Heat Transfer Technology to Convert Plastic Trash to Oil

2017 ◽  
Author(s):  
Mahmoud Elsharafi ◽  
Cody Chancellor ◽  
Cameron Duckworth ◽  
Moiz Tatla ◽  
Reuben Denwe ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Feedback Loop ◽  
Modern Society ◽  
Environmental Issue ◽  
Heating Rates ◽  
Waste Plastic ◽  
Control Temperature ◽  
The Road ◽  
Gaseous Products ◽  
Plastic Type

In modern society, plastic waste has become a serious environmental issue. The inability of most hydrocarbon based plastics to naturally decompose quickly causes concern. The material piles up in landfills, waterways, and along the side of the road. One way to combat this issue is the repurposing of the material. Plastic can be converted back into oil (called pyrolysis) and refined to produce fuels. To attempt this, a custom-built steel reactor is to be filled with waste plastic, and will be heated to the plastic’s boiling point in an inert (N2) environment. The resulting vapor will be recondensed in a specially designed heat exchanger, resulting in oil, wax, and gaseous byproducts. The oil and waxes are collected in one container, and the gases are collected in a separate container. The system will require the use of thermocouples and a feedback loop to properly control temperature. The results are expected to show a correlation between plastic type and resulting byproduct composition with Grade 1 plastics producing the most gas. In addition, faster heating rates, larger plastic particle size, and higher temperatures should increase gaseous products. This may aid in the creation of commercial/industrial sized pyrolysis systems.

scholarly journals Pyrolysis and Oxidation of PAN in Dry Air. Thermoanalytical Methods

1970 ◽  
Vol 17 (1) ◽  
pp. 38-42
Author(s):  
Anna BIEDUNKIEWICZ ◽  
Pawel FIGIEL ◽  
Marta SABARA
Keyword(s):  
Temperature Increase ◽  
Heating Rates ◽  
Linear Change ◽  
Dry Air ◽  
Isothermal Conditions ◽  
Gaseous Products ◽  
Heterogeneous Processes ◽  
Temperature Ranges ◽  
Higher Temperature ◽  
Kinetics Of

The results of investigations on pyrolysis and oxidation of pure polyacrylonitrile (PAN) and its mixture with N,N-dimethylformamide (DMF) under non-isothermal conditions at linear change of samples temperature in time are presented. In each case process proceeded in different way. During pyrolysis of pure PAN the material containing mainly the product after PAN cyclization was obtained, while pyrolysis of PAN+DMF mixture gave the product after cyclization and stabilization. Under conditions of measurements, in both temperature ranges, series of gaseous products were formed.For the PAN-DMF system measurements at different samples heating rates were performed. The obtained results were in accordance with the kinetics of heterogeneous processes theory. The process rates in stages increased along with the temperature increase, and TG, DTG and HF function curves were shifted into higher temperature range. This means that the process of pyrolysis and oxidation of PAN in dry air can be carried out in a controlled way.http://dx.doi.org/10.5755/j01.ms.17.1.246

Maximum heating rates for producing undistorted glassy carbon ware determined by wedge-shaped samples

1996 ◽  
Vol 11 (9) ◽  
pp. 2368-2375 ◽  
Author(s):  
Hossein Maleki ◽  
Lawrence R. Holland ◽  
Gwyn M. Jenkins ◽  
R. L. Zimmerman ◽  
Wally Porter
Keyword(s):  
Heating Rate ◽  
Treatment Process ◽  
Gaseous Product ◽  
Pyrolysis Mass Spectrometry ◽  
Heating Rates ◽  
Gaseous Products ◽  
Volatile Products ◽  
Solid Bodies ◽  
Polymeric Carbon ◽  
Maximum Heating

Polymeric carbon artifacts are particularly difficult to make in thick section. Heating rate, temperature, and sample thickness determine the outcome of carbonization of resin leading to a glassy polymeric carbon ware. Using wedge-shaped samples, we found the maximum thickness for various heating rates during gelling (300 K–360 K), curing (360 K–400 K), postcuring (400 K–500 K), and precarbonization (500 K–875 K). Excessive heating rate causes failure. In postcuring the critical heating rate varies inversely as the fifth power of thickness; in precarbonization this varies inversely as the third power of thickness. From thermogravimetric evidence we attribute such failure to low rates of diffusion of gaseous products of reactions occurring within the solid during pyrolysis. Mass spectrometry shows the main gaseous product is water vapor; some carboniferous gases are also evolved during precarbonization. We discuss a diffusion model applicable to any heat-treatment process in which volatile products are removed from solid bodies.

