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The P-Fuel Plastic-to-Diesel process reliably produces transportation-grade (road use), low-sulphur diesel from mixed waste plastics. The P-Fuel process has solved all the traditional problems associated with pyrolysis technology. The process employs patented highly-energetic far infra-red (FIR) heating rods that promote efficient cracking and minimise coking problems. Far infra-red radiation is highly energetic and close to the microwave region of the electromagnetic spectrum. |
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Frequently Asked Questions |
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The production of gasoline, kerosene and diesel from waste plastics is an emerging technological solution to the vast amount of plastics that cannot be economically recovered by conventional mechanical recycling operations. This involves the use of pyrolysis which permits recovery of valuable gasoline and diesel-range hydrocarbons from waste plastics that are otherwise landfilled.
Pyrolysis recycling of mixed waste plastics into generator and transportation fuels is now seen by many as the answer for deriving value from unwashed, commingled plastics as well as managing their desired diversion from landfill.
The viability of pyrolysis is assured by the lack of other recovery options for such waste plastics besides landfilling and incineration. Factors such as the increasing pressure on companies to adopt sustainable outlets for their end-of-life plastics; the introduction of extended producer responsibility and product stewardship directives; together with the implementation of legislative measures to deal with waste plastics, are significant drivers that will further increase the adoption of the pyrolysis route for waste plastics. |
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Question 1. What is the solution to the growing stockpiles of waste plastic destined for landfill? |
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Question 2. What is the P-Fuel Process? |
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The P-Fuel plant currently handles mixed plastics, waste oils and crude oils in any combination. In addition, engineers are presently developing a plant to process tyre chips but the pre-processing unit and the desulphurization system are different. |
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Question 3. What feedstocks does the P-Fuel process handle? |
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Question 4. What is Pyrolysis? |
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Pyrolysis of plastics thermally degrades the plastic, breaking the bonds of the polymer to produce lower molecular weight oligomers and monomers. The vapours resulting from the process are condensed to produce an oil/wax hydrocarbon product which has a high degree of purity and which are further refined in the process by selective fractionation to give predominantly diesel fuel. Pyrolysis typically takes place at relatively low temperatures in the range 350-450 deg.C. Pyrolysis transforms organic materials into carbonaceous char, oils and gases.
During pyrolysis, the macromolecular structures of polymeric materials are broken down into smaller molecules, resulting in a wide range of hydrocarbons being formed. These pyrolytic products can be divided into a noncondensable gas fraction, a liquid fraction (consisting of paraffins, olefins, naphthenes and aromatics), and solid residues (i.e. char).
Pyrolysis of waste plastics appears simple in concept. However, thermal cracking often yields low-value mixtures (cocktails) of hydrocarbons having very broad compositional range, sometimes extending from light alkane gases to coke. It is therefore necessary to find the optimal pyrolysis conditions and upgrading process (e.g. fractionation and desulphurization) to obtain marketable products (e.g. diesel fuel or gasoline) from plastic wastes. |
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Question 5 . How does the P-Fuel process ensure a high quality diesel output? |
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Controlled thermal degradation using internal far infra-red heating, as used by in its plant, yields a much narrower product distribution of carbon atom number and reduces the reaction temperature as compared with other processes.
The temperature and heating rates have considerable influence in the pyrolysis process and can be controlled to produce desired solid, gas and liquid products. Pyrolysis at very slow heating rates coupled with a low final maximum temperature maximizes the yield of solid (char). ’s plant is capable of faster heating rates than conventional processes (because it utilises internal far infra-red heating) and this reduces the yield of solid (char) resulting in increased efficiency. Far infra-red radiation is highly energetic since it is close to the microwave region of the electromagnetic spectrum (see figure below). In addition to temperature, the type of pyrolysis reactor is also important in determining product yield. High heating rates with short hot zone residence times and rapid quenching of the products are regarded as favouring the formation of diesel products. The removal of pyrolysis products from the hot zone reduces the extent of secondary reactions which are known to increase the yield of char and gas at the expense of liquid fuel formation. |
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Question 6. What are the product yields from pyrolysis? |
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Product yield is related directly to the type of plastic feedstock used, the reactor type and the process conditions, particularly pyrolysis temperature.
Through the use of low-temperature pyrolysis and efficient cracking, liquid fuel yields of up to 80–85% are possible, with the resultant product resembling diesel fuel, kerosene, gasoline or other useful hydrocarbon liquids. An added advantage of pyrolysis is that the light product gases (LPG and gasoline) produced (additionally to diesel) can be used to provide the energy requirements for the process.
The product yield depends on the distinction drawn between Mixed oil (Burnable industry fuel) (also called 'agricultural diesel') and Refined transportation diesel (which meets the EN590 specification). The liquid fuel yield (that consists of both diesel and petrol) is 80-85% while the yield for the refined transportation diesel (the gasoline fraction has been extracted) is 40-55%. |
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Question 7. What is the principal advantage of the P-Fuel process over conventional mechanical recycling of plastics? |
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Post-consumer plastics are often commingled and contaminated with extraneous materials such as soil, dirt, aluminium foils, paper labels and food remnants. While soil, dirt and glue can be removed from post-consumer plastics by washing, this is a fairly expensive operation and it leads to secondary waste streams such as waste-water.
The major advantage of the P-Fuel process is its ability to handle unsorted, unwashed used plastic. This means that heavily contaminated plastics such as mulch film (which sometimes contains as much as 20% adherent dirt/soil) can be processed without difficulty.
