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The decarbonization of hydrocarbons is explored in this work as a method to produce hydrogen and mitigate carbon dioxide (CO2) emissions. An integrated process for power generation and carbon capture based on a hydrocarbon fueled-decarbonization unit was proposed and simulated. Ethane and propane were used as fuels and subjected to the thermal decomposition (decarbonization) process. The system is also composed of a carbon fuel cell (CFC) and hydrogen fuel cell (HFC) for the production of power and a pure CO2 stream that is ready for sequestration. The HFC is a high-temperature proton exchange membrane fuel cell operating at 200 °C. Simulations were performed using ASPEN HYSYS V.10 for the entire process including the CFC and HFC being operated at various operating temperatures (200–800 °C). The power output from the CFC and the HFC as well as the overall process efficiency were calculated. The model incorporates an energy recovery system by adopting a counter-current shell and tube heat exchangers and a turbine. The water produced from the fuel cell system can be utilized in the plant to recover the heat from the furnace. The results showed a 100% carbon capture with a nominal plant capacity of 108 MWe produced when propane fuel was fed to the decarbonizer. The CFC theoretical efficiency is 100% and the practical efficiency was taken as 70% when all internal polarizations were considered. The results showed that, in the case of propane, the CFC power output was 89 MWe when the CFC operated at 650 °C, and the HFC power output was around 45 MWe at 200 °C with an overall actual plant efficiency of 35% and 100% carbon capture. Sensitivity analysis recommends a hydrocarbon fuel cost of 0.011 $/kW as the most feasible option. The results reported here on the decarbonization of hydrocarbon fuels are promising toward the direct production of hydrogen with full carbon dioxide sequestration at a potentially lower cost especially in rural areas. The overall actual efficiencies are very competitive to those of conventional power plants operated without carbon capture.

Paper and pulp mills generate substantial quantities of cellulose-rich sludge materials that are disposed in landfills at a large scale. For sustainability purposes, sludge materials can be bioprocessed to produce renewable fuels and useful chemicals. The enzymatic hydrolysis of cellulose is the process bottleneck that affects the conversion economics directly by using zero-cost raw materials. In order to study and optimize the process, the characteristics of the sludge raw materials should be first evaluated. In this work, sludge samples were obtained from paper mills located at different locations in Wisconsin and Minnesota. Part of the sludge samples was washed (de-ashed) with hydrochloric acid while the other part remained unwashed. The samples were subjected to multiple spectroscopic analyses techniques to evaluate the morphological properties of cellulose fibers and to estimate the total structural carbohydrate content. The results showed that the de-ashing process changed some fiber characteristics and cellulose crystallinity structure in all sludge samples. Sludge sample A (obtained from Kraft pulp and recycled paper mill region) showed a high percentage of fiber, with crystalline cellulose, compared to the other two sludge samples suggesting that sludge A is a valuable source to make value-added products. Aspen Plus mass and energy calculations performed in view of the ‘zero’ cost and the reliable supply of sludge raw materials producing 2 mol H2/mol glucose. Moreover, the results showed that extracting crystalline cellulose from these sludge samples is more profitable than crystalline cellulose made from the other lignocellulosic feedstocks. The results reported here showed that the utilization of these sludge materials would be an economically attractive and promising alternative for the production of hydrogen.

Composite membranes composed of zirconium phosphate (ZrP) and imidazolium-based ionic liquids (IL), supported on polytetrafluoroethylene (PTFE) were prepared and evaluated for their application in proton exchange membrane fuel cells (PEM) operating at 200 °C. The experimental results reported here demonstrate that the synthesized membrane has a high proton conductivity of 0.07 S cm−1, i.e, 70% of that reported for Nafion. Furthermore, the composite membranes possess a very high proton conductivity of 0.06 S cm−1 when processed at 200 °C under completely anhydrous conditions. Scanning electron microscopy (SEM) images indicate the formation of very small particles, with diameters in the range of 100–300 nm, within the confined pores of PTFE. Thermogravimetric analysis (TGA) reveals a maximum of 20% weight loss up to 500 °C for the synthesized membrane. The increase in proton conductivity is attributed to the creation of multiple proton conducting paths within the membrane matrix. The IL component is acting as a proton bridge. Therefore, these membranes have potential for use in PEM fuel cells operating at temperatures around 200 °C.

