Method of Converting Municipal Proportional Waste Plastics into Liquid Hydrocarbon Fuel by Using Activated Carbon

The demand for fossil fuel is at an all t ime h igh worldwide. Annually ~30 billion barrels of petroleum is being consumed worldwide. In this busy society, transportation is vital and, for transportation, petroleum is an obligation. All the major forms of business, agricultural, exports and imports depend on transportation. Transportation requires petroleum to function. Vehicles in the road require fuels, airway transportation requires Aviation fuel and sea transportation requires fuel oil. For not only transportation but also, petroleum is required to make all kind of daily usable plastics. Deplet ion of petroleum is inevitable at th is current rate of consumption. Emissions released from evaporation and combustion of these fuel contributes to too many environmental and health problems; including emitting greenhouse gases that contribute immensely to global warming. Annually ~7 billion tons of carbon dioxide is released to the environment due to petroleum emission. Moreover, when the plastics are discarded into the landfill, it becomes waste plastic and since plastic is non-biodegradable, it can remain in the landfill fo r thousands of year. Waste plastics presence in the landfill causes environmental problems e.g., it can cause soil to decay. Alternative source of energy created from Solar, W ind, Hydrogen Fuel, Biomass Fuel, Bio-Diesel, Green Diesel, Bio-ethanol, and Geo-thermal has been proposed as a solution to these problems. A developed process of thermally breaking down the hydrocarbon of chains of plastic has been studied and implemented to produce a liquid fuel in the presence of activated carbon. The activated carbon acts as a filter to absorb dye from the waste plastic during the thermal process to increase the quality of the final product. This fuel can be used for all kinds of transportation, and will emit much less emission compared to the current commercial fuel and it will be cost effective.


Introduction
In recent years the production and consumption of plastics have increased drastically; as a consequence the responsible disposal of plastic wastes has created serious social and environmental arguments. At present both land filling and incineration of plastic wastes are widely practiced. In Japan, the percentage of municipal plastic wastes, as a fract ion of mun icipal solid waste (MSW), that was land filled in the early 1980s was estimated to be 45%, incineration was 50%, an d the o th er 5% was s u b jected to s eparatio n and recycling [1]. In the USA, more than 15% of the total MSW was incinerated in 1990; only about 1% of post-consumer plastics were recycled [2][3][4]. Land filling of plastic wastes is expected to decrease in the future as landfill space is depleted and plastic wastes are resistant to environmental degradation. Co-incineration of plastic wastes with other municipal solid wastes may be increasingly practiced, because the high caloric value of p lastics can enhance the heating value of MSW and facilitate an efficient incineration, wh ile their energy content can also be recovered. But the potential relationship between plastics fed into an incinerator and the formation of so me highly to xic pollutants such as dioxins and furans is still unclear. It has been suggested that the chlorine content in PVC and other plastics is related to the formation o f d io xins and furans, which are ch lorinated polynuclear aro matic co mpounds. And although there is considerable evidence that these pollutants would still be generated in the absence of plastics, environmental pressures against incineration have never completely d isappeared.
Plastic wastes can be classified as industrial and municipal plastic wastes according to their origins; these groups have different qualities and properties and are subjected to different management strategies. Industrial p lastic wastes are those arising fro m the plastics manufacturing and processing industry. Usually they are homogeneous or heterogeneous plastic resins, relatively free of contamination and available in fairly large quantities. Recycling technologies for industrial plastic wastes are currently based on pelletization and mold ing into low grade plastic products; the recycled products have poor mechanical and color qualities and a lower market value [5]. The reclaimed product outputs of Japan in the early 1980s already amounted to some 15% of total industrial p lastic wastes [1]. Thus for industrial plastic wastes, repelletization and remolding seem to be a simp le and effective means of recycling. But when plastic wastes are heterogeneous or consist of mixed resins, they are unsuitable for reclamation. In this case thermal cracking into hydrocarbons may provide a suitable means of recycling, which is termed chemical recycling. Municipal plastic wastes normally remain a part of municipal solid wastes as they are discarded and collected as household wastes. Plastics usually account for about 7% of the total MSW by weight and much more by volume. In order to recycle municipal plastic wastes, separation of plastics from other household wastes is required. Although MSW separation technologies have been studied extensively, it is still not possible to classify MSW mechanically and obtain marketable fract ions. If household wastes are separately disposed into three parts: (1) co mbustibles such as paper, kitchen waste, text iles, and wood, (2) inco mbustibles such as meta ls, glass, ceramics, and (3) p lastics, then the collected plastics will be mixed plastic wastes with major co mponents of PE, PP, PS, PVC, etc. For mixed p lastics some mechanical separation equipment is currently availab le [1,6]. For example, using a wet separation process mixed plastics can be separated into two groups: those with a density greater than water such as PS and PVC, and those with a density lower than that of water such as PE, PP and expanded PS. The latter group is much larger than the first group. Consequently, recycling of mun icipal plastic wastes should deal with plastic mixtures of low and high PE, PP and PS, provided that the above separation procedures are practiced. Typical co mposition of such plastic mixture will be three parts PE, one part PP and one part PS. More investigations are needed to identify the sources and properties of plastic wastes, and their suitability fo r various recycling methods such as repelletization, remo lding and pyrolysis [7]. So me other research group also performed with p lastic to fuel production process with thermal degradation or thermal cracking process [8][9][10], catalyt ic cracking process [11][12][13], pyrolysis process [14][15] and kinetic method [16] also applied for plastic to fuel energy conversion process. Natural state research, Inc uses thermal degradation process to convert industrial and municipal waste mixtu re plastics to hydrocarbon liquid fuel. Activated carbon was added as a dye removing purposes because it's removed the different color dyes of plastics from fuel products. As a result fuel color co mes clear and transparent.

