LRG

Liquefied refinery gas is a mixture of hydrocarbon vapors compressed and cooled into liquid form at the refinery itself, rather than being burned off or vented. The product emerges from catalytic cracking units and other refining processes as a byproduct; instead of treating it as waste, refineries liquefy it under pressure (typically 15 to 20 bar for storage in mild steel tanks) and supply it as a fuel or chemical feedstock. LRG composition varies by refinery and crude source, but typically contains propane, butane, propylene, and butylene in shifting proportions.

In mining and extraction operations, LRG serves principally as a portable high-energy fuel for equipment that cannot access natural gas pipelines or where diesel supply is constrained. Drill rigs, compressors, and generator sets in remote pit mines or exploration camps consume it directly from pressure vessels. The energy density is high (around 46 megajoules per kilogram for typical propane-rich cuts), making it cost-effective for transport to remote sites by truck or rail tanker compared to shipping finished gasoline or diesel.

LRG differs from liquefied petroleum gas (LPG) primarily in origin and specification. LPG is often a refined, standardized product with stricter volatility and composition limits; LRG is a refinery stream with looser specifications and wider boiling-point ranges. This makes LRG cheaper but less consistent in combustion behavior. Some equipment designed for LPG will accept LRG, but the reverse is not guaranteed. Sulfur content in LRG can be higher than in commercial LPG, which matters if equipment has no emission controls.

Practical constraints and handling

The main operational hazard is vapor pressure: LRG can generate hazardous vapor concentrations in enclosed spaces or leaking equipment at ambient temperature. Bulk storage requires robust pressure vessels and regular integrity inspection. Vehicle-mounted tanks must meet pressure vessel codes and be equipped with pressure relief valves, liquid-level gauges, and shut-off blocks. In cold climates, the heaviest fractions (butane components) can condense preferentially, altering mixture composition and engine performance.

Supply reliability depends on refinery throughput and maintenance schedules; LRG availability is secondary to refinery crude processing demands. Mining operations using LRG typically maintain onsite inventory (one to three weeks of consumption) to buffer against supply interruptions. Pricing tracks crude oil and refinery utilization rates rather than being set independently, making it volatile for budget forecasting in small-scale extraction operations.