RO130109A2 - Process for preparing fuels from oil residues - Google Patents

Abstract

The invention relates to a process for preparing fuels obtained by processing oil residues. According to the invention, the process consists in taking over the starting material such as semi-solid or liquid oil residues from which, after settling, a fluid product and a semi-solid cake will be separated, cake which will be introduced in a thermal desorption furnace, the reaction gases at the temperature of 460°C being passed through a gas curing chamber from which they will be released towards a fractioning column, at the top of which a benzine fraction is collected, at the middle part there being collected a Diesel oil fraction, and from the tray, at the beginning of the rectification zone, a recycle oil fraction being collected, a part of which will be used for feeding the column and the other part for sweeping the filler and cooling the first third of the column, the mixture of benzine and non-condensed gases will be led through a condenser and then through a separating vessel from which the gas fraction will be taken over by a booster and discharged into a low pressure vessel, from which it will be sucked and discharged into a medium pressure gas vessel and from which the gases will be led into the furnace, the benzine which is separated from the water being directed in two fluxes, one of which is for maintaining the temperature at the top of the column, and which will be introduced as cold reflux, the other one being directed into a benzine buffer vessel, the Diesel oil being stripped with vapour and then pushed through a cooler and stored, where, in order to deplete the carbon remaining in the furnace, after finishing the thermal cracking reactions, vapour is introduced to increase the temperature of 550°C, which leads to the formation of water gas - CO plus H- which after being scrubbed is discharged to the stack.

Description

The invention relates to a process for preparing fuels from petroleum residues, used in the oil and energy industry, by processing fluid and semi-solid petroleum residues, in order to produce products with combustible properties.

A process is known for processing the petroleum residues suspected for recycling, from decanting, leakage, decontamination, or batches of petroleum residues, which consists of subjecting the waste to filtration in subassemblies of cascade filtration, followed by preliminary purification and neutralization, dehydration. , condensation and purification by sieve respectively. (RO 123197)

Also known is a process for processing petroleum waste which consists of processing the residues deposited in a vessel, by passing them through a heating coil connected to a recirculation pump that flows into a vertical exchanger, at which is connected to a de-emulsifying dosing pump. The product then passes into a mixer with additive, a storage tank and homogenization that connect to some decanting vessels, a centrifugal pump that takes over the organic phase from the top and discharges into the a heat exchanger, a reboiler of a dewatering column fed with a foaming agent through a metering pump and a drive agent taken from a centrifugal pump in a storage vessel. (RO 119731)

Also known is a process of thermal desorption applied to soils contaminated with petroleum products, which are excavated and placed in a rotary cylindrical furnace in which the raw material is heated to approx. 500 ° C, when the petroleum product with which the soil is soaked becomes VOCs that are discharged into the atmosphere, the decontaminated soil is then used as a filler.

The disadvantages of these installations are that:

The installations and processes listed above still generate hazardous waste and waste; it is true that they are in smaller quantities, but they still exist.

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In the case of waste incineration, the flue gases are harmful to the air as they contain a series of organic and inorganic compounds that exceed the maximum permissible limits of the emissions into the atmosphere.

The process of preparing the fuel from petroleum products, according to the invention, ensures the complete processing of residues by having a clean oil product with oil-like properties, stored in vertical tanks together with, or without any pre-decanted oil residues in a decanter. it is conveyed by means of pumps in a preheater with recycle oil and residual oil where it is heated to a temperature of 145 ° C and then introduced into a tubular oven where it is heated to 460 ° C, after which it enters a room of maturation M, where after a residence time of approx. 20 min. and a pressure of 9 bar completes the thermal cracking reactions started in the oven, the reaction product is then led to a fractionation column C, from which a three-phase compound consisting of gases, the vapor phase of gasoline and water vapor, which exits the vapor pipeline from the top of the column and goes to a capacitor R1, where it condenses and then separates the phases into the separator vessel V1, the gases being taken up by booster B and transferred into the low pressure vessel VG2 from where they are sucked by the compressor K and discharged into the medium pressure vessel VG3, where they are then passed through a vaporizer and burnt to the furnace, and on the base the water is collected which is drained periodically to the sewerage and above, the gasoline, with a temperature below 40 ° C it is taken with a pump that pushes it, one part as reflux at the top of the column and the other part, in a buffer vessel where it is directed to consumers, and from the u In the middle column of the column, the fraction of diesel oil that enters a condenser strip is collected, from which the striped vapors are returned in column C on a plate higher than the one from which it was extracted, and then in a cooler, followed by a temperature of 60 ° C diesel is collected in a buffer vessel, from which it is sucked and pushed into a storage vessel and into a tank where the mixture with the residual oil obtained at the base of column C is made, for conditioning it to the required quality of the fuel to be burned in the furnace, at the same time in the lower part of the column rectification area a fraction of recycled oil will be extracted which part will be passed through a exchanger with the raw material and reintroduced into the column, as an interval reflux, and the other part will be introduced into the feed pipe of the fractionation column C, from which the oil fraction having a temperature of 390 ° C will be taken, is t search through a changer