Significantly, other normally hard to recycle plastics such as laminates of incompatible polymers, multilayer films or polymer mixtures can also be processed with ease, unlike conventional plastic recycling techniques. In fact, most plastics can be processed directly, even if contaminated with dirt, aluminium laminates, printing inks, oil residues, etc |
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Question 8. Describe the P-Fuel Concept? |
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Using ’s technology, the P-Fuel process takes post-consumer plastics and thermally converts them into gasoline and low-sulfur diesel fuel. This diesel fuel meets or exceeds both European and Federal EPA standards for emissions and is designed specifically for the solid waste disposal industry that has significant investment in diesel-powered equipment. The types of plastic targeted as feedstock for this project have little or no commercial value and would otherwise be landfilled. |
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Question 9. Which plastics are suitable for the P-Fuel process? |
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Most commodity hydrocarbon plastics are suitable for pyrolysis. The plant can be used to convert all kinds of PP, PE, PS waste plastics into diesel by pyrolysis. It can also process waste plastics containing PVC, but the PVC content must be less than 1-2%.
Plastics suitable for the P-Fuel Process include: • low-density polyethylene (LDPE) used in plastic bags, cling film, flexible containers. • high-density polyethylene (HDPE) used in piping, shampoo and detergent bottles, oil bottles, milk crates. • polypropylene (PP) used in food containers, battery cases, bottle crates, automotive parts and fibres. • polystyrene (PS) used in dairy product containers, tape cassettes, cups and plates |
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The following waste plastics are all highly preferred: • pallet wrapping film (pallet wrap) • shrink and stretch film • shopping bags • silage and mulch films • commercial plastic packaging film • shredded PP Diaper Scrap • plastic packaging scrap • oil bottles and plastic oil containers • plastic packaging waste from curbside recyclables sorting stations -polystyrene foam Note: plastic films are generally polyethylene (PE) or polypropylene (PP) and these are the preferred feedstock for the process. |
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Question 10. Which plastics are not suitable for the P-Fuel Process? |
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Pyrolysis recycling of mixed plastics thus has great potential for heterogenous plastic waste that cannot be economically separated. However not all plastics can be processed by pyrolysis.
Plastics such as PET (also called PETE) and PVC are not suitable for pyrolysis. PET is not recommended as a feedstock for conversion into diesel fuel product because the pyrolysis of polyethylene terephthalate produces large quantities of gas dominated by carbon dioxide and carbon monoxide, in addition to a wax and significant yield of char.
PVC is also not recommended as a suitable plastic feedstock for pyrolysis. Polyvinyl chloride gives hydrogen chloride as by far the main gas. The carbon-chlorine bond in the PVC structure has a lower bond energy than other bonds in its structure and upon heating has a tendency to break first. As a consequence, PVC thermal degradation begins around 150°C which is a much lower temperature than the other common plastics but the hydrochloric acid that is evolved can cause fuel quality and corrosion issues and problems. |
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Question 11. What is the largest capacity P-Fuel plant? |
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Our engineering partner has designed a 25,000 tonnes a year plant comprising two double reactor systems, each system 12,500T/Y, each reactor 6,250T/Y. |
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Question 12. Is the technology protected by patents? |
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The technology underlying the EZ-Oil Generator™ is supported by a series of patents which are either pending or granted. Those patents include PCT/IB2004/000306 relating to “Enhanced oil recovery from waste plastics reactor” and Japanese Patent Pending No. 2002-145569 relating to “Moveable apparatus & method for extracting fuel from waste plastics and waste oil”. Additionally, there are a series of granted patents in China being Patents No. 00 2 365 77.4, 00 2 365 81.2, 00 1 207 28.8 and 01 2756083. |
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Question 13. What grade of diesel is produced by the P-Fuel Process? |
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The P-Fuel process can produce either industrial-use diesel oil (also known as 'agricultural diesel') or refined transportation-grade diesel (road use diesel which conforms to the European diesel fuel standard EN590).
The P-Fuel process which produces automotive grade diesel produces diesel that meets the road fuel standards. This is a specific cut of hydrocarbons with a specific property profile. Not all the liquid fuel that is formed from the pyrolysis of plastics is auto diesel. There is also heavy oil, light oil, gasoline (octane) and char (solid carbonaceous residue). Only by distillation and fractionation of the liquid fuel can specification diesel been produced. Extensive development work has found that actual auto diesel yields of 50-60 wt% are the highest that can be achieved with any technology.
The P-Fuel process is designed to produce automotive grade diesel or transportation-grade diesel, from a range of feedstock compositions. In addition to boiling point curves, cetane rating, flash point and viscosity there are low temperature properties such as pour point, cloud point, CFPP that must be in specification. |
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Question 14. What are the attributes of the P-Fuel process compared to competitive processes? |
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The attributes of the P-Fuel plant that sets it apart from the competition are: • excellent temperature control • no 'hot spots' (no coking) • no naked flames such as gas burners or flares (safe) • steady-state operation • continuous feeding • continuous removal of heavies/residues • high degree automation • reproducible operating conditions • energy savings by use of focussed far infra-red heating • no radiant heat losses • accurate and high-efficiency heating system (economical) • versatile shredder drum to handle a wide variety of plastics • vented extruder with melt filtration to remove contaminants • no expensive catalysts or consumable reagents • integrated distillation, fractionation, refining and stabilization steps • no hydrocarbon emissions/ no flare |
