RU2404230C1 - Method of producing biodiesel fuel - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method involves preliminary processing of mesopelagic fish to obtain lipids, transesterification of the obtained lipids and separation of the obtained biodisel fuel. Biomass is mechanically prepared from the fish. Fish fat is obtained by pressing and then undergoes enzymatic hydrolysis in the presence of protease. The obtained product is filtered to separate lipids. The obtained lipids undergo transesterification with an anhydrous solution of potassium methylate or sodium in methanol.

EFFECT: invention enables to obtain biodiesel which can be used in motor transport in winter conditions.

9 cl, 2 ex

Description

The present invention relates to the field of biotechnology, and in particular to a method for producing biodiesel from mesopelagic fish.

Around the world, as fuel prices rise significantly, there is also growing interest in the discovery and use of alternative energy sources. One such source is biodiesel. According to information from the National Biodiesel Board, biodiesel is called combustible fuel obtained from household renewable resources. This type of fuel does not contain petroleum products, but can be mixed in any proportion with conventional fuel to obtain a biodiesel mixture. In addition, its use in diesel engines requires a slight alteration. Finally, biofuels can decompose in the environment, are non-toxic and contain no sulfur and aromatic compounds, which makes it attractive to distributors and consumers.

A by-product of biodiesel production is glycerin. It can be used in many ways. Refined glycerin is used to produce technical detergents such as soaps. After deep cleaning, they get pharmacological glycerin, a ton of which costs about 1 thousand euros on the market. By adding phosphoric acid to glycerin, phosphoric fertilizers can be obtained.

For biodiesel, the European Organization of Standards developed the standard EN14214. In addition to it, there are EN590 and DIN51606 standards. The first describes the physical properties of all types of diesel fuel sold in the EU. This standard allows 5% biodiesel in mineral diesel. DIN51606 is a German standard designed to be compatible with the engines of almost all the leading automakers, so it is the most stringent. Most types of biodiesel produced for commercial purposes in the West correspond to it or even surpass it.

To date, different countries, taking into account climatic zones and agricultural traditions, have relied on various sources of oil and fat raw materials in the production of biodiesel. Thus, the United States mainly focuses on soy and animal fat, Europe - on rapeseed, Malaysia and Indonesia - on oil palm, and the Philippines - on coconut palm. In addition, many countries are trying to use technical and waste oils and fats.

Small mesopelagic fish (MMP) can serve as a promising source of oil and fat raw materials. Most of the traditional fishing areas are operated by fishing vessels of different countries very intensively. At the same time, in the open regions of the oceans outside the economic zones of foreign countries there are practically inexhaustible reserves of hydrobionts, which are still unused. Potential fishing targets include small mesopelagic fish (MMP). The volumes of possible catch of MMR in the Atlantic can reach 3.5 million tons. Conducted in 70-80 fisheries studies have shown the presence of significant populations of anchovy, silverfish, mavrolikus and other types of mesopelagic fish. The greatest prospect for the development of large-scale fisheries of mesopelagic hydrobionts is the Antarctic part of the Atlantic (AChA). It is in this area that natural concentrations of mesopelagic fish are observed. The potential annual catch of only one type of luminous anchovy electron is currently estimated at about 2 million tons.

MMPs are characterized by a high fat content of up to 25-28%, a special tissue structure, which makes them a promising source of fats for biodiesel production. Studies conducted by the authors of this invention showed the fundamental possibility of obtaining biodiesel from MMP. This opens up interesting prospects for the production of fuel directly on ships during sailing, while there is no need to refuel using special vessels.

In the application of the Russian Federation No. 2003113558 a method for producing biodiesel from waste oils containing fish oil using ozone. The disadvantages of this method are that, since the starting material is food waste in the form of a mixture of fish oil and vegetable oil wastes, therefore, the authors are dealing with non-standard raw materials, in which the ratio of saturated and unsaturated fatty acids will constantly change, i.e. biodiesel that does not meet existing standards will be obtained. The patent provides for the use of ozone and a redox compound (iron or copper oxide), which leads to the production of peroxide compounds and fatty acid oxides, which is unacceptable, since biodiesel can become explosive. In addition, the use of stabilized ozone is accompanied by its presence in products and in waste, which is unacceptable according to environmental requirements.

A known method for the selective production of hydrocarbons suitable for diesel fuel, described in the application of the Russian Federation No. 2007130918. The disadvantages of this method is that technology is used at high temperatures and pressure. This involves carrying out the process in a thick-walled reactor. Such technologies are under the supervision of a safety commission, i.e. these are explosive and fire hazardous technologies. In addition, explosive hydrogen is used here as a reagent and it is necessary to obtain complex catalysts, from which it is necessary to discharge and purify waste water from them in technological cycles. The above makes the proposed technology very dangerous for the environment and maintenance personnel. The patent proposes to use whale oil as a feedstock. Given that whale fishing is prohibited, it is hardly advisable to build a process on them.

