Recycling and utilization of oil sluge (acid tars)
Originally the issue of carbonaceous waste treatment regards a comprehensive environmental problems that have become particularly relevant in recent decades. Today, thanks to the advancement of technologies, waste utilization have turned into a highly profitable business with huge competition in the market of recycling equipment, waste materials and derived products.
One notable example is processing of oil sludge, namely acid sludge (or acid tar), with a large yield of the most valuable derived product – liquid fuel..
Danger of major ecological disaster
Environmental pollution by acid sludge was and still remains a very serious world problem since crude oil has been used as the main energy source. Oil-refining industry is a permanently operating source of wastes, discharges and emissions that cause appreciable damage to nature. Oil sludge disposal sites and containment ponds occupy hundreds of square kilometers; environmental fines for their storage rolled over millions.
On the largest scale the acid sludge processing by thermal destruction is implemented in the USA where acid sludge are the second most important – after sulfur – raw material applied to production of sulfuric acid. In Russia there was no simple and beneficial technology for utilization of acid sludge. Until recently.
Acid sludge is a viscous liquid waste containing about 15-70% of the sulfuric acid along with organic substances. It is a by-product of oil fraction purification by sulfuric acid at oil-refining and oil-cleaning facilities. Glossary.
Basically, acid sludge is kept in impounds and oil sludge lagoons that are classified as temporary storage and consider further disposal. Lifetime of many sites has already expired. Due to surface damage and leaking hazardous substances get straight into the groundwaters and settle in the soil preventing it from further usage due to health hazards.
Acid sludge - is a highly hazardous waste, alongside with formaldehyde, arsenic and cyanide. The recovery time of ecosystem after acid sludge pollution takes no less than 30 years since the source of harmful impact is fully eliminated.
Acid sludge belongs to the II class of hazard:
- Maximum Permissible Concentration of Emissions in the working area is 0.1 – 1.0 mg/m3;
- average lethal dose (LD50), oral is 15-150 mg/kg;
- average lethal dose, absorption through the skin is 100-500 mg/kg;
- average lethal concentration in the air - 500~5000 mg/m3/
For reference, scrap tres belong to IV class (low-hazard waste). Violation of safety rules during utilization is also harmful for the environment, but the recovery time is 10 times less taking minimum 3 years..
Acid sludge utilization.
Let's revise standard methods of oil sludge utilization:
- biotechnological - recovery of acid sludge in the presense of mineral fertilizers;
- chemotechnical - application of specific surface-active substances which act as demulsification agents;
- acoustical (cavitation) - processing of homogenized and dispersed acid sludge under the temperature range of 55-60°C in acoustic cavitational mixers;
- electroflame - creating the conditions of eco-friendly burning flame combusting toxic wastes when an electric field interacts with the radicas of carbon-containing substances at the atomic and molecular levels and simultaneously has a powerful impact on the hydrocarbon chain;
- thermal - processing of acid sludge by method of pyrolysis.
All technologies, except for the last, have one drawback, namely high material, energy and financial costs at a low economic efficiency.
In fact the chemical composition of oil sludge is extremely difficult and require “a fine tuning” of the most above mentioned technologies for successful utilization. Typically, this involves additional costs. The pyrolysis method, on the contrary, is suitable for utilization of acid sludge regardless of their composition.
Pyrolysis is the best method for utilization of acid tars.
With the Pirotex pyrolysis plant offered by Technokomplex the acid sludge disposal really turns into highly profitable and paid business. The technology provides an optimal balance between costs and income.
Experience has shown that in course of acid sludge pyrolysis in the Pirotex unit the largest output is a liquid fuel, which is the most commercially valuable and profitable product:
20-60% - liquid fuel,
10-40% - carbon-containing residue
and the rest is gas.
This means that one ton of acid sludge is able to provide up to 600 liters of liquid fuel. It can be directly used in boiler units or can be further distilled into gasoline, diesel and fuel oil.
The other pyrolysis products – carbon-containing residue and gas – have the same application as the products from scrap tires pyrolysis..
How to apply for the experiment:
- send a request to Technokomplex via the contacts;
- provide 400 kg of feedstock for the experiment.
What a client receives:
- videomaterial on experiment;
- samples of derived products;
- optionally: laboratory report of the derived products, if necessary.
However, 20%-60% is a serious range of values. Therefore, to provide correct economical efficiency analysis the yield and percentage of pyrolysis fuel from a particular feedstock should be clear. For this purpose Technokomplex offers its customers to carry out experiment in an operating pyrolysis unit located at the manufacturing plant's facility. In case of further purchase, the price of the experiment is returned as a discount for pyrolysis equipment.
Now when the benefits and commercial vitality of acid sludge disposal in the Pirotex unit are evident the only question that remains is safety. Since most of the oil sludge and acid sludge sites are located near explosive industrial facilities, it is necessary to be sure in reliable operation of any equipment, especially whose associated with a combustion process.
The Pirotex pyrolysis plant has specific design features, including hermetic connections of equipment units, high automatization of all processes, remote control of the operation, that assure truly reliable and safe operation. The equipment is recommended for utilization of containment ponds and oil sludge lagoons at the oil-processing and oil-cleaning facilities as well as disposal of other types of acid sludge sites.
The time to pay huge fines for environmental damage and invest in the development of infrastructure for temporary storage of acid sludge went by. Now it is time to think of future generations and ecological surrounding they will have. Today oil sludge pyrolysis is both ecologically and economically efficient business.