There’s a ton of different stuff, but broadly speaking, there are three major categories: ore processing, the blast furnaces / vacuum freezer, and utility machinery.
Ore processing is macerator -> water / mercury / sodium perfsulfate bath (depending on ore) -> thermal centrifuge -> macerator #2 -> centrifuge for some ores -> immediate smelting for some ores. As a sideline there are sorting facilities for “tiny” (1/9th ingot) and “small” (1/4 ingot) byproducts, since those have to be combined in groups of 4 or 9 to make usable dusts. I think ore processing draws about 500 watts while running, all told.
Ore processing is the most Factorio thing I do in Minecraft/Gregtech 5U. I’ve got more things planned for it too, like the platinum group extraction of specific nickel and copper ores. More for the osmium and iridium products than the platinum.
The blast furnace line’s much simpler, but required for steel or anything better. For many metals it’s just the blast furnace, but recently I’ve gotten into metals that require cooling in the freezer. Titanium requires conversion of rutile dust into titanium tetrachloride -> blast furnace -> freezer. All of it together draws a potential 1600 watts if it’s all going at once.
Current project is a chemical reactor dedicated to converting the magnesium chloride byproduct of titanium smelting back into magnesium and chlorine. I’m very short of magnesium, what little I’ve accumulated has been tiny byproducts of other ores, and I need more if I’m to smelt all the rutile dust I have into titanium. It’s just a single block, but it’s a 480-watt process, so it needs a dedicated power line, and a pipe to run the chlorine back to the chlorine tank.
Utility is pretty much anything else, stuff that usually doesn’t run continuously, and so rarely affects total power draw for long. There are several rooms full of this stuff, but it includes a wiremill, metal bender (for plates), lathe, extruder, assembler, polarizer (to magnetize iron or steel), chemical reactor to produce rubber for insulation, laser engraver to make printed circuit wiring, and form press to make circuit boards.
As for the chemicals - oxygen’s mainly used in steel smelting, hydrogen in petroleum refining, chlorine in titanium smelting, and fluorine in Teflon production. Teflon’s used for advanced circuit boards, which is silly, but that’s the way it is.