For example, a steam engine can use coal, newspaper or wood for the fuel, while an internal combustion engine needs pure, high-quality liquid or gaseous fuel.
例如，蒸汽发动机可以用煤，报纸或木头作为燃料，而内燃机需要用纯的，高质量液体燃料或气体燃料。
2
The methanol oil (liquidfuel) can be used as engine fuel, and can also be used to produce ethylene and propylene replaced petroleum material.
甲醇油除作发动机燃料外，还可加工转化成乙烯、丙烯替代短缺的石油原料。
3
The internal combustion engine is most common: this obtains its power by burning a liquidfuel inside the engine cylinder.