scholarly journals From Plastic to Fuel - New Challenges

2019 ◽  
Vol 56 (4) ◽  
pp. 721-729 ◽  
Author(s):  
Marius Constantinescu ◽  
Felicia Bucura ◽  
Eusebiu Ilarian Ionete ◽  
Daniela Ion-Ebrasu ◽  
claudia Sandru ◽  
...  

The increased demand for energy sources is the driving force to convert organic compounds into alternative fuels. Plastic waste disposal affects the environment, since they are not easily recycled and, during the recycling process, they can produce waste ash, heavy metals, or potentially harmful gas emissions. In the plant design for plastic converting into fuel, the chemical reactor is one of the advanced equipment in the field of chemical and process engineering. This study emphasizes the feasibility of pyrolysis process for valorisation plastics by producing energy-efficient products. In this respect, samples of polypropylene, polyethylene and polystyrene were used as models and subjected to pyrolysis processes at 450 �C, in the presence of two types of mesoporous silica materials, MCM-41 and SBA-15, using a modern developed reactor. The use of mesoporous materials increased the calorific value of the obtained oil and gas, thus improving the economic potential of the process end products. This study dealt with the extraction of oil from plastics termed as plastic pyrolysis oil (PPO) and plastics pyrolysis gas (PPG), with a composition rich in different types of hydrocarbons and they can be marketed at much cheaper rates compared to that present in the market.

2021 ◽  
Vol 3 (9) ◽  
Author(s):  
Anca Maria Zaharioiu ◽  
Felicia Bucura ◽  
Roxana Elena Ionete ◽  
Florian Marin ◽  
Marius Constantinescu ◽  
...  

Abstract Based on the global need to efficiently eliminate highly produced amounts of sewage sludge, alternative technologies are required to be practically developed. Reduction of sewage sludge waste quantities with energy recovery is the most important and modern practice, with least possible impact on the environment. Appropriate technologies for treating and disposal sewage sludge are currently considered: incineration, gasification and pyrolysis. The main products generated during the pyrolysis process are bio-gas, bio-oil and bio-residue, providing sustainable fuels/ biofuels and adsorbents. Compared to other disposal methods of sewage sludge, pyrolysis has advantages in terms of the environment: waste in small quantities, low emissions, low level of heavy metals. From a technological point of view, pyrolysis is the most efficient in relation to its final products, pyrolysis oil, pyrolysis gas and solid residue that can be transformed into CO2 adsorbent with the help of chemical and thermal activation processes. The incineration process of sewage sludge has a number of disadvantages both environmentally and technologically: organic pollutants, heavy metals, toxic pollutants and ash resulting from combustion that needs a disposal process. A comparison of different types of sewage sludge elimination for the energy recovery is described in the present paper. Article Highlights Sewage sludge is a waste in increasing quantities, which requires disposal and energy recovery, in a clean way for the environment. The pyrolysis process of sewage sludge is the cleanest method of its recovery. Pyrolysis products, bio-oil, syngas and biochar, can be used as alternative fuels to fossil fuels. The pyrolysis process of the sewage sludge is the most advantageous from the point of view of the obtained products and of the environment, in comparison with the incineration and gasification processes.


