How to make fuel from waste plastic, pyrolysis process, reactors, and procedure.

WHY TURN PLASTICS INTO FUELS ?

        Three million tones of waste plastics are produced every year in the U.K. alone, only 7% of which are recycled. In the current recycling process usually the plastics end up at city landfills or incinerator. As with any technological trend, the engineering profession plays an important role in the disposal of plastic waste.

           Discarded plastic products and packaging materials make up a growing portion of municipal solid waste. Expenditure incurred on disposal of plastic waste throughout the world is around US$ 2 billion every year.

       Even for a small country like Honk Kong spends about US$ 14 million a year on the exercise. The Global Environment Protentional Agency [GEPA] estimates that by the year 2004 the amount of plastic thrown away will be 65% greater than that in the 1990’s [1]. The recycling of the plastic is only about one percent of waste plastic in the stream of waste in developing countries as compared to a rate of recycling of aluminum which is about 40% and 20% for paper, where as recycling rate in India is very high up to 20% of waste plastic.

HOW CAN WE TURNS PLASTICS IN OTHER THINGS ?

         We can turn plastic into fuel from PYROLYSIS process . Waste plastic pyrolysis in liquid fuel (gasoline, diesel oil, etc.) or chemical raw materials not only can effectively solve the problem of white pollution, but also can alleviate the energy shortage to a certain extent. Recycling of waste plastics is expected to become the most effective way.

WHAT IS PYROLYSIS PROCESS ?

INTRODUCTION:

                                          The8th century Caliphate philosopher Jabir ibn Hayyan (known as Geber in the West) may be considered the father of experimental chemistry because of his development of the retort, which he used to discover  sulfuric, hydrochloric, and nitric acids, as well as aqua regia, by dry distillation of vitriol mixed with other salts. These discoveries became known in Europe in the 14th century, through the books of Pseudo-Geber. Pyrolysis was also instrumental in the discovery of many important chemical substances, such  phosphorus (from ammonium sodium hydrogen phosphate NH4NaHPO4 in concentrate  urine) and oxygen  (from mercuric oxide and various  nitrates).

PYROLYSIS PROCESS

        Pyrolysis is the thermal decomposition of materials at elevated temperatures in an inert atmosphere. It involves a change of chemical composition and is irreversible. The word is coined from the Greek-derived elements  pyro "fire" and lysis "separating".

                      Pyrolysis is most commonly used in the treatment of organic materials. It is one of the processes involved in charring wood. In general, pyrolysis of organic substances produces volatile products and leaves a solid residue enriched in carbon, char. Extreme pyrolysis, which leaves mostly carbon as the residue, is called carbonization. Pyrolysis is considered as the first step in the processes of gasification or combustion.

 PYROLYSIS REACTORS   :

                                                    The basic objective in designing a reactor is to produce a specified product at a given rate from known reactants. The principal features of the reactor are the following:

i)                            The overall size of the reactor, its general configuration and the more important dimensions of any internal structures.

ii)                        The exact composition and physical condition of the products emerging from the reactor. The composition of the products must of course lie within any limits set in the original specification of the process.

iii)                    The temperatures prevailing within the reactor and any provision which must be made for heat transfer.

iv)                     The operating pressure within the reactor and any pressure drop associated with the flow of the reaction mixture.

Reactors used for biomass pyrolysis is most commonly classified depending on the way the solids move through the reactor.

TYPES OF REACTORS  : 

There are four types of reactor mainly use in pyrolysis process:-

Type A:   No solid movement through the reactor during      pyrolysis (batch reactors)

Type B:   Moving bed (shaft furnaces)

TypeC: Movement caused by mechanical forces (e.g.,     rotary kiln, rotating screw etc.)

Type D:  Movement caused by fluid flow (e.g., fluidized bed, spouted bed, entrained bed etc.)

     Charcoal making today is mostly based on Type A and Type B reactors, Type A reactors are more common in developing countries.

FOR MORE IMFORMATION ABOUT REACORS. CLICK HERE