Production of Biodiesel From Balanites Aegyptiaca

Abstract

The invention provides methods for production of biodiesel from Balanites aegyptiaca oil or crushed nuts, and further relates to the biodiesel obtained. The Balanites aegyptiaca biodiesel obtained has a composition of triglycerides of mainly C16:0 and C18:0 saturated and unsaturated fatty acids, with a very high content of linoleic acid and of oleic acid, and it further contains Balanites saponins, acting as surfactants, which reduce the rate of corrosion and improve the performance of the engyne.

1 . A process for producing biodiesel from  Balanites aegyptiaca  oil, said process comprising the following steps:
 (i) reacting  Balanites aegyptiaca  oil with a C 1 -C 4  alkanol at a molar ratio of oil:alkanol from 1:12 to 1:3, at a temperature of about 25-100° C., under intensive mixture conditions, in the presence of a transesterification catalyst, and allowing the transesterification to occur while removing the glycerol formed during the reaction;   (ii) washing the mixture of C 1 -C 4  alkyl esters of fatty acids obtained in step (i) with water to remove the transesterification catalyst; and   (iii) recovering the  Balanites aegyptiaca  biodiesel comprising a mixture of C 1 -C 4  alkyl esters of fatty acids and, optionally,  Balanites aegyptiaca  saponins.   
     
     
         2 . The process of  claim 1 , wherein said C 1 -C 4  alkanol is methanol. 
     
     
         3 . The process of  claim 1 , wherein said C 1 -C 4  alkanol is ethanol. 
     
     
         4 . The process of  claim 1 , wherein said  Balanites aegyptiaca  oil:C 1 -C 4  alkanol molar ratio is 1:8 or 1:6. 
     
     
         5 . The process of  claim 1 , wherein said temperature is about 25-80° C. or about 25-60° C. 
     
     
         6 . The process of  claim 1 , wherein said transesterification catalyst is a homogeneous catalyst selected from the group consisting of potassium hydroxide, potassium methoxide, sodium hydroxide and sodium methoxide. 
     
     
         7 . The process of  claim 6 , wherein said transesterification catalyst is potassium hydroxide. 
     
     
         8 . The process of  claim 1 , wherein said transesterification catalyst is a heterogeneous solid basic catalyst, such as zeolite ETS-10. 
     
     
         9 . A process for producing biodiesel from  Balanites aegyptiaca  oil, said process comprising the following steps:
 (i) reacting  Balanites aegyptiaca  oil with ethanol at a molar ratio of oil:ethanol from 1:8 to 1:6, at room temperature (25° C.) or at about 63° C., under intensive mixture conditions, in the presence of potassium hydroxide, and allowing the transesterification to occur while removing the glycerol formed during the reaction;   (ii) washing the mixture of ethyl esters of fatty acids obtained in step (i) with water to remove the potassium hydroxide; and   (iii) recovering the  Balanites aegyptiaca  biodiesel comprising a mixture of ethyl esters of fatty acids of palmitic acid (12-18%), stearic acid (11-15%), oleic acid (22-27%) and linoleic acid (44-49%), and optionally  Balanites aegyptiaca  saponins.   
     
     
         10 . A process for producing  Balanites aegyptiaca  oil from  Balanites aegyptiaca  whole seeds, said process comprising the following steps:
 (i) washing the  Balanites aegyptiaca  whole seeds with water to dissolve and remove the glycosides from the seed coat;   (ii) drying the washed whole seeds;   (iii) crushing the whole seeds to obtain a powder;   (iv) extracting the powder to obtain a crude  Balanites aegyptiaca  oil; and   (v) filtering the crude  Balanites aegyptiaca  oil.   
     
     
         11 . The process of  claim 10 , wherein the washing in step (i) is performed with circulating water. 
     
     
         12 . The process of  claim 10 , wherein the extraction in step (iv) is performed by extruding said powder and draining the crude  Balanites aegyptiaca  oil. 
     
     
         13 . The process of  claim 10 , wherein the extraction in step (iv) is performed using an organic solvent. 
     
     
         14 . The process of  claim 10 , wherein the filtration in step (v) comprises centrifugation of said crude  Balanites aegyptiaca  oil followed by a vacuum filtration of the oily phase obtained. 
     
     
         15 . The process of  claim 10 , wherein the filtration in step (v) comprises decantation of said crude  Balanites aegyptiaca  oil. 
     
     
         16 . A process for producing biodiesel from  Balanites aegyptiaca  crushed nuts, said process comprising the following steps:
 (i) homogenizing  Balanites aegyptiaca  crushed nuts with a C 1 -C 4  alkanol, at a temperature of about 25-100° C.;   (ii) reacting the homogenate obtained in step (i) with a transesterification catalyst;   (iii) filtering the reaction mixture product obtained in step (ii);   (iv) extracting  Balanites aegyptiaca  biodiesel comprising a mixture of C 1 -C 4  alkyl esters of fatty acids and optionally  Balanites aegyptiaca  saponins from the filtrate obtained in step (iii);   (v) neutralizing the mixture product obtained in step (iv) and removing C 1 -C 4  alkanol;   (vi) drying and filtering the product obtained in step (v);   (vii) recovering the  Balanites aegyptiaca  biodiesel; and   (viii) drying the filter-cake obtained in step (iii) and extracting the dried filter-cake to recover additional  Balanites aegyptiaca  biodiesel left in said dried filter-cake.   
     
     
         17 . The process of  claim 16 , wherein said C 1 -C 4  alkanol is methanol. 
     
     
         18 . The process of  claim 16 , wherein said C 1 -C 4  alkanol is ethanol. 
     
     
         19 . The process of  claim 16 , wherein the temperature in step (i) is about 25-80° C. or about 25-60° C. 
     
     
         20 . The process of  claim 16 , wherein said transesterification catalyst is a homogeneous catalyst selected from the group consisting of potassium hydroxide, potassium methoxide, sodium hydroxide and sodium methoxide. 
     
     
         21 . The process of  claim 20 , wherein said transesterification catalyst is potassium hydroxide. 
     
     
         22 . The process of  claim 16 , wherein said transesterification catalyst is a heterogeneous solid basic catalyst, such as zeolite ETS-10. 
     
     
         23 . A biodiesel fuel mixture obtained by transesterification of  Balanites aegyptiaca  oil or crushed nuts. 
     
     
         24 . The biodiesel fuel mixture of  claim 23 , comprising a mixture of ethyl esters of palmitic acid (12-18%), stearic acid (11-15%), oleic acid (22-27%) and linoleic acid (44-49%), and  Balanites aegyptiaca  saponins (0.01-0.05%). 
     
     
         25 . The biodiesel of  claim 24 , having the properties disclosed in Table 3 herein. 
     
     
         26 . The biodiesel of  claim 24 , having the properties disclosed in Table 4 herein. 
     
     
         27 . The biodiesel of  claim 24 , having the properties disclosed in Table 6 herein.