This is a paid asset, but now you can download The processing plant Free.
Detail this asset from Unity Store: Original Link
The processing plant v1.0
“If possible, please buy the package to support the developer”
This pack of 3d models and textures allows to create different processing plants. The pack includes floor storage constructions, oil tank storages, constructions of metal and other objects.
The pack includes:
– 77 unique low-poly models;
– Every object has 3 textures (albedo, specular, normal map) and 2 UVs (UV0 for the texture and UV1 for lightmapping);
– This pack can be used in first person and top-down view projects;
– 2 demo scenes. First demo scene includes all models put on the floor, second scene is what you see in the video demo (trees are not included(SpeedTree)). All the scenes are lightmapped;