Processes for forming low molecular weight (C.sub.2-4) olefins from renewable resources, and polyolefins formed from the olefins, are disclosed. The C.sub.2-4 olefins are produced by first converting a renewable resource, capable of being converted to syngas, to syngas. The syngas is converted, using Fischer-Tropsch synthesis using a catalyst with low chain growth probabilities, to a composition comprising C.sub.2-4 olefins, which are then isolated to form a C.sub.2-4 olefin-rich stream. Propylene can be isolated from this stream, and the ethylene and butylene can be subjected to olefin metathesis to produce additional propylene. The propylene, or other olefins, can be subjected to a variety of polymerization conditions and used in a variety of products, to replace the propylene, and polypropylene, produced from crude oil. Thus, the olefins, and polymers, copolymer and terpolymers thereof, can help reduce U.S. dependence on foreign crude oil.