Energy Recovery Systems Research Papers (original) (raw)
The concept of the waste biorefinery is known as one of the several energy recovery technologies capable of producing multi-products in the form of biofuels and value-added products treating different fractions of municipal solid waste... more
The concept of the waste biorefinery is known as one of the several energy recovery technologies capable of producing multi-products in the form of biofuels and value-added products treating different fractions of municipal solid waste (MSW). The conversion technologies such as anaerobic digestion (AD), pyrolysis, transesterification, incineration treat food, plastic, meat, and lignocellulosic wastes to produce liquid, gaseous and solid biofuels. Makkah city landfills receive about 2750 tons of waste every day. While during the Ramadan and Hajj seasons, these quantities become 3000 tons and 4706 tons per day respectively. More than 2.5 million animals were sold for slaughtering in 2014 Hajj, and their blood and organic solid waste were disposed of untreated. Similarly, around 2.1 million plastic Zam-Zam cups were wasted every day during the 2014 Ramadan time. In the first three days of 2014's Ramadan, 5000 tons of food was wasted only in Makkah municipality. Collectively, about 3853 tons of waste were generated each day during 2014 Hajj and Ramadan. The waste from Al-Haram and Al-Masha’ir (Mina, Muzdalifah and Arafat) and their surroundings was mainly composed of organics (up to 68.5%). There is no waste-to-energy facility existing in Saudi Arabia. The waste biorefinery in Makkah will divert up to 94% of MSW from landfill to biorefinery. The energy potential of 2171.47 TJ and 8852.66 TJ can be produced if all of the food and plastic waste of the Makkah city are processed through AD and pyrolysis respectively. The development of AD and pyrolysis under waste biorefinery will also benefit the economy with gross savings of 405 and 565.7 million SR respectively, totalling to an annual profit of 970.7 million SR. Therefore, the benefits of waste biorefinery in Makkah city and other parts of the Saudi Arabia are numerous including the development of renewable-energy science and research, solving solid waste problems, new businesses and job creation opportunities and minimizing environmental pollution.
- by and +1
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- Renewable Energy, Energy, Recycling, Biorefinery
Municipal solid waste generation is a rapidly increasing challenge that is leading to severe pollution and environmental degradation in many urban areas of developing countries. Globally, the solid waste sector accounts for 18% of methane... more
Municipal solid waste generation is a rapidly increasing challenge that is leading to severe pollution and environmental degradation in many urban areas of developing countries. Globally, the solid waste sector accounts for 18% of methane emissions and 3e4% of greenhouse gas emissions overall. Waste handling and disposal systems in most large cities have largely been designed with minimal accounting of environmental issues. This study presents the Waste to Energy Recovery Assessment (WERA) framework, a new quantitative decision support model for initial evaluation and alternative comparisons of different thermochemical treatments of municipal wastes. The framework not only accounts for benefits through electricity generation but also accounts for emissions from facilities and the associated social cost of carbon in a cost-benefit assessment. The assessments are conducted with Monte Carlo simulations that explicitly account for uncertain factors such as future composition and generation of solid waste, technical efficiency of treatment processes, capital and operating costs, as well as future policies. The framework is used to study waste-to-energy (WtE) systems for Abu Dhabi, Riyadh, Tokyo and New York. The results show that WtE systems can fulfill only 1.4e3.6% of 2014 electricity demand in the analyzed cases. Furthermore, the net present value for different technologies can be positive if collection fees and electricity rates (potentially set through feed-in-tariff policies) are sufficiently high. The analysis for Abu Dhabi and Riyadh also reveals that in a limited set of conditions (of technology efficiencies, and waste collection rates etc.) the WtE facilities can be self-sustaining investments.
This paper deals with European TRY weather data processing for climatic indexes generation, useful for HVAC energy and cost simplified evaluation. For nine Italian locations are presented: 99 and 2)5% dry bulb temperatures, 2)5% wet bulb... more
This paper deals with European TRY weather data processing for climatic indexes generation, useful for HVAC energy and cost simplified evaluation. For nine Italian locations are presented: 99 and 2)5% dry bulb temperatures, 2)5% wet bulb temperatures, heating and cooling degree days, latent enthalpy days, unitary sensible and latent loads. TRY psychrometric data were processed according to a bin method that preserves the correlation between dry bulb temperature and moisture content, and then reduced by an averaging technique. An example is worked out in order to present an engineering shorthand for energy and cost evaluation of HVAC system.
The design of the powertrains for transportation on the road is even more oriented to the emission reduction. Recently, greenhouse gases commitments added new technological challenges. Energy recovery from exhaust gases has a great... more
The design of the powertrains for transportation on the road is even more oriented to the emission reduction. Recently, greenhouse gases commitments added new technological challenges. Energy recovery from exhaust gases has a great potential considering the amount of mechanical or electrical work which could be generated on board. The paper considers the recovery which could be obtained from the exhaust gases expanding them in an additional turbine (turbo compounding). An engine model has been developed and validated thanks to an extensive experimental activity which concerned the F1C Iveco engine equipped with a Variable Geometry Turbine (VGT). Two potential technologies are presented and the recovery has been calculated by the model which behaves as a virtual engine platform. Energy recoverable has been estimated referring to engine operating points which reproduce the NEDC and the ESC13 approval cycle.
This paper investigates the design of an optimal energy recovery system for a hydrogen hybrid electric vehicle to allow increased range. The proposed system includes two different energy recovery subsystems. These are; a regenerative... more
This paper investigates the design of an optimal energy recovery system for a hydrogen hybrid electric vehicle to allow increased range. The proposed system includes two different energy recovery subsystems. These are; a regenerative braking subsystem and an active suspension subsystem. A dynamic model of this optimal energy recovery subsystem is implemented in MATLAB/Simulink TM and integrated with a hydrogen hybrid electric vehicle model to investigate the effect of the optimal energy recovery mechanism. The simulation results indicate the energy recovery and hence, lead to the extended range capabilities.
Biodiesel is a promising liquid fuel that is mainly derived from triglycerides and is utilized in diesel engines directly or after blending with conventional gasoline. Triglycerides comprise fatty acid methyl esters (FAME), which are... more
Biodiesel is a promising liquid fuel that is mainly derived from triglycerides and is utilized in diesel engines directly or after blending with conventional gasoline. Triglycerides comprise fatty acid methyl esters (FAME), which are generated from plant or animal based sources. Biodiesel generated from vegetable oils is expensive than petroleum-based diesel and has concerns with food vs. fuels debate. Therefore, biodiesel from renewable sources such as non-food feedstocks has attained a considerable interest in last two decades. This paper aims to examine the biodiesel generation from the non-food feedstocks available in the Kingdom of Saudi Arabia (KSA) as a source of renewable energy and valueadded products along with and a solution to current waste disposal problems. In KSA, non-food feedstocks such as animal fats, waste cooking oil (WCO), agricultural wastes, sewage sludge, and microalgae are promising sources for biodiesel production. These feedstocks are relatively cheap, easily available, portable, and renewable in nature. A case study of waste to biodiesel refinery is presented for KSA under three different scenarios, including (1) KSA population in 2017, (2) KSA population and pilgrims in 2017, and (3) KSA population and pilgrims by 2030. It was assessed that around 482, 488 and 627 MW of electricity on a continuous basis could be generated every year for scenarios 1, 2 and 3 respectively if using the fat fraction of municipal solid waste in waste to biodiesel refineries in KSA. Similarly, a total net savings of US$ 272, 275.2 and 353.9 million can be achieved from scenarios 1, 2 and 3 respectively. However, there are many challenges in commercializing the waste to biodiesel refinery in KSA such as collection of feedstocks, separation of lipids, products separation, soap formation, preserving products, and adequate regulations.