The closest set of essential features to the proposed invention is the technical solution set forth in the international application WO 2008010253 "Process for the production of biological combustible and biofuel mixtures." This application is accepted as a prototype. This application describes a process for producing bio-combustible and biofuel mixtures suitable for various conditions of use, it includes pre-treatment of plant material to produce lipids (fatty acids), transesterification of the obtained lipids and separation of the resulting biofuel. The proposed method is applicable only to raw materials with a high lipid content - above 30%. The process also uses a solution of methanol and an alkaline catalyst, which is accompanied by a significant alkalization of the products. The application of the method requires the creation of treatment facilities.

The objective of the invention is the creation of an environmentally friendly and safe in production method for producing biodiesel from small mesopelagic fish.

To solve the problem in a method for producing biodiesel, which includes pretreatment of plant material to obtain lipids, transesterification of the obtained lipids and separation of the resulting biodiesel fuel, it is proposed to use mesopelagic fish as a preliminary material, the preliminary processing of which includes fishing, the formation of biomass from them mechanically, compression of fish oil, enzymatic hydrolysis in the presence of a protease to initiate decomposition yes biomass and lipid separation filtration. The process of transesterification of the obtained lipids is proposed to be carried out with a dehydrated solution of potassium methylate or sodium in methanol.

Additional differences of the proposed method is that:

- commercial mesopelagic fish, such as anchovy, sprat, smelt, are used as mesopelagic fish;

- the formation of biomass from mesopelagic fish is carried out in two stages, and at the first the net with the caught fish is kept suspended for 30-60 minutes, at the second stage the fish is placed in the press chamber and kept under pressure of 2-3 atm for 15-30 minutes;

- fish oil is obtained from biomass under a pressure of 5-10 atm;

- the enzymatic hydrolysis reaction is carried out in the presence of a protease at a temperature of 50-60 ° C for 30-40 minutes;

- the dehydrated solution of potassium methylate in methanol contains 25-35% potassium methylate in methanol and is introduced into the lipid fraction in a ratio of 0.1: 1;

- the dehydrated solution of sodium methylate in methanol contains 25-30% sodium methylate in methanol and is introduced into the lipid fraction in a ratio of 0.1: 1;

- the transesterification process is carried out at a temperature of 60-70 ° C for 30-60 minutes;

- the resulting biodiesel is suitable for use at low temperatures.

The transesterification process ends with the formation of two phases - the biodiesel phase and the glycerol phase.

Biodiesel is obtained with a yield of 65-70%, and glycerin 30-35%.

Biodiesel obtained from MMP lipids containing 25% unsaturated fatty acids is suitable for the operation of vehicles in winter conditions.

The use of dehydrated potassium or sodium methylate in methanol allows you to accurately dose the second component of the transesterification reaction simultaneously with the catalyst of the process (K + or Na + ions). This allows you to carry out the process of transesterification in one step and to avoid alkalization of the phase containing methyl esters of fatty acids, that is, it is not necessary to wash this phase to a neutral pH and purify the wastewater.

Example 1. A laboratory method for producing biodiesel from mesopelagic fish - the Black Sea anchovy.

Getting biodiesel was carried out according to the following scheme

Reception of anchovy, dehydration of squeezed anchovy, melting of fat by settling, transesterification, phase separation into glycerin and biodiesel, refining of the biodiesel phase, distillation of methanol, packaging of the finished product.

When catching mesopelagic fish - dehydration is carried out after the net with the fish is removed from the water. It hangs in the air for 30-60 minutes to dehydrate the anchovy (biomass containing fat). After dehydration, the biomass entered the laboratory, where it was placed in a Buchner funnel for more complete dehydration, and dehydration was carried out under vacuum. The dehydrated biomass was transferred to a 1 liter glass conical flask, which was placed in a water bath and heated to 50-60 ° C and the pH adjusted to 5.0-6.0. A solution of a proteolytic enzyme (bacterial protease - subtilin) was added to the flask in the ratio of 10 Units per 1 g of biomass. After hydrolysis (30-40 min), the biomass is transferred to a centrifuge. Centrifugation at 6000-8000 rpm is carried out on a benchtop centrifuge, with the separation of biomass in the form of sediment (it contains non-hydrolyzed protein). The supernatant is transferred to a separatory funnel, where the lower aqueous layer is removed, and the upper layer containing the lipid fraction is used in the future to produce biodiesel.

The lipid phase was transferred to a flask under reflux, to which was added a dehydrated solution of potassium methylate in methanol containing 25-35% potassium methylate in methanol and introduced into the lipid fraction in a ratio of 0.1: 1. Potassium methylate is produced by Himtek Engineering, St. Petersburg.

The mixture introduced in the flask under reflux was heated while stirring at a temperature of 60 ° C for 45-60 minutes. After the end of transesterification, two phases were obtained: the upper one contains alkyl esters of high molecular fatty acids (biodiesel) and methanol, and the lower one contains glycerol, which was drained in a separatory funnel.

The upper phase containing biodiesel and methanol was distilled off in a direct refrigerator. The biodiesel remaining after methanol stripping was analyzed. The analysis showed that biodiesel is obtained with a yield of 70-75%, and glycerol 25-30%. Biodiesel contains fatty acid esters that meet the requirements of the EU standard. The resulting biodiesel can be used in the cold season, as it contains unsaturated fatty acids.

