Purpose of URP Vapor recovery unitss
| The vapor recovery unit (VRU) is designed for capturing and returning volatile hydrocarbons to petroleum products. URP is used at oil refineries (mini refineries), oil depots, road and railway overpasses for filling oil products, at sea terminals. |  |
Working principle
The mixture of hydrocarbons and air present inside the tank (railway, auto -), the tank, is replaced by the injected petroleum product. The vapor-air mixture enters the vapor recovery unit through the inlet line with the fire suppressor. The built-in fan (gas blower) ensures the forced movement of the vapor air mixture through the URP and creates the required vacuum in the vapor collection pipeline before the URP.
The process of vapor recovery is based on the adsorption of hydrocarbon vapors by activated carbon and desorption through vacuum, followed by absorption - the absorption of concentrated hydrocarbons by a liquid absorbent (gasoline, diesel fuel, etc.).
A URP consists of two (or more) adsorbers working alternately to ensure continuity of the process. While one adsorber is on the line in the adsorption mode, the other is disconnected from the line and is in the regeneration mode - vacuum desorption.
The activated carbon saturated with hydrocarbons, removed from the adsorber work cycle, undergoes regeneration. For this purpose, a discharge is created inside the adsorber using a vacuum pump. Upon completion of the desorption process, atmospheric air is supplied to the adsorber to remove vacuum in the adsorber. After vacuum removal, the regeneration process is considered complete.
Непрерывный контроль за степенью насыщения адсорбента ведется с помощью датчика контроля концентрации углеводородных газов на выходе УРП. Очищенный воздух (остаточное содержание углеводородов менее 10 г/м?) выбрасывается через свечу в атмосферу.
Vapors with a high concentration of hydrocarbons from vacuum pumps enter the absorption column, where the vapors come into direct contact with the absorbent stream dissipated from above (gasoline, kerosene, diesel fuel), absorbed by them, and enters the cubic part, from where it is automatically pumped into the tank.
In the case of a high content of sulfur compounds in the vapor-air mixture, an additional filter-seroadsorber is installed before the URP, which provides filtration of sulfur compounds on iron-manganese nodules (IMC).
The main mode of operation of the URP is an automatic mode, additional - manual mode and continuous operation mode. The workplace of the operator provides a full visualization of the operation process of the plant, allows you to manually control the pumps, the shut-off and regulating valves of the URP in the main and additional modes.
The management system of the URP ensures the logging of all events at the URP, the actions of the URP operator. The operator’s workplace can be connected to the local network of the enterprise to transmit data on the functioning of the URP to the enterprise management system.
Security of SBMS
URP is manufactured according to the technical specifications (TU), registered by the Federal Agency for Technical Regulation and Metrology, agreed by the Federal Service for Environmental, Technological and Nuclear Supervision (Rostekhnadzor). All equipment has explosion-proof execution and is accompanied by the necessary certificates (compliance, explosion protection, type of measuring instruments).
The installation has permission to use Rostekhnadzor.
Technological calculations, optimization of the installation design, are performed using specialized programs of its own development.
At the design stage, a solid-state model of the installation is created using libraries of standard components, which allows to optimize the design and layout of pipelines, process equipment and load-bearing elements. On the basis of a solid-state model, isometric drawings of pipeline nodes are created for subsequent manufacture.
Disk shutters are controlled by one-way pneumatic actuators. The use of pneumatic control increases the safety of the installation and reduces power consumption. In case of loss of power supply, the disk gates automatically, under the action of return springs, return to their original state, the installation goes to a safe state. In the case of electrical actuators, uninterruptible power supplies are used to return to the original state.
CONTROL AT ALL STAGES
In the manufacture of URP, 100% of the input control of the components used (locking and regulating fittings, electrical products, etc.) is carried out.
Equipment delivery is carried out in the form of functionally completed open-type units, which simplifies the installation process at the Customer’s site.
The main pipeline part of the URP is mounted on the frame in factory conditions, which significantly accelerates the installation of URP at the installation site. Binding and testing for tightness of pipeline assembly are carried out in factory conditions at the assembly site of Energocomplekt JSC. In factory conditions, the operability of pumping equipment, valves, control and measuring devices, pneumatic or electric drive systems, electrical distribution and automation systems is checked.
Installation of devices and frame assembly at the Customer’s site is carried out under the guidance of specialists of Energocomplekt JSC after checking the control dimensions of the foundations. Before the start of commissioning works, an inspection of the delivered equipment for the absence of transport damage, a quality check of the installation of complex equipment of URP and their connections is performed.
Commissioning works are carried out by specially trained personnel of Energocomplekt JSC. The term of work before the installation is put into commercial operation is three weeks with the signing of the relevant documents.
During the period of warranty obligations, the technological parameters of the installation and proper industrial operation at the Customer's facility are monitored.
After the termination of the warranty obligations, the conclusion of a service contract is recommended. Within the framework of the service contract, remote control of the main technological parameters of URP is carried out from the service center of Energocomplekt JSC (by modem or via the Internet), technical support by phone is provided, annual on-site maintenance of URP is provided.
ENVIRONMENTAL SECURITY
According to the press service of the Ministry of Natural Resources of Russia on March 30, 2011, on behalf of the President, the Ministry has prepared new environmental requirements for the industry, in particular, the bill “On improving the system of rationing and economic incentives in the field of environmental protection”. From 2016, it is proposed to abolish individual limits and raise payments for emissions nine times.
It is proposed to establish standards for harmful effects on nature on the basis of indicators of the best available technologies. Now payment for negative impact on the environment is calculated on the basis of sanitary and epidemiological standards. If the company is not able to meet the standard, it is set individual limits above the norm. For emissions on limits, the fee rate increases five times, and over limits – 25 times.
The installation of vapor recovery completely avoids increasing environmental fines and completely regenerates vapors of the C3-C5 limit hydrocarbon mixture from the facilities for receiving, storing and shipping light oil products as part of tank parks, drain-loading railway and road overpasses.
The recovery installation shall ensure:
- high productivity;
- high degree of capture of hydrocarbon vapors;
- safety in operation;
- low operating costs;
- no pollution of the atmosphere and groundwater;
- reduced environmental payments.