Natural rubber is an essential material, especially for plane and truck tyres but also for medical gloves. Asia ranks first in the production of natural rubber, of which the Hevea tree is currently the sole source. However, it is anticipated that this source alone will not be able to fulfill the growing demand. Guayule, a shrub native to northern Mexico and southern United States, may also contribute. This plant not only contains polyisoprene, but also resin, a mixture of lipids and terpenoids. This review summarizes various aspects of this plant, from the usage history, botanical description, geographical distribution and cultivation practices, down to polyisoprene and resin biosynthesis including their distribution within the plant and molecular composition. Finally, the main processes yielding dry rubber or latex are depicted, as well as the properties of the various extracts along with economic considerations. The aim is to provide a wide picture of current knowledge available about this promising crop, a good feedstock candidate for a multiple-product biorefinery.
This study deals with the covalorization of spent bleaching clay (SBC) and palm fatty acid distillate (PFAD), the by-products of palm oil-refining plants (3 Mt. year −1 ), through soap manufacture. Obtained SBC and PFAD samples show differing acidity and saponification values depending on their content of free fatty acids and of acylglycerols. The SBC sample had an acidity of 60.5% and a saponification value of 182 mg KOH g −1 of oil, and the PFAD sample has an acidity of 88.4% and a saponification value of 204 mg KOH g −1 of oil. Soaps are prepared using the stoichiometric amount of NaOH, under varying proportion of water introduced through the basic solution. The overall reaction (neutralization and saponification) is complete (99.9%) with PFAD, whereas the yield reaches only 56.1% with SBC. When mixing SBC and PFAD, for example under a 1:1 weight ratio, the overall reaction completion (87.7%) is surprisingly higher than expected based on the computed individual reaction yields (78%), showing a synergistic effect of about 10% on the course of the saponification reaction of acylglycerols in SBC. The water content was found to be a critical parameter, 30% w/w of added water providing the highest yield. These results show an innovative way for covalorizing two important by-products of palm oil industrial processing as a single final product. By-products of the physical refining of other oils could also be valorized following the same method.Keywords Palm fatty acid distillate Á Spent bleaching clay Á Palm oil by-product Á Soap J Am Oil Chem Soc (2019) 96: 329-336. Values within the same column having the same or without superscript are not significantly different (P > 0.05); Data are written as mean value and SD. 333 J Am Oil Chem Soc J Am Oil Chem Soc (2019) 96: 329-336
Fortification of vegetable oils with vitamin A for consumers of different socioeconomic status is feasible; however, light protection is needed for better stability.
This study deals with the co-valorization of spent bleaching clay (SBC) and palm fatty acid distillate (PFAD) –by-products of palm oil refining plants- through soap manufacture. Obtained SBC and PFAD samples show differing acidity and saponification values depending on fatty acids and acylglycerols content. Soaps are prepared using the stoichiometric amount of NaOH, under the varying proportion of water introduced through the basic solution. The mixing SBC and PFAD (ratio 1:3), the reaction completion (92.5%) is surprisingly higher than expected, indicating a synergistic effect on the course of the saponification reaction. The water is also a critical parameter, 30% w/w of added water allowing the highest yield. When testing for cleaning efficiency the products having the highest soap content, those from individual by-products give a low microbial count reduction after hand-washing (30-37%). But a much better score (74%) is obtained when using SBC:PFAD soap mixtures. This improvement could be due to abrasive and absorption effects of the clay, combined with the high soap content. The acceptability through a panel test is good for all soaps when formulated with citrus oil. The most active product corresponds to a SBC:PFAD ratio close to the production one in refining plants. Therefore these results provide an easy way for co-valorising these by-products, after further optimizing the saponification reaction in this complex triphasic medium (aqueous solution, oil, clay).
Microwave-assisted pyrolysis was applied using four magnetrons to implement a high intensity at a power density of 0.3107 W/m3 with 800 g specimen size. The 23 full factorial experimental design manipulated the factors temperature, mixture ratio, and pyrolysis time, seeking to maximize %yield at minimum cost of crude bio-oil. The optimum according to model fit had a temperature of 611 °C with a 70:30 sample mixture ratio of oil palm shell (OPS) to activated carbon (AC), and time 39.6 min for a yield of 15.3% and 8.48 Thai-Baht/cc cost. The coefficients of determination were R2 = 93.99% and 94.00% for the respective models. In the aqueous phase of crude bio-oil, acetic acid was the dominant chemical component at 55.2%, whereas phenol was dominant in the bio-oil phase at 44.2%, from 400 °C pyrolysis temperature. The assessed properties of bio-char were proximate composition, heating value, specific surface, and pore volume, and these were improved compared to the raw OPS. However, these properties must be improved further to match commercial-grade activated carbon.
The important parameters characterizing microwave pyrolysis kinetics, namely the activation energy (E
a) and the rate constant pre-exponential factor (A), were investigated for oil palm shell mixed with activated carbon and palm oil fuel ash as microwave absorbers, using simple lab-scale equipment. These parameters were estimated for the Kissinger model. The estimates for E
a ranged within 31.55–58.04 kJ mol−1 and for A within 6.40E0–6.84E+1 s−1, in good agreement with prior studies that employed standard techniques: Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). The E
a and A were used with the Arrhenius reaction rate equation, solved by the 4th order Runge-Kutta method. The statistical parameters coefficient of determination (R
2) and root mean square error (RMSE) were used to verify the good fit of simulation to the experimental results. The best fit had R
2 = 0.900 and RMSE = 4.438, respectively, for MW pyrolysis at power 440 W for OPS with AC as MW absorber.
A study on scale up biodiesel production from palm fatty acid distillate at palm
oil refining plant, namely palm oil derived using palm fatty acid distillate (PFAD),
collected from the Oleen Palm Oil industrial refining plant. This PFAD showed free fatty
acid content and a saponification value of 88.4 % and 204 mg KOH/g respectively. An acid
catalyst was successfully used to produce biodiesel in the esterification reaction, and
a 97.11% conversion to biodiesel based on the European Standard EN 14214:2003 was
achieved under the conditions (PFAD to methanol molar ratio 1:3.71 with 1.834 % H2SO4
catalyzed at 121 ºC for 15 minute). Overall, this novel process achieved highly
enhanced FAME (95.82% to 97.31%) with a significantly increased reaction time (10 to 30
minutes) and catalyst requirements (1.834 % H2SO4). In conclusion, the acid catalyst
with high temperature and pressure showed potential to enhance the esterification
reaction rate of PFAD with low biodiesel production costs, high FAME yields and short
reaction times.
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