Qahtan Thabit

Mr. Qahtan Thabit

University of Rostock, Rostock, Mecklenburg-Western Pomerania, Germany

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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22 May 2022 in Applied Sciences
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Journal Article
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QTQahtan Thabit
Qahtan Thabit
ANAbdallah Nassour
Abdallah Nassour
MNMichael Nelles
Michael Nelles
Waste-to-energy (WtE) incineration is an important technique in waste management systems and waste hierarchy. It is used to treat approximately 63% of the waste in European countries. The flue gas volumetric rate and its composition are essential to determine and monitor the emissions from waste incineration plants. This paper presents two methodologies used to evaluate the emissions from incinerators during the design phase. The first consists of a set of equations applicable in Excel (calculation model), while the second is the built-in components in Ebsilon 13.2 software which simulates the emissions from a furnace. This paper also proposes a comprehensive flue gas cleaning system for a simulated waste incineration plant in Jordan. According to Ebsilon, the results showed that for a 25 kg/s loading rate, there was 258,514 mg/Nm3, 749.90 mg/Nm3, 890.20 mg/Nm3, and 717 mg/Nm3 of CO2, NO2, SO2, and HCL, respectively. It was noted that these values relate to 1.5 of excess air ratio, where the effect of excess air ratio as the main driver for any combustion process was examined. The calculation method (set of equations) evaluated the flue gas volumetric rate, the CO2 emissions, and N2O and SO2 levels. Ebsilon allows for simulation of the treatment stages and calculates the amount of materials required. Selective non-catalytic reduction (SNCR) (a built-in component in the Ebsilon library) was used to treat the NO2 emissions. For 1.5 of excess air ratio, those emissions were reduced from 749 mg/Nm3 to 180 mg/Nm3, while the Ca(OH)2 injector used to treat the SO2 and HCL emissions reduced emissions from 890.20 mg/Nm3 and 717 mg/Nm3 to 44 mg/Nm3 and 7.16 mg/Nm3, respectively. Regarding the reduction in CO2, the spherical carbon absorption concept was simulated using 9.4 kg/s of carbon which was adequate to verify a 91% reduction rate of CO2. Furthermore, the calculation model was validated and approved as a valuable model to predict the flue gas volume, the oxygen required, and flue gas emissions at the design stage.

3 September 2022 in Materials
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QTQahtan Thabit
Qahtan Thabit
ANAbdallah Nassour
Abdallah Nassour
MNMichael Nelles
Michael Nelles
Thermal water desalination is one of the most important techniques to solve the water scarcity problem in many regions of the world. Out of around 7.8 billion people in the world, only about 6 billion of them have access to clean water; notably, climate change plays a major role in accelerating the evaporation rate of water from water bodies, which in turn increases the scarcity. Multi-stage flash, recognized to have a high rate of water production in comparison with other available technologies, accounts for 35% of water desalination facilities worldwide. This paper presents a detailed Excel model to evaluate the amount of energy required to drive 16 stages of multi-stage flash. This model aims to design and evaluate the amount of thermal energy required for such projects and optimize their performance by calibrating the governing parameters. Furthermore, the 16 stages were simulated via the Ebsilon 13.02 software package to match the results and evaluate the fulfillment of the plant requirements. The temperature drop of the brine stream was 2.34 °C/stage. The top brine temperature was 130 °C. The results show that 29.5 kg/s of superheated steam is required to desalinate 162 kg/s of 2500 kg/s influent mass flow of brine. The effect of water intake temperature was also examined by using Ebsilon. The performance ratio decreased from 5.49 to 2.66 when the water intake temperature decreased from 30 °C to 5 °C.

14 November 2022 in Waste
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QTQahtan Thabit
Qahtan Thabit
ANAbdallah Nassour
Abdallah Nassour
MNMichael Nelles
Michael Nelles
The waste management field in Middle Eastern and North African countries suffers from multiple drawbacks and chronic problems that require strategic solutions and collaboration among various institutions. Due to a lack of data, a financial deficit, limited economic resources for the municipalities, and singular treatment processes, until recently, waste has been dealt with as garbage that needs to be disposed of, while, in a large number of developed countries, waste now represents a substantial economic resource and an important source of materials that can be reinserted into the industrial sector. This paper presents a review of several aspects and sectors that are directly related to waste generation and the current situation regarding the waste management system in the Middle East and North Africa (MENA) region in terms of composition, generated amount/capita, existing treatment routes, and institutional frameworks. Furthermore, gross domestic production and population growth are specified as critical factors governing the waste sector in the region. Such data and information will increase the possibility of drawing a roadmap to convert the current waste treatment stream into a material flow concept and circular economy. The energy sector (energy consumption) is also considered to illustrate the potential role of waste if incineration technology (energy recovery from waste) is realized as a radical solution for the waste system in the region. Following a review of the literature, the main challenges in the waste management sector that need to be solved are summarized. The novelty of this work is two-fold. First, it elucidates the connection between gross domestic product (GDP), waste composition, and waste generation. According to the literature, countries with a high GDP produce a greater amount of waste (around 1.5–2.7 kg/capita/day) with a lower organic share of waste composition of around 40%, as they have an increased lifestyle rate. Second, a review of energy consumption per capita illuminates the essential role of waste as a source of energy.

