Abstract: Waste polyethylene (PE) is classified as waste low
density polyethylene (LDPE) and waste high density polyethylene
(HDPE) according to their densities. Pyrolysis of plastic waste may
have an important role in dealing with the enormous amounts of
plastic waste produced all over the world, by decreasing their
negative impact on the environment. This waste may be converted
into economically valuable hydrocarbons, which can be used both as
fuels and as feed stock in the petrochemical industry. End product
yields and properties depend on the plastic waste composition.
Pyrolytic biochar is one of the most important products of waste
plastics pyrolysis. In this study, HDPE and LDPE plastic wastes were
co-pyrolyzed together with waste olive pomace. Pyrolysis runs were
performed at temperature 700°C with heating rates of 5°C/min.
Higher pyrolysis oil and gas yields were observed by the using waste
olive pomace. The biochar yields of HDPE- olive pomace and LDPEolive
pomace were 6.37% and 7.26% respectively for 50% olive
pomace doses. The calorific value of HDPE-olive pomace and
LDPE-olive pomace of pyrolysis oil were 8350 and 8495 kCal.
Abstract: The disposal of waste plastics has become a major worldwide environmental problem. Pyrolysis of waste plastics is one of the routes to waste minimization and recycling that has been gaining interest. In pyrolysis, the pyrolysed material is separated into gas, liquid (both are fuel) and solid (char) products. All fractions have utilities and economical value depending upon their characteristics. The first objective of this study is to determine the co-pyrolysis product fractions of waste HDPE- (high density polyethylene) and LDPE (low density polyethylene)-olive pomace (OP) and to determine the qualities of the solid product char. Chars obtained at 700 °C pyrolysis were used in biocomposite preparation as additive. As the second objective, the effects of char on biocomposite quality were investigated. Pyrolysis runs were performed at temperature 700 °C with heating rates of 5 °C/min. Biocomposites were prepared by mixing of chars with bisphenol-F type epoxy resin in various wt%. Biocomposite properties were determined by measuring electrical conductivity, surface hardness, Young’s modulus and tensile strength of the composites. The best electrical conductivity results were obtained with HDPE-OP char. For HDPE-OP char and LDPE-OP char, compared to neat epoxy, the tensile strength values of the composites increased by 102% and 78%, respectively, at 10% char dose. The hardness measurements showed similar results to the tensile tests, since there is a correlation between the hardness and the tensile strength.
Abstract: Renewable energy sources have gained ultimate urgency due to the need of the preservation of the environment for a sustainable development. Pyrolysis is an ultimate promising process in the recycling and acquisition of precious chemicals from wastes. Here, the co-pyrolysis of hazelnut shell with ultra-high molecular weight polyethylene was carried out catalytically and noncatalytically at 500 and 650 ºC. Potassium dichromate was added in certain amounts to act as a catalyst. The liquid, solid and gas products quantities were determined by gravimetry. As a main result, remarkable increases in gasification were observed by using this catalyst for pure components and their blends especially at 650 ºC. The increase in gas product quantity was compensated mainly with the decreases in the solid products and additionally in some cases liquid products quantities. These observations may stem from mainly the activation of carbon-carbon bonds rather than carbon-hydrogen bonds via potassium dichromate. Also, the catalytic effect of potassium dichromate on HS: PEO and HS: UHMWPE co-pyrolysis was compared.