RU2646755C1 - Production line of biodiesel fuel - Google Patents

Abstract

FIELD: machine building; technological processes.

SUBSTANCE: invention relates to the complex processing of oilseeds, as well as the production of biodiesel fuel from them and can be used in food, fuel industry and agriculture. Biodiesel production line includes a washing machine, dryer, roller machine, separating machine, fryer, forepress, storage tank for oil, oil pumps, drum filter, retention vessel, intermediate oil collector, cyclone, filters, condensate collector, high-temperature steam compression heat pump including a compressor, condenser, thermostatic expansion valve, evaporator; as well as a flow distributor output from the recirculation loop, flow heater, recuperative heat exchanger, methanol collector, potassium hydroxide collector, mixer, hydromechanical mixer with heating jacket, pump-cavitator, separating centrifuge, washing machine is designed for preliminary washing of oil seeds; two parallelly installed and alternating filters in a separation mode with discharge of a filtrate into the condensate collector and withdrawal of sediment in a countercurrent regeneration mode with water supplied from the condensate collector to restore the capacity of the filtering partitions are intended for cleaning the water from the water washing chamber; flow distributor output from the recirculation loop is designed to divert a portion of the spent superheated steam in two streams in an amount evaporated from the product, where one of the streams is fed through a flow distributor of waste steam into a flow heater to heat the oil, and a second stream is fed into the heating jacket of the hydromechanical mixer; condensate collector with possible fresh water make-up is designed to drain the formed condensate in the flow heater and after the hydromechanical mixer together with the condensate after the heat pump evaporator; and the hydromechanical mixer is designed to supply the heated in-flow heater oil together with a previously prepared in the mixer solution of potassium hydroxide in methanol to accomplish the first stage of the transesterification reaction; pump-cavitator is designed to carry out the second stage of the transesterification reaction; and the separation centrifuge is designed to separate the resulting mixture into biodiesel and glycerin, which are taken as target products. Method makes it possible to increase energy efficiency in the production of oil from oil-bearing crops, to ensure a reduction in specific energy inputs, to implement a process line that will allow producing environmentally cleaner biodiesel and glycerine; to create safe conditions for obtaining target and intermediate products in the absence of waste coolant emissions to atmosphere.

EFFECT: technical task of the invention is to increase the energy efficiency and ecological safety of oil production line from various oil-bearing crops due to the maximum recovery and utilization of secondary energy resources, implementation of closed thermodynamic cycles for material and heat flows using a steam compression heat pump, as well as the possibility of using a line for producing biodiesel and glycerine.

1 cl, 1 tbl, 1 dwg

Description

The invention relates to a method for producing biodiesel using the transesterification process and can be used in the petrochemical, fuel and other industries.

A known line for the production of vegetable oil [US Pat. No. 2595152 of the Russian Federation, IPC С11В 1/06; Vegetable oil production line / Frolova L.N., Shevtsov A.A., Vasilenko V.N., Dragan I.V., Mikhailova N.A., Krivova A.S .; Applicant and patent holder Voronezh. state University. engineering technol. - No. 2015111115/06; declared 03/27/2015; publ. 08/20/2016, bull. No. 23], including: a dryer, a roller machine, a separating machine, a fryer, prepress, a filter press, an expositor, a cyclone, a heat exchanger-recuperator and a vapor compression heat pump that provides the preparation of superheated steam for frying oilseeds with repeated use of superheated steam in the circuit recirculation and removal of part of the superheated steam from the recirculation circuit in the amount of moisture evaporated from the seeds to the heat exchanger-recuperator to heat the conditioned air sent to dry the seeds with the image Closed thermodynamic cycles in material and heat fluxes.

However, this line does not provide for biodiesel fuel, since it does not contain equipment for carrying out the transesterification reaction of vegetable oil with alcohol in the presence of a catalyst.