Flare gas recovery is one of the most attractive methods to improve energy efficiency in oil refineries to decrease greenhouse gas emissions. The recovered gas is used to feed refinery processes, granting advantages in terms of fuel... more
Flare gas recovery is one of the most attractive methods to improve energy efficiency in oil refineries to decrease greenhouse gas emissions. The recovered gas is used to feed refinery processes, granting advantages in terms of fuel economy and flare stress. This paper presents the results obtained by a feasibility study of a flare gas recovery system in a real refinery; the work focused on: i) the choice and the design of the flare gas recovery system; ii) the gas treatment and reuse; iii) the economic feasibility, and the payback period. An experimental campaign has been performed to evaluate both the composition and the flow rate of the flare gas. Results showed that the flare gas had a strongly variable flow rate and composition due to the different gas species processed in refinery. A methodology for the system selection is presented: a 400 kg/h liquid ring compression device is chosen; its basic design is described as well as the chemical treatments of inert gases and hydrogen sulphide (H 2 S). The yearly energy recovery was estimated to be 2900 TOE, corresponding to 6600 tons of CDE (Carbon Dioxide Equivalent). Finally, an economic evaluation was carried out, showing a payback period of about 2.5 years.
En su más de un siglo de existencia, los hornos eléctricos de arco han evolucionado radicalmente, tanto en los aspectos tecnológicos como en la función que cumplen y los tipos de acero que producen. Desarrollados para producir aceros... more
En su más de un siglo de existencia, los hornos eléctricos de arco han evolucionado radicalmente, tanto en los aspectos tecnológicos como en la función que cumplen y los tipos de acero que producen. Desarrollados para producir aceros especiales, con requerimientos de altas temperaturas para la fusión de ferroaleaciones, penetraron luego en la década del ’60 en las miniacerías, acompañando a las máquinas de colada continua de palanquillas, para la producción de barras de refuerzo de hormigón y alambrones de aceros al carbono. En las décadas del ‘80 y el ’90 se produce un nuevo salto, acompañando la introducción de las máquinas de colada continua de planchones delgados, para la fabricación de productos planos de aceros al carbono
y de alta aleación. Paralelamente a la ampliación de su campo de aplicación, se los fue dotando de tecnologías que permitieron acercar
sus tiempos de proceso a los de las acerías al oxígeno. La escoria espumosa y los paneles refrigerados hicieron posible el uso de ultra alta potencia. Se incorporó la energía química, inicialmente mediante lanzas y actualmente mediante inyectores. Los métodos de control se fueron
haciendo cada vez más sofisticados. Con la incorporación de la metalurgia de cuchara, la función del horno se centró en la fusión de la carga, siendo el eje de la productividad de las acerías. Actualmente
los hornos eléctricos de arco son poderosas máquinas de reciclar acero, que hacen la tercera parte de la producción mundial, con una menor emisión de gases de efecto invernadero con respecto a la ruta basada en altos hornos y acería al oxígeno. Pero es inherente al proceso una significativa pérdida de energía, principalmente a través de los gases de escape. En la Figura 1 se presenta un balance de energía típico de un horno eléctrico moderno [1]. Se observa que cerca de un tercio de la
energía ingresada se pierde en los gases de escape, en forma de calor sensible y energía química. Una distribución similar ocurre en las acerías al oxígeno. En este campo, el tema está más avanzado y hay una cantidad importante de acerías, sobre todo en Europa y Japón, que recuperan el calor de los gases para generar vapor. En la actualidad, el esfuerzo en los hornos eléctricos, desde el punto de vista energético, se centra en disminuir el consumo total de energía más que en recuperar la energía perdida. Es mejor usar 1 kWh menos que recuperar 1 kWh [2]. Sin embargo, esto tiene un límite. En la medida que los hornos se modernizan, se acercan a ese límite. Esto hace que se empiece a poner la mirada en la posibilidad de recuperar la energía. Este problema no es sencillo de resolver, dado que la liberación de calor a los gases de escape es muy variable a lo largo de la colada (Figura 2). Se ha introducido la recuperación del calor de los gases para el precalentamiento de la chatarra en los procesos con carga continua (Consteel) y en los procesos con cubas por sobre la bóveda (finger
shaft furnace) [1]. Se están proponiendo soluciones para la recuperación de la energía de los gases en la generación de vapor, mediante diversos esquemas que comienzan a aplicarse industrialmente en hornos eléctricos. En este trabajo se detallan los diversos esquemas propuestos para resolver el problema.
This paper reviews the progress and challenges of the catalytic pyrolysis of plastic waste along with future perspectives in comparison to thermal pyrolysis. The factors affecting the catalytic pyrolysis process such as the temperature,... more
This paper reviews the progress and challenges of the catalytic pyrolysis of plastic waste along with future perspectives in comparison to thermal pyrolysis. The factors affecting the catalytic pyrolysis process such as the temperature, retention time, feedstock composition and the use of catalyst were evaluated in detail to improve the process of catalytic pyrolysis. Pyrolysis can be carried out via thermal or catalytic routes. Thermal pyrolysis produces low quality liquid oil and requires both a high temperature and retention time. In order to overcome these issues, catalytic pyrolysis of plastic waste has emerged with the use of a catalyst. It has the potential to convert 70–80% of plastic waste into liquid oil that has similar characteristics to conventional diesel fuel; such as the high heating value (HHV) of 38–45.86 MJ/kg, a density of 0.77–0.84 g/cm 3 , a viscosity of 1.74–2.5 mm 2 /s, a kinematic viscosity of 1.1–2.27 cSt, a pour point of (−9) to (−67) • C, a boiling point of 68–352 • C, and a flash point of 26.1–48 • C. Thus the liquid oil from catalytic pyrolysis is of higher quality and can be used in several energy-related applications such as electricity generation, transport fuel and heating source. Moreover, process by-products such as char has the potential to be used as an adsorbent material for the removal of heavy metals, pollutants and odor from wastewater and polluted air, while the produced gases have the potential to be used as energy carriers. Despite all the potential advantages of the catalytic pyrolysis, some limitations such as high parasitic energy demand, catalyst costs and less reuse of catalyst are still remaining. The recommended solutions for these challenges include exploration of cheaper catalysts, catalyst regeneration and overall process optimization.
Waste biorefinery is proposed to convert waste in Makkah into renewable energy. Total revenue of 758 million SAR can be achieved from waste biorefinery. 1.95 million barrels of oil and 11.2 million MCF of natural gas can be saved.... more
Waste biorefinery is proposed to convert waste in Makkah into renewable energy. Total revenue of 758 million SAR can be achieved from waste biorefinery. 1.95 million barrels of oil and 11.2 million MCF of natural gas can be saved. Reduction in global warming potential of 1.15 million Mt.CO 2 eq. can be achieved.
