07 March 2024

Loading skids for Benzene and Toluene

Benzene and toluene are natural components of petroleum requiring special measuring systems such as loading skids to grant precision and safety of operation.

In this article we will deepen:

Overview of ISOIL Loading Skids for Benzene and Toluene
Potential Problems and How Rail Tank Loading Systems can solve them
Application of Benzene and Toluene in different fields
ISOIL Rail Tank Loading Skids: a Reference Project

Overview of ISOIL Loading Skids for Benzene and Toluene

ISOIL, as a solution provider, offers reliable and complete measuring skids for many different products including Benzene and Toluene.

Main features of Loading Skids:

complete ready-to-install solution;
design flexibility to integrate with existing equipment and systems;
accurate and reliable measurement with ISOIL P.D. Meters, Strainer Air Separators and Electronic Counters.

Potential Problems and How Rail Tank Loading Systems can solve them

Benzene and toluene are volatile liquids and they are also harmful to health when dispersed in the atmosphere.

The adoption of the European Directive EEC 94/63 on the control of emissions of volatile organic compounds (VOCs) has therefore required refineries to modify the loading skids used for Benzene and Toluene to avoid dangers both to the environment and to the operators.

Complying with the Directive is not an option and specific loading systems are necessary.

The best solution to this situation is setting up closed-cycle bottom loading systems with vapor recovery which can both reduce the dispersion of these substances in the environment and greatly limit the exposure of operators.

Moreover, when working with loading systems for fluids, melting temperature must always be considered.

While toluene has a melting temperature of -95°C and it shows no problems for its handling in cold weather, the melting temperature of benzene is 5.5°C.

In order to keep the temperature inside the equipment and piping at least at +15°C, loading skids must be provided with heating system with self-regulating heating cable and rock wool insulation.

Application of Benzene and Toluene in Different Fields

Benzene and toluene have many applications, mainly as raw materials for the production of organic chemicals.

Toluene is the source for the production of polyurethane polymers, Trinitro Toluene (TNT-Tritol), is also used as a synthetic raw material for the production of pharmaceuticals and as a solvent for paints, inks, adhesives and for the production of nanomaterials.

Benzene is mainly used as a raw material for the synthesis of other organic chemical compounds and it is an intermediate in the production of particular chemicals used in pharmaceuticals, dyes, insecticides and plastics.

These two are also related to gasoline and added as antidetonating agents to replace the tetraethyl lead previously used and later eliminated due to its toxic effects.

Loading skid are therefore required in each of the mentioned sectors to measure these products safely.

ISOIL Rail Tank Loading Skids: a Reference Project

An important Customer in Romania needed to update the loading systems in its terminal and therefore a technical analysis was required to identify the best solutions for metering and loading automation.

In 2022 ISOIL Impianti was involved in providing support and suggested the best loading system, including loading arms and vapour recovery arms to face the needs of the terminal and comply with the EU Directive.

The project developed in 2023 included 4 loading skids with 4” measuring systems in compliance with PED, ATEX and MID Directives, plus bottom loading and vapor recovery arms whose dimensions were sized to allow handling in the limited space available in the oil terminal.

Each loading skid was designed with two lines and provided with the following devices:

BM400 pd meters with magnetic drive and EM6422 pulse emitter;

VEGA 3 Multi Meter Flow Computer (Bay controller). Thanks to its totalizer and preset functions, temperature compensation and loading management, VEGA 3 was the perfect solution for this loading systems and it also enabled interfacing with the existing Terminal Automation System (TAS) and connection with the ST500/M to allow metrological data printing.

DSH100 strainer air separators to allow filtration of the product to be loaded as well as the release of possible air bubbles in the line which may affect the accuracy of the meter;

MT40 Grounding System to discharge electrostatic charges during loading operations and to grant a safe operation thanks to the ground connection monitoring;

Root ball valves with pneumatic actuator and control valves with electropneumatic actuator.