The closest in technical essence and the achieved effect is a line that implements a method for producing biodiesel by transesterifying vegetable oil with alcohol in the presence of a catalyst during subsequent separation of the obtained products by extraction with carbon dioxide by separating glycerol from the obtained mixture in the first separator and separating the target product from carbon dioxide in the second closed-loop carbon dioxide separator [US Pat. No. 2412236 of the Russian Federation, C11C 3/04; A method of producing biodiesel / Vinokurov V.A., Dadashev M.N., Barkov A.V. applicants and patent holders GOU VPO Russian State University of Oil and Gas named after THEM. Gubkina ”and the Association of business cooperation in the field of advanced integrated technologies“ ASPECT ”(Association“ ASPECT ”) (RU). - No. 2008149226/10; declared 12/15/2008; publ. 02/20/2011, bull. No. 5].

However, in the known method, only the final part of the technology for producing diesel fuel is considered and the equipment of that part of the process stream that is directly related to the production of oil is not considered. The use of two separators for the separation of the obtained products by extraction with carbon dioxide may not be appropriate in the absence of a production space.

The common disadvantages of the known lines include the fact that they do not implement the basic principles of energy conservation associated with the organization of closed thermodynamic cycles with the possibility of recovery and utilization of secondary energy resources; preparation of the initial seeds is not provided, and first of all, their washing, which cannot ensure the production of high-quality diesel fuel and entails an increase in the likelihood of technological failures associated with possible equipment failure and loss of line productivity due to downtime to restore working capacity.

An object of the invention is to increase the operational reliability of the biodiesel production line, reduce heat energy costs, improve the quality of biodiesel, create environmental safety conditions.

The task is achieved in that the biodiesel production line, including a washer, dryer, roller mill, separation machine, fryer, prepressor, oil storage tank, oil pumps, drum filter, expositor, intermediate oil collector, cyclone, filters, collector condensate, a high-temperature vapor compression heat pump, including a compressor, a condenser, a thermostatic valve, an evaporator; as well as a distributor of the flow discharged from the recirculation circuit, a flow heater, a recuperative heat exchanger, a methanol collector, a potassium hydroxide collector, a mixer, a hydromechanical mixer with a heating jacket, a cavitation pump, a separation centrifuge, and the washing machine is intended for preliminary washing of oilseeds; two parallel-mounted and alternately working filters in the separation mode with the filtrate discharge to the condensate collector and the sediment outlet in the countercurrent regeneration mode with water supplied from the condensate collector to restore the filtering filters throughput, designed to clean the waste water from the washing chamber; the distributor of the stream withdrawn from the recirculation loop is designed to divert part of the spent superheated steam through the two streams in an amount evaporated from the product, where one of the streams is fed to the flow heater to heat the oil with the help of the spent steam stream distributor, and the second stream is fed to the heating jacket hydromechanical mixer; in this case, the condensate collector with the possible replenishment with fresh water is designed to drain the condensate formed in the flow heater and after the hydromechanical mixer along with the condensate after the heat pump evaporator; and a hydromechanical mixer is designed to supply oil heated in a flow heater with a solution of potassium hydroxide in methanol pre-prepared in the mixer for the first stage of the transesterification reaction; the cavitation pump is designed to carry out the second stage of the transesterification reaction; and a separation centrifuge is designed to separate the resulting mixture into biodiesel and glycerin, which are removed as target products.

The technical result of the invention is to increase the operational reliability of the biodiesel production line, reduce heat energy costs, improve the quality of biodiesel, create environmental safety conditions.

In FIG. 1 shows a biodiesel production line.