This study presents a novel design that combines cooling tower (CT) and traditional solar chimney power plant (SCPP) technologies for electricity generation and seawater desalination. The proposed hybrid solar chimney power plant (HSCPP) shares the operation of the chimney part and the bi-directional turbine between the SCPP and CT, allowing alternative operation of the CT during the nighttime and the SCPP during the daytime, and achieving continuous system utilization. The performance of the HSCPP design was validated against baseline models using 1 year of weather data from the city of Aqaba in Jordan. Results revealed that the HSCPP has the potential to produce ~50% electricity (528 MWh/year) higher than the traditional SCPP (365 MWh/year). The annual seawater desalination capacity of the HSCPP was estimated at 138300 m3, which is 1.5 folds higher than the traditional SCPP. The HSCPP reduced the annual CO2 emissions by 40% (~500 tons) compared to traditional SCPP with annual revenue of US$190 000. Furthermore, the results show that the HSCPP is 1.4 times more efficient than the traditional SCPP. The HSCPP achieved a system utilization factor of 0.73% compared to 0.52% for the traditional SCPP. The HSCPP showed promising sustainable and economical technology for the production of electricity and water while reducing the emission of GHG. Scopus

The present study explores a new method of steel particle-reinforced copper matrix composite synthesis. Steel reinforced copper was prepared by stir casting processing method at variable percentages between 10 wt% and 50 wt%. Characterization and mechanical testing were performed on these composites using a variety of techniques. The results showed that the microstructure of the composites has a uniform distribution of steel particles in the matrix with good interfacial integrity. Brinell hardness, tensile and yield strengths, impact energy and compressive yield strength of the composites increased with increasing steel particle contents. Vickers micro-hardness increased markedly at the interface region between particle and matrix evident by the hardness maps. The friction coefficient increased proportionally with increasing steel particle content in the composite, but the contrary was noticed for accumulative wear amount. A slight decrease in deformability is expected by increasing particle content. A ductile fracture was noticed in fractographs of fracture surfaces. Cracks are propagated in the Cu matrix up to the point of fracture, i.e. not through the interfacial boundaries.

A smooth coupling is implemented between the grid and doubly fed induction generator-based wind turbines (DFIG-WTs) during grid voltage imbalance. The nonlinear characteristics of a grid-connected DFIG-WT system may increase stresses on the mechanical and electrical components of wind turbines. Such difficulties are greatly increased during periods of voltage imbalance. Consequently, in this paper, a new control scheme is proposed to regulate DFIGs in order to support a smooth connection to the grid during voltage imbalance. In synchronization mode, the positive sequence of the rotor dq-axes currents regulates the stator q-axis EMF that is to be synchronized with the q-axis voltage of the grid-side voltage. The phase difference between the grid and stator voltages is compensated by adjusting the stator d-axis EMF to zero. Under normal conditions, a PR controller is used to dampen the negative sequence of the rotor dq-axes currents. PI current controllers are tuned to control the positive sequence of the DFIG rotor currents, while PR current controllers are used to regulate the negative sequence of the rotor currents during synchronization and under normal operation conditions. Experiments are performed to verify the smooth synchronization of the DFIG and the robustness of the proposed control scheme during grid voltage imbalance.

The classical solar chimney offers passive electricity and water production at a low operating cost. However, the solar chimney suffers from high capital cost and low energy output density per construction area. The high capital investment increases the levelized cost of energy (LCOE), making the design less economically competitive versus other solar technologies. This work presents a new noteworthy solar chimney design for high energy density and maximizing water production. This was achieved by integrating a cooling tower with the solar chimney and optimizing the operating mood. The new design operated day and night as a hybrid solar double-chimney power plant (HSDCPP) for continuous electricity and water production. During the daytime, the HSDCPP operated as a cooling tower and solar chimney, while during the night, it operated as a cooling tower. The annual energy output from the cooling towers and solar chimney (i.e., the HSDCPP) totaled 1,457,423 kWh. The annual energy production from the cooling towers alone was 1,077,134 kWh, while the solar chimney produced 380,289 kWh. The annual energy production of the HSDCPP was ~3.83-fold greater than that of a traditional solar chimney (380,289 kWh). Furthermore, the HSDCPP produced 172,344 tons of fresh water per year, compared with zero tons in a traditional solar chimney. This led to lower overall capital expenditures maximizing energy production and lower LCOE.

