Short Path Distillation Equipment & Lab Glassware
Short path distillation is a laboratory-grade purification technique that separates compounds by their boiling points under vacuum conditions. In botanical extract processing, short path distillation takes a crude extract and distills it into purer fractions -- isolating specific compounds by progressively heating the crude material under vacuum, vaporizing each target compound at its reduced-pressure boiling point, and condensing it in a separate receiving flask. The "short path" refers to the short distance the vapor travels from the boiling flask to the condenser, which reduces the pressure drop in the system and allows operation at lower temperatures than conventional distillation.
Equipment Components
A complete short path distillation system includes: a boiling flask (where the crude extract is heated), a short path distillation head with a built-in cold finger condenser, a receiving flask (or set of receiving flasks for fraction collection), a vacuum pump to maintain sub-atmospheric pressure, a heating mantle to control the boiling flask temperature precisely, and a recirculating chiller or cold water supply to cool the condenser. Each component must be compatible with the others in terms of glass joint size (typically 24/40 or 29/42 standard taper joints) and vacuum rating. Browse our lab chillers collection for condenser cooling equipment and our vacuum equipment collection for compatible vacuum pumps.
Operating Parameters
Short path distillation of botanical extracts typically operates at vacuum levels of 50-500 microns Hg (much lower pressure than vacuum purging) to achieve the reduced boiling points needed for fractional separation without thermal degradation. Operating temperatures in the boiling flask range from 100-250 degrees C depending on the target fraction -- lower temperatures at deeper vacuum for the most temperature-sensitive compounds, higher temperatures for less volatile fractions. The process requires precise temperature and vacuum control to achieve clean fraction separation; imprecise control produces fractions with mixed compounds rather than the isolated fractions that make distillation valuable. Fast shipping.
Short Path Distillation FAQ
What is short path distillation used for?
Short path distillation purifies and separates a crude botanical extract into distinct compound fractions by exploiting differences in boiling point under vacuum. The crude extract is heated under vacuum; as temperature rises, compounds boil in order of their vacuum-adjusted boiling points, travel a short distance to the condenser, and collect in a receiving flask as a purified fraction. The technique produces high-purity single-compound or narrow-fraction isolates from crude extracts that contain a complex mixture of compounds. It is a refinement step applied after initial extraction, not a primary extraction method.
What vacuum level do I need for short path distillation?
Short path distillation requires deep vacuum -- typically 50-500 microns Hg (absolute pressure) for most botanical extract applications. This is significantly deeper than vacuum purging (50-200 microns) and requires a two-stage rotary vane pump with an ultimate vacuum of 10-50 microns Hg. A vacuum gauge with micron-level resolution (a Pirani gauge or thermocouple gauge) is required to monitor and confirm operating vacuum -- standard compound gauges reading in inches of mercury do not provide adequate resolution for short path distillation work.
What is the difference between short path and wiped film distillation?
Short path distillation uses a simple boiling flask and condenser setup -- the crude extract sits in the boiling flask and is heated from below. It is batch-process equipment suitable for laboratory and small commercial volumes. Wiped film (or thin film) distillation passes the feed material as a thin film over a heated surface while a rotor continuously wipes the film -- producing a shorter residence time at temperature, lower thermal degradation, and much higher throughput. Wiped film is the industrial-scale upgrade from short path for commercial production. Short path is the accessible laboratory starting point; wiped film is the commercial production tool.
How do I know when to change receiver flasks during distillation?
Fraction changes during short path distillation are identified by: changes in the vapor temperature reading at the distillation head (the temperature at which vapor reaches the condenser, indicating which compound is distilling); changes in the color or clarity of the condensate flowing into the receiver; and the target boiling point range for each fraction based on known properties of the compounds being separated. The initial low-temperature fractions (called "heads") are typically discarded; the main fraction at target temperature is collected; the final high-temperature fractions ("tails") are collected separately or discarded. Changing the receiver flask at the right moment between fractions maintains fraction purity.
What glassware joint size should I use?
24/40 standard taper joints are the most common size for personal and small commercial short path setups -- the most widely available glassware size with the broadest accessory compatibility. 29/42 joints provide slightly higher throughput capacity for larger boiling flasks (500 ml to 2+ liters) used in commercial production. Verify all glassware components in your system use the same joint size -- mixing 24/40 and 29/42 components requires adapters that add vacuum leak risk at each additional connection point.