The line contains a washer 1; dryer 2; roller machine 3; separation machine 4; fryer 5; prepress 6; cumulative capacity for oil 7; oil pumps 8, 36; drum filter 9; expositor 10; intermediate oil reservoir 11; cyclone 12; filters 13.14; condensate collector 15; high-temperature vapor compression heat pump, including a compressor 16, a condenser 17, a thermostatic valve 18, an evaporator 19; flow distributor 20; instantaneous heater 21; recuperative heat exchanger 22; a collection of methanol 23; potassium hydroxide collector 24; mixer 25; hydromechanical mixer with a heating jacket 26; cavitation pump 27; separation centrifuge 28; pumps 29, 30, 31, 32, 33; fans 34, 35; material and heat flow lines: 1.0 - supply of initial oilseeds to the washing chamber; 1.1 - removal of oilseeds to the dryer; 1.2 - drainage of dried oilseeds from the dryer for grinding into a roller mill; 1.3 - removal of crushed oilseeds from the roller mill to the separating machine; 1.4 - drain off the sieve of the separating machine for regrinding; 7.5 - removal of crushed seeds to the fryer; 1.6 - drainage of pulp from the fryer to the prepress; 1.7 - drainage of oil from the prepress to the drum filter; 1.8 - tap forpress cake; 1.9 - sediment discharge from the drum filter; 1.10 - filtered oil from prepress to the expositor; 1.11 - removal of wax substances from the expositor; 1.12 - oil supply to the intermediate reservoir; 1.13 - drainage of oil into the flow heater; 1.14 - oil supply to the hydromechanical mixer; 1.15 - supply of methanol to the mixer; 1.16 - supply of potassium hydroxide to the mixer; 1.17 - feeding a solution of potassium hydroxide in methanol to a hydromechanical mixer; 1.18 - supply of the mixture to the pump-cavitator; 1.19 - feeding the mixture into a separation centrifuge; 1.20 - biodiesel exhaust; 1.21 - removal of glycerol; 2.0 - refrigerant recirculation; 3.0 - supply of conditioned air after the evaporator to the condenser; 3.1 - exhaust air into the cyclone; 3.2 - supply of purified exhaust air to the evaporator; 3.3 - supply of compressed air to the drum filter; 4.0 - recirculation of superheated steam; 5.0 - condensate drain; 5.1 - water recirculation; 5.2 - drainage of purified water; 5.3 - sediment from water filters; 5.4 - water for the regeneration of the filter element; 5.5 - replenishment with fresh water; 6.0 - removal of solid particles from the cyclone.

The diesel fuel production line operates as follows.

After preliminary cleaning of the seeds from impurities, they are sent along line 1.0 to the washer 1 and washed for 5 ... 10 min at a temperature of 20 ... 25 ° C with clean water supplied through line 5.1 from the condensate collector 15 to the washer 1.

Waste water from the washer 1 along line 5.1 is diverted to filtration and purified in two parallel-mounted and alternately working filters 13 and 14, respectively, in the separation mode with clean water being discharged through line 5.2 to the condensate collector 15 and sediment outlet along lines 5.3, and in the mode countercurrent regeneration with water supplied through line 5.4 under the pressure generated by pump 30 from the condensate collector to restore the throughput of the filtering baffles. Pure water from the condensate collector is continuously supplied by the pump 29 via line 5.1 to the washer 1 with the formation of a closed cycle.

Washed seeds with a moisture content of 17 ... 19% from the washing machine through line 1.1 are fed to dryer 1 and the seeds are dried at a temperature of a drying agent of 85 ... 90 ° C to a moisture content of 9 ... 11%. Dried seeds on line 1.2 are taken to a roller mill 3 and crushed to particles with an equivalent diameter of not more than 1 mm, after which line 1.3 is sent to a separating machine 4. Descent from the sieve of the separating machine along line 1.4 is taken to regrind into a roller mill 3, and the passage in the form of a crushed seed fraction along line 1.5 is sent to the fryer 5. Fried seeds with a moisture content of 2 ... 3% from the fryer are fed through line 1.6 to prepress 6, where they are subjected to mechanical extraction. The squeezed oil through line 1.7 from forpress 6 is diverted to storage tank 7, and the forpress cake along line 1.8 is diverted to extraction.

From the storage tank 7, the pressed oil is pumped out by the pump 8 under a pressure of 2 ... 5 atm through the lower pipe of the drum filter 9 operating under pressure. Through the upper pipe of the filter 9 through line 3.3, compressed air enters, the pressure of which corresponds to the pressure of the oil pumped by the pump 8, which allows for a continuous filtration process with a given capacity.