This study illustrates the structuring of the TiO2 within carbon nano-tubes to enhance the solar-driven production of hydrogen (S-DPOH) via water splitting. The newly developed Carbon-TiO2 nano-tubes (C-Ti-NTs) aimed at improving the practical applications of TiO2 composites under natural solar irradiation conditions, enhancing the absorption of UV and VIS-light, reduces the required bandgap energy and decreases the chance for photo-induced-charges recombination. The C-Ti-NTs were prepared using an alkaline hydrothermal method, characterized using different state of art techniques and tested for the S-DPOH via water splitting. Adding a carbon layer on the surface of TiO2 nano-tube with a thickness of ~1 nm reduced the bandgap of the C-Ti-NTs ≤ 0.88 eV, improved the quantum efficiency under UV light to 100%, enhanced the absorption capacity under VIS-light and extremely suppressed the charge recombination. The S-DPOH achieved a cumulative production of hydrogen (CPOH) during 50 h of solar irradiation of 43.75 mmol at a rate R P O H ′ of H2 production of 38.66 ± 0.655 mmol/h.g, which is 1.5 folds higher than the maxim rate reported for pure TiO2-based photocatalyst. The obtained results confirmed the contribution of TiO2 for the production of hydrogen, which is expected to open a new insight towards the importance of architectural design and band engineering in the practical development of sustainable solar energy harvesting applications.

Mediterranean countries produce up to 97% of the total global olive production. Besides being a serious environmental burden, olive mill waste represents a potential resource of useful materials for recovery and valorization. In this work, the adsorption characteristics and potential of bioadsorbent material manufactured by alkali treatment of olive cake was evaluated. The resultant bioadsorbent was able to purify biodiesel to meets both ASTM D6751 and EN 14214 standards. Further, the sorption equilibrium was investigated at 25 °C. Langmuir, Freundlich, and Temkin isotherms fit to the experimental data were evaluated by applying the non-linear Chi-square test. Freundlich and Temkin isotherms were shown to adequately described the adsorption isotherms of the produced bioadsorbent.

Carbon dioxide (CO

This research paper is exploring the possibility of retrofitting one selected residential apartment in Amman, Jordan. While the green building is exclusively conducted for commercial companies and foreign organization, there are no information for residential site within buildings unit. The study provided systematic analysis and energy and water consumption. Since water and energy sectors in Jordan suffers from several major problems, a systematic solution from induvial people is proposed. Therefore, this study suggests various modifications and retrofitting in one single apartment, then I apply them and recording the differences based on the LEED rating system.

The remote areas in the United Arab Emirates (UAE) doesn’t have access to the electricity grid, therefore the standalone hybrid power system uses to provide the electrical power required to meet the demand in these areas. The components of the hybrid system were selected and optimized for this area instead of bringing the gird to this area based on the load profile for the appliance household in the area. Thousands of simulation trials were performed using HOMER Pro to achieve the best renewable fraction and Levelized cost of energy (LCOE). The LCOE was found 0.34 $/kWh after including the capital, recourses, operation and maintenance, and replacement cost for the lifetime of the project which is 25 years. The unmet electrical load and shortage capacity were 0.0102 % and 0.0912 %, respectively. Furthermore, the environmental impact of the system was compared with the diesel energy system based on the carbon footprint and emission as in carbon dioxide, carbon monoxide, unburn hydrocarbon, sulfur dioxide, and nitrogen oxide. The carbon footprint was 90.1 which equivalent to 1000 saving diesel gallons.

