This is the residual class for processes for separating a liquid mixture (distilland) by vaporizing and condensing at least a portion thereof to isolate in the condensed liquid (distillate) or in the unvaporized portion (residue) a comparatively pure compound which was present as such in the original mixture. The original mixture may be a solid under normal atmospheric conditions if it liquifies below the vaporization temperature.
To come within the purview of this class (203) the distilland must have a boiling point above 0 deg.C. under normal atmospheric pressure. Because the C4 hydrocarbons have boiling points above and below 0 deg.C., all C4 hydrocarbons are arbitrarily classified as having boiling points above 0 deg.C.
Sublimination (see Glossary) is excluded from this class (203). See References to Other Classes, below.
When claims are presented which recite a specific chemical compound or mixture to be recovered, the enumerated classifications set forth in Lines With Other Classes must be consulted to see if such subject matter is provided for in other than Class 203.
LINES WITH OTHER CLASSES
LINES WITH CHEMICAL COMPOSITION CLASSES
(1) Products whether claimed in terms of their composition or claimed in terms of the process of making are classified in the appropriate composition class even if the process merely recites a separatory distillation operation.
(2) Processes including a chemical reaction and a separatory distillation operation are classified here only when the chemical reaction merely facilitates the isolation by the separatory distillation operation of a preexisting substance in the distilland. See Class 260, Chemistry of Carbon Compounds, Class 423, Chemistry of Inorganic Compounds, or Class 585, Chemistry of Hydrocarbon Compounds for a process of preparing a compound and isolating it by a separatory distillation process. (3) Processes including a separatory distillation step and a disparate physical separation step, such as extraction, are classified in this class (203) if the disparate separating step follows the distillation step and the process is not otherwise provided for. When the disparate separation step precedes the distillation step, the process is generally provided for elsewhere.
See Class 260, Chemistry of Carbon Compounds (including Class 585, Chemistry of Hydrocarbon Compounds) or Class 423, Chemistry of Inorganic Componds, for a process of extraction of a compound, either as a sole step or followed by isolating the compound by a separatory distillation process.
(4) Processes directed solely to a separatory distillation operation are classified in this class (203) unless otherwise provided for:
(a) Processes for the distillation of metals, such as mercury or zinc are classified in Class 75, Specialized Metallurgical Processes, Compositions for Use Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures.
(b) Processes for distilling a mineral oil in which the product isolated is a pure compound are classified in this class (203). However, when the distillation process produces as the product a mineral oil, it is classified in Class 208, Mineral Oils: Processes and Products.
(c) Processes which include fermentation are classified in 435, Chemistry: Molecular Biology and Microbiology, even if such processes also include distillation.
(d) Processes for distilling fermented beverage to produce a distilled beverage are classified in Class 426, Food or Edible Material: Processes, Compositions, and Products, but processes for distilling a fermented beverage to isolate alcohol are classified here (203).
(e) When a patent contains a Class 423, Chemistry of Inorganic Compounds, process claim and a Class 203, Distillation: Processes, Separatory, process claim, the patent is classified in Class 423 and cross-referenced to Class 203.
PROCESSES INCLUDING EVAPORATION
Processes for evaporating without a condensing step are generally excluded from this class. For specific lines between the processes of this class and other processes including an evaporating step, see below.
This class (203) is distinguished from Class 34, Drying and Gas or Vapor Contact With Solids, in that the material treated herein (203) is a liquid or a liquefiable solid from which volatile material is to be separated and condensed or absorbed. The product recovered must be a relatively pure substance which existed as such in the original material. The material of Class 34 is a solid or semi-solid from which it is desired to remove a liquid, leaving the residue chemically unchanged. Class 134, Cleaning and Liquid Contact With Solids, takes claimed combinations of work handling or supporting means or
steps with means or steps to apply a liquid to the work, as by spraying or immersion, where said liquid is distilled or evaporated, whether or not the resulting vapor is (1) directly contacted with the work or (2) condensed for reuse to contact the work. When only the liquid distillation subcombination or the vapor-phase work contact subcombination has been claimed, see above for the line between Class 203 and Class 34.
Class 62, Refrigeration, includes processes for separating a mixture of substances having boiling points below 0 deg.C. (32 deg.F) at atmospheric pressure by the steps of vaporizing a component and condensing the vapor. When a patent includes species claims classifiable in Class 62 and Class 203, it is classified in Class 62 and cross-referenced to Class 203.
Class 95, Gas Separation: Processes, takes processes in which gas is removed from a liquid wherein the gas is normally gaseous at a temperature of 0 deg.C and a pressure of 760 mm Hg (e.g., hydrogen sulfide (H2S), carbon monoxide (CO), carbon dioxide (CO2), etc.). The volatile need not be condensed. The line between Class 95 and Class 203 is that a Class 203 operation requires vaporizing and condensing a material which is normally a liquid, while Class 95 does not.
Class 159, Concentrating Evaporators, takes processes for concentrating solids in solution or suspension by volatilizing the liquid. It is distinguished from this class (203) by the fact that the volatile material is not condensed.
Some additional classes which provide for processes that include an evaporating step or a concentrating step are: Class 23, Chemistry: Physical Processes; Class 127, Sugar, Starch, and Carbohydrates; Class 260, Chemistry, Carbon Compounds; Class 426, Food or Edible Material: Processes, Compositions, and Products; Class 520, Synthetic Resins or Natural Rubbers; Class 585, Chemistry of Hydrocarbon Compounds; Class 588, Hazardous or Toxic Waste Destruction or Containment.