Material
Waste plastics raw materials collected fro m local area grocery stores and coffee shops. The waste plastics collected comes with foreign materials such as paper, sand, food, coffee, insect etc. After collection waste plastic are separated out of all fo reign material. Waste plastic components are a mixtu re of white co lor milk containers, red co lor coffee cups, transparent food containers, black co lor food containers and some different color shopping bags. Separated waste plastics are washed with liquid soap and dried in room temperature. During the washing period of the waste plastics a considerable amount of waste water is generated. The waste water is kept into a separate container for waste water treatment. The waste water is treated with acidic and alkali method with coagulation and flocculation process. For the waste water treat ment process potash alum and sodium hydroxide solution with different normality is used.

Sample Preparation and Pre-analysis
Wash plastics are cut into small pieces, ~3-4 inch 2 using scissor. The small p ieces of plastics are put into the grinder mach ine and grounded into 2-3 mm pieces. Grounded plastic mixed with ratio wise equally. Four category of waste plastic (HDPE, LDPE, PP & PS) was uses for the liquefaction process and ratio was 25% each samp le by weight. The raw materials were analysed by using Perkin Elmer GC/M S with pyroprobe for solid materials and solid samp le vo latile temperature with pyroprobe 1200ºC. GC and MS result showed raw materials compound structure and FTIR was use for materials functional group and functional g roup wave band energy. TGA (Py ris-1) was used for materials onset temperature wh ich was representing liquefaction average temperature.