Author(s):  
Г.В. Черкаев

В статье рассматриваются вопросы, связанные с анализом достоинств и недостатков различных видов альтернативных топлив. Эти топлива могут применяться на судах различного назначения со средне- и высокооборотными дизельными двигателями. Наиболее актуальной альтернативой для полной или частичной замены жидкого нефтяного топлива является биотопливо. Особое внимание уделено микроводорослям, темпы роста которых значительно выше, чем у выращиваемых наземных культур. Рассматриваются такие виды альтернативных топлив, как биодизель, биоэтанол, биогаз, растительное масло, пиролизное масло, биобутанол, диметиловый эфир. Показано, что для расчета количества выбросов загрязняющих веществ, выделяющихся при сжигании биотоплив в судовых ДВС, может подойти модель «черного ящика». Зная основные физико-химические свойства топлива (теплотворная способность, плотность, вязкость, содержание кислорода и др.), можно оценить расход топлива, определить выбросы углекислого газа. Представлены результаты расчетов выбросов загрязняющих веществ при сжигании биотоплив. В итоге все полученные результаты могут быть переведены в условные единицы и пересчитаны в эквиваленты выбрасываемых парниковых газов. The article discusses issues related to the analysis of the advantages and disadvantages of various types of alternative fuels. These fuels can be used on ships for various purposes equipped with MSD and HSD engines. Biofuels are the most relevant alternative for the complete or partial replacement of liquid fuel oil. Particular attention is paid to microalgae, the growth rate of which is much higher than that of grown terrestrial crops. These types of alternative fuels are considered as biodiesel, bioethanol, biogas, vegetable oil, pyrolysis oil, biobutanol, dimethyl ether, etc. It is shown that the “black box” model may be suitable for calculating the amount of pollutant emissions released during the combustion of biofuels in ship internal combustion engines. Knowing the basic physicochemical properties of fuel (calorific value, density, viscosity, oxygen content, etc.), it is possible to estimate fuel consumption and determine CO2emissions. The calculation results of pollutant emissions from biofuel combustion are presented. As a result, all the results obtained can be converted into conventional units and recalculated into the equivalents of the emitted greenhouse gases.


Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6945
Author(s):  
Hancheng Ma ◽  
Jianye Bei ◽  
Mingxiu Zhan ◽  
Wentao Jiao ◽  
Xu Xu ◽  
...  

The calorific value of household refuse (HR) is greatly improved after classification, which includes the implementation of sufficient pyrolysis conditions. Therefore, a better pyrolysis effect can be achieved by co-pyrolysis with industrial solid waste (ISW) with high calorific value. In this work, HR and ISW were used as raw materials for co-pyrolysis experiments. The influence on the distribution of three-phase products after co-pyrolysis, the concentration of heavy metals and dioxins in the flue gas, and the distribution of PCDD/Fs isomers were studied. The results showed that, at a temperature of 600 °C and H/C = 1.3, of the formed material, the quantity of pyrolysis gas was approximately 27 wt.%, and the quantity of pyrolysis oil was approximately 40.75 wt.%, which mainly contained alkanes, olefins, and aromatic hydrocarbons. When S/C = 0.008, pyrolysis gas accounted for 25.95 wt.% of the formed material, and pyrolysis oil for 41.95 wt.% of the formed material. The ignition loss rate of pyrolysis coke was approximately 20%, and the maximal calorific value was 14,217 KJ/kg. According to the thermogravimetric experiment, the co-pyrolysis of HR and ISW can promote the positive reaction of pyrolysis, and the weight loss reached 62% at 550 °C. The emission of gaseous heavy metals was relatively stable, and the concentration of heavy metals slightly decreased. The main heavy metals in the ash were Cu, Fe, and Zn. The emission of dioxins could be effectively reduced by the pyrolysis of HR with ISW, and the produced dioxins were mainly synthesized from de novo synthesis. After pyrolysis, the toxic equivalent of dioxins in the flue gas was reduced from 0.69 to 0.29 ng I-TEQ/Nm3, and the distribution of dioxin isomers in the flue gas had little influence. The experimental results provide a theoretical basis for the application of co-pyrolysis technology with HR and ISW.


