Hexane has been used for decades to extract edible oil from cottonseed. However, due to increased regulations affecting hexane because of the 1990 Clean Air Act and potential health risks, the oil-extraction industry urgently needs alternative hydrocarbon solvents to replace hexane. Five solvents,n-heptane, isohexane, neohexane, cyclohexane, and cylopentane, were compared with commercial hexane using a benchscale extractor. The extractions were done with a solvent to cottonseed flake ratio of 5.5 to 1 (w/w) and a miscella recycle flow rate of 36 mL/min/sq cm (9 gal/min/sq ft) at a temperature of 10 to 45°C below the boiling point of the solvent. After a 10-min single-stage extraction, commercial hexane removed 100% of the oil from the flakes at 55°C; heptane extracted 100% at 75°C and 95.9% at 55°C; isohexane extracted 93.1% at 45°C; while cyclopentane, cyclohexane, and neohexane removed 93.3, 89.4, and 89.6% at 35, 55, and 35°C, respectively. Each solvent removed gossypol from cottonseed flakes at a different rate, with cyclopentane being most and neohexane least effective. Based on the bench-scale extraction results and the availability of these candidate solvents, heptane and isohexane are the alternative hydrocarbon solvents most likely to replace hexane.

The Hexane Market is Segmented by Type (n-Hexane, Isohexane, Neohexane), Grade (Polymer Grade, Food Grade, Other Grades), Application (Industrial Solvents, Edible Oil Extractant, Adhesives and Sealants, Paints and Coatings, Other Applications), and Geography (Asia-Pacific, North America, Europe, South America, and Middle East & Africa).

The hexane arket report include: 

Edible Oil Extraction to Dominate the Market

• Hexane is increasingly being used as a solvent to extract edible oils from seed and vegetable crops, e.g., peanuts, soybeans, corn, etc.
• Hexane has a greater ability to extract oil, compared to other solvents, like petroleum ether and ethyl acetate. It easily mixes with vegetable oil and washes it out without disturbing fiber, protein, sugar, and undesired gums.
• Growth in the edible oil segment can be attributed to the rising awareness among consumers about the use of refined oil and the impact it has on health.
• According to the United States Department of Agriculture, the consumption of edible oils like soybean oil, in 2019, in the United States, was 10,659 metric ton and canola oil was 2,465 metric ton. Moreover, according to the Department for Promotion of Industry & Internal Trade, in India, the investment value in the vegetable oil sector, in 2019, was around INR 18 billion.
• Additionally, the consumers are inclined to pay higher prices for healthy food products, owing to the increasing food-based health challenges, such as high cholesterol, obesity, etc.
• The growing popularity of edible oils with added health benefits in many countries is shaping the purchase decisions of edible oils, which are high in omega 3, vitamins, oryzanol, natural antioxidants, and others. Thus, exhibiting the likely demand for edible oils in the forthcoming years.

Use of leaching solvent in preparing edible fat and oil

A leaching solvent used for preparing edible oils is characterized in that the solvent is applied to the leaching process of edible oil preparation so as to leach oil from materials. The solvent consists of the following components by weight ratio: 94 to 100 percent of isohexane, 0 to 3 percent of normal hexane and 0 to 3 percent of butane and pentane; the leaching process includes the following steps of: 1) leaching: the leaching temperature is 48 to 53 DEG C and a mass ratio between the materials and solvent is 1/1 to 0.8; mixed oil and leached wet meal are obtained; 2) desolventizing: the finished meal is obtained; 3) the evaporation of a first long-tube; 4) the evaporation of a second long-tube; mixed oil is obtained; and 5) steam stripping: raw oil is obtained. The solvent of the invention is mainly composed of isohexane so as to largely reduce the harm to the health of operators exposed in the manufacturing environment; the product quality can be enhanced and the protection to environment can be enhanced; the latent heat for the evaporation of isohexane is low and then the energy cost required by the solvent recycling can be effectively reduced.

Corn oil (maize oil) is oil extracted from the germ of corn (maize). Its main use is in cooking, where its high smoke point makes refined corn oil a valuable frying oil. It is also a key ingredient in some margarines. Corn oil is generally less expensive than most other types of vegetable oils.

Corn oil is also a feedstock used for biodiesel. Other industrial uses for corn oil include soap, salve, paint, erasers, rustproofing for metal surfaces, inks, textiles, nitroglycerin, and insecticides. It is sometimes used as a carrier for drug molecules in pharmaceutical preparations.

Global n-Hexane market dynamics 

Demand for n-Hexane, especially in developing region such Asia Pacific, is expected to boost the demand of the global n-Hexane market over the forecast period. Excellent properties of n-Hexane to remove odor and unwanted taste are expected to propel the demand of n-Hexane from the edible oil industry. n-Hexane has the ability to remove unwanted taste and odor and this is the precise reason that the demand for n-Hexane has increased in edible oil industry. However, the consumers from developed regions are shifting from refined oil to cold-pressed oil owing to its superior health benefits. Cold pressing is a natural way to produce oil which does not contain solvent residues, no preservatives with natural antioxidants. In addition, Isohexane, a hexane isomer is used as a substitute of n-Hexane in few oilseed extraction applications. Due to toxic nature of n-Hexane, it has been substituted by n-heptane in some pharmaceutical applications. This may retard the growth of the n-Hexane market.

Almost all corn oil is expeller-pressed, then solvent-extracted using hexane or 2-methylpentane (isohexane). The solvent is evaporated from the corn oil, recovered, and re-used. After extraction, the corn oil is then refined by degumming and/or alkali treatment, both of which remove phosphatides. Alkali treatment also neutralizes free fatty acids and removes color (bleaching). Final steps in refining include winterization (the removal of waxes), and deodorization by steam distillation of the oil at 232–260 °C (450–500 °F) under a high vacuum.

Some specialty oil producers manufacture unrefined, 100%-expeller-pressed corn oil. This is a more expensive product since it has a much lower yield than the combination expeller and solvent process, as well as a smaller market share.