used oil recycling plant

WFE has a lesser recovery rate when it comes to used motor oil, but good for transformer oils, circulating oils, thermal oils which has lesser viscosity or molecular wt up to 450 and carbon-carbon bonds up to 33 carbons, were as  used motor, gear oils has molecular wt up to 650. Hence not recommended.The processing cost per ltr used oil in my version is as low as 9 us cents per ltr but not so in a wfe or hydro treatment version.

Is thin film economical.

Clay treatment can be avoided using a method called hydro treatment. Were in the main raw material required is hydrogen which is converted to nascent hydrogen with in the process. Hydrogen is a costly gas to have an economical run with hydro treatment you require a hydrogen generation plant, spent hydrogen regeneration unit, attached to the same. The capital cost of hydro treatment plant of the capacity referred 50kl per day can go 3 times the capital requirement of a clay treatment refinery. Further the operational risk is very high. Used oil comes under the excluded class of fire safety standards. If we use hydro treatment , hydrogen is required, a dangerous gas. All plant would go to the higher end of designs with requirements to have explosion and flame proof equipments which again is very expensive.Technologiess with bigger capacity either runs on clay treatment or hydrotratment no other process is viable. In a crude refinery, they have lots of waste gases. Which can be converted to hydrogen hence all most all refineries are in to hydro treatment process?

Can clay treatment be avoided?

Oils are distilled out , condensed  and we get the raw base oil RBO. RBO is clay/ hydro treated o get the final colour. For both thin film technology and vaccum distillation technology.

Is Clay treatment or hydro treatment. Required for thin film process.

There are lots of claims about the recovery in this process ranging from 65 to 85 % between black engine oil & transforer oil). What I feel is also same. But it all depends on the composition of waste oil used. Different oils have different type of base oil.

The recovery in a thin film process.

Heat transfer with both the above process is a costly daily utility.

1. Thermic boiler. Normal mineral oil type thermic fluid gives a temperature of 275 o C while at the evaporator can transfer only a temp of 225 oC due to losses., this is cheaper. Silicon based thermic fluid gives a temperature of 375 o C while at the evaporator can transfer only a temp of 325 oC due to loses. This oil is 10 times costlier than mineral oil based thermic fluids. Further it is mostly made in a hand full of developed countries. Hence require imports. Hence costly. Further none of the oils referred above is life long it requires to be changed yearly or biyearly as per usage.
2. Cooling tower and a refrigeration cycle. Cooling of plates is a must for the thin film process. A normal cooling to the wet bulb temperature of an area is only possible with cooling tower. Irrespective of the capacity. But the cooling to a level of 5 o C is required to enhance recovery to a tone of at least 20 % extra. A plant for used oil with thin film technology with out a refrigeration system is a fake.

The main utility requirements of a thin film process.

In a get it easy language. Take an example when we boil water in a closed lid container, you may find a thin layer of water condensed on the lid bottom, this thin layer is called the thin film of water. Similarly a thin layer of oil is formed on the collection plate either in top or/and side of the evaporator based on the design which is called thin film. The next stage is to remove this thin film from the plate .this is done in different methods but accomplished most effectively using a wiping rotary blade mechanism. Hence the name WFE or wiped film evaporator.

Thin film evaporation: this is a process of evaporating oils from base oil and condensing off using a thin film rotary or stationary mechanism. The advantage of this process is that it gives a finer clear distillation and the distillates are even superior.

What is thin film process?

1. The waste black oil is allowed to under go a dehydration process its normally done under atmospheric conditions in some cases under vaccum but heating to about 120o c.
2. This dehydrated oil is allowed to cool below 60oC so as to prevent charring when treated with con H2SO4.
3. Then 15 % (Volume) treatment with 98% con H2SO4 is done, by slow mixing and strong agitation and circulation of oil. This process of agitation is allowed to be done for about 30 mts.
4. This oil is allowed to settle in a conical bottom tank for 24 to 48 hrs and not disturbed.
5. The sludge (tarry and slurry type) is removed manually from the bottom, and then latter comes the liquid form of sludge called the pepper sludge. The volume of all the sludge together will be 55 parts considering the feed taken as 100 parts.
6. This oil is allowed to undergo clay treatment with fullers earth at about 15 % wt basis and treated to about 150oC and allowed to undergo a filtration process using filter press.
7. The filtered oil is the finished base oil.

The working of an acid process.

The apt method to be incorporated would be a vaccum distillation with clay treatment method.

• Thin film evaporation: this is a process of evaporating oils from base oil and condensing off using a thin film rotary or stationary mechanism. The advantage of this process is that it gives a finer clear distillation and the distillates are even superior. The disadvantage is that the capacity of the plant would be terribly low if we go for a lesser investment. But a capacity of say 50 kl feed per day would cost billions of investment. Further few feed also result in clogging of the film drum very frequently there by increasing the down time as well.
• Total vaccum distillation with clay treatment. : This would be the ideal process for any industry to adopt looking in to the aspects of conversions of an acid plant on basis of cost and investment. The process involves distilling, condensing and the raw base oil, which we get, requires some colour correction this is being done with clay treatment.
• Total distillation and hydro treatment: this process is a repetition of the process referred above but only difference is that the clay process is replaced by hydro treatment for colour improvement, a process involving a catalyst and treatment with nascent hydrogen. The advantage being that the quality and efficiency of the process is very high only the investment part would be very high.

Alternate method of recycling than acid process presently widely functional

  check earlier post on description

consultant for used oil,black oil recycling