The main objective of this research work is to evaluate the performance of the reaction to obtain biodiesel from used domestic oils, as a function of time and catalyst, using microwaves as a heat source. A biodiesel was obtained that conforms to the technical considerations of National and International Standards; with 92

% yield, 12.62 cetane index, peroxide index of 0.3667, 102.63 iodine index, 3.65 mm2/s viscosity and a calorific value of 90 390 KJ/Kg. This work can serve as a model for the development of new biodiesel fuels that are interested in contributing to mitigate the environmental impact. It stresses the importance of producing an environmentally friendly fuel, mainly using an input with no commercial value, such as discarded domestic oil. In this context, there is the other contribution of this thesis, the ostensible reduction of the biodiesel production time, which normally takes two hours on average, with microwave activation, is obtained in minutes. The novelty of this work consists in using a statistical method to indicate, in a theoretical way, values where we can start the research. Thus, the Two Level Factorial Design is used, obtaining two theoretical values: the microwave exposure time and the percentage of the catalyst. The experimental values were close to these statistical values obtained and indicated in this Thesis. This was of vital importance in the achievement of the proposed objectives.

Global warming and the high demand for fuels, induce the search for new alternative energy sources, especially if they are renewable resources, and even better, if recyclable raw materials are used. The constantly increasing costs of environmental care make it a very attractive source, belonging to the waste- to-energy (WTE) category, which has enormouspotential for fuel production. The main inputsfor this type of processesare recycled domestic oils, municipal solid waste, industrial and agricultural wastes.In order to maintain a policy of environmental protection, toxic wastes emitted by an overpopulated world and, each time in continuous growth, force to look for synthesis methods that are less harmful to the environment. Techniques are also being soughtto mitigate the environmental impact.To generate biodieselfrom plants, the oil contained in their seeds must first be obtained, either by mechanical pressing or by chemical extraction using solvents. High oil prices, the crisis in agriculture, low international oil prices, are some of the factors that have contributed to give additional prominence to biodiesel. Sensitizing elements of society, such as the sanitary crisis of lead, the existence of foreign investors interested in producing this fuel in the country, contribute to thisprocess.The virtues derived from substituting, even partially, the oil, imported in its totality, by another fuel, produced in the country, means foreign currency that we pay to third parties versus foreign currency that we choose to leave in the country, which generates jobs and a chain of multiplying effects in the internal economy. There are few signs that there is political will to work on this issue, that there is a market that demands this product, producers capable of generating the raw material and industrialists interested in processing it, but at least there is interest from certain environmentalist sectors..

Problematic Reality

The search for alternative energy sources to oil is not a recent phenomenon in the world.Based on economicissues, the environmental issue was added to it during the oil crisis of the 1970's. International treaties, particularly those related to Climate Change, have reflected pressures from various sectors to research and implement alternative energy sources to oil. International treaties, particularly those related to Climate Change, have reflected pressures from various sectors to research and implement alternative energies to fossil fuels. In the particular case of biodiesel, its discovery was made a century ago and it has been used for years in Europe and North America. The virtues derived from substituting, even partially, oil, imported in its entirety, with another fuel, produced in the country, means foreign currency that we pay to third parties versus foreign currency that we choose to leave in the country, which generates jobs and a chain of multiplying effects in the domestic economy. There are few signs that there is political will to work on this issue,that there is a marketthat demands this product, producers capable of generating the raw material and industrialists interested in processing it, but at leastthere is interest from certain environmentalist sectors.

1.Equipments, Materials And Reagents

Sansung microwave oven, model T 750 Pot of 250 W. Thermometer from 0 to 400°C. Erlenmeyer flasks 250 ml. Glass beakers, Pyrex brand. Small mortar of 10 cm diameter. Decanting funnels. Vigreoux column of 2.54 cm in diameter and 30 cm long. Glass cooler of concentric tubes of 30 cm in length. Pipettes, micropipettes. Watman No. 90 filter paper. Fisher brand. Equipment to determine the calorific value. Calorimetric pump. Engler viscometer equipment. Equipment to determine the flash point (Pensky-Martens test apparatus).

Reagents: Methanol. KOH in pellets. Glacial acetic acid. Metallic iodine. Chloroform. 0.1 N sodium thiosulfate. 1% starch solution. Distilled water.

Experimental Procedure

1.1.Collection of used oil

1.2.The oil used for this experiment is of vegetable origin, collected from kitchen waste, obtaining a total of 3 liters.