Experi mental Process
Plastic to fuel production process into laboratory scale was use thermal degradation at temperature 25-420 ºC under atmospheric pressure and under fume hood. For the experiment 1 kilogram o f samp le was used in a 316 stainless steel reactor. Reactor temperature can range up to 500 ºC. 25% LDPE, 25% HDPE, 25% PP and 25% PS with 5% activated carbon in a fu lly closed system. Waste plastic sample were put into the reactor chamber with activated carbon and heating started from room temperature up to 420 ºC. When the plastics started to melt as temperature was increased vapor started to form inside the reactor, the vapor then passes through a condenser unit. The condensation of the vapor becomes liquid in a form called p lastic fuel (See fig.1). This waste plastic to fuel conversion rate is 89%. This produced fuel density is 0.78 g. / ml. No catalyst and no extra chemical used in this conversion process because already metal content are present in the plastic raw materials. Those metal contents act as a catalyst for breaking down long chain hydrocarbon to short chain hydrocarbon during the thermal degradation process. During plastic convert to fuel all vapor are not turn into fuel some vapor portion is co me out as a light gas because gas boiling point is minus temperature. To clean the light gas (C 1 -C 4 ) a 0.5 (N) NaOH/NaHCO 3 and Liquid Hydrocarbon Fuel by Using Activated Carbon after alkali wash light gases passing through also water wash and at the end we put light gas into gas storage tank by using small pu mp. This light gas percentage is 7%. The produced plastic fuel passes through RCI fuel purificat ion unit due to centrifugal force fuel making clean and water and sediment come out separately its call fuel sediment, this sediment and water we can retreat. Activated carbon was added in the process to remove plastic dye because during the production period plastic industries use about 3% additive for different shape or model and that dye affects the quality of the end product. The activated carbon filters the heavy contents of the dye and neutralizes them during the thermal degradation process. Waste plastic to fuel production period some black solid residue is generated from the plastics. This residue amount is about 4%. This solid residue has good Btu value and experiment run time was 4.50 hours.

Anal ysis Technique
For analysis purpose a GC colu mn was use (Perkin Elmer) with a elite-5MS length 30 meter, 0.25 mm ID, 0.5u m df, maximu m program temperature 350ºC and min imu m bleed at 330 ºC (cat.# N9316284) and also it can be used -60ºC. Capillary colu mn internal silica coating of viscous liquid such as carbowax or wall bonded organic materials. GC/MS operational purpose was used carrier gas as Heliu m gas. For GC method setup init ial temperature 40ºC and in itial hold for 1 minute. Final temperature setup is 330ºC. Temperature ramping rate is 10ºC/ minutes up to 325ºC and hold for 15 minutes 325 ºC. Total experiment runs time 44.50 minutes. MS method setup for samp le analysis MS scan time 1 to 44.50 minutes and mass detection 35-528 EI+ centroid. Internal scan time used 0.15 second. Mass detection is creating m/ z ratio. FT-IR analysis purpose used Perkin Elme r FT-IR spectrum 100, range 4000-400 cm -1 , number of scan 32 and resolution 4. NaCl cell was used as a fuel sample holder. NaCl cell thickness is 0.05 mm. Liquid fuel analysis by Perkin Elmer DSC and analysis purpose used temperature 5-400ºC, ramping rate 10ºC/ min. 50 micro liter alu miniu m pan used for sample holding and nitrogen gas used for carrier. TGA (Pyris-1) was used raw sample analysis and by TGA can measurement raw sample onset temperature. Temperature profile was use for raw sample analysis 50 -800 ºC and ramping rate was 10ºC/ min. Heliu m gas was use as carrier gas.