Filtered oil passing through the inner cavity of the perforated drum of the drum filter 9 is diverted along line 1.10 to the expositor 10 for freezing wax substances; the precipitate formed on the perforated surface of the drum is purged with compressed air and the perforated surface is freed from the sediment and then it is removed from the filter along line 1.9 for further processing.

Wax substances are removed from the expositor 10 through line 1.11, and the finished oil is withdrawn through line 1.12 into an intermediate collector 11, after which, via line 1.13, it is directed to a flow heater 21 and heated to 25..30 ° C, reducing its viscosity.

At the same time, methanol and potassium hydroxide are fed from mixer 23 and 24 through lines 1.15 and 1.16 to mixer 25 and a solution of potassium hydroxide in methanol is prepared.

The oil heated in the flow heater 21 by the oil pump 36 along line 1.14 together with a solution of potassium hydroxide in methanol previously prepared in the mixer 25 is fed through line 1.17 to the hydrodynamic mixer 26 with a heating jacket and the first step of the transesterification reaction is carried out first at a temperature of 40 ... 50 ° C; and then the second stage of the transesterification reaction in the cavitation pump 27 at a temperature of 15 ... 20 ° C. Due to intensive cavitation processes in the hydrodynamic mixer 26 and the cavitation pump 27, fatty acid molecules break, which significantly increases the reaction rate and improves the quality of the energy characteristics of the future fuel. Next, the resulting mixture is separated in a separation centrifuge 28 into glycerin, which is taken off along line 1.21, and biodiesel, which is taken off through line 1.20 as the target product.

To prepare a drying agent, which is used as air for drying oilseeds in the dryer 2; refrigerant for freezing wax substances in the expositor 10; superheated steam for frying the crushed seeds in the fryer 5 use a high-temperature vapor compression heat pump, including a compressor 16, a condenser 17, a thermostatic valve 19.

The refrigerant (working fluid) is absorbed by the compressor 16, compressed to a condensing pressure and sent to a condenser 17 through a closed circuit 2.0. Due to compression compression in the compressor 16, the refrigerant is brought to a condensation temperature of 160 ... 180 ° С and, due to regenerative heat exchange, in the condenser section 17 gives up heat to overheat the steam supplied to the fryer 5. Then the refrigerant is sent to the thermostatic valve 18, where it is throttled to a predetermined pressure. With this pressure, the refrigerant enters the evaporator 19 and the expositor 10 and boils at a temperature of -5 ... -10 ° C, which allows for the condensation of water vapor of the drying agent in the evaporator 19 due to regenerative heat transfer and provides the necessary temperature regime for freezing wax substances from the oil in the expositor 10. The refrigerant vapor in a closed circuit 2.0 is sent to the compressor 16, compressed to a condensing pressure, and the thermodynamic cycle is repeated.

After drying the oil seeds from the dryer 2, the spent drying agent is first sent through stream 3.1 to cyclone 12 to clean the suspended solids contained in it, which are removed via line 6.0. Then, the spent purified drying agent is fed through stream 3.2 for drying and cooling to the evaporator 19 of the high-temperature heat pump. In this case, the temperature of the drying agent is brought to the “dew point” temperature, and the moisture contained in the drying agent condenses in the form of a droplet liquid or fog. The dried and cooled (conditioned) drying agent from the evaporator 19 is fed by a fan 34 through a line 3.0 to a recuperative heat exchanger 22, in which, due to the regenerative heat exchange with spent superheated steam, the drying agent is heated to a temperature of 87 ... 92 ° C and fed to the dryer in a closed cycle mode 2.

Superheated steam with a temperature of 140 ... 160 ° C after the condenser 17 is sent by a pump 35 to a fryer 5 through a stream 4.0. After the fryer 5 using a flow distributor 29, one part of the superheated steam is sent to a recuperative heat exchanger 22 to heat the drying agent and then to the recirculation loop superheated steam 4.0, and the other part, in the amount of moisture evaporated from the seeds during frying, is directed through streams 4.1 through the flow distributor 20 to heat the oil in the flow heater 21 and to heat the thermal jacket of the hydromechanical Cesky mixer 26.