scholarly journals Nusselt number evaluation for combined radiative and convective heat transfer in flow of gaseous products from combustion

2013 ◽  
Vol 17 (4) ◽  
pp. 1093-1106 ◽  
Author(s):  
Soraya Trabelsi ◽  
Wissem Lakhal ◽  
Ezeddine Sediki ◽  
Mahmoud Moussa
Keyword(s):  
Heat Transfer ◽  
Radiation Effects ◽  
Combustion Products ◽  
Radiative Properties ◽  
Inlet Temperature ◽  
Gaseous Products ◽  
Nusselt Numbers ◽  
Coupled Heat Transfer ◽  
Flow And Heat Transfer ◽  
Fluid Properties

Combined convection and radiation in simultaneously developing laminar flow and heat transfer is numerically considered with a discrete-direction method. Coupled heat transfer in absorbing emitting but not scattering gases is presented in some cases of practical situations such as combustion of natural gas, propane and heavy fuel. Numerical calculations are performed to evaluate the thermal radiation effects on heat transfer through combustion products flowing inside circular ducts. The radiative properties of the flowing gases are modeled by using the absorption distribution function (ADF) model. The fluid is a mixture of carbon dioxide, water vapor, and nitrogen. The flow and energy balance equations are solved simultaneously with temperature dependent fluid properties. The bulk mean temperature variations and Nusselt numbers are shown for a uniform inlet temperature. Total, radiative and convective mean Nusselt numbers and their axial evolution for different gas mixtures produced by combustion with oxygen are explored.

Effect of High Temperatures and Heating Rates on High Strength Concrete for Use as Thermal Energy Storage

2010 ◽  
Author(s):  
Emerson E. John ◽  
W. Micah Hale ◽  
R. Panneer Selvam
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Molten Salt ◽  
High Temperatures ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Heat Transfer Fluid ◽  
Heating Rates ◽  
Storage Media ◽  
Concrete Mixtures

In recent years due to rising energy costs as well as an increased interest in the reduction of greenhouse gas emissions, there is great interest in developing alternative sources of energy. One of the most viable alternative energy resources is solar energy. Concentrating solar power (CSP) technologies have been identified as an option for meeting utility needs in the U.S. Southwest. Areas where CSP technologies can be improved are improved heat transfer fluid (HTF) and improved methods of thermal energy storage (TES). One viable option for TES storage media is concrete. The material costs of concrete can be very inexpensive and the costs/ kWhthermal, which is based on the operating temperature, are reported to be approximately $1. Researchers using concrete as a TES storage media have achieved maximum operating temperatures of 400°C. However, there are concerns for using concrete as the TES medium, and these concerns center on the effects and the limitations that the high temperatures may have on the concrete. As the concrete temperature increases, decomposition of the calcium hydroxide (CH) occurs at 500°C, and there is significant strength loss due to degeneration of the calcium silicate hydrates (C-S-H). Additionally concrete exposed to high temperatures has a propensity to spall explosively. This proposed paper examines the effect of heating rates on high performance concrete mixtures. Concrete mixtures with water to cementitious material ratios (w/cm) of 0.15 to 0.30 and compressive strengths of up to 180 MPa (26 ksi) were cast and subjected to heating rates of 3, 5, 7, and 9° C/min. These concrete mixtures are to be used in tests modules where molten salt is used as the heat transfer fluid. Molten salt becomes liquid at temperatures exceeding 220°C and therefore the concrete will be exposed to high initial temperatures and subsequently at controlled heating rates up to desired operating temperatures. Preliminary results consistently show that concrete mixtures without polypropylene fibres (PP) cannot resist temperatures beyond 500° C, regardless of the heating rate employed. These mixtures spall at higher temperatures when heated at a faster rate (7° C/min). Additionally, mixtures which incorporate PP fibres can withstand temperatures up to 600° C without spalling irrespective of the heating rate.