Jordan is one of the few countries in the Middle East that has very limited resources of fossil fuel such as natural gas and crude oil. The country is fast growing with a population growth rate of 1.8%. The Gross Domestic Product (GDP) of Jordan reached USD 40.4 billion in 2015 with a population exceeding 9.96 million. Food and energy demands are increasing every year. Energy security and maintaining energy flow to meet the yearly demands are the biggest economic challenges facing Jordan. Renewable energies are the most vital solutions that provide energy security and accelerate economic growth. There are numerous studies and projects that focused on solar and wind power systems as an energy mix strategy. However, biomass to energy is not deeply explored in Jordan. Biofuel production from renewable biomass has a big potential for biogas and bioethanol production. The biofuels in Jordan can play significant roles in reducing dependency on imported oil and gas, and significantly reduce Jordan’s energy bill. The bioethanol utilization as a source of fuel can reduce the oil import bill by mixing it with classical gasoline. From a mechanical point of view, a normal car engine can handle up to 10% bioethanol blend without engine modifications. The bioethanol blend can save up to 200 kt of imported oil which will have a direct impact on the Jordanian economy. Jordan has a big biogas production potential despite the very humble projects for biogas production from renewable resources. The available resources for direct biogas production can replace about 5% of the total gas consumption for power generation. In this paper, we will discuss the right policy and mechanism to implement biofuel mix and blend which aims at reducing the energy bill.

The present work involves a new and novel upgrading design to the classical solar chimney power plant (SCPP) structure. The SCPP design was modified by adding a co-centric secondary external chimney to the SCPP structure to enhance energy production. In the new improved design, named the solar double-chimney power plant (SDCPP), the internal chimney, operates like a traditional SCPP to produce electricity during the daytime whereas the secondary external chimney operates as 10 cooling towers (CT) in a series. Each CT is equipped with a turbine and water sprinklers for further energy production. The new design offers the operation of the SCPP during the day and the continuous operation of the CT (day-and-night). A mathematical model that includes the energy and mass balance equations of the system was built using MATLAB. The SDCPP system produced up to 993 MWh of electrical energy, which is 2.6 times higher than the traditional SCPP (377 MWh). The new design configuration achieved a percentage of thermal efficiency (%?th) of 1.6%, which is 200 times greater than the SCPP. The economic assessment of the new system revealed a 50% reduction in the localized cost of energy (LCOE) compared with traditional SCPP. The key advantage of the new design is related to the use of low-cost material in constructing the secondary chimney to reduce the fixed capital cost and prompt the economic feasibility of the system. Overall, the proposed SDCPP offers a feasible and economic solution to produce electricity and to potentially reduce greenhouse gas emissions.. Qatar University Scopus

A new process for the production of bioethanol from paper mill sludge (PMS) is described in this work. PMS biomass feedstock was processed via the simultaneous saccharification and fermentation (SSF) with and without accelerants. The enzymatic hydrolysis and fermentation were first evaluated, and the energy demand was 2.2 MJ/L of produced ethanol. When the enzymatic hydrolysis and fermentation were combined, the energy demand was reduced to 1.0 MJ/L ethanol, the sugars production increased, and the overall capital cost of the process decreased. The sugar yield was improved by adding accelerant and selecting the optimal fiber recovery method. The accelerant improved the enzymatic hydrolysis via a pathing/bridging mechanism. The SSF with the chemical fiber recovery method coupled with accelerant addition would be the best process configuration. Upon this combination, the glucose profile was enhanced from 9.8 g/L to 17.0 g/L. The sludge fiber conversion by SSF was improved by selecting an efficient fiber recovery method combined with the accelerant addition. SSF in chemical fiber recovery with accelerant addition was the best process by a 10% improvement of ethanol yield. The proposed process configuration offers a lower cost and sustainable process and contributes to the circular economy of zero waste discharges.