- by K. Shahzad and +3
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- Renewable Energy, Energy, Bioenergy, Recycling
This paper aims to investigate the effect of temperature and reaction time on the yield and quality of liquid oil produced from a pyrolysis process. Polystyrene (PS) type plastic waste was used as a feedstock in a small pilot scale batch... more
This paper aims to investigate the effect of temperature and reaction time on the yield and quality of liquid oil produced from a pyrolysis process. Polystyrene (PS) type plastic waste was used as a feedstock in a small pilot scale batch pyrolysis reactor. At 400 °C with a reaction time of 75 min, the gas yield was 8% by mass, the char yield was 16% by mass, while the liquid oil yield was 76% by mass. Raising the temperature to 450 °C increased the gas production to 13% by mass, reduced the char production to 6.2% and increased the liquid oil yield to 80.8% by mass. The optimum temperature and reaction time was found to be 450 °C and 75 min. The liquid oil at optimum conditions had a dynamic viscosity of 1.77 mPa s, kinematic viscosity of 1.92 cSt, a density of 0.92 g/cm 3 , a pour point of À60 °C, a freezing point of À64 °C, a flash point of 30.2 °C and a high heating value (HHV) of 41.6 MJ/kg this is similar to conventional diesel. The gas chromatography with mass spectrophotometry (GC–MS) analysis showed that liquid oil contains mainly styrene (48%), toluene (26%) and ethyl-benzene (21%) compounds.
Pyrolysis based biorefineries have great potential to convert waste such as plastic and biomass waste into energy and other valuable products, to achieve maximum economic and environmental benefits. In this study, the catalytic pyrolysis... more
Pyrolysis based biorefineries have great potential to convert waste such as plastic and biomass waste into energy and other valuable products, to achieve maximum economic and environmental benefits. In this study, the catalytic pyrolysis of different types of plastics wastes (PS, PE, PP, and PET) as single or mixed in different ratios, in the presence of modified natural zeolite (NZ) catalysts, in a small pilot scale pyrolysis reactor was carried out. The NZ was modified by thermal activation (TA-NZ) at 550 • C and acid activation (AA-NZ) with HNO 3 , to enhance its catalytic properties. The catalytic pyrolysis of PS produced a higher liquid oil (70 and 60%) than PP (40 and 54%) and PE (40 and 42%), using TA-NZ and AA-NZ catalysts, respectively. The gas chromatography-mass spectrometry (GC-MS) analysis of oil showed a mixture of aromatics, aliphatic and other hydrocarbon compounds. The TA-NZ and AA-NZ catalysts showed a different effect on the wt% of catalytic pyrolysis products and liquid oil chemical compositions, with AA-NZ showing higher catalytic activity than TA-NZ. FT-IR results showed clear peaks of aromatic compounds in all liquid oil samples with some peaks of alkanes that further confirmed the GC-MS results. The liquid oil has a high heating value (HHV) range of 41.7-44.2 MJ/kg, close to conventional diesel. Therefore, it has the potential to be used as an alternative source of energy and as transportation fuel after refining/blending with conventional fuels.
The utility of orthogonal collocation methods in the solution of optimal control problems relating to Formula One racing is demonstrated. These methods can be used to optimise driver controls such as the steering, braking and throttle... more
The utility of orthogonal collocation methods in the solution of optimal control problems relating to Formula One racing is demonstrated. These methods can be used to optimise driver controls such as the steering, braking and throttle usage, and to optimise vehicle parameters such as the aerodynamic down force and mass distributions. Of particular interest is the optimal usage of energy recovery systems (ERSs). Contemporary kinetic energy recovery systems are studied and compared with future hybrid kinetic and thermal/heat ERSs known as ERS-K and ERS-H, respectively. It is demonstrated that these systems, when properly controlled, can produce contemporary lap time using approximately two-thirds of the fuel required by earlier generation (2013 and prior) vehicles.
This paper aims to examine the effect of different plastic waste types such as polystyrene (PS), poly-ethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET) on the yield and quality of produced liquid oil from the... more
This paper aims to examine the effect of different plastic waste types such as polystyrene (PS), poly-ethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET) on the yield and quality of produced liquid oil from the pyrolysis process. A small pilot scale pyrolysis reactor was commissioned for this purpose, and operated at optimum temperature and retention time of 450 C and 75 min respectively. PS plastic waste showed maximum production of liquid oil (80.8%) along with least production of gases (13%) and char (6.2%) in comparison to other plastic types. Liquid oils from all plastic types contained mostly aromatic compounds with some alkanes and alkenes. Liquid oil from PS pyrolysis contained styrene (48.3%), ethylbenzene (21.2%) and toluene (25.6%). Pyrolysis liquid oils found to have ranges of dynamic viscosity (1.77e1.90 mPa s), kinematic viscosity (1.92e2.09 cSt), density (0.91e0.92 g/ cm 3), pour point (À11(-60 C)), freezing point (À15-(-65 C)), flash point (28.1e30.2 C) and high heating value (HHV) (41.4e41.8 MJ/kg) similar to conventional diesel, thus have potential as an alternative energy source for electricity generation. Upgrading of liquid oil using different post-treatment methods such as distillation, refining and blending with conventional diesel is required to make it suitable as a transport fuel due to presence of high aromatic compounds. The recovery of aromatic compounds especially styrene from pyrolysis oil can be a potential source of precursor chemical in industries for polymerization of styrene monomers.
This paper aims to examine the potential of waste biorefineries in developing countries as a solution to current waste disposal problems and as facilities to produce fuels, power, heat, and value-added products. The waste in developing... more
This paper aims to examine the potential of waste biorefineries in developing countries as a solution to current waste disposal problems and as facilities to produce fuels, power, heat, and value-added products. The waste in developing countries represents a significant source of biomass, recycled materials, chemicals, energy, and revenue if wisely managed and used as a potential feedstock in various biorefinery technologies such as fermentation, anaerobic digestion (AD), pyrolysis, incineration, and gasification. However, the selection or integration of biorefinery technologies in any developing country should be based on its waste characterization. Waste biorefineries if developed in developing countries could provide energy generation, land savings, new businesses and consequent job creation, savings of landfills costs, GHG emissions reduction, and savings of natural resources of land, soil, and groundwater. The challenges in route to successful implementation of biorefinery concept in the developing countries are also presented using life cycle assessment (LCA) studies.
Plastic usage in daily life has increased from 5 to 100 million tons per year since the 1950s due to their light-weight, non-corrosive nature, durability and cheap price. Plastic products consist mainly of polyethylene (PE), polystyrene... more
Plastic usage in daily life has increased from 5 to 100 million tons per year since the 1950s due to their light-weight, non-corrosive nature, durability and cheap price. Plastic products consist mainly of polyethylene (PE), polystyrene (PS), polypropylene (PP) and polyvinyl chloride (PVC) type plastics. The disposal of plastic waste causes environmental and operational burden to landfills. Conventional mechanical recycling methods such as sorting, grinding, washing and extrusion can recycle only 15–20 % of all plastic waste. The use of open or uncontrolled incineration or combustion of plastic waste has resulted in air and waterborne pollutants. Recently, pyrolysis technology with catalytic reforming is being used to convert plastic waste into liquid oil and char as energy and value-added products. Pyrolysis is one of the tertiary recycling techniques in which plastic polymers are broken down into smaller organic molecules (monomers) in the absence of oxygen at elevated temperatures (>400 °C). Use of catalysts such as aluminum oxides, natural and synthetic zeolites, fly ash, calcium hydroxide, and red mud can improve the yield and quality of liquid oil. The pyrolysis yield depends on a number of parameters such as temperature, heating rate, moisture contents, retention time, type of plastic and particle size. A yield of up to 80 % of liquid oil by weight can be achieved from plastic waste. The produced liquid oil has similar characteristics to conventional diesel; density (0.8 kg/m3), viscosity (up to 2.96 mm2/s), cloud point (−18 °C), flash point (30.5 °C) and energy content (41.58 MJ/kg). Char produced from pyrolysis can be activated at standard conditions to be used in wastewater treatment, heavy metals removal, and smoke and odor removal. The produced gases from pyrolysis are hydrogen (H2), carbon monoxide (CO) and carbon dioxide (CO2) and can be used as energy carriers. This chapter reviews the challenges and, perspectives of pyrolysis technology for production of energy and value-added products from waste plastics.
