Biodiesel production from crude Jatropha Curcas oil using calcium based mixed oxide catalysts

Calcium-based, CaO–NiO (calcium nickel) and CaO–Nd2O3 (calcium neodymium) mixed oxides, were synthesized via co-precipitation process. Non-edible crude Jatropha curcus oil (JCO) was used as feedstocks for fatty acid methyl esters (FAME) synthesis in the presence of CaO–NiO and CaO–Nd2O3 mixed oxides. It was found that mixed solid bases oxides depicted high basicity and stability. Temperature programmed desorption of CO2 (CO2-TPD) confirmed that both strong and strongest basic sites existed on the surface of CaO–NiO and CaO–Nd2O3 catalysts, respectively. Both mixed oxide catalysts also demonstrated high thermal stability, since X-ray diffraction (XRD) proved that the crystalline phases present in both mixed oxide catalysts preserved well as pure oxide even up to 900 °C. The FAME yield produced by CaO–NiO and CaO–Nd2O3 catalysts were studied and compared with calcium oxide (CaO), nickel oxide (NiO), and neodymium oxide (Nd2O3) catalysts. Both CaO–NiO and CaO–Nd2O3 catalysts exhibited high activity as CaO and were easily separated from the product. CaO–NiO catalyst was found more active than CaO–Nd2O3 during the transesterification reaction. The optimal reaction parameters for achieving the >80% of FAME yield were methanol/oil molar ratio 15:1, catalyst amount 5 wt.% and reaction temperature 65 °C. Reusability study suggests that catalysts could be recycled for six successive runs without significant loss in activity. As a result, these new solid base mixed catalysts showed remarkable activity and durability in the synthesis of fatty acid methyl esters from crude JCO. Hence, the mixed oxides catalyst might be a valuable heterogeneous catalyst for FAME production

Optimization of simultaneous production of waste cooking oil based-biodiesel using iron-manganese doped zirconia-supported molybdenum oxide nanopeprintss catalyst

Biodiesel derived from simultaneous esterification and transesterification of waste cooking oil has been attracting consideration as a replacement green fuel for diesel fuels, as it is economically feasible and circumvents the issue of energy versus food, which is estimated to take place with current biodiesel production techniques. In this optimization study, iron-manganese doped zirconia-supported molybdenum oxide catalyst has been prepared and used in the synthesis of waste cooking oil based biodiesel by a simultaneous esterification and transesterification method. The catalyst is prepared via an impregnation method and consequently characterized by XRD, TEM, TGA (thermogravimetric analysis), TPD-NH3, and Brunauer–Emmer–Teller (BET) techniques. The simultaneous process for biodiesel production has been assessed and improved statistically via response surface methodology in combination with the central composite design. It has been established that the process for synthesis of waste cooking oil based biodiesel achieved about 96.8% biodiesel yield at a best condition of 200 °C, waste cooking oil/ methanol molar ratio of 1:30 and 5.0 wt. % as loading of the catalyst. The highest ester yield of 96.8% has been obtained due to the improved physicochemical properties of zirconia-supported molybdenum oxide catalyst which accesses diffusion of the reactants to the active sites

CeO2–SiO2 supported nickel catalysts for dry reforming of methane toward syngas production

Supported nickel catalysts (5 wt.% Ni) on binary CeO2–SiO2 (CS) with different ceria loading were prepared by wet impregnation and evaluated under catalytic dry reforming of methane (DRM) reaction to produce syngas. Analytical methods of characterization i.e. EDX, BET surface area, XRD, H2-TPR, CO2-TPD, TEM, SEM and TGA were conducted to analyze the physico-chemical properties of the prepared samples as well as to identify the carbon formation of the spent catalysts. The results showed that the properties of CeO2–SiO2 (Ni/xCS) catalysts were superior to the Ni/SiO2 and Ni/CeO2 catalysts, in terms of particle sizes, Ni dispersion, reducibility and basicity. The catalyst evaluation showed that ceria addition on the Ni-supported catalysts influenced the catalytic performances and hindered the carbon formation significantly. In this study, Ni/CS catalyst with 9 wt.% ceria exhibited good properties, high catalytic performance, elevated stability and low carbon deposition, thus considered to be the best catalyst with the optimal amount of ceria

