Flexicoking accomodations possible?

[PB500]

I am looking for your scientific advise on the feasibility of feeding flexicoking plants for the destruction of solid wastes, instead of petcoke or heavy oil fractions. I refer in particular to the rationale of producing syngas from slurry, dewatered oily sludge - which are produced in large amounts from refineries and often disposed off-sites at high price - in the gasification train. Are there any experience of this kind in the world? If not, where do you people of the business meet the limits for such extension? Is it in the materials, operating conditions, et cet. Anyway and in general, is it possible to use these units batchwise for a different feedstock like the one I described?
Thanks a lot for any feedback, hope to raise interests from You.

 

[JJPellin]

I am a machinery engineer, so I appoligize if I misunderstood the question. At our refinery, we inject the dewatered sludge from our waste water plant into one of our vacuum units, into the vacuum tower. The sludge is dewatered in a centrifuge and pumped into a stream refluxing to the vacuum tower using progressive cavity pumps. I believe that there is a project in the works to change the sludge injection to a coker unit. In the US, there is a patent on the most effective process of injecting the sludge directly into the coke drum. I believe we plan to use an alternate process, but I am not sure exactly where the sludge will be injected. Of course, we do all of this in order to get rid of the sludge and not to provide any significant process advantage. However, I am sure that a good precentage of the material in the sludge ends up coking and producing some useful streams. I have never heard of anyone using a coker exlusively to process a sludge stream. I would hate to have responsibility for the reliability of the heater charge pumps.

 

[PB500]

I understand that capital equipment investment is the major, if not unsustainable, problem to accomodate coking units and inlet pumps to incineration, e.g. for idle refineries. Yet due to the global shortage of refining capacity this is not in the works but, in 20-30 years, a gradual conversion is thinkable and I am happy to hear that US engineers are facing the problem and planning solutions ahead, also in an EPR optic. I am aware that resid upgrading is one industry's priority as the average crude oil quality is decreasing; my focus as industrial waste processing consultant is on the diversion of secondary sludge from offsite transport and landfilling/incineration to in-process disposal. The patent proecss You mentioned is a step closer to reduce effluents shipment and the environmental impact of related operation (loading, unloading, storage). Thank You for Your valuable post that shifted my attention from flexicoking trains and gasification units to coking mills; and, I suggest, the related opportunity for plants suppliers to make synergies in the production process instead of forcing users to make costly accomodations. But this is a plantmakers' issue...