- by Mohammad Rehan and +1
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- Renewable Energy, Hydrogen, Energy, Municipal Solid Waste Management
The aim of this study was to determine the quality and applications of liquid oil produced by thermal and catalytic pyrolysis of polystyrene (PS) plastic waste by using a small pilot scale pyrolysis reactor. Thermal pyrolysis produced... more
The aim of this study was to determine the quality and applications of liquid oil produced by thermal and catalytic pyrolysis of polystyrene (PS) plastic waste by using a small pilot scale pyrolysis reactor. Thermal pyrolysis produced maximum liquid oil (80.8%) with gases (13%) and char (6.2%), while catalytic pyrolysis using synthetic and natural zeolite decreased the liquid oil yield (52%) with an increase in gases (17.7%) and char (30.1%) production. The lower yield but improved quality of liquid oil through catalytic pyrolysis are due to catalytic features of zeolites such as microporous structure and high BET surface area. The liquid oils, both from thermal and catalytic pyrolysis consist of around 99% aromatic hydrocarbons, as further confirmed by GC-MS results. FT-IR analysis further showed chemical bonding and functional groups of mostly aromatic hydrocarbons, which is consistent with GC-MS results. The produced liquid oils can be suitable for energy generation and heating purposes after the removal of acid, solid residues and contaminants. Further upgrading of liquid oil and blending with diesel is required for its potential use as a transport fuel.
- by Dr. Abdul-Sattar Nizami and +1
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- Renewable Energy, Energy, Catalysts, Biorefinery
The current world population of 7.2 billion is projected to reach up to 8.2 billion in 2025 with current annual growth rate of 1%. The Asia, Middle East, Africa and Latin America are the places, where most of this growth will occur due to... more
The current world population of 7.2 billion is projected to reach up to 8.2 billion in 2025 with current annual growth rate of 1%. The Asia, Middle East, Africa and Latin America are the places, where most of this growth will occur due to rapidly growing industries and urbanization. As a consequence, the generation rate of municipal solid waste (MSW) will increase from 1.2 to 1.5 kg per capita per day in next 15 years. Globally, around 2.4 billion tons of MSW is generated every year that will reach up to 2.6 billion tons by 2025. Similarly, the energy demand will increase significantly in developing countries, especially in Asia with an increase of 46-58% at annual rate of 3.7% till 2025. Fossil fuels are the most relied source at the moment to meet the world's energy demands. The intensive and solely utilization of fossil resources are not only depleting our natural reserves but also causing global climate change. The municipal waste can be a cheap and valuable source of renewable energy, recycled materials, value-added products (VAP) and revenue, if properly and wisely managed. The possibilities for converting waste-to-energy (WTE) are plentiful and can include a wide range of waste sources, conversion technologies, and infrastructure and end-use applications. Several WTE technologies such as pyrolysis, anaerobic digestion (AD), incineration, transesterification, gasification, refused derived fuel (RDF) and plasma arc gasification are being utilized to generate energy and VAP in the form of electricity, transportation fuels, heat, fertilizer, animal feed, and useful materials and chemicals. However, there are certain limitations with each WTE technology, as an individual technology cannot achieve zero waste concept and competes with other renewable-energy sources like wind, solar, and geothermal. A conceptual and technological solution to these limitations is to integrate appropriate WTE technologies based on the country/or region specific waste characterization and available infrastructure, labor skill requirements, and end-use applications under a biorefinery concept. Such waste-based biorefinery should integrate several WTE technologies to produce multiple fuels and VAP from different waste sources, including agriculture, forestry, industry and municipal waste. This paper aims to assess the value of waste-based biorefinery in developing countries as a solution to waste-related environmental and human health problems with additional bonus of renewable energy and VAP.
This study aims to (1) convert agricultural waste to biochar through pyrolysis, (2) examine its physiochemical characteristics, and (3) investigate its potential role as fuel and catalyst in energy recovery technologies. The produced... more
This study aims to (1) convert agricultural waste to biochar through pyrolysis, (2) examine its physiochemical characteristics, and (3) investigate its potential role as fuel and catalyst in energy recovery technologies. The produced biochars at 250, 350, and 450 °C showed a wide range of mineralogical composition, high porosity, and thermal stability, and alkaline pH that make biochar suitable for improving the processes of energy recovery technologies such as anaerobic digestion (AD), transesterification and pyrolysis. The alkaline pH of biochars can neutralize the acidic condition and increase the digestibility of the feedstock in AD process for enhanced methane (CH4) production. Biochar favors the transesterification process for biodiesel production due to products separation and high stability under basic and acidic conditions. In pyrolysis process, biochar can act as a catalyst to increase the degradation rates of plastic or biomass wastes or can be used as an adsorbent material during the post-treatment to improve the quality of the liquid oil. The high heating values (HHV) of biochars produced at 250, 350 and 450 °C were 24, 23.64 and 23.08 MJ kg-1. This characteristic of biochar along with the high tendency of slagging indicate that biochar could be used itself as a source of energy. Biochar can also act as a promising low-cost adsorbent for capturing carbon dioxide (CO2) due to its highly porous structure and sorptive capacity and subsequently the conversion of absorbed CO2 to fuel. Research is yet required on the application of biochar in pyrolysis and capturing and catalyzing the conversion reactions of CO2 to fuels.
Recently, new environment-friendly energy conversion technologies are required for using energy resources valid to power generation. Accordingly, low-grade heat sources as solar heat, geothermal energy, and waste heat, which have... more
Recently, new environment-friendly energy conversion technologies are required for using energy resources valid to power generation. Accordingly, low-grade heat sources as solar heat, geothermal energy, and waste heat, which have available temperatures ranging between 60 and 200°C, are supposed as applicants for recent new generation energy resources. As an alternative energy source, such low-grade heat sources usage generating electricity with the help of power turbine cycles was examined through this study. Such systems have existing technologies applicable at low temperatures and a compact structure at low cost, however, these systems have a low thermal efficiency of the Rankine cycles operated at low temperatures. An Organic Rankine Cycle (ORC) is alike to a conventional steam power plant, except the working fluid, which is an organic, high molecular mass fluid with a liquid-vapor phase change, or boiling point, at a lower temperature than the water-steam phase change. The efficiency of an ORC is about between 10% and 20%, depending on temperature levels and availability of a valid fluid.