3 October 2020 in Sustainability
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NCNour El Houda Chaher
Nour El Houda Chaher
SHSafwat Hemidat
Safwat Hemidat
QTQahtan Thabit
Qahtan Thabit
MCMehrez Chakchouk
Mehrez Chakchouk
ANAbdallah Nassour
Abdallah Nassour
MNMichael Nelles
Michael Nelles
Nowadays, Tunisia is seeking to implement cost-efficient and sustainable solutions in relation to the treatment of organic waste which, at up to 65%, makes up the largest proportion of total waste generated in the country. Therefore, an efficient tool for decision makers is needed to provide a clear approach about the potential of organic waste as well as the treatment concept, which can be adapted based on technical requirements and local conditions. Results revealed that there is a high variation in terms of the nature of the collected biowaste, which affects the selection of the adopted bioprocess for each geographical zone of the study area. Three main categories of biowaste are produced along the coastline of Tunisia: food waste (FW) (102.543 t/a); green waste (GW) (1.326.930 t/a); and cattle manure (CM) (1.548.350 t/a). Based on the results of similar projects and laboratory-scale research work, anaerobic and aerobic digestion were examined. Regarding aerobic digestion, the monitoring of several physicochemical parameters ascertained that the co-composting of FW and GW at different ratios (GW: FW = 100:0, 75:25, 50:50, and 25:75) allowed the production of a stable and mature compost. A highly qualified end-product was generated from each trial categorized as a finished compost of class V with reference to German Standards of compost. Regarding the anaerobic process, different feedstock mixtures (FW:CM = 0:1, 1:1, 2:1, and 3:1) were prepared to feed semi-continuous anaerobic reactors. However, a significant improvement in the process development was recorded for digesters including a higher fraction of FW, which produced 0.846 LN/kg VSin as the maximum biogas production. Therefore, biological treatments of food waste and different co-substrates seems to be a suitable technique for Tunisia in terms of waste management, environmental, and energy aspects. However, the evaluation of the efficiency of the proposed biological treatments was also verified by a draw-up of a technical and economic feasibility analysis. Although the cost–benefit estimations proved that the profits from both the compost and biogas plants would be very modest, the feasibility of such sustainable projects should not only be evaluated on an economic basis, but also by taking into account socio-environmental considerations including decreasing environmental threats, providing work opportunities, increasing incomes, stimulating public awareness as well as reducing the operating costs linked to landfilling.

1 June 2020 in Energies
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Journal Article
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QTQahtan Thabit
Qahtan Thabit
ANAbdallah Nassour
Abdallah Nassour
MNMichael Nelles
Michael Nelles
Population growth, urbanization, and changes in lifestyle have led to an increase in waste generation quantities. The waste management system in the Middle East and North Africa (MENA) region is still considered an adolescent system, while developed countries have made great progress in this field, including regulation, financing, administration, separation at source, recycling, and converting waste to energy. At the same time, in the MENA region, the best performance of the recycling process is around 7–10% of total waste. Nowadays, many developed countries like Germany are shifting from waste management to material flow systems, which represent the core of a circular economy. Also, it should be stated here that all countries that have a robust and integrated waste management system include waste-to-energy (W-to-E) incineration plants in their solutions for dealing with residual waste, which is still generated after passing through the entire treatment cycle (hierarchy). Therefore, this paper illustrates the potentiality of embedding waste incineration plants in the MENA region, especially in large cities, and addressing the economic and financial issues for the municipalities. Cities in these countries would like to build and operate waste treatment plants; however, municipalities do not have the sustainable investment and operating costs. The solution is to maximize the income from the output, such as energy, recycling materials, etc. In addition, the MENA region is facing another dilemma, which is water scarcity due to climate change, increasing evaporation, and reduction of precipitation. This research illustrates a simulated model for a waste incineration plant in the MENA region. The EBSILON 13.2 software package was used to achieve this process. Furthermore, the simulated plant applies the concept of waste-to-energy-to-water, so that not only is waste converted to energy but, by efficient usage of multi-stage flash (MSF) technology, this system is able to generate 23 MWe of electric power and 8500 m3/day of potable water. A cost analysis was also implemented to calculate the cost of thermal treatment of each ton of municipal solid waste (MSW) during the life span of the plant. It was found that the average cost of treatment over 30 years would be around US$39/ton.

1 March 2020 in Detritus
Verified
Journal Article
Open access
JSJan Sprafke
Jan Sprafke
NENils Engler
Nils Engler
QTQahtan Thabit
Qahtan Thabit
MNMichael Nelles
Michael Nelles
ASAndrea Schüch
Andrea Schüch