The use of rice bran oil within a biorefinery concept

Abstract

Background: A waste of the rice production chain, namely bran, can be used to produce an oil with a very high content in free fatty acids (FFA). Due to its very high acidity, this material cannot be used neither to feed power generators nor as raw material for oleochemicals synthesis, and therefore it is not even extracted. Results: Rice bran oil with a content of 84 % in free fatty acids can be converted into a mixture of triglycerides or into useful oleochemicals such as monoglycerides, widely used as emulsifiers in food. Monoglycerides were obtained carrying out a one step esterification + transesterification reaction over an amorphous solid acid. Yields are higher than those obtained by enzymatic transesterification of oil and competitive with the esterification of free fatty acids involving the use of homogeneous acids generating significant amounts of wastewaters. On the other hand, esterification with higher amount of glycerol, a low value by-product of the biodiesel industry, gave an oil with low acidity suitable to feed power generators. Conclusions:The use of solid acid catalysts is a valuable tool for the valorization of rice bran oil. The chance to produce a low acidity oil or monoglycerides in one step from RBO may add value to the whole rice productive chain while setting the stage for the design of biorefineries based on the use of agro-industrial residues.

Value Chain Analysis of Rice Industry by Products in a Circular Economy Context: A Review

“…Considering the concept of circular economy and green product technology, the biorefinery plan would be the best option for managing and utilizing rice bran [145]. In addition to providing more nutrients than other cereal grains, rice bran has more lipids, protein, and calories [146][147][148] (Table 5).…”

Solid Acid Catalysts: New Routes to Food Additives and Antibacterials

“…As already shown in other applications this system has a higher tendency to promote transesterification with respect to the other materials here proposed. [22] Under these conditions a content in monoglyceride up to 65.6 % is reached, with complete transesterification of triglycerides.…”

“…[17][18][19] On the other hand, some of us already explored the potentiality of simple mesoporous amorphous mixed oxides such as SiO 2 -Al 2 O 3 , SiO 2 -TiO 2 and SiO 2 -ZrO 2 not only in the esterification of fatty acids with methanol, [20] but also with polyols such as trimethylolpropane for the preparation of biolubricants [21] and glycerol. [22] In the present paper the use of the same class of mesoporous oxides in the esterification of different kind of fatty acids with glycerol is presented, in order to obtain mixtures with high content in the corresponding monoglycerides.…”

Application of Phosphonium- and Choline Chloride Based Deep Eutectic Solvents as Catalyst for Emulsifier Production from Low Quality Oil Assisted by Microwave Irradiation

“…Together with rice husks accounting for 20% of the total number of crops processed, that means its potential reaches 31.9 million metric tons (MMT) per year in the world [6]. Rice bran contains an amount of 15-25% oil, potentially reaching 6.4 MMT/year [6], an amount comparable to other important commodities such as cottonseed and oil palm. The use of rice bran oil (RBO) is still limited as a by-product in rice production.…”