Sub- and supercritical esterification of palm fatty acid distillate with carbohydrate-derived solid acid catalyst

The esterification of palm fatty acid distillate (PFAD) in supercritical methanol was investigated by using carbohydrate-derived solid acid catalyst. The catalysts were prepared by sulfonation of incomplete carbonized glucose and starch, which had been coded as sulfonated-ICG and sulfonated-ICS, respectively. The contents of fatty acid methyl ester (FAME) and its yield were determined by using gas chromatography techniques. The effects of sub- and supercritical operating conditions such as methanol/PFAD molar ratio, catalyst amount, reaction temperature and reaction time were analyzed to determine their optimum operating conditions. At optimum reaction temperature of 290 °C, methanol/PFAD molar ratio of 6/1, catalyst amount of 1 wt.% and 5 min reaction time, the esterification of PFAD in supercritical methanol with the presence of sulfonated-ICS and -ICG catalysts resulted 97.3% and 95.4% of FAME; both catalysts yield significantly higher percentages compared to uncatalyzed reaction. Alongside of its potential in enhancing the efficiency of production process, the utilization of carbohydrate-derived solid acid catalyst in supercritical methanol method had also resulting fast reaction and energy saving

Efficient waste Gallus domesticus shell derived calcium-based catalyst for biodiesel production

In this study, waste shells derived calcium-based catalysts were synthesized via wet-impregnation process in the presence of Mo-Zr mixed salt. The synthesized catalysts were characterized using CO2-TPD, XRD, BET surface measurement, SEM and EDX spectrometry, respectively. This heterogeneous catalyst was used to synthesize biodiesel via transesterification of waste cooking palm oil (WCPO) to fatty acid methyl ester in the presence of methanol. The catalyst demonstrated a superior catalytic performance in transesterification reaction, yielded 90.1% in 3 h. Reusability of this waste shell derived catalyst was examined and results showed that the prepared catalysts are able to be reused up to 3 times with yield of more than 70% after the third cycles. Therefore, this new modified calcium-based catalyst exhibited outstanding activity and durability in the synthesis of biodiesel. The as-synthesized catalyst is recyclable and reusable, which successfully reduces the biodiesel production cost

Carbohydrate-derived solid acid catalysts for biodiesel production from low-cost feedstocks: a review

Currently, most biodiesels are produced from virgin vegetable oils using a transesterification reaction. However, there are a number of other potential cheap sources for biodiesels, such as deep-frying oils/fats and palm fatty acid distillate (PFAD). PFAD is a lower-value by-product of the palm oil industry and is an economical source for biodiesel production. Due to the high cost of biodiesel production, the formulation of a new method to produce a cheaper biodiesel is imperative. Low-quality feedstocks (especially PFAD) using green and highly reusable catalysts have gained popularity due to their low production cost. High free fatty acids (HFFA) in the feedstock causes problems during the biodiesel production process, especially with the use of basic heterogeneous and homogenous catalysts. Recently, the effectiveness of a solid acid catalyst to catalyze biodiesel production from HFFA feedstock has caught the attention of researchers. This comprehensive article explores the use of low-quality feedstocks and carbon-based catalysts for the conversion of a waste refinery crude palm oil product which contains a high percentage of FFA. The production and characterization of carbohydrate-derived solid acid catalysts are discussed, including their physico-chemical property measurements. Techniques used for the synthesis of biodiesels are also included. In addition, transesterification process variables such as the oil/methanol molar ratio, catalyst concentration, reaction time, and temperature are investigated. The final part of the article contains the combustion, emissions, and performance of produced biodiesels. Finally, conclusions, including perspectives and future developments, are also presented. The aim of this article is to demonstrate the current state of the use of low-quality feedstocks and green heterogeneous solid acid catalysts for the use in biodiesel production

Synthesis of char-based acidic catalyst for methanolysis of waste cooking oil: an insight into a possible valorization pathway for the solid by-product of gasification

