Large Chemical Reactor

From GT New Horizons

The Gregtech Large Chemical Reactor (LCR) is functionally a multiblock version of a regular, single-block chemical reactor. Like many other multiblocks, they can wallshare.


An LCR is a 3x3x3 structure that requires:

  • x1 Controller block; front, centered
  • x1 Maintenance Hatch; anywhere
  • x1 Energy Hatch, anywhere
  • x0+ Input Bus, optional, anywhere
  • x0+ Output Bus optional, anywhere
  • x0+ Input Hatch optional, anywhere[1]
  • x0+ Output Hatch, optional, anywhere[2]
  • x1 PTFE Pipe Casing, in the very center of the 3x3x3
  • x1 Cupronickel Coil Block, must be physically touching the PTFE Pipe [3]
  • x8+ Chemically Inert Machine Casing, everywhere else

  1. One Input Hatch required for each fluid ingredient of the recipe.
  2. One Output Hatch required for each fluid output of the recipe.
  3. More than one coil block is not allowed in the multiblock structure.


The LCR deals with pure liquid inputs/outputs; no cells are needed. Lock output hatches to specific fluids using a screwdriver or the GUI of the hatch. To lock it to the currently held fluid (or the next to enter in case of an empty hatch), use Shift-right-click. The LCR can be recipe locked by using a screwdriver on the controller. It wont process other recipes when applied. Otherwise, it can have multiple hatches for different recipes but will do only one recipe per operation. By default it will stop processing if there isn't enough room for the recipe products in the output buses/hatches. This behavior can be toggled in the controller GUI with Void Mode.

The LCR will overclock with 100% efficiency (very much like an EBF when it performs a "special" overclock). This means that, instead of the standard GT overclock of 4x energy/2x speed, an LCR will actually overclock with 4x energy/4x speed.

Key Differences Between Single-Block and Multi-Block

A single LCR can be used to make diesel with credit to bitonality

The LCR has several key differences from the single-block chemical reactor:

  • The LCR has special recipes that make certain chemical chains into an "all-in-one" recipe (note: in older versions of GT:NH, this may not be the case). For example, if we look at sulfuric acid, we can see that a single-block chemical reactor recipe involves repeatedly adding oxygen to sulfur in multiple stages to yield sulfuric acid. An LCR, on the other hand, will accept all of the oxygen in a single recipe, along with sulfur and water, to yield sulfuric acid in one step. Typically, such recipes involve the use of a Programmable Circuit #24.
  • One must also consider the ease of upgrading a multiblock vs upgrading a single block. Upgrading a multiblock usually involves a simple swap of the energy hatch with a new higher tier energy hatch, whereas upgrading a single block means having to build a whole new single block.


Problem Solution
Wrong Recipe Ensure the recipe is not locked. LCR's do not have Input Bus Separation and will potentially use another's circuit setting if wallsharing.