CLASS 201, DISTILLATION: PROCESSES, THERMOLYTIC, IS SUPERIORTO CLASS 203.
REFERENCES TO OTHER CLASSES
SEE OR SEARCH CLASS
23, Chemistry: Physical Processes,
294, For general sublimation processes see and Class
62, Refrigeration, appropriate subclasses for processes and apparatus peculiar to removing heat from a substance. 75, Specialized Metallurgical Processes, Compositions for Use
Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures, appropriate subclasses for a process of reducing an ore to the metallic state or refining molten metal involving distillation or for a sublimination process.
75, Specialized Metallurgical Processes, Compositions for Use Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures, for the sublimation of metals.
95, Gas Separation: Processes, for processes involving steps resulting in separation of a gas from a fluid mixture comprising (a) a gas and solid or liquid particles entrained therein, (b) a liquid and gas entrained therein, or (c) a plurality of gases.
99, Foods and Beverages: Apparatus,
275+, for apparatus for preparing beverages.
106, Compositions: Coating and Plastic, appropriate subclasses for a coating composition which may be applied to surfaces of the distillation apparatus or utilized for making apparatus of a particular composition.
122, Liquid Heaters and Vaporizers, appropriate subclass for heating liquids, superheating or cooling the vapors generated and conserving the heat in the liquid or vapor in a closed system.
134, Cleaning and Liquid Contact With Solids,
1+, for a cleaning process, particularly subclass 12 for a process including the step of distilling the treating agent and subclass 31 for a process including the step of condensing a gas or vapor.
159, Concentrating Evaporators, for apparatus and processes not more specifically provided for elsewhere, peculiar to the concentration of solids held in solution or suspension by evaporation of the liquid containing them. See
48.1+, for a process of concentrating by spraying and subclass 49 for a process of concentrating by a filming operation. See also subclasses 5+ for a film type evaporator. 210, Liquid Purification or Separation, appropriate subclasses for a process for purifying or separating a liquid by (1) sorption or ionic exchange, (2) filtration, (3) liquid-liquid extraction, (4) purification by destruction or conversion of a constituent thereof.
260, Chemistry of Carbon Compounds,
706, for general sublimation processes.
261, Gas and Liquid Contact Apparatus, appropriate subclasses for apparatus adapted to produce an intimate contact between gases and liquids and see (2) Note under the class definition.
366, Agitating,
219+, for apparatus for agitating a liquid or a particulate material by motion of the container, and subclasses 241+ for a fixed container with movable stirring apparatus, particularly subclasses 262+ for pump type stirrers.
426, Food or Edible Material: Processes, Compositions, and Products,
11+, for processes of preparing alcoholic beverages including distillation.
585, Chemistry of Hydrocarbon Compounds,
801, for general sublimation processes.
588, Hazardous or Toxic Waste Destruction or Containment, appropriate subclasses for distillation process in the destruction of hazardous or toxic waste. GLOSSARY:
AZEOTROPIC DISTILLATION
A separatory distillation of a liquid in which a substance is added to the distilland mixture in order to assist separation of its components by forming with one or more of the components a mixture having a minimum boiling point. (The art has also used the term for a distillation process in which two substances in the starting material are removed by their forming a minimum boiling mixture).
CONDENSATE
See "distillate" in the class definition.
CONVECTIVE DISTILLATION
A separatory distillation operation in which an inert vapor is passed through a heated liquid to reduce the partial vapor pressure of the component in the liquid desired to be recovered. It permits the separation of heat sensitive high boiling substances at temperatures below their decomposition temperature. Steam distillation is the most commonly used type of convective distillation.
DISTILLAND
For purposes of this class the liquid or liquefied material which is undergoing a distillation operation.
DISTILLATE
The liquid product condensed from vapor during the distillation operation. EVAPORATION
The process of changing a solid or liquid into a vapor. This is the generic term for both sublumination and vaporization. It differs from "distillation" in that distillation includes the additional step of condensing vapor produced to a liquid.
EXTRACTIVE DISTILLATION
A separatory distillation in which a generally less volatile substance, often referred to as a solvent, is added to the distillation column to preferentially remove some component of the vapor by dissolving it. The added substance and the dissolved component are removed below the point at which the less volatile substance is added to the distillation column.
FLASH VAPORIZATION
The process in which the distilland is heated under pressure high enough to prevent ebullition (usually above atmospheric pressure) and the heated distilland is then introduced into a zone of lesser pressure resulting in the volatilization of at least a position of the distilland.
FRACTIONAL DISTILLATION
A separatory distillation operation in which distillate is collected over specific temperature intervals.
MOLECULAR DISTILLATION
A high vacuum separatory distillation process for distilling high boiling, heat sensitive substances in which the distance from the liquid surface to the condensing surface is less than the mean free path.
SEPARATORY DISTILLATION
A process of vaporizing at least a portion of a liquid mixture (distilland) and condensing at least a portion of the vapor to separate the liquid mixture into distinct parts. The substances recovered as products must have preexisted in the original mixture. STEAM DISTILLATION
A form of convective distillation in which the inert vapor passed through the heated liquid is steam. The adding of water or steam to a distillation column or the adding of water to a distilland is not within the meaning of this term.
SUBLIMATION
A process in which a solid passes into the vapor state without liquefaction and the vapor returns to the solid state without passing through the liquid phase.
THERMOLYTIC DISTILLATION
A distillation in which material found in the distilland undergoes chemical decomposition (thermolysis) to form different substances at least some of which are volatile at the temperature employed. The volatile substances are recovered by condensation or sorption.
VAPORIZATION
The process of changing a liquid into a vapor. See "Evaporation".