Below are a few videos to watch about absorption units
Lithium Bromide/Ammonia Chillers
*Generally speaking-they are basically the same
Ammonia Chillers
Lithium Bromide Chillers
*No need to watch this whole video: Start at 17:50 – End at 23:35
Ammonia Industrial Refrigeration System (using a compressor)
Below are a few diagrams of the absorption cycles.