TECHNOVACUUM

NEW TECHNOLOGY RESEARCH INNOVATION

 
Vacuum creating systems

1) based on vacuum hydrocirculating units

2) based on steam ejectors

Jet compression units
for flare and low-pressure gases recovery

1) based on two-phase jet devices

2) based on steam ejectors

 
Jet absorption gas cleaning units
for hydrocarbons removal from breathing gases and oil and petroleum products gases recovery

 
Jet devices
ejectors and injectors for various purposes







Technovacuum Ltd.
+7 (495) 956-76-21
+7 (499) 261-99-98
+7 (499) 267-82-03
Russia, 105082, Moscow
B.Pochtovaya str., 26 "B", build.2, 5-th floor, office 1, room 11A
 

JET ABSORPTION GAS CLEANING UNITS
for hydrocarbons removal from breathing gases and recovery of oil and petroleum products gases at loading racks, terminals and tank batteries

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At present the oil industry uses various methods to reduce the loss of oil products by recovery of breathing gases. It is the recovery systems for light hydrocarbon fractions that are currently considered as the most promising and can radically increase the environmental and economical levels of all production operations connected with intake, storage and distribution of crude oil and petroleum products.

There are several methods of breathing gases cleaning from hydrocarbons, among which the adsorption-absorption method and the method using membrane technology are the most known.

Technovacuum Ltd. offers its new technology based on jet systems a jet absorption unit for breathing gases cleaning and recovery of oil and petroleum products gases at loading racks, terminals and tank batteries.

Layout of jet absorption unit

1 liquid-gas jet device
2 separator
3 heat exchanger (if necessary)
4 pump
5 absorber
6 chilling unit



I air-vapor mixture
II purified air
III fresh motive liquid
IV excess of motive liquid


Principle of jet absorption unit operation (for gasoline loading racks)

The air-vapor mixture (I) from the gasoline loading rack is delivered to the inlet of the jet device 1. Gasoline delivered by the pump 4 is used as a motive liquid in the jet device. As a result of ejection process, compression of the air-vapor mixture and absorption of gasoline vapor by motive liquid occur in the jet device 1.

The gas-liquid mixture is delivered from the jet device 1 to the separator 2, where the further absorption of gasoline vapors by motive liquid and air separation occurs. The final purification of air from hydrocarbon vapors is carried out in the absorber 5, where the gasoline cooled in the chilling unit 6 is delivered as an absorbent. The purified air being free of hydrocarbons (II) is vented from the absorber 5 to atmosphere.

Up to 99% of hydrocarbons is extracted from a gas-vapor flow entering the jet absorption unit. The pressure in the absorber 5 is maintained due to a control valve installed in the line for gas discharge from the jet absorption unit. The circulating motive liquid is delivered from the separator 2 to the heat exchanger 3 (is installed if necessary) for cooling, and then it is delivered to the suction of the pump 4. Makeup (III) with fresh gasoline for refreshment of the motive liquid is provided. Excess of the motive liquid (IV) is discharged from the unit to the loading rack or to the tank battery via a level control valve of the separator 2.



Jet absorption unit for oil vapor recovery

The unit is intended for recovery of oil vapor (light hydrocarbons) from breathing gases generated during oil loading into tankers or railway tanks.
This jet absorption unit ensures high efficiency of breathing gas purification (more than 95%) from oil vapor at any content of sulfur compounds (H2S, methylmercaptane etc.).

For example, similar systems of other firms use carbon adsorbers which cant provide cleaning efficiency higher than 85% (excluding methane). Such adsorbers cant clean breathing gases from methane. Also they have low efficiency of breathing gases cleaning from ethane.

Moreover, the systems that use carbon adsorbers have the strict limitation for hydrogen sulfide concentration in breathing gases. It should be less than 20 ppm because higher H2S concentrations cause pollution of carbon adsorbers by sulfide which cannot be removed during the process of the adsorber regeneration. To reach H2S concentration in breathing gases of 20 ppm or less, the crude oil should have hydrogen sulfide concentration less than 1.0 ppm. If oil with 20 ppm H2S concentration is poured, H2S content in breathing gas is more than 1000 ppm. Some crude oils may have H2S concentration up to 100 ppm.

