Assertion: gas | /r/CreatedBy | condensation
Facets:
value: from natural gas
type: OTHER
Source sentences:
text: It is produced by the incomplete refinement of petroleum; by condensation or adsorption from natural gas; by thermal or catalytic decomposition of petroleum or its fractions; by the hydrogenation of producer gas or coal; or by the polymerization of hydrocarbons of lower molecular weight.