The condensate formed in the evaporator 19, in the flow heater 21 and after the hydromechanical mixer with the heat jacket 26, is discharged by pumps 31, 32, 33 to the condensate collector 15 via lines 5.0. In case of technological failures, the condensate collector is equipped with a fresh water recharge line 5.5.

The biodiesel production method is implemented on an experimental production line with a productivity of 3 ... 5 t / h for the original soy beans with an oil content of 19 ... 22% under the production conditions of Sogal-ECO LLC.

Energy-efficient modes of technological operations in the field of permissible properties were carried out using a high-temperature vapor compression heat pump ZTN series, with the following parameters:

The high-temperature vapor compression heat pump provided the necessary capacity of a tubular condenser with an operating temperature of condensation of ozone-safe freon R-134 160..180 ° С upon receipt of superheated steam with a temperature of 140 ... 160 ° С, which is necessary both for the efficient implementation of the roasting process of pre-dried and ground oilseeds, and for the implementation of the previous drying of seeds associated with the heating of the drying agent due to the heat of the spent superheated steam; reducing the viscosity of the oil in the flow heater and the intensification of the transesterification process in the hydromechanical mixer.

Thus, the proposed biodiesel production line allows us to create conditions for the implementation of energy-efficient technology in the continuous operation of the main and auxiliary equipment.

Additional technological methods allow:

- implement the proposed line as energy-saving and environmentally friendly, ensure the preparation of heat carriers of different temperature potentials using a high-temperature vapor compression heat pump in closed thermodynamic cycles and improve the quality of the resulting diesel fuel compared to biodiesel obtained in the traditional way (table) (the task of improving the quality of the finished products);

- ensure the reliability of the operation of the production line of biodiesel production at a given level of quality (a purely technological task);

- minimize the emission of waste coolant into the surrounding atmosphere (environmental challenge);

- use the recovery heat of condensation of the refrigerant in the condenser of the heat pump for superheating of superheated steam in its recirculation circuit and the boiling point of the refrigerant in the evaporator of the heat pump for cooling and drying air for repeated use in a closed thermodynamic cycle during the continuous process of drying soybeans (energy saving task).

Claims (1)

Biodiesel production line, including washer, dryer, roller mill, separator, fryer, forpress, oil storage tank, oil pumps, drum filter, expositor, intermediate oil collector, cyclone, filters, condensate collector, high temperature vapor compression heat pump including compressor, condenser, thermostatic valve, evaporator; as well as a distributor of the flow discharged from the recirculation circuit, a flow heater, a recuperative heat exchanger, a methanol collector, a potassium hydroxide collector, a mixer, a hydromechanical mixer with a heating jacket, a cavitation pump, a separation centrifuge, and the washing machine is intended for preliminary washing of oilseeds; two parallel-mounted and alternately working filters in the separation mode with the filtrate discharge to the condensate collector and the sediment outlet in the countercurrent regeneration mode with water supplied from the condensate collector to restore the filtering filters throughput, designed to clean the waste water from the washing chamber; the distributor of the stream withdrawn from the recirculation loop is designed to divert part of the spent superheated steam through the two streams in an amount evaporated from the product, where one of the streams is fed to the flow heater to heat the oil with the help of the spent steam stream distributor, and the second stream is fed to the heating jacket hydromechanical mixer; in this case, the condensate collector with the possible replenishment with fresh water is designed to drain the condensate formed in the flow heater and after the hydromechanical mixer along with the condensate after the heat pump evaporator; and a hydromechanical mixer is designed to supply oil heated in a flow heater with a solution of potassium hydroxide in methanol pre-prepared in the mixer for the first stage of the transesterification reaction; the cavitation pump is designed to carry out the second stage of the transesterification reaction; and a separation centrifuge is designed to separate the resulting mixture into biodiesel and glycerin, which are removed as target products.

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