Raw Materi al Analysis Result
ICP (Inductively coupled plasma atomic emission spectroscopy) analysis results showed (table 1) waste plastic has different category of metal present into raw material in ppm level. A ll metal co mes fro m the p lastic manufacture period when different kind of additives and catalyst are added for better quality and shape. Some research study indicates that waste plastic has different kind of additives. Plastics are manufactured by poly merization, polycondensat ion, or polyaddition reactions wheremono meric mo lecules are joined sequentially under controlled conditions to produce high-molecu lar-weight polymers whose basic properties are defined by their co mposition, mo lecular weight distribution, and their degree of branching or cross-lin king. To control the polymerization process, a broad range of structurally specific proprietary chemical compounds is used for polymerizat ion init iation, breaking, and cross-linking reactions (pero xides, Ziegler-Natta, and metallocene catalysts). The polymerized materials are admixed with proprietary antio xidants (sterically hindered phenols, organophosphites), UV and light stability improvers (hindered amines and piperidyl esters), antistatic agents (ethoxy lated amines), impact modifiers (methacrylat ebutadiene-styrene compounds), heat stabilizers (methyl t in mercaptides), lubricants (esters), biostabilizers (arsine, thiazoline, and phenol compounds), and plasticizers used to modify the plasticity, softness, and pliability of plastics (phthalates and esters) [17]. For that reason waste plastics conversion into fuel doesn't need any kind of catalyst. Without catalyst waste plastic can conversion into fuel by using this technology.   Waste plastic to produced fuel analysed by gas chromatography and mass spectrometer (GC/MS) seen fig.2 and table 3. GC-MS analysis of proportionally mixture of HDPE, LDPE, PP & PS plastics to fuel in order to measure retention time and molecu lar weight nu merous aliphatic, aromat ic derivatives and different types of hydrocarbon compounds and hydrocarbon chain ranges C 3 to C 28 . At the initial stage of the analysis phases at retention time and mo lecular weight 44, co mpound is Propane ( C 3 H 8      After fuel samp le analysis by FT-IR (Spectru m 100) was found some functional group seen fig.3  , functional group is CH 3 ,wave nu mber 1029.91 cm -1 ,co mpound is Secondary Cyclic A lcohol, wave number 1020.53 cm -1 ,functional group is Acetates. Again iterat ively wave number 989.91 cm -1 and 909.21 cm -1 wave functional group is -CH=CH 2 and fo llo wing way wave number 965.28 cm -1 ,functional group is -CH=CH-(t rans) and finally wave number 728.08 cm -1 and 697.90 cm -1 functional group is -CH=CH-(cis) respectively. In accordance with some functional group were calculated energy value of each band of derived co mpound such as for H bonded NH, energy value is 6.11x10 -20 J, for C-CH 3 energy value is 5.83x10 -20 J, for C-C=--C-C energy value is 2.04x10 -20 J, for Non-Conjugated energy value is 3. For proportional waste plastic to fuel analysis purpose was use DSC equip ment for measuring boiling point temperature and enthalpy value ( fig.4). For fuel analysis purpose was used Nitrogen (N 2 ) gas as a carrier. Program setup was initial temperature 10ºC and height 400ºC and temperature ramp ing rate was per minute 10ºC. After fuel analysis found some informat ion such as onset temperature 158.94ºC, peak temperature 159.5 ºC, peak height 29.6585 mW and enthalpy delta H is 19040.5867 J/g. ASTM test also performed according to standard method as follo ws such as API Grav ity @60 ºF (ASTM D4052), Baro metric Pressure (ASTM D86), A STM color (ASTM D1500), metal analysis (ASTM D5708), Ash @775 ºC (ASTM D482) etc showed

Conclusions
Waste plastic are major p roblem for environ ment. Waste plastics are releasing gas emission into environment because waste plastic are not bio degradable. This waste plastic can remain long period in landfill. The thermal degradation process applied with mixture waste plastics of high density polyethylene (HDPE), low density polyethylene (LDPE), Polypropylene (PP) and Polystyrene (PS) using stainless steel reactor with activated carbon. The polymer has been selected for the experiment 25% each of HDPE, LDPE, PP and PS by weight. The temperature used for thermal degradation at 25-420ºC. The obtained products are liquid fuel, light gas and black carbon solid residue. Various technique (Gas Chro matography and Mass Spectrometer, FT-IR and DSC) are used for produced fuel analysis. GC/MS result is showing hydrocarbon compound ranges fro m C 3 -C 28 and light gas are present C 1 -C 4 . Using activated carbon with waste plastic its removing plastic dye fro m fuel, this activated used as filtered. Activated carbon is seated with black residue end of the experiment is not come out with liquid fuel. Activated carbon using with this experiment fuel is clean and color is bright yellow. Th is fuel burns cleaner and burning time is also longer.