasant odor — a sweet musky scent much like that of barbecue. Producing tar from wood was known in ancient Greece, and has probably been used in Scandinavia since the Iron Age. For centuries, dating back at least to the 14th century, tar was among [|Sweden] 's most important exports. Sweden exported 13,000 barrels of tar in [|1615] and 227,000 barrels in the peak year of [|1863]. Production nearly stopped in the early 20th century, when other chemicals replaced tar and wooden ships were replaced by steel ships. The heating ( [|dry distilling] ) of [|pine] wood causes [|tar] and [|pitch] to drip away from the wood and leave behind charcoal. Birchbark is used to make particularly fine tar, known as "Russian oil", suitable for leather protection. The by-products of wood tar are [|turpentine] and [|charcoal]. When [|deciduous] tree woods are subjected to destructive distillation the products are [|methanol] (wood alcohol) and [|charcoal].
 * Tar kilns** ( [|Swedish] : //tjärdal//, [|Norwegian] : //tjæremila//, [|Finnish] : //tervamiilu//) are dry distillation ovens, historically used in [|Scandinavia] for producing tar from wood. They were built close to the forest, from limestone or from more primitive holes in the ground. The bottom is sloped into an outlet hole, to allow the tar to pour out. The wood is split to dimensions of a finger and stacked densely, and finally covered tight with dirt and moss. If oxygen can enter, the wood might catch fire, and the production would be ruined. On top of this, a fire is stacked and lit. After a few hours, the tar starts to pour out, and continues to do so for a few days.