- by İsmail Ekmekçi and +1
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- Energy Recovery Systems
This study aims to examine the effect of various advanced catalysts on tire waste pyrolysis oil using a small pilot-scale pyrolysis reactor with a capacity of 20 L. The catalytic pyrolysis with activated alumina (Al2O3) catalyst produced... more
This study aims to examine the effect of various advanced catalysts on tire waste pyrolysis oil using a small pilot-scale pyrolysis reactor with a capacity of 20 L. The catalytic pyrolysis with activated alumina (Al2O3) catalyst produced maximum liquid oil (32 wt.%) followed by activated calcium hydroxide (Ca(OH)2) (26 wt.%), natural zeolite (22 wt.%) and zeolite (H-SDUSY) (14 wt.%) catalysts, whereas liquid oil yield of 40% was obtained without catalyst. The gas chromatography-mass spectrometry results confirmed the pyrolysis liquid oil produced without catalyst consist of up to 93.3% of mixed aromatic compounds. The use of catalysts decreased the concentration of aromatic compounds in liquid oil down to 60.9% with activated calcium hydroxide, 71.0% with natural zeolite, 84.6% with activated alumina, except for synthetic zeolite producing 93.7% aromatic compounds. The Fourier-transform infrared spectroscopy data revealed that the mixture of aromatic and aliphatic hydrocarbon compounds were found in all liquid oil samples, which further confirmed the gas chromatography results. The characteristics of pyrolysis liquid oil had viscosity (1.9 cSt), density (0.9 g/cm3), pour point (-2 °C) and flash point (27 °C), similar to conventional diesel. The liquid oil had higher heating values, key feature of a fuel, in the range of 42-43.5 MJ/kg that is same to conventional diesel (42.7 MJ/kg). However, liquid oil requires post-treatments, including refining and blending with conventional diesel to be used as a transport fuel, source of energy and value-added chemicals.
The current status of small-scale desalination (produced water capa- city 100 m3/day or less) is reviewed to provide an overview of the market segment. The use of energy-recovery devices in this market segment is also reviewed. We find... more
The current status of small-scale desalination (produced water capa-
city 100 m3/day or less) is reviewed to provide an overview of the market segment. The use of energy-recovery devices in this market segment is also reviewed. We find that the Middle East accounts for the largest market share worldwide at present, and reverse osmosis is overwhelmingly dominant among the desalination technologies adopted. Implementation of energy-recovery devices at small scale is rare, which leads to relatively high energy consumption for small-scale seawater reverse osmosis desalination systems.
This study deals with the pyrolysis of waste tires supplied from the transport industry. The base material of tire is latex, which is derived from natural rubber trees. Nowadays rubber (Hevea brasiliensis) is a fast-growing tropical tree... more
This study deals with the pyrolysis of waste tires supplied from the transport industry. The base material of tire is latex, which is derived from natural rubber trees. Nowadays rubber (Hevea brasiliensis) is a fast-growing tropical tree crop, which is being cultivated for latex and ultimately for tire production. Waste tires can be recycled for energy and valuable materials in many ways; however tire burning is the most common practice for heat generation. In recent years, the catalytic conversion of waste tires through pyrolysis into liquid, solid, and gas products was investigated. Liquids product was produced from the catalytic pyrolysis of waste tire at high temperature (up to 600°C) using sodium carbonate (Na2CO3) as a catalyst. Thermo-physical characteristics of the produced liquid samples showed that up to 85% of
the produced oil can be used in internal combustion engines. Gasoline and diesel fuel contents in the liquid products are 45% and 40%, respectively. The gas chromatographic (GC) analysis of the volatile fraction of pyrolysis products showed styrene (28.1%) and butadiene (10.7%) as dominant compounds. The gaseous phase includes C1–C4 hydrocarbons (4.8%) and the liquid phase includes C5–C8 hydrocarbons (6.5%) of the total products.
We studied the hydrolytic pretreatment at thermophilic temperature of grass silage. Different organic loading rates and hydraulic retention times were carried out. A two-phase system for anaerobic digestion improved methane production by... more
We studied the hydrolytic pretreatment at thermophilic temperature of grass silage. Different organic loading rates and hydraulic retention times were carried out. A two-phase system for anaerobic digestion improved methane production by 30%. A maximum of 368 L N CH 4 kg À1 VS was obtained in the mesophilic phase. a b s t r a c t Thermophilic hydrolysis of grass silage (GS) at 55 °C with organic loading rates (OLRs) of 6.5, 5, 2.5 and 1.0 kg VS m À3 days À1 and hydraulic retention times (HRT) of 10, 6, 4 and 2 days were evaluated in 12 glass bioreactors side by side. The hydrolytic process was measured by variation in pH, volatile solids (VS), VS destruction, soluble chemical oxygen demand (sCOD), hydrolysis and acidification yields. Biological methane potential (BMP) assays were carried out to measure the upper limit for methane production of grass silage with different hydrolytic pretreatments at mesophilic temperature (37 °C). The optimum methane yield of 368 L N CH 4 kg À1 VS was obtained at an OLR of 1 kg VS m À3 days À1 and a HRT of 4 days, showing an increase of 30% in the methane potential in comparison to non-hydrolysed GS.
An ORC based power plant for waste heat recovery in stationary applications has been developed and experimentally characterized. The aim of the study was to investigate the performance of a sliding vane rotary expander as the device to... more
An ORC based power plant for waste heat recovery in stationary applications has been developed and experimentally characterized. The aim of the study was to investigate the performance of a sliding vane rotary expander as the device to convert the enthalpy of the working fluid, namely R236fa, into mechanical and electric energy. A theoretical model of the expander supported the design and allowed to assess the thermodynamic transformations that take place in it. Furthermore, a deep experimental campaign explored the behavior of the expander and the one of the recovery system also at off design conditions. The experimental activity on the expander included the reconstruction of the indicated diagram using a set of high frequency piezoelectric pressure transducers that provided an accurate prediction of the pressure evolution inside the cell. The overall cycle efficiency achieved was close to 8% and further improvements concerned to the expander design have been addressed. The temperature of the upper thermal source at around 120 • C and the mechanical output power close to 2 kW make the expander and the whole system suitable for plenty of potential recovery applications.
Environmental pollution is the major problem associated with rapid industrialization, urbanization and rise in living standards of people. Increasing of the amount of solid waste and the pressure what it has on the environment, impose the... more
Environmental pollution is the major problem associated with rapid industrialization, urbanization and rise in living standards of people. Increasing of the amount of solid waste and the pressure what it has on the environment, impose the need to introduce advanced approach to effectively managing of solid waste. This advanced approach includes technologies for solid waste treatment, that fall into the category of "Renewable". This paper put emphasis on technologies for material and energy utilization of solid waste, such as: composting, gasification, pyrolysis and incineration. These kinds of technologies allow obtaining volume reduction, material and energy recovery.
Team ASUNM will present current results of the design of the SHADE house- team’s entry into the DOE Solar Decathlon 2013 competition. The work is concentrated on finding the right balance between passive building technologies and... more
Team ASUNM will present current results of the design of the SHADE house- team’s entry into the DOE Solar Decathlon 2013 competition. The work is concentrated on finding the right balance between passive building technologies and photovoltaics utilization, while at the same time incorporating home energy automation, controls, energy consumption monitoring and demand reduction techniques. The designed house incorporates state of the art thermal technologies – such as radiant cooling and thermal storage with phase-change materials. An important feature of the house is the SHADE canopy structure which not only serves as an area for photovoltaic power production, but provides shade – a much needed element in the arid southwest. Appliances and electronics inside the house are networked through a centralized home automation system which can be controlled through smart phone applications.