Q ² O 1 1 - O 1 3 5 2 o β -12- 2011 heat where it exchanges heat with the raw material, reaching a temperature of 240 ° C, after which the residual oil passes through some coolers and cools to the temperature of 90 ° C, being then taken with a pump and stored in some tanks where it is also additive with diesel and other additives, to meet the qualities needed for a focal fuel, and the hot water coming out of the coolers is passed through a cooling tower where it is brought to a temperature of 26 ° C and then recirculated in the system.

The following advantages are obtained by applying the invention:

- a significant part of the oil residues is recovered;

- reduce environmental pollution.

The following is an example of embodiment of the invention, in connection with FIG. 1, which represents a schematic diagram of the proposed process.

The process of preparing the fuel from fluid and semi-solid oil residues, according to the invention, comprises the unloading from a car ramp of the raw material.which may be a clean petroleum product with oil-like properties, or an impure petroleum product that will have to be purified by sifting. Also, semisolid organic waste from sifting or centrifugation of petroleum residues, foil waste, PETs, bag filters, used mineral and vegetable oils, etc., can be received in the plant, which will be stored in the concrete tank. waterproof, specially designed for this purpose. The tankers and the special vehicles with the raw material, after the qualitative and quantitative reception, are unloaded in parallel-piped concrete tanks with volumes of 60 m3 and 1200 m3 respectively. After reception, from these open underground tanks, equipped with steam heating coils, with the help of a pump the oil residue is pumped through a vibrating screen, from which the purified product is pumped into the T1 tank, and the semi-solid cake is transferred to the concrete tank. high capacity, where it mixes with the other semi-solid residues received in the plant.

In the case when processing fluid oil residues from T1, these after a prior decantation will be drawn with a P8 pump and pumped through the type A technological furnace where they are heated to 460 ° C, the temperature at which the thermal cracking reactions take place. of hydrocarbons. Following these reactions, the residues formed from long chains of hydrocarbons break down and give rise to other hydrocarbons with small molecular masses. The reaction products leave the oven and enter the maturation chamber M. In order to avoid the firing of the tubes in the oven, steam is injected into the furnace.

ζ / these, steam which also leads to an increase in pressure in the maturation chamber up to 9 bar. The reaction time of the reaction products in the aging chamber is approx. 20 min., During which these reactions are complete which started in the H1 oven. From here, the reaction product is gradually released to a fractional distillation column C, where the separation of the oil fractions takes place in the order of boiling points, so that at the top of the column a two-phase mixture consisting of gases C1-C4, vapors is separated. gasoline and water vapor. The vapor temperature is 130 ° C and the column pressure is maintained at 1.5 bar. The vapors leaving column C at the top go to a condensation block R1 where cooling and condensation of the liquid fractions takes place using aerators and tubular water coolers. The gas-liquid mixture cooled below 40 ° C is collected in a V1 decanter vessel. After water leaks, using a P1 pump, gasoline is drawn from the vessel and will be pushed in two directions: a part as a cold reflux at the top of the distillation column to maintain the temperature in this area, and the surplus will be pumped. in a V2 buffer vessel working at atmospheric pressure. From here the gasoline is taken with a pump, it is stored, analyzed and according to the physical-chemical characteristics it will be directed to consumers, as a car component or for the manufacture of solvents.

The non-condensed gases in vessel V1 are taken up with booster B and compressed to a pressure of 2.5 bar in vessel VG2. The condensation fraction of isopentane will be directed back to vessel V1. The gas mixture in the vessel will be taken up by a two-stage K compressor and compressed into the VG3 vessel up to 16 bar pressure. From here, by means of a vaporizer, the gases will be directed according to the needs to the mixed burner of the furnace H, for use in combustion.