Jet absorption unit for oil vapor recovery offered by Technovacuum Ltd. has no analogues around the world and is covered by a number of patents.

Major advantages of jet absorption system offered by Technovacuum Ltd. in comparison with similar systems of other firms are the following:

  • high cleaning efficiency of crude oil breathing gases with any concentration of sulfureous substances;
  • it does not need any other power utilities except electric power;
  • using of blowers to overpass hydraulic resistance of adsorbers is not required;
  • high reliability, easy maintenance, no need in expensive spares and materials;
  • fire and explosive safety due to outer installation and absence of direct contact of the gas with any moving parts;
  • low capital expenditure (it may be easily installed at existing structure);
  • application of the unit eliminates problems with explosion and fire safety as well as ecological problems that arise when loading tankers and railway tanks.
Layout of the jet absorption unit for oil vapor recovery
Principle of operation of the jet absorption unit for oil vapor recovery

Breathing gases, i.e. mixture of air and oil vapor, are delivered at pressure 0 from the oil loading rack 1 via the pipeline 2 at inlet of the jet device CA-1 and are compressed to pressure 1 at the separator C-1.
Pouring oil is fed as a motive liquid by the pump H-1 to the jet device CA-1.
During mixing of breathing gas and oil and compression of produced gas-liquid mixture, absorption of oil vapor by motive liquid takes place.

Gas-liquid mixture is delivered from the CA-1 to the separator C-1 where motive liquid is separated from breathing gas which is partly cleaned from oil vapor. Motive liquid is fed from the separator C-1 to inlet of the pump H-1 and then to the CA-1. To ensure absorption quality at required level and to remove heat from circulation loop, part of fresh oil which is pumped from the reservoirs 5 to the tankers (railway tanks) 1 is delivered via the pipeline 3 to the first stage of breathing gas compression. Oil excess is removed from the separator C-1 via the pipeline 4.

The second compression stage which includes the liquid-gas jet device CA-2, the separator C-2 and the pump H-2, operates similarly.
At the second compression stage pressure rises from 1 to 2. At the same time efficiency of breathing gas purification from oil vapor increases.
Final purification takes place at the third compression stage where pressure increases from 2 to 3 (in the separator C-3). The third compression stage operates on diesel fraction as motive liquid which is delivered by the pump H-3 to the liquid-gas jet device CA-3. During mixing of diesel fraction and breathing gas and compression of two-phase fluid in the CA-3, diesel fraction absorbs oil vapor which remains in breathing gas.

To keep absorption efficiency of diesel fraction, it is regenerated by pressure decrease in the desorber D. Diesel fraction saturated with oil vapor is delivered from the separator C-3 at pressure 3 to the desorber D at pressure which is close to pressure 0 at inlet of the jet device CA-1. Separated oil vapor is evacuated by the CA-1 and is absorbed at first compression stages.

Heat which released at the third compression stage is discharged to environment by air cooler or shell and tube heat exchanger. In case of shell and tube heat exchanger application pouring oil can be used as cooling agent.

In autumn 2015 the jet absorption unit for oil vapor recovery was commissioned at an oil railway loading rack station in Russia. According to Customer's technical specification cleaning efficiency must be more than 80%. Hence, for the purpose of capital expenditure reduction the jet absorption unit includes only two stages (1st and 2nd compression stages). Hydrocarbons cleaning efficiency of the unit is 85-90 %.

These values of cleaning efficiency are computed on base of continuous measurements of breathing gas flow rate as well as breathing gas hydrocarbons concentrations at inlet and outlet of the jet absorption unit during oil pouring. Cleaning efficiency is calculated as ratio of mass of hydrocarbons absorbed by the unit to mass of hydrocarbons supplied to inlet of the unit during its operation.

 


If you are interested in the technology of jet absorption gas cleaning units for removal of hydrocarbons from tank breathing gases of loading racks, terminals and tank batteries and you plan to introduce it at your enterprise, please, fill in the following

Questionnaire for jet absorption unit of loading rack.

Questionnaire for jet absorption unit of tank battery.

 




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