Customer SUCCESS STORY
Using NETZSCH Simultaneous Thermal Analyzers to Convert Solid Waste into Energy Materials
Read our latest customer success story by Professor Guozhao Ji, Dalian University of Technology, China! It is about the conversion of solid waste into valuable products by means of the NETZSCH Simultaneous Thermal Analyzer (STA). Several scientific papers on this topic have been published.
Dr. Guozhao Ji, born in 1986, received his PhD degree in chemical engineering in 2014 from the University of Queensland, Australia. He completed his MS and BS in mechanical engineering at Northeastern University, People's Republic of China in 2010 and 2008, respectively. Currently, as an Associate Professor, he works at the School of Environmental Science and Technology at Dalian University of Technology in China. Dr. Ji's research interests include solid waste gasification, kinetic modeling of thermochemical conversions, high-temperature CO2 capture, and computational fluid dynamic applications in thermochemical processes. He has authored over 100 refereed journal publications, two books and three book chapters, with over 3200 citations and an H-index of 35.
In the following, Dr. Guozhao Ji will give us insights into his research on converting solid waste into energy.
„With the accurate measurement by means of the NETZSCH STA instruments, we get a reliable comparison of our prepared materials, which not only facilitates the selection of materials, but also provides guidance or direction for functional material preparation.“
Dr. Guozhao Ji: “The lab of solid waste recycling in DUT is devoted to converting solid waste into high-value products that could be used in energy, environment and material industries via thermochemical reactions. The lab provides solutions, equipment and materials related to solid waste treatment.
In 2019, we sent some CO2 sorbent samples to NETZSCH Scientific Instruments Trading (Shanghai) Ltd., and NETZSCH provided a very professional testing service. This awesome experience promoted our further cooperation with NETZSCH. In 2020, our lab ordered a NETZSCH STA 449 F3 mainly intended for testing the Decomposition reactionA decomposition reaction is a thermally induced reaction of a chemical compound forming solid and/or gaseous products. decomposition behavior of organic solid wastes. In 2021, our lab bought an STA 2500 for testing the CO2 Sorption ProcessSorption is a physical and chemical process by which a substance (typically a gas or liquid) accumulates within another phase or on the phase boundary of two phases. Depending on the place of accumulation, a differentiation is made between absorption (accumulation in a phase) and adsorption (accumulation at the phase boundary).sorption behavior of our functional materials that would be used in the enhancement of solid waste gasification. In 2023, a NETZSCH DSC 404 F3 was purchased to help us measure the thermodynamic information during organic waste PyrolysisPyrolysis is the thermal decomposition of organic compounds in an inert atmosphere.pyrolysis as well as identify Phase TransitionsThe term phase transition (or phase change) is most commonly used to describe transitions between the solid, liquid and gaseous states.phase transition of inorganic waste during the thermal treatment process.”
Dr. Ji, what were the specific challenges your company had before using our solutions and/or what issues or problems did you want to solve with them?
- "Accurate temperature control: We developed a functional material which is used for organic waste gasification. This material needs to capture CO2 under gasification conditions and the CO2 release under regeneration conditions. The main difference between gasification conditions and regeneration conditions is the temperature. For gasification, the temperature is around 700°C and for regeneration, it is roughly 900°C. In order to measure the performance of our functional material, we need to switch the temperature frequently, swiftly and accurately.
- Large mass sample: We mainly work on organic waste thermal treatment, and the organic waste property varies within a certain range. Due to the poor uniformity of real organic waste, the TGA test results might vary if we take a sample mass of only a few milligrams each time. To enhance the representativeness of the waste feed stock, we have to take a larger sample quantity that would be more inclusive of every part of the organic waste."
Why did you choose NETZSCH?
"The NETZSCH brand has a good reputation in the research field. We read massive research articles during our daily work, and NETZSCH is the most frequently found brand in thermogravimetric analysis sections in research journal articles.
Moreover, NETZSCH instruments feature accurate temperature control, ramping rate, and gas environment, which enabled efficient cyclic tests of our functional material. Based on our limited survey, NETZSCH allowed for the largest sample quantity, which provided more stable or repeatable results of the solid-waste Decomposition reactionA decomposition reaction is a thermally induced reaction of a chemical compound forming solid and/or gaseous products. decomposition."
Please provide a specific example of how you used our solutions.
An example is the thermal degradation behaviors of waste tires.
"As automobiles became more widespread and global tire manufacturing was advancing, a significant amount of waste tires was being produced after they were worn out. Because of their ecological toxicity and resistance to degradation, waste tires could pose a threat to human health and the environment. A promising pathway to treating waste tires is PyrolysisPyrolysis is the thermal decomposition of organic compounds in an inert atmosphere.pyrolysis, which not only achieves waste minimization but also generates valuable products such as syngas, fuel oil and char. Thermogravimetric analysis (TGA) is regarded as an effective technology for investigating the thermal behavior of waste tire PyrolysisPyrolysis is the thermal decomposition of organic compounds in an inert atmosphere.pyrolysis including the initial temperature, final temperature, and peak temperature of the PyrolysisPyrolysis is the thermal decomposition of organic compounds in an inert atmosphere.pyrolysis reaction, etc.; this helps us understand the PyrolysisPyrolysis is the thermal decomposition of organic compounds in an inert atmosphere.pyrolysis process and contributes to PyrolysisPyrolysis is the thermal decomposition of organic compounds in an inert atmosphere.pyrolysis reactor design and process optimization. The TGA experiments were carried out by means of a NETZSCH STA 2500 and a NETZSCH STA 449 F3 . About 6 mg of feedstock were loaded into an Al2O3 ceramic crucible and heated from room temperature to 600°C at three heating rates of 10, 20 and 30°C·min-1. Nitrogen was used as the carrier gas at a flow rate of 200 ml·min-1."