From the central part of the fractionation column C, the diesel fraction will be extracted at a temperature of 260 ° C, which will be steam striped in strip C1, to correct the inflammation temperature, so that the steam striped together with the steam strip. they will be reintroduced in column C on the upper plate of the one from which the fraction of diesel was extracted, and the diesel will be sucked at the base of the C1 scraper with pump P2 and discharged through a group of heat exchangers and tubular coolers with water R2, of where it will exit at a temperature of 60 ° C and then enter a V3 buffer vessel, which operates at atmospheric pressure. From here, the diesel will be pumped into the storage tanks, from where certain quantities will be taken with which _q -20 1 1 -O 1 3 5 2 'o B -12- 2011 will dilute the residual oil obtained on the base of column C , for the preparation of various types of combustion fuels in a fire.

At the bottom of the rectification area of column C will be extracted with the help of pump P7, a recycle oil that after cooling in a heat exchanger with the raw material R3 will be sent for washing the first filling layer in the column, and the other side it will be reinjected into the feed pipe of column C.

At the base of column C, using the P3 pump, the residual oil that will be pumped into the V4 vessel will be aspirated through a group of heat exchangers with the raw material and water-cooled R4. The storage temperature of the oil fraction will not exceed 90 ° C. The fraction of residual oil will be diluted up to 50% with diesel fuel, in a special tank intended for this purpose, from where it will be delivered to the beneficiaries through the car ramp, and a part will be consumed in the installation to supply the fuel vessels. day V5 and V7 serving the burners of the two furnaces H and H1, respectively of the two steam generators G and G1 in the installation.

In the second embodiment, when processing semi-solid residues deposited in the 1200 m3 concrete tank, they will be taken from here with the help of a portal crane graft and placed in the bunker of the horizontal cylindrical furnace of thermal desorption H. This bunker, which is provided with a blanket for heating, it will charge up to a maximum of 80% of its capacity, in order to allow vaporization of the product inside. The bunker is heated by means of the flue gases that discharge to the basket. In this way, the temperature of the product in the hopper reaches 115 ° C, the temperature at which most of the water contained and any volatile products will be evacuated. These vapors will be removed from the bunker through a pipeline that goes to a SC scrubber, where they do their washing, condensation of water and elimination of uncondensed gas in the basket. The bunker is provided at the base with a hydraulically operated hatch, which separates the bunker from the desorption furnace, and at the top is also provided with two sliding doors that are automatically activated, which close after loading. The first batch that is loaded into the hopper is practically measured in it, and by opening the hatch, it is inserted into the desorption oven H. After feeding the oven, the separation hatch is closed, the bunker is fed again with a new amount of semi-solid residue and the sliding doors at the top of the hopper are closed. The oven heater is started and the solenoid valve is opened on the steam line that goes to the maturation vessel M. In this situation, the solenoid valve on the gas line that goes to the SC scrubber will be closed. To the scruber, go

CȚZ ο 1 t - Ο 13 5 2 • β -iz- am // only the pipe connecting the bunker and the scrubber remains open. After reaching the first temperature level of 460 ° C in the heat desorption oven, it will be observed that after the thermal cracking reactions, the temperature will have a tendency to increase. At this time, the regulating valve that opens the steam inlet to the furnace will be ordered and the pressure in the maturation vessel M will be monitored. from the supply of the ripening vessel M. During this time, the connection of the ripening vessel with the fractional distillation column will be interrupted. Timer mounted in the automation system, after 20 min. will command the progressive opening of the pneumatic valve mounted on the pipe at the top of the ripening vessel, thus supplying the fractional distillation plant with the reaction product. From this moment, the installation works the same and at the same parameters as in the previous description.

Depending on the raw material subject to processing, the yield of fractions obtained from the installation will be different, from one raw material to another and from one process to another.

In the heat desorption oven H, the heating is continued until 550 ° C with permanent steam insufflation. It has the role of reacting with the remaining carbon following thermal cracking reactions, resulting in water gas (C + H2O = CO + H2). After the carbon depletion, a tendency to decrease the temperature will be observed, in which case the supply of the burner from the furnace H. will be interrupted. The formed water gas will be permanently washed in the SC scrubber with recirculated water and the washed gas will be evacuated to basket. Steam in the oven will continue to be cooled and the gases from the oven will be evacuated. The gearmotor is started which, by means of a Gali chain, rotates the axis of the furnace from which the rotations which fix the inert tailings to the discharge mouth provided at the bottom of the cylinder are fixed. The automatic opening of the hatch which ensures the sealing of the furnace in that area is activated and the inert tailings are discharged into the cup of a Wolla self-loading unit. After the tailings are discharged, the exhaust hatch is closed and the furnace feed hopper hatch, which contains the preheated semi-solid cake, is opened. The hatch is automatically closed, the sliding doors of the bunker are opened and a new load of semi-solid oil residue material, made of 1200 m3 concrete tank, is executed.