Gasification-based char from a commercial small-scale gasification plant was converted into an acidic catalyst for methanolysis of waste cooking oil (WCO). The char-based acidic catalyst was synthesized by the sulfonation of gasification char with sulfuric acid. Functional groups, acid density, morphological and surface properties were characterized and measured by using Fourier transform infrared red spectroscopy, ammonia temperature programmed desorption, field emission scanning electron microscope and Brunauer-Emmett-Teller, respectively. Wood char based acid catalyst showed higher surface area of 337 m2/g and acid density of 2.94 mmol/g. The reaction variables such as methanol/oil molar ratio, catalyst loading, reaction time and temperature, were studied. The optimum reaction conditions, 9:1 methanol/oil ratio, 6 wt% catalyst loadincxg, 130 min reaction time at 65 °C, gave 96% of ester conversion. The recovered catalyst was washed and reused without any activation (calcination), still giving 81% of ester conversion after five reaction cycles. Furthermore, fuel properties of WCO methyl esters were determined as per the ASTM and EN biodiesel standards. The utilization of char from biomass gasification for the synthesis of an acid catalyst for biodiesel production allows achieving a twofold objective. On the one side, the valorization of a material which is presently wasted. On the other side, the production of a catalyst that can effectively convert WCO into biodiesel in a single step process, therefore allowing a simplified procedure and lower operational temperatures. In addition, the obtained catalyst showed an interesting efficiency in decreasing free fatty acid of WCO and a considerable recyclability of the catalyst

Identifying and Forecasting Potential Biophysical Risk Areas within a Tropical Mangrove Ecosystem Using Multi-Sensor Data

Mangroves are one of the most productive ecosystems known for provisioning of various ecosystem goods and services. They help in sequestering large amounts of carbon, protecting coastline against erosion, and reducing impacts of natural disasters such as hurricanes. Bhitarkanika Wildlife Sanctuary in Odisha harbors the second largest mangrove ecosystem in India. This study used Terra, Landsat and Sentinel-1 satellite data for spatio-temporal monitoring of mangrove forest within Bhitarkanika Wildlife Sanctuary between 2000 and 2016. Three biophysical parameters were used to assess mangrove ecosystem health: leaf chlorophyll (CHL), Leaf Area Index (LAI), and Gross Primary Productivity (GPP). A long-term analysis of meteorological data such as precipitation and temperature was performed to determine an association between these parameters and mangrove biophysical characteristics. The correlation between meteorological parameters and mangrove biophysical characteristics enabled forecasting of mangrove health and productivity for year 2050 by incorporating IPCC projected climate data. A historical analysis of land cover maps was also performed using Landsat 5 and 8 data to determine changes in mangrove area estimates in years 1995, 2004 and 2017. There was a decrease in dense mangrove extent with an increase in open mangroves and agricultural area. Despite conservation efforts, the current extent of dense mangrove is projected to decrease up to 10% by the year 2050. All three biophysical characteristics including GPP, LAI and CHL, are projected to experience a net decrease of 7.7%, 20.83% and 25.96% respectively by 2050 compared to the mean annual value in 2016. This study will help the Forest Department, Government of Odisha in managing and taking appropriate decisions for conserving and sustaining the remaining mangrove forest under the changing climate and developmental activities

Post-functionalization of polymeric mesoporous C@Zn coreeshell spheres used for methyl ester production

In the present study, the mesoporous carbon@zinc (C@Zn) core-shell spheres were hydrothermally synthesized, using polyethylene glycol (PEG) as the surfactant and d-glucose as the pore forming agent. Then, the post-sulfonation treatment was carried out to prepare polymeric mesoporous SO3H-ZnO catalyst. The physicochemical, structural, textural and morphological properties of the synthesized catalysts were characterized by X-ray powder diffraction (XRPD), surface area analysis (Brunauer–Emmett–Teller equation), temperature programed desorption (TPD), field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The polymeric mesoporous SO3H-ZnO catalyst owned a high surface area of 396.56 m2/g with the average pore size of 3.45 nm and acid strength of 1.92 ± 0.05 mmol/g. The catalytic activity of the synthesized catalyst was further studied via esterification of the palm fatty acid distillate (PFAD), using a microwave-assisted technique. The biodiesel yield of 91.20% was achieved under the optimized esterification conditions as follows: the methanol to PFAD molar ratio of 9:1, catalyst concentration of 1.5 wt%, reaction temperature of 90 °C and reaction time of 15 min. The spent mesoporous catalyst was highly stable for reuse with nine continuous runs without further treatment