In the present work, we developed a novel method for transferring monolayer graphene onto four different commercial hydrophilic micro/ultra-filtration substrates. The developed method used electrostatic charging to maintain the contact between the graphene and the target substrate intact during the etching step through the wet transfer process. Several measurement/analysis techniques were used in order to evaluate the properties of the surfaces and to assess the quality of the transferred graphene. The techniques included water contact angle (CA), atomic force microscopy (AFM), and field emission scanning electron microscopy (FESEM). Potassium chloride (KCl) ions were used for the transport study through the developed graphene-based membranes. The results revealed that 70% rejection of KCI ions was recorded for the graphene/polyvinylidene difluoride (PVDF1) membrane, followed by 67% rejection for the graphene/polyethersulfone (PES) membrane, and 65% rejection for graphene/PVDF3 membrane. It was revealed that the smoothest substrate was the most effective in rejecting the ions. Although defects such as tears and cracks within the graphene layer were still evolving in this new transfer method, however, the use of Nylon 6,6 interfacial polymerization allowed sealing the tears and cracks within the graphene monolayer. This enhanced the KCl ions rejection of up to 85% through the defect-sealed graphene/polymer composite membranes.

Water scarcity remains the major looming challenge that is facing Jordan. Wastewater reclamation is considered as an alternative source of fresh water in semi-arid areas with water shortage or increased consumption. In the present study, the current status of wastewater reclamation and reuse in Jordan was analyzed considering 30 wastewater treatment plants (WWTPs). The assessment was based on the WWWTPs&rsquo, treatment processes in Jordan, the flowrates scale, and the effluents&rsquo, average total dissolved solid (TDS) contents. Accordingly, 60% of the WWTPs in Jordan used activated sludge as a treatment technology, 30 WWTPs were small scale (˂1 &times, 104 m3/day), and a total of 17.932 million m3 treated wastewater had low TDS (˂1000 ppm) that generally can be used in industries with relatively minimal cost of treatment. Moreover, the analysis classified the 26 million m3 groundwater abstraction by major industries in Jordanian governorates. The results showed that the reclaimed wastewater can fully offset the industrial demand of fresh water in Amman, Zarqa, and Aqaba governorates. Hence, the environmental assessment showed positive impacts of reclaimed wastewater reuse scenario in terms of water depletion (saving of 72.55 million m3 groundwater per year) and climate change (17.683 million kg CO2Eq reduction). The energy recovery assessment in the small- and medium-scale WWTPs (˂10 &times, 104 m3/day) revealed that generation of electricity by anaerobic sludge digestion equates potentially to an offset of 0.11&ndash, 0.53 kWh/m3. Finally, several barriers and prospects were put forth to help the stakeholders when considering entering into an agreement to supply and/or reuse reclaimed water.

Photovoltaic (PV) solar panels are one of the most important sources of renewable energy. The life cycle analysis is a tool used to evaluate components or systems in terms of cost and environmental impact. This paper discusses the life cycle analysis for PV solar panels technology. Two distinct technologies of cells based on single crystalline silicon (reference) and polycrystalline gallium were studied. The reference cell material, manufacturing process, maintenance, transport, disposal and end of life (EOL) potential were analyzed during the lifetime of the solar panel. The analysis focused on three main elements: the energy consumption, the CO 2 footprint and the cost for all phases of the life cycle process. The materials used, maintenance, transportation, manufacturing processes, disposal, EOL potential were also discussed in detail for both technologies. The results showed that a change in the material has a massive influence on the total energy consumption, CO 2 footprint, and cost. These values were 7.35 × 1010 J, 0.510 metric ton of CO 2 and the US $ 584, respectively, for reference cell (silicon) whereas for Gallium the values were 7.7 × 1010J, 0.717 metric ton CO 2 and US $ 986, respectively.

Camelina sativa is a cool-season oil seed crop that has been proven to produce various biofuels. The present study investigated the technical possibilities of using whole camelina biomass as a model feedstock in a biorefinery. This investigation examined the possibilities of using camelina seeds as a source of oil for biodiesel, sugars for ethanol, and meal for one-portfolio products. The camelina harvest residues (straw) can serve as the main source for green sugars. This study found that the energy input for the whole biorefinery process was 25.1 MJ/L ethanol, while the energy output was 54.3 MJ/L ethanol. The net energy ratio of 2.16 MJ/L ethanol was found to be competitive with other energy crops. The process was environmentally friendly, and it reduced greenhouse gas emissions by 40% if the produced biodiesel replaced petroleum diesel. The seed meals and glycerin were found to be a good source of revenue as high value-added products and can provide an additional revenue of $1/kg of produced oil.