Example 2. Laboratory method for producing biodiesel from sprats.

Unlike anchovy, sprats are caught using a net that contains special small cells. After fishing, the net is left for 30-40 minutes in a suspended state to drain external water. The dehydrated biomass is placed in the cylinder of the press and the piston of the press is gradually lowered, which allows additional removal of liquid from the biomass under a pressure of 2-3 atm. Thus, almost 100% removal of external water occurs. In this example, we used the hydromechanical method of fat isolation, which included the following stages:

- grinding sprats in a laboratory disintegrator to particles 5-6 mm in size was carried out by adding hot water in a ratio of 1: 1.3 at a temperature of 55-60 ° C,

- disintegration was carried out for 20-30 minutes,

- the crushed biomass was transferred into a conical flask placed in a water bath and equipped with a mixing device,

- water was added to the flask in a ratio of 1: 2 and heated to 50-60 ° C,

- after that, a proteolytic enzyme was added here in an amount of 5-10 u / g biomass.

Proteolysis was carried out for 30-40 minutes, and then the temperature was raised to 80-85 ° C. At this temperature, the action of the protease ceases and a water-lipid emulsion is formed. The emulsion is transferred to a centrifuge, where the upper phase containing the lipid fraction is separated at 6000 rpm. At the next stage, to purify the lipid phase from impurities, it was heated to 90 ° C and hot water (90 ° C) was added here in a ratio of 5: 1, and after centrifugation at 6000 rpm, a transparent layer of the lipid fraction was obtained. Cooled to a temperature of 25 ° C and used to obtain biodiesel. The lipid phase was transferred to a flask under reflux, to which was added a dehydrated solution of potassium methylate in methanol containing 25-35% potassium methylate in methanol and introduced into the lipid fraction in a ratio of 0.1: 1.

Sodium methylate was used manufactured by Himtek Engineering, St. Petersburg.

The mixture introduced in the flask under reflux was heated while stirring at a temperature of 60 ° C for 45-60 minutes. After the end of transesterification, two phases were obtained: the upper one contains alkyl esters of high molecular fatty acids (biodiesel) and methanol, and the lower one contains glycerol, which was drained in a separatory funnel.

The upper phase containing biodiesel and methanol was distilled off in a direct refrigerator. The biodiesel remaining after methanol stripping was analyzed. The analysis showed that biodiesel is obtained with a yield of 65-70%, and glycerol 35-30%. Biodiesel contains fatty acid esters that meet the requirements of the EU standard.

The proposed method allows to obtain high-quality biodiesel from mesopelagic fish, which can be used at negative air temperature, since it contains unsaturated fatty acids. The potassium and sodium methylates used in this method have several advantages: they are soluble in both hydrophilic and hydrophobic media, therefore, the amount of waste compared with the alkaline catalyst is significantly lower.

The use of potassium methylate (sodium) in methanol does not require re-esterification, which reduces the time to obtain biodiesel by 3-5 times. With this method, neither washing nor drying of the biodiesel is required and there is no need to dispose of the used water.

In our technology, there is no need to add an excess of methanol and, accordingly, its subsequent distillation. The use of expensive and hazardous methanol distillation equipment is excluded.

The inevitable loss of alcohol is eliminated and the environmental situation and explosion safety are improved.

Claims (9)

1. A method of producing biodiesel fuel, including preliminary processing of the source material to obtain lipids, transesterification of the obtained lipids and separation of the resulting biodiesel fuel, characterized in that the source material is mesopelagic fish, the preliminary processing of which includes fishing, the formation of biomass from them mechanically, production of fish oil by pressing, enzymatic hydrolysis in the presence of a protease to initiate the decay of biomass, filtering with separated lipids, and transesterification of the obtained lipids is carried out with a dehydrated solution of potassium methylate or sodium in methanol. 2. The method according to claim 1, characterized in that as mesopelagic fish use commercial mesopelagic fish, for example, anchovy, sprat, smelt. 3. The method according to claim 2, characterized in that the formation of biomass from mesopelargic fish is carried out in two stages, with the first fish net being held for 30-60 minutes in a suspended state, at the second stage the fish is placed in a press chamber and kept under pressure in 2-3 atm. within 15-30 minutes 4. The method according to claim 3, characterized in that fish oil is obtained from biomass under a pressure of 5-10 atm. 5. The method according to claim 4, characterized in that the enzymatic hydrolysis reaction is carried out in the presence of a protease at a temperature of 50-60 ° C for 30-40 minutes 6. The method according to claim 5, characterized in that the dehydrated solution of potassium methylate in methanol contains 25-35% potassium methylate in methanol and is introduced into the lipid fraction in a ratio of 0.1: 1. 7. The method according to claim 5, characterized in that the dehydrated solution of sodium methylate in methanol contains 25-30% sodium methylate in methanol and is introduced into the lipid fraction in a ratio of 0.1: 1. 8. The method according to any one of claims 6 and 7, characterized in that the transesterification process is carried out at a temperature of 60-70 ° C for 30-60 minutes 9. The method according to claim 8, characterized in that the obtained biodiesel fuel is suitable for use at negative air temperatures.