Thermal Decomposition of Energetic Materials 26. Simultaneous Temperature Measurements of the Condensed Phase and Rapid-Scan FT-IR Spectroscopy of the Gas Phase at High Heating Rates

1987 ◽  
Vol 41 (7) ◽  
pp. 1147-1151 ◽  
Author(s):  
J. T. Cronin ◽  
T. B. Brill
Keyword(s):  
Real Time ◽  
Condensed Phase ◽  
Energetic Materials ◽  
Buffer Gas ◽  
Heating Rates ◽  
Decomposition Products ◽  
Gaseous Products ◽  
Rapid Scan ◽  
Ft Ir ◽  
Better Than

Rapid-scan infrared spectroscopy (RSFT-IR) with better than 100-ms temporal resolution has been used to quantify the gas decomposition products of energetic materials in real time at various heating rates up to 800°C/s and under buffer gas pressures of 1 to 1000 psi. A new method is described that permits simultaneous real-time recording of the temperature of the condensed phase and of the IR spectra of the gaseous products under the above conditions. Endothermic and exothermic events in the condensed phase can now be correlated with the evolved gases under conditions approaching those of combustion. The design and procedure for using the cell are given and are applied to the thermolysis of 1,7-diazido-2,4,6-trinitro-2,4,6-triazaheptane (DATH) and pentaery-thrityltetrammonium nitrate (PTTN).

Dynamic Performance of Conventional and Electrically Activated Engine Thermostats

2001 ◽  
Author(s):  
L. Alan Gunter ◽  
M. Razi Nalim
Keyword(s):  
Heat Transfer ◽  
Dynamic Performance ◽  
Control Device ◽  
The Road ◽  
Engine Control System ◽  
Passive Devices ◽  
Heating Device ◽  
Set Up ◽  
Spool Valve ◽  
Engine Coolant

Abstract This study concerns the dynamic performance of passive and active wax-actuator driven thermostats. The study is extended to wax actuator driven thermostats that have been fitted with a heating device, such that the thermostat can be actuated electrically. The thermostat valve type chosen for this study is a balanced, sleeve-type thermostat typically used in large over-the-road and industrial diesel engines. The valve operates like a spool valve to direct the flow of the engine coolant to the bypass, the heat exchanger, or partially to each. Since conventional thermostats are passive devices they lag in response to dynamic engine conditions, and under certain circumstances overheating can occur as a result of the device’s inability to respond quickly. Also, conventional thermostats are designed to protect an engine against overheating year round. Therefore, a thermostat designed to protect against overheating in the summer will often result in an overcooling condition in the winter. One possible solution to the problem is to control the thermostat electrically through the electronic engine control system, or other system, making the thermostat an active control device instead of a passive one. In this study, a mathematical model is developed to determine wax temperature, and thereby predict the thermostat operation and response. The wax temperature depends on the heat transfer from the engine coolant through the brass cup that encapsulates the wax, as well as heat transfer from the heater. The simulations are compared with measurements of temperature, thermostat position and flow at several locations around the thermostat in an experimental set-up. The outcome is used to analyze the accuracy of the methods used in the thermodynamic calculations.

A Numerical Study of Fast Pyrolysis of Beetle Killed Pine Trees

2011 ◽  
Author(s):  
Saeed Danaei Kenarsari ◽  
Yuan Zheng
Keyword(s):  
Heat Transfer ◽  
Chemical Kinetics ◽  
Fast Pyrolysis ◽  
Kinetics Model ◽  
Unsteady State ◽  
Pyrolysis Process ◽  
Conservation Equations ◽  
Gaseous Products ◽  
Pine Trees ◽  
Secondary Reactions

Since 1990s, as a result of unprecedented drought and warm winters, mountain pine beetles have devastated mature pine trees in the forests of western North America from Mexico to Canada. Especially, in the State of Wyoming, there are more than 1 million acres of dead forest now. These beetle killed trees are a source of wildfire and if left unharvested will decay and release carbon back to the atmosphere. Fast pyrolysis is a promising method to transfer the beetle killed pine trees into bio-oils. In the present study, an unsteady state mathematical model is developed to simulate the fast pyrolysis process, which converts solid pine wood pellets into char (solid), bio-oils (liquid) and gaseous products in the absence of oxidizer in a temperature range from 500°C to 1000°C within short residence time. The main goal of the study is to advance the understanding of kinetics and convective and radiative heat transfer in biomass fast pyrolysis process. Conservation equations of total mass, species, momentum, and energy, coupled with the chemical kinetics model, have been developed and solved numerically to simulate fast pyrolysis of various cylindrical beetle killed pine pellets (10 mm diameter and 3 mm thickness) in a reactor (30 mm inside diameter and 50 mm height) exposed to various radiative heating flux (0.2 MW/m2 to 0.8 MW/m2). A fast pyrolysis kinetics model for pine wood that includes competitive path ways for the formation of solid, liquid, and gaseous products plus secondary reactions of primary products has been adapted. Several heat transfer correlations and thermo property models available in the literature have been evaluated and adapted in the simulation. Finite element method is used to solve the conservation equations and a 4th order Runge-Kutta method is used to solve the chemical kinetics. Unsteady-state two dimensional temperature and product distributions throughout the entire pyrolysis process were simulated and the simulated product yields were compared to the experimental data available in the literature. This study demonstrates the importance of the secondary reactions and appropriate convective and radiative modeling in the numerical simulation of biomass fast pyrolysis.