The thermal degradation behavior of waste tire is depicted in Figure 1. Clearly, the main PyrolysisPyrolysis is the thermal decomposition of organic compounds in an inert atmosphere.pyrolysis reaction of waste tire occurred within the temperature range of 200°C to 500°C with a mass loss fraction of 64%. Two peaks observed in the DTG curves, located in the temperature ranges of 300°C ~ 410°C and 410°C ~ 450°C, corresponded to the degradation of the main component of waste tire, natural rubber and synthetic rubber. As the heating rate increases, the initial temperature (Ts) of the PyrolysisPyrolysis is the thermal decomposition of organic compounds in an inert atmosphere.pyrolysis reaction, the temperature corresponding to the maximum weight loss rate (Tmax), and the final temperature (Te) of the PyrolysisPyrolysis is the thermal decomposition of organic compounds in an inert atmosphere.pyrolysis reaction all present an increasing trend (Table 1).
Table 1. PyrolysisPyrolysis is the thermal decomposition of organic compounds in an inert atmosphere.Pyrolysis characteristics; parameters of waste tire pyrolysis at three different heating rates
Heating rate (◦C·min-1) | Ts(◦C) | Tmax(◦C) | Te(◦C) |
10 | 288 | 375 | 524 |
20 | 298 | 388 | 530 |
30 | 308 | 395 | 544 |
CaO-based sorbents have broad application prospects in pre-combustion carbon capture. In a typical steam reforming hydrogen production reaction, the addition of CaO-based sorbents can remove the CO2 generated in situ, breaking the thermodynamic equilibrium and increasing the reaction driving force, thereby shifting the reaction towards hydrogen production. This improves the concentration and yield of H2. However, due to their tendency of SinteringSintering is a production process for forming a mechanically strong body out of a ceramic or metallic powder. sintering, it is necessary to dope inert stabilizers that have a high Tamman temperature.
Ca-based CO2 sorbents typically require studies on the weight changes during carbonation and calcination reactions under N2 or CO2 atmospheres at high temperatures (650°C-850°C) to reflect the material's CO2 adsorption performance and adsorption kinetics. In this study, steel slag and limestone were mixed to prepare steel slag-based sorbents. We tested the adsorption performance of the steel slag-based sorbents using TGA (NETZSCH STA 449 F5 ).
The results are as follows:
"As shown in Figure 2, the CO2 adsorption capacity of pure CaO declines rapidly (0.293 CO2/g sorbent to 0.097 CO2/g sorbent), whereas the adsorption capacity of the sorbent prepared with an initial acid concentration of 2 mol/l shows a significantly reduced rate of decline. Moreover, as the proportion of steel slag doping increases, the stability of the sorbent is also enhanced. The steel slag-based sorbents also exhibit better overall CO2 absorption performance over 30 cycles. Figure 3 also illustrates the variation in its adsorption rate. Initially, CaO exhibits a clear advantage in the adsorption rate. However, with the increase in cycle numbers, the adsorption rate of CaO decreases significantly, eventually stabilizing at a lower level. In contrast, sorbents doped with steel slag show significant improvement, with the effect becoming more pronounced as the cycle number increases."
How did you use the results obtained?
"The NETZSCH STA 2500 and STA 449 F3 have very accurate and fast control of temperature. This temperature swinging control is very useful and helpful in testing our functional materials for waste gasification.
With the accurate measurement by means of the NETZSCH devices, we get a reliable comparison of our prepared materials, which not only facilitates the selection of materials, but also provides guidance or direction for functional material preparation. We have published over 50 research articles in journals such as Energy & Environmental Science, Environmental Science & Technology, Chemical Engineering Journal, Fuel Processing Technology, Journal of Cleaner Production etc."
Do you also have any experience with our customer support and service?
"Yes, and I would say more than great experience. Mr. Haiming Zhang and Ms. Shenjun Sheng provided unlimited help before we actually bought NETZSCH instruments. After buying the NETZSCH STA 2500 and STA 449 F3 , we always got a fast response from Mr. Shuaitao Zeng when we had questions.
The seminar on May 9th, 2023 in Dalian was also a great event. My students and I received very comprehensive, practical and useful information from the engineers and experts."
Dr. Ji, thank you very much for this positive feedback!
How do you envision your future collaboration with us? Are there new challenges you would like to address?
"The next topic on which I would like to further collaborate with NETZSCH might be the gasification test of organic waste by adding vapor to the TGA furnace. We currently do not have sufficient funding for that, but sooner or later, we will perform this type of tests with available funding.
The second one I would like to address is fast heating, which could match the heating rate in real scenarios. We are keen on measuring the Decomposition reactionA decomposition reaction is a thermally induced reaction of a chemical compound forming solid and/or gaseous products. decomposition behavior of organic waste when it comes into contact with heat carriers in reactors. In these situations, the heating rate could reach up to 102~103 K s-1. Achieving this heating rate with accurate mass measurement will be a big revolutionary step for waste treatment."