2019 ◽  
Vol 5 (12) ◽  
pp. 37-46
Author(s):  
K. Chalov ◽  
Yu. Lugovoy ◽  
Yu. Kosivtsov ◽  
E. Sulman

This paper presents a study of the process of thermal degradation of crosslinked polyethylene. The kinetics of polymer decomposition was studied by thermogravimetry. Crosslinked polyethylene showed high heat resistance to temperatures of 400 °C. The temperature range of 430–500 °C was determined for the loss of the bulk of the sample. According to thermogravimetric data, the decomposition process proceeds in a single stage and includes a large number of fracture, cyclization, dehydrogenation, and other reactions. The process of pyrolysis of a crosslinked polymer in a stationary-bed metal reactor was investigated. The influence of the process temperature on the yield of solid, liquid, and gaseous pyrolysis products was investigated. The optimum process temperature was 500 °C. At this temperature, the yield of liquid and gaseous products was 85.0 and 12.5% (mass.), Respectively. Samples of crosslinked polyester decomposed almost completely. The amount of carbon–containing residue was 3.5% by weight of the feedstock. With increasing temperature, the yield of liquid products decreased slightly and the yield of gaseous products increased, but their total yield did not increase. For gaseous products, a qualitative and quantitative composition was determined. The main components of the pyrolysis gas were hydrocarbons C1–C4. The calorific value of pyrolysis gas obtained at a temperature of 500 °C was 17 MJ/m3. Thus, the pyrolysis process can be used to process crosslinked polyethylene wastes to produce liquid hydrocarbons and combustible gases.


Author(s):  
O. M. Salamov ◽  
F. F. Aliyev

The paper discusses the possibility of obtaining liquid and gaseous fuels from different types of biomass (BM) and combustible solid waste (CSW) of various origins. The available world reserves of traditional types of fuel are analyzed and a number of environmental shortcomings that created during their use are indicated. The tables present the data on the conditional calorific value (CCV) of the main traditional and alternative types of solid, liquid and gaseous fuels which compared with CCV of various types of BM and CSW. Possible methods for utilization of BM and CSW are analyzed, as well as the methods for converting them into alternative types of fuel, especially into combustible gases.Reliable information is given on the available oil and gas reserves in Azerbaijan. As a result of the research, it was revealed that the currently available oil reserves of Azerbaijan can completely dry out after 33.5 years, and gas reserves–after 117 years, without taking into account the growth rates of the exported part of these fuels to European countries. In order to fix this situation, first of all it is necessary to use as much as possible alternative and renewable energy sources, especially wind power plants (WPP) and solar photovoltaic energy sources (SFES) in the energy sector of the republic. Azerbaijan has large reserves of solar and wind energy. In addition, all regions of the country have large reserves of BM, and in the big cities, especially in industrial ones, there are CSW from which through pyrolysis and gasification is possible to obtain a high-quality combustible gas mixture, comprising: H2 + CO + CH4, with the least amount of harmful waste. The remains of the reaction of thermochemical decomposition of BM and CSW to combustible gases can also be used as mineral fertilizers in agriculture. The available and projected resources of Azerbaijan for the BM and the CSW are given, as well as their assumed energy intensity in the energy sector of the republic.Given the high energy intensity of the pyrolysis and gasification of the BM and CSW, at the present time for carrying out these reactions, the high-temperature solar installations with limited power are used as energy sources, and further preference is given to the use of WPP and SFES on industrial scale.


2019 ◽  
Vol 38 (2) ◽  
pp. 406-416 ◽  
Author(s):  
Marcel Mikeska ◽  
Jan Najser ◽  
Václav Peer ◽  
Jaroslav Frantík ◽  
Jan Kielar

Gas from the gasification of pellets made from renewable sources of energy or from lower-quality fuels often contains a number of pollutants. This may cause technical difficulties during the gas use in internal combustion gas engines used for energy and heat cogeneration. Therefore, an adequate system of gas cleaning must be selected. In line with such requirements, this paper focuses on the characterization and comparison of gases produced from different types of biomass during gasification. The biomass tested was wood, straw, and hay pellets. The paper gives a detailed description and evaluation of the measurements from a fix-bed gasifier for the properties of the produced gases, raw fuels, tar composition, and its particle content before and after the cleaning process. The results of elemental composition, net calorific value, moisture, and ash content show that the cleaned gases are suitable for internal combustion engine-based cogeneration systems, but unsuitable for gas turbines, where a different cleaning technology would be needed.


Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1539
Author(s):  
Karolina Wojtacha-Rychter ◽  
Piotr Kucharski ◽  
Adam Smolinski

The article evaluates the reduction of carbon dioxide emission due to the partial substitution of coal with alternative fuels in clinker manufacture. For this purpose, the calculations were performed for seventy waste-derived samples of alternative fuels with variable calorific value and variable share in the fuel mixture. Based on annual clinker production data of the Polish Cement Association and the laboratory analysis of fuels, it was estimated that the direct net CO2 emissions from fossil fuel combustion alone were 543 Mg of CO2 per hour. By contrast with the full substitution of coal with alternative fuels (including 30% of biomass), the emission ranged from 302 up to 438 Mg of CO2 per hour, depending on fuel properties. A reduction of 70% in the share of fossil fuels resulted in about a 23% decrease in net emissions. It was proved that the increased use of alternative fuels as an additive to the fuel mix is also of economic importance. It was determined that thanks to the combustion of 70% of alternative fuels of calorific value from 15 to 26 MJ/kg, the hourly financial profit gain due to avoided CO2 emission and saved 136 megatons of coal totaled an average of 9718 euros. The results confirmed that the co-incineration of waste in cement kilns can be an effective, long-term way to mitigate carbon emissions and to lower clinker production costs. This paper may constitute a starting point for future research activities and specific case studies in terms of reducing CO2 emissions.


Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3837
Author(s):  
Mohammad I. Jahirul ◽  
Farhad M. Hossain ◽  
Mohammad G. Rasul ◽  
Ashfaque Ahmed Chowdhury

Utilising pyrolysis as a waste tyre processing technology has various economic and social advantages, along with the fact that it is an effective conversion method. Despite extensive research and a notable likelihood of success, this technology has not yet seen implementation in industrial and commercial settings. In this review, over 100 recent publications are reviewed and summarised to give attention to the current state of global tyre waste management, pyrolysis technology, and plastic waste conversion into liquid fuel. The study also investigated the suitability of pyrolysis oil for use in diesel engines and provided the results on diesel engine performance and emission characteristics. Most studies show that discarded tyres can yield 40–60% liquid oil with a calorific value of more than 40 MJ/kg, indicating that they are appropriate for direct use as boiler and furnace fuel. It has a low cetane index, as well as high viscosity, density, and aromatic content. According to diesel engine performance and emission studies, the power output and combustion efficiency of tyre pyrolysis oil are equivalent to diesel fuel, but engine emissions (NOX, CO, CO, SOX, and HC) are significantly greater in most circumstances. These findings indicate that tyre pyrolysis oil is not suitable for direct use in commercial automobile engines, but it can be utilised as a fuel additive or combined with other fuels.


2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Reza Wahyudi ◽  
Muhammad Ivanto ◽  
Murti Juliandari

Dependence on the provision of electricity using fossil fuels is a major energy supply problem in Indonesia. Therefore, it is necessary to provide new and renewable alternative fuels that are effective, efficient, and environmentally friendly. One of the alternative fuels is bagasse biomass. The purpose of this study was to determine the amount of bagasse produced by sellers of sugarcane juice drink in Pontianak City, in order to determine the estimated value of bagasse. The research method used was direct data collection and laboratory testing . Based on the results of the study, the number of vendors of sugarcane juice beverages producing bagasse was 169. Of this amount, produce bagasse that can reach 1,030.9 kg/day. Based on the test results, the estimated moisture content of bagasse was 3.28%, ash content was 0.77%, and carbon remained at 7.65%. So, if converted with the test results of the calorific value of bagasse and made into briquettes bagasse (bio briquettes), which is 19,648 kJ/kg with a density of 0.416 kg/m3, then converted into a potential calorific value of 242,849,280 J/year.


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