Effect of the Pressure and Feedstock State on the Yield and Properties of Waste Tire Thermolysis Products

Abstract

Scrap tires of passenger cars have been depolymerized by applying a thermal destruction method, thermolysis. The process was conducted in a semi-continuous distillation reactor. The investigation was made on the effect of the pressure and feedstock chopping degree variation on the yield of thermolysis products, oil, char, and gas, as well as their properties and composition. The maximum yield of the liquid product was obtained under 40 bar thermolysis pressure when the feedstock was prepared as a type 2 fraction. Liquid products were analyzed by gas chromatography/mass spectrometry (GC/MS) and standard fuel analysis methods. The chromatographic results show a complex mixture of organic compounds with a considerable amount of arenes (34−41%, w/w). A high calorific value (41.5−42.6 MJ/kg) of the thermolysis liquid is consistent with its chemical composition, which is close to the petroleum-derived products. Sulfur and ash contents in the liquid product are 0.50−0.74 and 0.02−0.07% (w/w), respectively. The tire thermolysis gaseous product is composed of the lightest alkanes (over 55%, v/v), hydrogen (8.60−15.82%, v/v), carbon oxides (over 5.5%, v/v), and butenes (about 4%, v/v) as the main alkenes. The elemental analysis of residual char shows carbon as the main element; however, a significant share (about 11%, w/w) is taken by inorganic impurities. The thermolysis char average calorific value is −31 MJ/kg.

Pore Development During CO2 and Steam Activation of a Spent Tyre Pyrolysis Char

“…Over % of spent tyres were landfilled and stockpiled [2]. By their very nature, spent tyres represent both health and environmental hazards as they are non-biodegradable, sulphur-rich, highly flammable, and, when ignited, they release toxic, carcinogenic and mutagenic pollutants [3][4][5][6]. There are some available thermochemical conversion processes to deal with the current challenges in spent tyre accumulation such as pyrolysis, gasification, hydrothermal liquefaction and incineration [7,8].…”

Liquid Hydrocarbons Production by the Steam Gasification of Used Tires: Energy Characteristics and Environmental Sustainability

“…One of the most promising ways to recycle automobile tires is the steam gasification technology [4][5][6][7]. Its advantages are explosion safety, neutralization of environmentally hazardous compounds in the vapor-gas mixture, higher the energy value of gas-phase products, activation of the carbon particles pore structure and the possibility of the smooth regulation of raw materials thermal conversion.…”

Influence of the Process Conditions on Yield, Composition, and Properties of the Products Derived from the Thermolysis of Scrap Tire and Used Engine Oil Blends

“…Statistical data also shows that the U.S. is one of the leaders not only by the amount of the ELTs, but also because of a pool of more than 6.3 million tons of waste engine oil . During this period in the European Union (EU), the quantity of worn out tires and used motor oil was lower than in the U.S. and comprised a little more than 3.4 and 5.2 million tons, respectively. , The ever growing amount of end-of-life tires and used oil is caused by an expansion of the vehicle manufacture industry, which, in turn, is dependent upon world population and economic growth as well as social welfare …”

“…A tire is a complex structure of a number of materials, such as various types of synthetic and natural rubber, carbon black, steel, polyester, nylon, silica, and over 40 more different kinds of chemicals, such as waxes, oils, and pigments, that make the waste virtually nonbiodegradable. ,, Waste automotive engine oil (WAO), such as scrap tires, is environmentally hazardous, because it may contaminate groundwater and soil, if discharged to the environment, and cause air pollution, if burnt as a low-grade fuel. ,, Besides, it is a high-volume waste that is difficult to regenerate and dispose of because of a number of undesirable components: soot, polycyclic aromatic hydrocarbons (PAHs), and chlorinated paraffins, polychlorinated biphenyls (PCBs), and metal containing compounds that are incorporated as oil additives. − …”