V arious heat pump assisted process con® gurations are analysed for two industrial case studies using a design strategy based on preliminary screening, rigorous steady state simulation and economic evaluation. The in¯uence of heat pump... more
V arious heat pump assisted process con® gurations are analysed for two industrial case studies using a design strategy based on preliminary screening, rigorous steady state simulation and economic evaluation. The in¯uence of heat pump type, heat load, column temperature difference, utility cost, exchanger minimum approach temperature (EMAT) on the energetic aspects and economic range of application are examined.
Management of municipal solid waste (MSW) has been a grave issue all over the world. The conventional environment friendly techniques adopted to tackle the matter is turning futile owing to the appalling increase in the waste generation... more
Management of municipal solid waste (MSW) has been a grave issue all over the world. The conventional
environment friendly techniques adopted to tackle the matter is turning futile owing to the appalling
increase in the waste generation rate. The resultant environmental and health hazards emphasise the need
for a more rapid solution. An apt and quick response to India’s mounting waste management and energy
demand crisesis the promotion and execution of waste to energy technologies. Although the MSW
composition and characteristics in the past have been unfavourable for the successful implementation of
waste to energy thermal facilities, there have been variations in the waste characteristics of late, in this
regard. Inert fraction which constituted almost 50% of the Indian MSW in the 1970s reduced by 30-40%by
the early 2000s, making energy recovery facilities an economically and environmentally feasible option.
The varying trends in MSW characteristics in India are analysed and its implications on the thermal energy
recovery techniques are investigated.
In light of global warming mitigation efforts, increasing sludge disposal costs, and need for reduction in the carbon footprint of wastewater treatment plants, innovation in treatment technology has been tailored towards energy... more
In light of global warming mitigation efforts, increasing sludge disposal costs, and need for reduction
in the carbon footprint of wastewater treatment plants, innovation in treatment technology has been
tailored towards energy self-sufficiency. The AB process is a promising technology for achieving
maximal energy recovery from wastewaters with minimum energy expenditure and therefore
inherently reducing excess sludge production. Characterization of this novel sludge and its
comparison with the more conventional B-stage sludge are necessary for a deeper understanding of
AB treatment process design. This paper presents a case study of a pilot-scale AB system treating
municipal wastewaters as well as a bio- (biochemical methane potential and adenosine
tri-phosphate analysis) and physico-chemical properties (chemical oxygen demand, sludge volume
index, dewaterability, calorific value, zeta potential and particle size distribution) comparison of the
organic-rich A-stage against the B-stage activated sludge. Compared to the B-sludge, the A-sludge
yielded 1.4 to 4.9 times more methane throughout the 62-week operation.
Thermophotovoltaics (TPV) is complimentary to Solar Photovoltaics but it operates at night and in cold climates TPV is ideal for small and large scale Combined Heat & Power and it uses natural gas TPV is lightweight and can be used as a... more
Thermophotovoltaics (TPV) is complimentary to Solar Photovoltaics but it operates at night and in cold climates
TPV is ideal for small and large scale Combined Heat & Power and it uses natural gas
TPV is lightweight and can be used as a battery replacement or in UAVs
TPV can be used in steel mills to convert waste heat into electricity 24 hrs per day 7 days a week and this is a huge market
JX Crystals IR cells in quantity are key to a large number of new applications
This paper presents the study of municipal solid waste (MSW) as a potential source of renewable energy in Arusha city. The city of Arusha annual average MSW generated was estimated at 43,772 tonnes. Characterization revealed the main... more
This paper presents the study of municipal solid waste (MSW) as a potential source of renewable energy in Arusha city. The city of Arusha annual average MSW generated was estimated at 43,772 tonnes. Characterization revealed the main components of MSW to compose of biomass materials such as food, paper and wood waste. Based on the characteristics of the MSW, evaluation was conducted to determine energy potential that would be recovered. Results from proximate analysis of MSW samples showed average calorific value of about 12MJ/kg which indicate annual energy potential of 128.9 GWh. Results indicate there is a substantial energy potential to recover from MSW the largest share being renewable energy. The composition of waste from developing and developed countries was further compared with that of Arusha city. Results indicated that in developing countries characteristics of MSW is mainly composed of food waste as was the case of Arusha city.
Millions of Muslims from all over the world visit the Holy Cities of Saudi Arabia: Makkah and Madinah every year to perform Hajj and Umrah. The rapid growth in urbanization and the local population of Makkah city along with an ever... more
Millions of Muslims from all over the world visit the Holy Cities of Saudi Arabia: Makkah and Madinah every year to perform Hajj and Umrah. The rapid growth in urbanization and the local population of Makkah city along with an ever increasing number of visitors result in huge municipal solid waste (MSW) generation every year. Most of this waste is currently dumped into landfill sites without any treatment, thus causing environmental and health issues. For example, on average around 2.4 thousand tons of waste is dumped into Makkah city’s landfill sites every day that increases to around 3.1 and 4.6 thousand tons per day during Ramadan and Hajj periods, respectively. Around 23% on average of this waste is a plastic waste in the form of plastic bottles, water cups, food plates and shopping bags (Abdul Aziz et al. 2007). A pilot scale catalytic pyrolysis process has been used to convert plastic waste into liquid fuel at Center of Excellence in Environmental Studies (CEES) of King Abdulaziz University, Jeddah. The produced liquid fuel has been found to have a high energy value of around 40 MJ/Kg, the viscosity of 0.9 mm2/s, the density of 0.92 g/cm3, the flash point of 30°C, pour point of -18°C and freezing point of -64°C, characteristics similar to conventional diesel. Thus the produced liquid fuel has the potential to be used in several energy-related applications such as electricity generation, transportation fuel, and heating purposes. It has been estimated that the plastic waste in Makkah city in 2016 could produce around 87.91 MW of electricity with net revenue of 297.52 million SAR. This is projected to increase up to around 172.80 MW of electricity and a total net revenue of 584.83 million SAR by 2040.
- by Mohammad Rehan and +1
- •
- Renewable Energy, Biomass, Energy, Bioenergy
En la medida que los hornos eléctricos de arco se acercan a su eficiencia energética teórica, disminuyendo su consumo específico de energía eléctrica y química, empieza a presentar interés la posibilidad de recuperar la energía que se... more
En la medida que los hornos eléctricos de arco se acercan a su eficiencia energética teórica, disminuyendo su consumo específico de energía eléctrica y química, empieza a presentar interés la posibilidad de recuperar la energía que se pierde en los gases de escape. Se están comenzando a discutir las posibles alternativas tecnológicas y surgen las primeras experiencias industriales.