Performance of a Multi-Cell MgCl2/NH3 Thermo-Chemical Battery During Recharge and Operation

2015 ◽  
Author(s):  
Kent S. Udell ◽  
Bidzina Kekelia ◽  
Peng Fan ◽  
Chengshang Zhou ◽  
Zhigang Fang
Keyword(s):  
Heat Transfer ◽  
Waste Heat ◽  
Gaseous Ammonia ◽  
Air Cooling ◽  
Ammonia Vapor ◽  
Heating Rates ◽  
Cell Array ◽  
Cooling Rates ◽  
Operational Test ◽  
Storage Technologies

The development of thermal energy storage technologies to match sustainable energy production is of interest. A prototype of a multi-cell thermochemical battery consisting of connected cells containing MgCl2 salt, and additional air-cooled or air-heated cells containing liquid ammonia of varying quality, was constructed and tested. Each of the 17 cells contained thermocouple probes at three different axial locations within the cylindrical cells. Heat transfer rates, pressures, and ammonia condensation and vaporization rates were measured. Three tests were run. In the first test, the hot bed containing 10 cells was heated using cartridge heaters, driving vaporous ammonia from the salt phase once sufficient salt temperatures were reached. The evolved gaseous ammonia was condensed in an additional 7 empty air-cooled cells. Once the recharging cycle was complete, a valve in the ammonia vapor line connecting the cold and hot beds was closed, allowing indefinite storage of cooling or heating capacity. The second operational test involved the opening of the valve while simultaneous air-cooling the hot bed cells and air-heating the cold bed cells. Heating rates and cooling rates to/from air forced through the hot bed and cold bed, respectively, were monitored to gauge HVAC performance. The second recharge was performed by using a air/air heat exchanger that captured waste heat from an automobile engine exhaust manifold and transferred it to air that was re-circulated through the hot bed array. Temperatures, pressures, heating rates, cooling rates, and cell array heat transfer specifications are reported.

Influence of Hydrocolloid Concentration, Salinity and Citric Acid Addition on Heat Transfer in the Ohmic Heating Process

2011 ◽  
Vol 7 (5) ◽  
Author(s):  
Mostafa Keshavarz Moraveji ◽  
Emad Ghaderi ◽  
Reza Davarnejad
Keyword(s):  
Heat Transfer ◽  
Electrical Conductivity ◽  
Citric Acid ◽  
Ohmic Heating ◽  
Solid Particles ◽  
Heating Process ◽  
Process Conditions ◽  
Heating Rates ◽  
Acid Addition ◽  
Ph Level

In this article, the effects of Ohmic heating process conditions on electrical conductivity and heat transfer were investigated. In order to study the Ohmic heating process, various hydrocolloid solutions containing starch in water with concentrations of 4–8% in the static cells were used. Temperature increments increased electrical conductivity of the solution, linearly. The concentration of dispersed solid particles in the solution caused a progressive trend in time-temperature curve for hydrocolloid solutions (with concentrations of 4, 5.5 and 8%) without electrolytes. The electrical conductivity was raised by increasing temperatures. In order to consider the salinity impact on electrical conductivity and the heating rate, sodium chloride (with concentrations of 1–0.25%) was added to the solution. It was observed that the salt addition to the system had a major effect on electrical conductivity and time-temperature curves. The pH level was modified with Citric acid addition, and the influence of pH level on the time-temperature curves and heating rates were investigated. The Citric acid addition had no on significant effect on the time-temperature curves.

Sign in / Sign up

Export Citation Format

Share Document