Products & Uses
Part of Electrochemistry
Electrochemical processes yield a remarkable range of products — from refined metals to industrial chemicals — using only electricity, water, and raw materials.
Why This Matters
Electrochemistry is one of the most productive technologies available to a rebuilding civilization. A single electrochemical setup can produce hydrogen fuel, pure oxygen, refined copper, plated steel tools, chlorine for water disinfection, sodium hydroxide for soap-making, and aluminum metal — all from electricity and basic chemicals. Understanding the full range of electrochemical products helps you prioritize which processes to develop first based on your community’s needs.
The key insight is that different electrolyte and electrode combinations yield completely different products. The same basic apparatus — a container, two electrodes, a power source, and a solution — produces entirely different outputs depending on what you put in it. This versatility makes electrochemistry uniquely valuable when industrial supply chains are gone.
Developing even two or three electrochemical processes gives a community access to materials and chemicals that would otherwise require extensive mining, smelting, or chemical manufacturing infrastructure.
Metal Refining and Deposition
Copper refining is historically the first major industrial electrochemical application. Crude copper (from smelting) contains impurities of zinc, lead, iron, and sometimes silver and gold. Using the crude copper as the anode and pure copper as the cathode in copper sulfate solution, current drives copper from the anode, through solution, and deposits it pure on the cathode. Impurities either remain in solution or fall as anode sludge — which may contain recoverable precious metals.
Setup: dissolve copper sulfate (from oxidized copper ore or made by dissolving copper in dilute sulfuric acid) in water to create a blue electrolyte. Run current at 0.2–0.5 A/cm² of cathode area. Harvest pure copper sheets from the cathode after 24–72 hours depending on current.
Nickel, zinc, and tin plating follow the same principle — dissolve the plating metal as sulfate salts, use the object to be plated as cathode. Applications include rust-proofing steel (zinc or tin), decorative finishes, and improving electrical contacts.
Chromium plating requires chromic acid (hexavalent chromium), which is toxic and should only be attempted with full hazard controls. For most survival scenarios, zinc or tin plating achieves adequate corrosion protection without the toxicity.
Aluminum production via the Hall-Héroult process requires dissolving aluminum oxide in molten cryolite at 960°C and passing large currents — impractical until substantial electrical infrastructure exists. However, aluminum refining from scrap using electrochemical methods can recover aluminum from alloys.
Chlor-Alkali Products
Electrolysis of brine (sodium chloride solution) produces three valuable products simultaneously:
- Chlorine gas at the anode
- Hydrogen gas at the cathode
- Sodium hydroxide (lye) in the cathode chamber
This single process supplies the raw materials for water disinfection (chlorine), soap and paper making (sodium hydroxide), and fuel (hydrogen). It is arguably the most productive electrochemical process for a developing community.
Practical setup: Use a divided cell to prevent chlorine and sodium hydroxide from mixing (they react to form sodium hypochlorite — useful in itself as bleach, but undesirable if you want separate products). Carbon or graphite anodes withstand chlorine attack reasonably well; steel cathodes work well for hydrogen evolution.
Brine concentration: Use 25–30% sodium chloride solution (saturated brine). Higher salt concentration improves efficiency and reduces unwanted oxygen evolution at the anode.
Sodium hypochlorite (bleach): If you skip the divided cell and allow chlorine to mix with sodium hydroxide, you get sodium hypochlorite solution directly — effective water disinfectant and wound antiseptic at 0.5–1% concentration. This is often the simpler and more immediately useful approach.
Hydrogen Production
Hydrogen from water electrolysis is the cleanest fuel available through electrochemistry. It burns with water vapor as the only product, produces no ash or residue, and can be stored (with care) in pressurized vessels.
Primary uses:
- Fuel for high-temperature torches (oxyhydrogen torch reaches 2,800°C — sufficient to weld steel, cut rock, and work precious metals)
- Reducing agent in metallurgy — hydrogen atmosphere prevents oxidation during metal annealing
- Chemical feedstock — hydrogen reacts with nitrogen over iron catalyst (Haber process) to make ammonia, which produces fertilizer
Storage caution: Hydrogen has the widest flammability range of any common gas (4–75% in air) and the lowest ignition energy. Store in sealed metal containers away from ignition sources. Never store hydrogen and oxygen together.
Chemical Synthesis
Potassium permanganate can be synthesized electrochemically by oxidizing manganese compounds. Used as a water purifier, wound disinfectant, and oxidizing agent.
Hydrogen peroxide at low concentrations forms during oxygen evolution in acidic electrolytes, though yields are low with simple equipment.
Ferrate (iron VI) from iron anodes in concentrated alkali — a powerful disinfectant and flocculent for water treatment, though unstable and must be used immediately.
Sodium perchlorate from concentrated sodium chloride in acidic conditions with platinum or lead dioxide anodes — a rocket oxidizer, though requiring careful safety management.
Prioritization for Rebuilding Communities
Not all products are equally important. A practical priority list:
- Copper refining — improves electrical conductivity of all wiring immediately
- Chlor-alkali (sodium hypochlorite) — water disinfection, soap-making lye
- Zinc plating — rust-proofs critical steel tools and hardware
- Hydrogen production — oxyhydrogen welding and cutting capability
- Oxygen production — enhanced forge temperatures, medical use
- Nickel plating — battery electrode improvement, corrosion resistance
Each step up this list requires the same basic infrastructure as the previous — the investments compound. Start with copper refining since it directly improves the electrical infrastructure needed for all other processes.