1.3.Inputs and reagents used

The raw material used for the production of biodiesel was used domestic oil. The solvent was reagent grade methanol, the catalyst was sodium hydroxide in an amount of 0.7 to 1.5% weight/weight, as supported by the statistical model.

1.4.Conditioning of the microwave equipment

To carry out the experiments, a hole of 2.60 cm in diameter was drilled in the upper part of the microwave oven, a hole large enough to allow the Vigreoux column to pass into the straight condenser and to obtain the first distillate in the decanting funnel, the by-product to be obtained.

1.5.Characteristis of used oil

Table 01: Analysis carried out at the Chemistry Laboratory-University of Trujillo

1.6.Oil preparation and biodiesel production

First, the used oil was filtered trhoug one Fisher Brand watman No. 90, which It was placed in a 400 mL beaker, weighed 0.63 g of NaOH pellets and, after finely grinding them, placed them in the 400 mL beaker. Then, poured into the beaker 50 mL of pure methanol. Once the mixture was well stirred with a glass rod and transferred to the beaker, There was activated the microwave for a time from 1 to 8 minutes to obtain biodiesel immediately.There have repeated the process several times, varying the time of exposure to the microwave, from 1 to 8 min. See Table of Yields. For this part, with the data obtained, I observed that at 2.0 minutes I obtained better yields.Then, it was established this time of 2.0 min and varied the amounts of catalyst, from 0.7 to 1.5 wt/wt %. Always keeping constant the quantity of oil ( 50.0 g ) and the solvent ( 50 mL CH3OH ), looking for the best ratio of oil to solvent. Thus, with 50.0 g oil, 1.0 ?talyst, was varied the amounts of methanol from 10 to 100 mL. 

Figure. 03. Biodiesel purification.

Finally, the oil was purified: The biodiesel obtained was heated at 60 °C to eliminate residual methanol. It was then transferred to a 500 mL separatory funnel to be washed with distilled water and decanted three times, then it was distilled using a Vigroux column, collecting 500 mL of purified biodiesel.

Molar ratio between solvent and catalystMolar ratio (mole of solvent / mole of oil): If we calculate the ratio of solvent to oil moles (6/1), we have : a) Used oil: 50 g oil/(274g/mol) = 0.182 mol. b) The average density of used oil is 0.80 g/mL.

Methanol (CH3OH): 0.182 x 6 = 1.092 mol CH3OH, 1.092 mol CH3OH x ( 32 g /mol CH3OH ) = 34.94

g Calculating, the volume is approximately 44.00 mL. Catalyst: 0.74 % x ( 84.94 g solution ) = 0.63 g NaOH. To determine the solvent / oil ratio, the percentage of KOH constant

Table02: Molar ratio between solventand catalyst

Source: Own elaboration

( * ) Density of methanol = 0.792 g/mL (**) Molecular weight = 32 g /mol

(***) Average molecular weight = 274 g /mol

Figure: 04.Molar ratio betweensolvent and catalyst

1.7.Exposure time to microwave vs. performance

Table 03: Exposure time to microwave (250 watts) vs. performance

(*) Density of methanol = 0.792 g/mL

Figure 05. Exposure time to microwave (250 watts) vs. performance1.1.KOH concentration vs. Performance

Table04. KOH concentration vs. Performance

Figure. 06. KOH concentration vs. Performance

Table 05. Comparison of biodiesel parameters obtained with national and international standards

1. Tadistical Data Processing

Table06. Effect of microwaveexposure time for biodiesel production.

Table 07. Effect of catalyst for biodiesel production using microwave

According to the experimental data, the statistical model used suggests a time of 1.30 min. The average effect of the time in the experiments carried out is 1.30 min.

Similarly, the concentration suggested by the statistical model, the concentration of the catalyst used (KOH) in the experiment performed is 1.0 %.

1.In this work, it is demonstrated that the most appropriate time for the exposure to the microwave of the reagents and input (discarded oil), at a power of 250 W, is 2.0 min.

2.It is also observed that the most appropriate KOH concentration for this purpose is 0.8 %.

3.A biodiesel can be obtained from recycled domestic oil by the transesterification process using a microwave oven as a heat source; with an acceptable quality, according to National and International Standards.

4.The use of statistics has been of great support to me, since thanks to the two-level factorial design, I was able to save time in the search for the optimum values.

5.The values are close to those indicated by mathematics and statistics.

Good control of the reaction temperature is recommended, because an increase of the reaction temperature above 70°C leads to saponification.

Decant by gravity for at least two days, then distill, making sure to remove many impurities that are generated during transesterification.