Enhancing the catalytic performance of calcium-based catalyst derived from gypsum waste for renewable light fuel production through a pyrolysis process: A study on the effect of magnesium content.

The thermochemical conversion of abundant renewable resources through pyrolytic catalysis cracking (PCC) is one of the most promising technologies for producing green biofuels. In this study, the pyrolysis of palm oil was investigated over a sustainable CaO-based catalyst derived from waste gypsum. PCC was conducted in a continuous packed-bed reactor under atmospheric pressure without purge gas. The effects of Mg doping and reaction temperature were also examined. A wet ball milling process was used to prepare the well-mixed catalysts and to subsequently form a heterojunction structure between the CaO and MgO particles. CaO was synthesized using the Ca(OH)2 derived from the reaction between gypsum and sodium hydroxide. The pyrolytic oil was separated from the crude oil to remove water and other impurities. The pyrolytic oil was then distilled following ASTM D86, and the three separated products were classified as bio-gasoline, bio-kerosene, and bio-diesel. The highest renewable light fuel volume (bio-gasoline and bio-kerosene) of about 75% (74 %wt.) was obtained at a reaction temperature of 525 °C with 10% MgCO3 content. The percent volume of light fuel increased with increasing reaction temperature. Renewable light fuel production over the Mg-doped CaO-based catalyst was related to both the Mg content and reaction temperature.

Hydrophobic Starch-Based Films Using Potato Washing Slurries and Spent Frying Oil.

Starch is a promising candidate for preparing biodegradable films with useful gas barriers and thermoplastic capabilities. However, these materials are hydrophilic and brittle, thus limiting their application range. To overcome these drawbacks, it has been hypothesized that starch can be hydrophobized and plasticized during the starch-based film production using a single-step approach and following transesterification principles. In this work, KOH powder and spent frying oil (SFO) were used as an alkaline catalyst and a source for triacylglycerides, respectively, to promote the modification of starch. Different ratios of SFO (w/w related to the dried starch weight) were tested. When compared to the neat films (without a catalyst and SFO), the incorporation of at least 15% SFO/KOH gave rise to transparent, hydrophobic (water contact angles of ca. 90∘), stretchable (ca. 20×), elastic (ca. 5×), and water tolerant starch-based films, contrary to the films produced without the catalyst. ATR-FTIR and 1H NMR revealed structural differences among the produced films, suggesting that starch was modified with the SFO-derived fatty acids. Therefore, adding KOH during the potato starch/spent frying oil-based film's production was determined to be a promising in situ strategy to develop starch-based materials with improved hydrophobicity and flexibility, while valorizing the potato chip industry's byproducts.

Effects of alkaline catalysts on acetone-based organosolv pretreatment of rice straw.

Organosolv is an effective pretreatment strategy for increasing digestibility of lignocellulosic materials owing to selectivity of solvents on separating biopolymeric constituents of plant biomass. In the present work, a novel low-temperature alkali-catalyzed organosolv pretreatment of rice straw was studied. The effects of alkaline catalysts (i.e., NaOH, ammonia, and tri-ethylamine) and solvent types (i.e., acetone, ethanol, and water) were carried out. Addition of alkalis led to increasing sugar from enzymatic hydrolysis while acetone was found to be superior to ethanol and water on selectivity towards cellulose preservation. The optimal alkaline-catalyzed pretreatment reaction contained 5% (w/v) NaOH in an aqueous-acetone mixture (1:4) at 80 °C for 5 min. A glucose yield of 913 mg/g of pretreated biomass was achieved, equivalent to a maximal glucose recovery of 93.0% from glucan in the native biomass. Scanning electron microscope revealed efficient removal of non-cellulosic components, resulting in exposed cellulose microfibers with a reduced crystallite size as determined by X-ray diffraction. With potential on obtaining high-quality lignin, the work demonstrated potential of the novel low-temperature alkaline-catalyzed acetone-based organosolv process for pretreatment of lignocellulosic materials in biorefineries.

An experimental study on the formation of methoxyaromatics during pyrolysis of Eucalyptus pulverulenta: Yields and mechanisms.

The production of bio-oil rich in methoxyaromatics during catalytic pyrolysis of Eucalyptus pulverulenta (EP) was studied using a fixed-bed reactor in the temperature range of 300-500°C and the bio-oil composition was analyzed by using a GC-MS. The results showed that the highest bio-oil yield of 38.45wt% was obtained at 400°C in the presence of Na2CO3, and the concentration of methoxyaromatics reached the maximum value of 63.4%(area) in the bio-oil. The major methoxyaromatics identified in bio-oil were guaiacol, syringol, 4-ethyl-2-methoxy phenol, and 1,2,4-trimethoxybenzene. The analysis of gaseous products indicated that CO2 was the major gas at low-temperatures and concentrations of H2 and CH4 increased with increasing pyrolysis temperature. Na2CO3 promoted the formation of methoxyaromatics, while NaOH seems to have enhanced the formation of phenolics. The mechanism of the formation of methoxyaromatics during pyrolysis of EP was proposed.

Ferric chloride based downstream process for microalgae based biodiesel production.

In this study, ferric chloride (FeCl3) was used to integrate downstream processes (harvesting, lipid extraction, and esterification). At concentration of 200 mg/L and at pH 3, FeCl3 exhibited an expected degree of coagulation and an increase in cell density of ten times (170 mg/10 mL). An iron-mediated oxidation reaction, Fenton-like reaction, was used to extract lipid from the harvested biomass, and efficiency of 80% was obtained with 0.5% H2O2 at 90 °C. The iron compound was also employed in the esterification step, and converted free fatty acids to fatty acid methyl esters under acidic conditions; thus, the fatal problem of saponification during esterification with alkaline catalysts was avoided, and esterification efficiency over 90% was obtained. This study clearly showed that FeCl3 in the harvesting process is beneficial in all downstream steps and have a potential to greatly reduce the production cost of microalgae-originated biodiesel.