This review discusses the technical aspects of improving the efficiency of the pyrolysis of lignocellulosic materials to increase the yield of the main products, which are bio-oil, biochar, and syngas. The latest aspects of catalyst development in the biomass pyrolysis process are presented focusing on the various catalyst structures, the physical and chemical performance of the catalysts, and the mode of the catalytic reaction. In bio-oil upgrading, atmospheric catalytic cracking is shown to be more economical than catalytic hydrotreating. Catalysts help in the upgrading process by facilitating several reaction pathways such as polymerization, aromatization, and alkyl condensation. However, the grade of bio-oil must be similar to that of diesel fuel. Hence, the properties of the pyrolysis liquid such as viscosity, kinematic viscosity, density, and boiling point are important and have been highlighted. Switching between types of catalysts has a significant influence on the final product yields and exhibits different levels of durability. Various catalysts have been shown to enhance gas yield at the expense of the yields of bio-oil and biochar that shift the overall purpose of pyrolysis. Therefore, the catalytic activity as a function of temperature, pressure, and catalyst biomass ratio is discussed in detail. These operational parameters are crucial because they determine the overall yield as well as the ratio of the oil, char, and gas products. Although significant progress has been made in catalytic pyrolysis, the economic feasibility of the process and the catalyst cost remain the major obstacles. This review concludes that the catalytic process would be feasible when the fuel selling price is reduced to less than US $ 4 per gallon of gasoline-equivalent, and when the selectivity of catalysts is further enhanced.

Using renewable energy sources provides a promising solution to minimize the overuse of conventional energy sources as well as to reduce pollution. Biogas technology is one solution that offers the conversion of waste streams to a renewable source of higher value. Anaerobic digestion of organic waste from industrial processes produces energy in the form of biogas, which has an advantage of preventing odor release, and has minimal pathogens. In this study, two different sources of bio-waste were investigated for their biogas potential, namely palm date waste and olive pomace. All of the samples produced biogas; however, the amount produced was only 20% to 40% of what conventional substrates typically produced. Producing biogas that uses only olive biomass offers a solution to the waste disposal problem, but it is not efficient for biogas production. For optimal heat utilization and maximizing biogas production, mixing of different feedstock was identified as a valid solution. Hence, a model of mixing other sources of bio-waste, such as chicken manure, can activate sludge and is proposed to boost the biogas production.

Photovoltaic (PV) systems are regarded as clean and sustainable sources of energy. Although the operation of PV systems exhibits minimal pollution during their lifetime, the probable environmental impacts of such systems from manufacturing until disposal cannot be ignored. The production of hazardous contaminates, water resources pollution, and emissions of air pollutants during the manufacturing process as well as the impact of PV installations on land use are important environmental factors to consider. The present study aims at developing a comprehensive analysis of all possible environmental challenges as well as presenting novel design proposals to mitigate and solve the aforementioned environmental problems. The emissions of greenhouse gas (GHG) from various PV systems were also explored and compared with fossil fuel energy resources. The results revealed that the negative environmental impacts of PV systems could be substantially mitigated using optimized design, development of novel materials, minimize the use of hazardous materials, recycling whenever possible, and careful site selection. Such mitigation actions will reduce the emissions of GHG to the environment, decrease the accumulation of solid wastes, and preserve valuable water resources. The carbon footprint emission from PV systems was found to be in the range of 14–73 g CO2-eq/kWh, which is 10 to 53 orders of magnitude lower than emission reported from the burning of oil (742 g CO2-eq/kWh from oil). It was concluded that the carbon footprint of the PV system could be decreased further by one order of magnitude using novel manufacturing materials. Recycling solar cell materials can also contribute up to a 42% reduction in GHG emissions. The present study offers a valuable management strategy that can be used to improve the sustainability of PV manufacturing processes, improve its economic value, and mitigate its negative impacts on the environment.