Thermal Desalinator

Thermal Desalinator

Heats saline water into vapor to collect it as clean water. Produces brine as a byproduct. Not really efficient but does the job.

Construction	30 + 30
Workers	4
Electricity	400 KW
Maintenance	2.0 / 60
Footprint	11x4
Required Research	Thermal Desalination
Boost by Unity	Available
Designation	Water Extraction & Processing

The Thermal Desalinator is a machine which converts Seawater and either Steam (Super), Steam (High), Steam (Low), or Steam Depleted into Water and Brine. Due to the high fuel cost for making steam, Groundwater Pump is vastly more efficient if there is sufficient rainfall to replenish groundwater aquifers.

The Brine byproduct can be utilized in Electrolyzers to create Chlorine to treat Waste Water or in fed into Wastewater Treatment machines to convert Toxic Slurry into Slag. The Evaporation Pond and Evaporation Pond (Heated) can also process Brine into Salt. However due to the high fuel cost for making steam, the production of Salt from Seawater with the Evaporation Pond is several times more energy efficient.

Energy Cost of Desalination

When using steam from existing sources (coal/nuclear power plant, exhaust scubbers/arc furnaces) to desalinate, there are several choices. The simplest method is to run depleted steam from a power plant into cooling towers, and have a separate desalination plant using high steam to make up for the lost water. Vacuum desalination offers an alternative, where we can use depleted steam to make water instead of burning extra fuel to make high-steam. However, vacuum desalination requires many times more desalinators to work, and it's not obvious how much it costs / saves.

The following table shows the cost to produce a full Pipe III of water using each of the different recipes:

Costs per full Pipe-III ( 450 / 60 )

Desalination Recipe	# of desals.	Input Steam / 60	Steam Energy ( -Equivalent)	Total Energy	Total Workers	Cooling Towers Replaced	Net Workers	/ 60
Steam (Super)	6.6	40	20.8 MW	23.4 MW	26.7	0.4	24.2	13.3
Steam (High)	6.5	78.3	24.4 MW	27.0 MW	26.1	0.8	21.2	13
Steam (Low)	8.3	200	20.8 MW	24.1 MW	33.3	2.1	20.8	16.7
Steam Depleted	30	720	0 MW	12.0 MW	120	7.5	75	60

Note: This calculates net water production, as compared to simply running that steam into a power plant / cooling towers. For example, 30 depleted steam desalinators will output 990 / 60 , but you would have gotten 540 of that just by cooling the steam; so this table counts only 450 of that as"extra" that the desalinators made. This also assumes that the steam is being made anyway (e.g. waste steam from scrubbers/arc furnaces or siphoning steam from a running power plant) and so only counts each steam as 0.75 water. If you were designing a standalone desalinator plant that feeds its boilers from its own water, you'd need slightly more desalinators to hit 450 / 60 output, but the relative energy efficiencies would stay the same.

"Total Energy" is a combination of the electricity used directly by the desalinators, and the electricity that could have been produced from the steam (assuming you're using Power Generator (Large)).

"Net Workers" is total workers discounted for the workers saved by not having to build cooling towers (mostly matters for depleted steam)Some factors that make comparing recipes tricky:

• Comparing the recipes for low/high steam: 24 Units of Steam(Low) is worth 3MW mechanical, but 12 Steam(High) can be 4.5MW Mechanical if you run it through both high and low pressure turbines. Therefore the Steam(High) gives you only 8% more water, but uses 50% more energy, meaning that it's more efficient to siphon low-steam off a power plant for desalination than high-steam.
• Every unit of steam becomes 0.75 water in a cooling tower for free, so the Steam Low and Steam Depleted recipes don't give you as much water as they seem to. For example, a thermal desalinator running on depleted steam appears to give you 33 / 60 , but we could have gotten 18 / 60 of that for free by running the depleted steam into a large cooling tower. Therefore, for the cost of 400KW and 4 workers, the net water production of that desalinator is actually only 15 / 60 . This also means that the low-steam recipe isn't quite as efficient as it seems, since it consumes more water in the steam it inputs, leaving it only about 10% more efficient as high-steam.
• Using depleted steam costs about half the energy of the others, but it is important to note that all of that energy is electrical (the 400KW desalinator power consumption), requiring an extra 12MW worth of electrical turbines/generators. Meanwhile the other recipes have most of their energy cost in the steam, so they will use more total fuel (coal/nuclear fuel/etc), but put less of a strain on the electrical grid.

Recipes

Below are all the recipes, which this building is capable of producing. Note, that some of them may be locked behind Research, and not immediately available in your game.

5

15

8

24

20 

60 

11

33

2

6

12

72

4

24

10 

60 

12

72

4

24

18

108

2

12

10 

60 

13

78

7

42

18

108

1

6

10 

60 

12

72

7

42