Abderrahim Bouaid

Production of biodiesel from bioethanol and Brassica carinata oil: oxidation stability study.

In the present work the synthesis from bioethanol and Brassica carinata, as alternative vegetable oil, using KOH as catalyst, has been developed and optimized by application of the factorial design and response surface methodology (RSM). Temperature and catalyst concentration were found to have significant influence on conversion. A second-order model was obtained to predict conversions as a function of temperature and catalyst concentration. The maximum yield of ester (98.04%) was obtained working with an initial concentration of catalyst (1.5%) and an operation temperature of (35 degrees C). Results show that the acid value, peroxide value, and viscosity, increased while the iodine value decreased with increasing storage time of the biodiesel sample. Fatty acid ethyl esters (biodiesel) from B. carinata oil were very stable because they did not demonstrate rapid increase in peroxide value, acid value, and viscosity with increasing storage time to a period of 12 months.

Enhancement of lipid accumulation in Scenedesmus obliquus by Optimizing CO2 and Fe3+ levels for biodiesel production

The effects of cultivation of Scenedesmus obliquus in nutrient medium supplemented with 0.03%, 3, 9% and 12% CO(2) or 2.5-20 mg L(-1) of Fe(3+) on dry weight of biomass (DW), total lipid accumulation (TL contents) and total lipid productivity (TLP) were evaluated under indoor conditions. The accumulation of TL and TLP showed an increasing trend with increasing of CO(2) or Fe(3+) levels. In cultures with 12% CO(2) or 20mg/L Fe(3+), maximum TL contents of 33.14% and 28.12%, respectively were obtained. These lipids displayed a fatty acid profile which is suitable for biodiesel production as the most abundant compounds were oleic (32.19-34.44%), palmitic (29.54-25.12%) and stearic (12.26-16.58% of total FAMEs) acids. The properties of biodiesel obtained from S. obliquus, were the same with those specification for biodiesel standards including ASTM D 6751 (American Society for Testing Material) and the European Standard En 14214. Thus, S. obliquus biomass could be used as suitable feedstock for biodiesel production.

Process Optimization for Biodiesel Production from Corn Oil and Its Oxidative Stability

Response surface methodology (RSM) based on central composite design (CCD) was used to optimize biodiesel production process from corn oil. The process variables, temperature and catalyst concentration were found to have significant influence on biodiesel yield. The optimum combination derived via RSM for high corn oil methyl ester yield (99.48%) was found to be 1.18% wt catalyst concentration at a reaction temperature of C. To determine how long biodiesel can safely be stored, it is desirable to have a measurement for the stability of the biodiesel against such oxidation. Storage time and oxygen availability have been considered as possible factors influencing oxidative instability. Biodiesel from corn oil was stored for a period of 30 months, and the physico-chemical parameters of samples were measured at regular interval of time. Results show that the acid value (AV), peroxide value (PV), and viscosity () increased while the iodine value (IV) decreased. These parameters changed very significantly when the sample was stored under normal oxygen atmosphere. However, the , AV, and IV of the biodiesel sample which was stored under argon atmosphere were within the limit by the European specifications (EN 14214).

Biorefinery approach for coconut oil valorisation: a statistical study.

The biorefinery approach, consisting in transesterification using methanol and potassium hydroxide as catalyst, has been used to assess coconut oil valorisation. Due to the fatty acid composition of coconut oil, low (LMWME) and high (HMWME) molecular weight fatty acid methyl esters were obtained. Methyl laurate (78.30 wt.%) is the major component of the low molecular weight fraction. The influence of variables such as temperature and catalyst concentration on the production of both fractions has been studied and optimized by means of factorial design and response surface methodology (RSM). Two separate optimum conditions were found to be a catalyst concentration of 0.9% and 1% and an operation temperature of 42.5 degrees C and 57 degrees C for LMWME and HMWME, respectively, obtaining conversion rates of 77.54% and 25.41%. The valuable components of LMWME may be recovered for sale as biolubricants or biosolvents, the remaining fraction could be used as biodiesel, matching the corresponding European Standard.

Lipid induction in Dunaliella salina culture aerated with various levels CO2 and its biodiesel production.

In this work, the effect of various levels of CO2 (0.01, 0.03, 3.0, 9.0 and 12.0%) aeration on the biomass production, lipid accumulation and its fatty acid profile as well as biodiesel properties of marine microalgae Dunaliella salina were investigated. The results show that the maximal biomass and lipid productivity (in parenthesis) in cultures aerated with different levels of 0.01, 0.03, 3.0, 9.0 and 12.0% CO2 were 255 (5.36), 412 (15.10), 781 (25.32), 1451 (41.96) and 951 mg/L (59.23 mg L-1d-1), respectively. Whereas, the lipid contents in cells were 2.33, 5.62, 10.28, 28.36 and 40.65%, respectively. Moreover, the levels of CO2 in culture medium had significant effect on fatty acid composition of D. salina. Linolenic and palmitic acids were identified as the major fatty acids in D. salina cells grown at different levels of CO2. The quality of biodiesel produced from algal lipid by a transesterification reaction was located between the limit imposed by the European Standards (EU 14214) and ASTM (US D6751). Based on the results obtained, D. salina could be used for mass-cultured in outdoor ponds, as a promising alternative to current CO2 mitigation strategy and as a suitable feedstock for biodiesel production.

Biodiesel Production from Babassu Oil: A Statistical Approach

The methyl esters synthesis from babassu oil and methanol using potassium methoxide (KOCH3) as catalyst has been developed and optimized by application of the Factorial Design of Experiments and Response Surface Methodology. The different variables affecting the alkaline methanolysis of babassu oil were studied. Temperature reaction was found to have the most significant influence on conversion. According to this study and from an economical point of view, the best conditions for overall process are catalyst concentration of 0.95% and an operation temperature of 45°C working with 6:1 methanol/oil molar ratio. With these conditions the maximum conversion obtained was 99.85%. The biodiesel produced from babassu oil has a high percentage of saturated fatty acids, 91%, mainly composed of lauric (51.8%) and myristic (22.2%) fatty acids making it particularly stable towards oxidation and resulting in good low temperature properties. The babassu oil methyl esters (BOME) could be converted in a highly promising substitute for conventional fuel possibly due to the good cold flow properties, high oxidative stability displayed and matching the European Biodiesel Standard EN 14214. These properties could make babassu oil methyl esters of a great interest.

Enhancing Biodiesel Production Using Green Glycerol-Enriched Calcium Oxide Catalyst: An Optimization Study

The present article demonstrates a superior catalytic performance of glycerol-enriched calcium oxide for biodiesel production than other calcium-based counterparts. The proficiency of glycerol-enriched calcium oxide in catalyzing the methanolysis of crude Jatropha curcas oil containing high free fatty acids content was systematically researched by examining the effects of glycerol dose, temperature, time, methanol-to-oil molar ratio and calcium oxide (CaO) amount on the process. Acid value of oil was lowered by 49 times and the maximum oil conversion of 96.1% was reported after the methanolysis reaction that indicated the improved performance of calcium oxide, after its treatment with glycerol, in accelerating biodiesel production from crude oil with very high free fatty acids amount. An interaction between the reaction variables, their influence on the methanolysis and optimum conditions affecting the process were moreover determined by means of the regression analysis (response surface methodology). The statistical analysis suggested that both CaO amount and mole ratio of methanol-to-oil had a significant impact on the current biodiesel production process.Graphical Abstract