Utilizing compressors, natural gas compression stations (NGCS) supply the required pressure to transport the natural gas in pipelines. This study proposes to utilize the waste heat of gas turbines (GT), employed in these stations, to... more
Utilizing compressors, natural gas compression stations (NGCS) supply the required pressure to transport the natural gas in pipelines. This study proposes to utilize the waste heat of gas turbines (GT), employed in these stations, to produce shaft power for compressors. A NGCS coupled to an Organic Rankine Cycle (ORC) is simulated by THERMOFLEX in this study. Ten different working fluids are compared against each other in the ORC to select a working fluid with the highest possible efficiency and obtainable power, and lowest possible environmental impacts. According to the results, n-Pentane is selected to be the working fluid, as compared to others, it better meets these criteria. The effects of the variation of the ambient temperature and the condenser pressure on the net power of the cycle working with n-Pentane are investigated in details. It was found that the utilization of waste heat in NGCS by an ORC can improve the energy efficiency and generates electricity for near rural areas.
Mathematical heat transfer equations for finned double pipe heat exchangers based on experimental work carried out in the 1970s can be programmed in a spreadsheet for repetitive use. Thus avoiding CFD analysis which can be time consuming... more
Mathematical heat transfer equations for finned double pipe heat exchangers based on experimental work
carried out in the 1970s can be programmed in a spreadsheet for repetitive use. Thus avoiding CFD
analysis which can be time consuming and costly. However, it is important that such mathematical
equations be evaluated for their accuracy. This paper uses CFD methods in evaluating the accuracy of
mathematical equations. Several models were created with varying; geometry, flue gas entry temperature,
and flow rates. The analysis should provide designers and manufacturers a judgment on the expected level
of accuracy when using mathematical modelling methodology. This paper simultaneously identifies best
practices in carrying out such CFD analysis.
Methodology; CFD software was used to simulate different models. Results were tabulated and graphically
presented. The investigated mathematical equations were programmed in a spreadsheet, for data entry.
Results and analysis; data obtained from the two methods were compared and differences were recorded.
Discussions were included explaining the possible reasons for the deviations that surfaced between the two
methodologies.
Conclusions; this analysis has shown that although mathematical equations are effective and simple tools
in producing results, the results may not reflect the actual physical conditions. The analysis showed that the
exhaust gas temperature outlet of a double pipe heat exchanger is actually higher than what were
calculated using mathematical equations, and therefore, more heat energy is available for recapturing.
k-epsilon RNG turbulence model was found to be the most suitable method in analyzing heat transfer in a
finned double pipe heat exchanger.
The paper presents results from a study to evaluate the potential of waste heat recovery technology within the context of the commercial kitchen in Northern Ireland. The study involved both numerical simulation and measured data from five... more
The paper presents results from a study to evaluate the potential of waste heat recovery technology within the context of the commercial kitchen in Northern Ireland. The study involved both numerical simulation and measured data from five kitchens in Belfast that revealed heat recovery technology provided substantial economic and environmental savings. Utilising compact devices such as a spiral tube heat exchanger, these sustainable solutions can be easily retrofitted to enhance existing hot water systems. However, subsequent research should be conducted to broaden the scope of this study by complementing this technology with a solar panel or wind turbine. This would provide a more holistic and sustainable solution to the catering industry.
Within the framework of the European Combined Efficient Large Scale Integrated Urban Systems (CELSIUS) project, the Genoa demonstrator involves the insertion of a turbo expander (TE) to substitute the standard throttling process in a... more
Within the framework of the European Combined Efficient Large Scale Integrated Urban Systems (CELSIUS) project, the Genoa demonstrator involves the insertion of a turbo expander (TE) to substitute the standard throttling process in a natural gas expansion station. In this way, the currently wasted mechanical energy will be recovered, while an internal combustion combined heat and power (CHP) unit will be used to meet the heating requirements of the gas before the expansion and to serve a small district heating network (DHN). Both TE and CHP are capable of delivering electric power (EP) up to 1 MW. In order to match the EP production vs demand is highly desirable to use the EP extra capacity for local EP final users, such as a nearby public school and a gas refueling station (RS). For limiting the school's consumption of fossil fuel, it is possible to use the EP surplus generated by the demonstrator to feed a heat pump in parallel to the heating conventional system. With regard to the RS, the compressors are currently driven by electric motors, with a high-energy consumption. The integrated system gives the possibility of exploiting the surplus of electricity production and of recovering heat, which would be otherwise wasted, from the intercooling of compressed gas, thus powering the DHN through a preheating system. The result expected from this strategy is a relevant energy and emissions saving due to an integrated use of the electricity generated by the Genoese demonstrator for feeding the nearby school and RS.
- by Davide Borelli and +2
- •
- Energy, Energy and Environment, Energy Conversion, Electricity
This paper deals with European TRY weather data processing for climatic indexes generation, useful for HVAC energy and cost simplified evaluation. For nine Italian locations are presented: 99 and 2·5% dry bulb temperatures, 2·5% wet bulb... more
This paper deals with European TRY weather data processing for climatic indexes generation, useful for HVAC energy and cost simplified evaluation. For nine Italian locations are presented: 99 and 2·5% dry bulb temperatures, 2·5% wet bulb temperatures, heating and cooling degree days, latent enthalpy days, unitary sensible and latent loads. TRY psychrometric data were processed according to a bin method that preserves the correlation between dry bulb temperature and moisture content, and then reduced by an averaging technique. An example is worked out in order to present an engineering shorthand for energy and cost evaluation of HVAC system.
In the last years “thinking green” has become the keyword for a more sustainable future; the prevention of the worsening of the environmental conditions produced a strong reduction on ICE emissions that has been, in the recent past, the... more
In the last years “thinking green” has become the keyword for a more sustainable future; the prevention of the worsening of the environmental conditions produced a strong reduction on ICE emissions that has been, in the recent past, the driving force of the engine evolution. Today, a new interest appeared on the scene and it is CO 2 reduction: this goal is focusing the attention of the actual ICE technological evolution and a huge interest is characterizing the market. In this paper the Authors studied an energy recovery system from the exhaust gasses, integrated with the turbocharger, considering that the enthalpy drop across the turbine is usually higher than that requested by the compressor.
Greenhouse gas (GHG) emissions contribute to climate change. The public water utility of Amsterdam wants to operate climate neutrally in 2020 to reduce its GHG emissions. Energy recovery from the water cycle has a large potential to... more
Greenhouse gas (GHG) emissions contribute to climate change. The public water utility of Amsterdam wants to operate climate neutrally in 2020 to reduce its GHG emissions. Energy recovery from the water cycle has a large potential to contribute to this goal: the recovered energy is an alternative for fossil fuel and thus contributes to the reduction of GHG emissions. One of the options concerns thermal energy recovery from drinking water. In Amsterdam, drinking water is produced from surface water, resulting in high drinking water temperatures in summer and low drinking water temperatures in winter. This makes it possible to apply both cold recovery and heat recovery from drinking water. For a specific case, the effects of cold recovery from drinking water were analyzed on three decisive criteria: the effect on the GHG emissions, the financial implications, and the effect on the microbiological drinking water quality. It is shown that cold recovery from drinking water results in a 90% reduction of GHG emissions, and that it has a positive financial business case: Total Cost of Ownership reduced with 17%. The microbial drinking water quality is not affected, but biofilm formation in the drinking water pipes increased after cold recovery.