Resume the heating cycle described above.

The thermal desorption plant, coupled with the viscosity reduction plant will be sized according to the practical possibilities of raw material insurance and the investment possibilities. In the present case, after completing the pilot phase, we decided to build a plant with a processing capacity of 6 m3 / h or 42000 t / year.

From the balance of materials made on the pilot station, depending on the raw material used, the following distribution of products resulted:

- 7-8% water gas

- 3-4% C1-C4 gas

- 3-5% gasoline;

- 12-16% diesel;

- 25-30% residual oil;

- 18-21% sterile inert.

When processing oil residues, a percentage of up to 10% technological losses is estimated, representing the emulsified water in the product and leaks.

Depending on the recipe for manufacturing the fuels for outbreaks that we want to market, it will mix in a tank provided with mechanical agitation, the residual oil with up to 50% diesel oil and other additives depressants, antifoam and rust.

From each batch of product are collected samples that will be analyzed in the physico-chemical analysis laboratory, at the main parameters, depending on the equipment of the laboratory.

The results of the batch analyzes are recorded in the register of records "Finished product control".

From this moment, the finished product can be delivered to the beneficiaries.

Claims (4)

CLAIM Process for preparing the fuel from oil residues consisting of taking the raw material from third parties, such as semi-solid or liquid oil residues, which after settling in a concrete tank, provided with a steam heating coil and a vibrating screen, will separate in turn into a fluid product, which will be stored in the tank (T1), and the semi-solid cake that will be stored in the waterproofed concrete tank for the raw material, from where it will be taken with a crane graft and placed in a bunker. of the thermal desorption furnace (H), from where the reaction gases which will have a temperature of 460 ° C, will be passed through a maturation chamber (M), where they will react for approx. 20 min. and then they will be released to the fractionation column (C), at the top of which a fraction of gasoline will be collected, on the middle part, a fraction of diesel fuel, and a fraction will be collected from the treadmill at the beginning of the rectification area. of recycle oil which will be introduced part in the column feed and part for washing the filling and cooling the first third of the fractionation column (C). The mixture of gas and non-condensed gas obtained at the top of the column (C) will be driven through a condenser (R1) and then through a separating vessel (V1), where the fraction of gas will be taken over by the booster (B) and discharged into the low pressure vessel (VG 2), from where it will be sucked by the compressor (K) and discharged into the gas tank (VG 3) medium pressure, where the pressure reaches 16 bar and from where, the gases will be directed to the furnace burner (H), for use in combustion. The gasoline, which separates from the accumulated water in the process, which in turn will be drained at the decanter vessel's dome (V1), will be directed by means of the pump (P1) in two streams: one to maintain the temperature at the top of the column (C) , being introduced as a cold reflux, and the other, the surplus, will be directed to the gasoline tank (V2), from where it will continue to be directed to other uses (auto gasoline component or solvent manufacturing). The diesel that is collected in the middle area of the column, will be steam striped in the stripper (C1) and then, with the help of the pump (P2) it will be pushed through the cooler (R2), from where with a temperature of 60 ° C it will leave this and will be stored in the buffer vessel (V3). Next, it can be used for the dilution of heavy fuels. On the first cutting board at the beginning of the grinding area a recycle oil will be extracted, which will be pumped with 4 ^{2 0 1} ί ο 1 3 5 2 ⁰ θ Ί2- 2011 the aid of the pump ()7), ο part in the feed of the column, and part through the cooler R3, will be directed in the column (C), above the area from which it was collected. , to maintain the temperature on the extraction pad. The fuel that is collected at the base of the fractionation column will be sucked in by the pump (P3), discharged through the cooler (R4) and then stored in the buffer vessel (V4). From here it can be driven by the pump (P4) directly to the furnace burner, or it can be conditioned with diesel, to obtain superior combustion properties. In order to exhaust the remaining carbon in the thermal desorption oven, after the thermal cracking reactions are completed, steam will be introduced into the oven and the temperature will rise to 55O ° C, which will lead to the formation of water gas (CO + H2). The gas will be washed in a scrubber (SC) and then discarded. If the purified liquid oil residue from the tank (T1) will be used to supply the plant, it will be taken up by the pump (P8) and discharged through the tubular furnace (H1), from where at 460 ° C, the reaction gases will be introduced into the ripening vessel (M). The technological process that continues, is identical to the one described above. From the installation can be delivered to the beneficiaries light liquid fuel type I, type II and type III, as well as gasoline naphtha. The inert tailings obtained from the thermal desorption furnace will be stored in non-hazardous inert waste deposits.