Refinery Decontamination

Solutions For Refinery Decontamination - HYDROSOL®

In petroleum refineries, distillation and storage equipment frequently needs to be inspected during turnarounds. Necessary cleaning procedures can require several weeks of downtime if storage tanks, distillation columns, product lines and heat exchangers have to be drained.
The presence of volatile hydrocarbons and hydrogen sulfide gas as well as deposits of pyrophoric iron and other fouling material can be particularly problematic and have to be removed before any attempt at vessel entry.

Also energy savings are fundamental to maintaining or improving refinery profitability and the presence of clean equipment is the mainstay of improved heat transfer.

Spanchem Technologies has developed an advanced decontamination program based on its proprietary HYDROSOL® chemistry that can help refineries achieve H aromatics and LEL targets in various process units prior to the actual turnarounds. The program removes both volatile and deposited hydrocarbons and also converts pyrophoric iron into a nascent form.
HYDROSOL® is a unique degreasing formulation that is versatile enough to be used d in the vapor or liquid phase and thus can handle a wide variety of equipment geometries and deposit types.

HYDROSOL® is completely soluble in aqueous media and so it can be circulated/vapor phased through process equipment in metered quantities to achieve a clean interior. HYDROSOL® - HD in liquid phase decontamination is used in Pre-Heat Exchanger Trains, CDU Units, Vacuum Units, units where the precipitation of asphaltenes, waxes and coke particles may have caused fouling during operation.

Typically a liquid phase decontamination starts with using a temporary pump to fill and circulate clean filtered water through the equipment to be decontaminated. Steam is then introduced into the coils of the temporary circulation tank to heat the water to 70 - 80oC.

On reaching the target temperature a pre-calculated quantity of HYDROSOL® - HD is added to the circulation tank and circulation continues for 8 hours. During the circulation emulsion stability is checked and random tests are carried to check parameters like e H2S and LELs. Based on this data process temperature, chemical addition and flow reversals are carried out. As the decontamination process is completed we start pumping cold water into the system to push the aqueous emulsion of the chemical into the slop drain or a break tank. We then add OXONIA®, the pyrophoric iron converter into the fresh water now circulating in the system, run this for 2 - 4 hrs and drain the system.
In a liquid phase decontamination the client is expected to provide clean filtered water to the extent of 3 - 4 times system volume for decontamination process. Besides this standard utilities like MP steam, Air and Electricity are required. The time required to clean an equipment is 24 hrs and entire units take anywhere between 48 - 60 hrs to clean using multiple circulation skids provided by the decontamination contractor.

In large systems and where steam is available HYDROSOL® - VP can be entrained directly through the steam source into a process vessel, this allows increased contact time and more uniform penetration of the solvent into all the interstitial space. Vapor Phase decontaminations are appropriate for: fractionation columns in CDU, vacuum units, FCCU, visbreakers, lube units, amine units, heat exchangers, separators drums and overhead fin fan coolers.
A typical vapor phase decontamination starts off with the client steaming the vessel to be decontaminated for 6 - 8 hrs. After this we inject HYDROSOL® – VP using a combination of steam ejectors and dosing pumps via a stream of steam into the vessel, the steam then carries the chemical into the vessel and as it condenses on the side of the vessel it emulsifies the hydrocarbon residue and volatiles the harmful gases. The injection process continues for 6 - 8 hrs. On completion of the vapor phase decontamination the vessel is washed down with water and then OXONIA® is dosed either in a liquid or a vapor phase to neutralize pyrophoric iron.

In a vapor phase decontamination the client is expected to provide clean filtered water to the extent of 1 - 2 times system volume for decontamination process. Besides this standard utilities like MP steam, Air and Electricity are required.

The time required to clean an equipment is 24 hrs and entire units take anywhere between 36 – 48 hrs to clean using multiple circulation ejector-dosing units provided by the decontamination contractor.

In many cases we use a combination of the vapor and liquid phase in towers to achieve a perfect decontamination. For eg. in equipment with large void volumes like Fractionation towers and Desalters which are expected to have bottom sludge contamination we set up vapor phasing units to tackle contamination at the top of the desalter/tower and circulation units to liquid phase the column bottoms.

HYDROSOL® - HD and OXONIA ® can be delivered by impact spray balls enabling us to clean sour water tanks, underground vessels and sumps effectively.

HYDROSOL® - HD is also used in dip cleaning & foam cleaning applications and can work at ambient temperatures for removing preservation coatings, fouled up air fin coolers and lube oil coolers.
The HYDROSOL® decontamination chemistry is based on environmentally friendly chemicals that are biodegradable and so it has a very small environmental footprint even allowing for limited recovery of the oil that has been emulsified during the decontamination process.

After use the aqueous chemical mix can be directly disposed to a sewer where it will break down naturally in a water body. In case the solution contains a large amount of free oil, the oil can be separated in a API catcher or by adding a chemical breaker to separate oil & draw it off and the clean mix can then be disposed to a sewer.

HYDROSOL® decontamination processes run and operated by Spanchem Technologies have the following key objectives –
  • Obtainment of gas-free equipment (to allow access for inspection and maintenance)
  • Reduction of steam-out time, shutdown time, maintenance costs, and time required to perform the mechanical cleaning.
The key benefits of effective and efficient HYDROSOL® based decontamination include:
  • Reduction of:
  • Maintenance costs and down time
  • Steam consumption and out time
  • Mechanical cleaning time
  • Waste generation and discharge cost
  • Pre-maintenance work by up to 50%
  • Faster attainment of “gas-free” equipment
  • Avoidance of odor problems when opening the column
  • The ability to easily dispose the wastewater in the wastewater plant.

The key performance indicators that are achieved by using HYDROSOL ® for a refinery decontamination –

H2S < 1.0 ppm
LEL ≈ 0

The HYDROSOL® range of products is primarily based on non-aggressive chemistries and so are completely safe on all metallurgies in terms of corrosion potential and reactivity.

In terms of human handling it has low reactivity and is not flammable.

In keeping with Spanchem Technologies customer-focused business practices, our dedicated specialists will work with you to assist in meeting economic, quality, safety and environmental performance objectives.

Through our unrivaled combination of innovation, technical on-site support, and field engineering, we can provide you a complete solution to refinery decontamination.

Efficient Decontamination - Reduce Energy Consumption, Emissions and Waste

Reach Us

Spanchem Technologies is capable of providing chemical cleaning services across many industries including Refining, Chemical processing, Offshore Rigs, Pulp & Paper, Sugar, Steel & Power.