Energy consumption in KSA (kingdom of Saudi Arabia) is growing rapidly due to economic development with raised levels of population, urbanization and living standards. Fossil fuels are currently solely used to meet the energy... more
Energy consumption in KSA (kingdom of Saudi Arabia) is growing rapidly due to economic development
with raised levels of population, urbanization and living standards. Fossil fuels are currently solely used
to meet the energy requirements. The KSA government have planned to double its energy generating
capacity (upto 120 GW(gigawatts)) by 2032. About half of the electricity capacity of this targeted energy
will come from renewable resources such as nuclear, wind, solar, WTE (waste-to-energy) etc. Natural
zeolites are found abundantly in KSA at Jabal Shamah occurrence near Jeddah city, whose characteristics
have never been investigated in energy related applications. This research aims to study the physical and
chemical characteristics of natural zeolite in KSA and to review its potential utilization in selected WTE
technologies and solar energy. The standard zeolite group of aluminaesilicate minerals were found with
the presence of other elements such as Na, Mg and K etc. A highly crystalline structure and thermal
stability of natural zeolites together with unique ion exchange, adsorption properties, high surface area
and porosity make them suitable in energy applications such as WTE and solar energy as an additive or
catalyst. A simple solidegas absorption system for storing solar energy in natural zeolites will be a cheap
alternative method for KSA. In AD (anaerobic digestion), the dual characteristics of natural zeolite like
Mordenite will increase the CH4 production of OFMSW (organic fraction of municipal solid waste).
Further investigations are recommended to study the technical, economical, and environmental feasibility
of natural zeolite utilization in WTE technologies in KSA.
- by Omar Ouda and +3
- •
- Renewable Energy, Pyrolysis, Biogas, Biomass to fuel conversion
Greenhouse gas (GHG) emissions contribute to climate change. The public water utility of Amsterdam wants to operate climate neutrally in 2020 to reduce its GHG emissions. Energy recovery from the water cycle has a large potential to... more
Greenhouse gas (GHG) emissions contribute to climate change. The public water utility of Amsterdam wants to operate climate neutrally in 2020 to reduce its GHG emissions. Energy recovery from the water cycle has a large potential to contribute to this goal: the recovered energy is an alternative for fossil fuel and thus contributes to the reduction of GHG emissions. One of the options concerns thermal energy recovery from drinking water. In Amsterdam, drinking water is produced from surface water, resulting in high drinking water temperatures in summer and low drinking water temperatures in winter. This makes it possible to apply both cold recovery and heat recovery from drinking water. For a specific case, the effects of cold recovery from drinking water were analyzed on three decisive criteria: the effect on the GHG emissions, the financial implications, and the effect on the microbiological drinking water quality. It is shown that cold recovery from drinking water results in a 90% reduction of GHG emissions, and that it has a positive financial business case: Total Cost of Ownership reduced with 17%. The microbial drinking water quality is not affected, but biofilm formation in the drinking water pipes increased after cold recovery.
A RF (radio frequency) plasma pyrolysis reactor was presented in this paper. Application of this reactor to the pyrolysis treatment of biomass at different operating pressures (3000-8000Pa), with various input powers (1600-2000W) was... more
A RF (radio frequency) plasma pyrolysis reactor was presented in this paper. Application of this reactor to the pyrolysis treatment of biomass at different operating pressures (3000-8000Pa), with various input powers (1600-2000W) was investigated. Interest was focused on the effect of the pyrolysis conditions on the yield of gas and char, the gas composition as well as the quality of the char. On average, the gas yield can reach 66 wt% of the biomass feed at the input power 1800W and operating pressure 5000Pa. The total content of CO and H 2 in the gas product reached 76 vol.% on a nitrogen-free basis. Thus the utilization efficiency is increased after the biomass is converted into gaseous fuel, which has wider applications such as city gas, burning in utility boilers, gas turbines or gas engines to generate electricity.
Biodiesel is a promising liquid fuel that is mainly derived from triglycerides and is utilized in diesel engines directly or after blending with conventional gasoline. Triglycerides comprise fatty acid methyl esters (FAME), which are... more
Biodiesel is a promising liquid fuel that is mainly derived from triglycerides and is utilized in diesel engines directly or after blending with conventional gasoline. Triglycerides comprise fatty acid methyl esters (FAME), which are generated from plant or animal based sources. Biodiesel generated from vegetable oils is expensive than petroleum-based diesel and has concerns with food vs. fuels debate. Therefore, biodiesel from renewable sources such as non-food feedstocks has attained a considerable interest in last two decades. This paper aims to examine the biodiesel generation from the non-food feedstocks available in the Kingdom of Saudi Arabia (KSA) as a source of renewable energy and valueadded products along with and a solution to current waste disposal problems. In KSA, non-food feedstocks such as animal fats, waste cooking oil (WCO), agricultural wastes, sewage sludge, and microalgae are promising sources for biodiesel production. These feedstocks are relatively cheap, eas...
This paper presents the study of municipal solid waste (MSW) as a potential source of renewable energy in Arusha city. The city of Arusha annual average MSW generated was estimated at 43,772 tonnes. Characterization revealed the main... more
This paper presents the study of municipal solid waste (MSW) as a potential source of renewable energy in Arusha city. The city of Arusha annual average MSW generated was estimated at 43,772 tonnes. Characterization revealed the main components of MSW to compose of biomass materials such as food, paper and wood waste. Based on the characteristics of the MSW, evaluation was conducted to determine energy potential that would be recovered. Results from proximate analysis of MSW samples showed average calorific value of about 12MJ/kg which indicate annual energy potential of 128.9 GWh. Results indicate there is a substantial energy potential to recover from MSW the largest share being renewable energy. The composition of waste from developing and developed countries was further compared with that of Arusha city. Results indicated that in developing countries characteristics of MSW is mainly composed of food waste as was the case of Arusha city.
Evaporative cooling, extensively used in dry climates, can be justified in wetter areas by integration into HVAC systems; in this way the saving-energy technique will not always replace mechanical cooling, but has to be integrated with... more
Evaporative cooling, extensively used in dry climates, can be justified in wetter areas by integration into HVAC systems; in this way the saving-energy technique will not always replace mechanical cooling, but has to be integrated with commonly employed equipment. In this paper Test Reference Year (TRY) data for Italy were processed to estimate using potential of multistage integrated evaporative HVAC systems. Specific humidity and wet-bulb temperature were computed to define five regions for external air, and then to evaluate hours per year and relative energy saving for each of these regions and Italian climatic areas. The systems subjected to comparison were a multi-stage evaporative—direct, indirect and mechanical—and a traditional mechanical one; both all air, single duct, single zone, constant volume systems with wet-bulb economizer. The method of analysis is based on a strongly simplified approach. It is not intended as a substitute for accurate modelling schemes to simulate building and system behaviour, but as a tool to estimate the energy saving potential related to the Italian climate. The following parameters have been assumed as constant throughout: sensible heat ratio of the conditioned space, adiabatic saturation and heat exchanger effectivenesses, indoor space and supply air temperatures and relative humidities. Outside air temperature and relative humidity are assumed to change hour by hour following the TRY profile. Energy savings are evaluated hourly, the mass flow rate of the supply air being kept constant. Seasonal energy savings for the majority of the climatic areas appears to be encouraging, ranging between 28% and 67% (space air temperature and relative humidity: 26°C −60%) or 36% and 74% (space air temperature and relative humidity: 26°C −70%). If it is assumed that the system operates always with 100% outside air (also for regions with outside wet-bulb air temperature greater than space wet-bulb air temperature) energy cooling requirements display different trends for different climatic areas.