A test setup was designed and built to test energy recovery ventilator membranes. The purpose of this test setup was to measure the heat transfer and water vapor transfer rates through energy recover ventilator membranes and find their effectiveness, with air conditions that resemble residential use. Two test chambers were constructed with different channel heights above the membrane; one was 1mm and the other 2mm. The 2mm setup gave measureable results, but small air leaks in the system of 7.0% and 6.2% left room for error. The 1mm setup also had air leaks but they were smaller than the 2mm setup, with leak rates of 1.0% and 5.1%. The permeance of the membrane was found to be 2.58x10^-5 g/(m2*s*Pa) for the 2mm test chamber and 9.90x10^-54 g/(m2*s*Pa) for the 1mm test chamber.

No description available.

<p>Energy recovering techniques for air conditioning has increased in recent years and new prod- </p><p>ucts have been introduced to the market where the Membrane-based Energy Recovery Ventilator </p><p>(ERV) is one promising product. The aim of this study was to evaluate a new type of membrane </p><p>material for an ERV and give an analysis of the need for digital control of the air flow rate to </p><p>improve efficiency. A prototype counter-flow ERV was used in the test to validate the performance under different </p><p>flow conditions. The result was promising for the tested membrane material with high moisture </p><p>and heat transfer. The optimisation of the flow rate was found to be superfluous, since the relation </p><p>between the energy transferred by the ERV and the air flow rate was almost linear.</p>

Energy recovering techniques for air conditioning has increased in recent years and new prod- ucts have been introduced to the market where the Membrane-based Energy Recovery Ventilator (ERV) is one promising product. The aim of this study was to evaluate a new type of membrane material for an ERV and give an analysis of the need for digital control of the air flow rate to improve efficiency. A prototype counter-flow ERV was used in the test to validate the performance under different flow conditions. The result was promising for the tested membrane material with high moisture and heat transfer. The optimisation of the flow rate was found to be superfluous, since the relation between the energy transferred by the ERV and the air flow rate was almost linear.

In the process of electricity generation, water is used as the working fluid to transport energy from the fuel to the turbine. This water has to be ultrapure in order to reduce maintenance cost on the boilers. For the production of ultrapure water, a desalination process is used. This process consists of an ultrafiltration pretreatment section, two reverse osmosis stages and a continuous electrodeionisation stage. Reverse osmosis desalination plants are, however, inherently inefficient with a high specific energy consumption. In an attempt to improve the efficiency of low recovery seawater applications, energy recovery devices are installed on the brine outlet of the reverse osmosis stages. The energy recovery device recovers the energy that is released through the high pressure brine stream and reintroduces it to the system. The investigated desalination process has a fresh water feed with a salinity of 71 ppm and is operated at recoveries above 85%. The plant produces demineralised water at a salinity lower than 0.001ppm for the purpose of high pressure boiler feed. A thermodynamic analysis determined the Second Law efficiencies for the first and second reverse osmosis sections as 3.85% and 3.68% respectively. The specific energy consumption for the reverse osmosis plants is 353 Wh/m3 and 1.31 Wh/m3. This was used as the baseline for the investigation. An exergy analysis determined that energy is lost through the brine throttling process and that a pressure exchanging system can be installed on all reverse osmosis brine streams. Energy recovery devices are untested in high recovery fresh water applications due to the low brine pressure and low brine flow. It was determined that pressure exchanging systems can reduce the specific energy consumption of the first reverse osmosis stage with 12.2% whereas the second RO stage energy consumption can be improved with 7.7%. The Second Law efficiency can be improved by 25.6% for the first reverse osmosis stage while the efficiency is improved with 18.1% for the second stage. The optimal operating recovery for the PES is between 80% and 90%. / MIng (Chemical Engineering), North-West University, Potchefstroom Campus, 2015

In the process of electricity generation, water is used as the working fluid to transport energy from the fuel to the turbine. This water has to be ultrapure in order to reduce maintenance cost on the boilers. For the production of ultrapure water, a desalination process is used. This process consists of an ultrafiltration pretreatment section, two reverse osmosis stages and a continuous electrodeionisation stage. Reverse osmosis desalination plants are, however, inherently inefficient with a high specific energy consumption. In an attempt to improve the efficiency of low recovery seawater applications, energy recovery devices are installed on the brine outlet of the reverse osmosis stages. The energy recovery device recovers the energy that is released through the high pressure brine stream and reintroduces it to the system. The investigated desalination process has a fresh water feed with a salinity of 71 ppm and is operated at recoveries above 85%. The plant produces demineralised water at a salinity lower than 0.001ppm for the purpose of high pressure boiler feed. A thermodynamic analysis determined the Second Law efficiencies for the first and second reverse osmosis sections as 3.85% and 3.68% respectively. The specific energy consumption for the reverse osmosis plants is 353 Wh/m3 and 1.31 Wh/m3. This was used as the baseline for the investigation. An exergy analysis determined that energy is lost through the brine throttling process and that a pressure exchanging system can be installed on all reverse osmosis brine streams. Energy recovery devices are untested in high recovery fresh water applications due to the low brine pressure and low brine flow. It was determined that pressure exchanging systems can reduce the specific energy consumption of the first reverse osmosis stage with 12.2% whereas the second RO stage energy consumption can be improved with 7.7%. The Second Law efficiency can be improved by 25.6% for the first reverse osmosis stage while the efficiency is improved with 18.1% for the second stage. The optimal operating recovery for the PES is between 80% and 90%. / MIng (Chemical Engineering), North-West University, Potchefstroom Campus, 2015

A gestão dos resíduos sólidos está se tornando prioridade tanto no sistema público como no privado. Considerando o tripé da sustentabilidade (social, ambiental e econômico), as indústrias vêm adotando a transformação dos resíduos em coprodutos como um negócio estratégico. Um exemplo é a indústria do aço. Na produção do aço em usina semi-integrada, utiliza-se pelo menos 70% de sucata de ferro e aço como matéria-prima. O grupo das sucatas de pós-consumo é o mais utilizado, devido à maior disponibilidade no mercado. Entretanto, este grupo de sucata possui alto teor de impurezas. A remoção destas impurezas geralmente é feita em um equipamento chamado Shredder , uma máquina trituradora de sucata. Os metais não ferrosos separados neste beneficiamento tem alto valor de mercado e são comercializados, e sobram os resíduos não metálicos que são chamados de Resíduos da Shredder. O foco deste trabalho foi a caracterização físico-química e a classificação de periculosidade destes resíduos, para identificação de aplicações viáveis. O trabalho foi realizado em uma Shredder situada no município de Iracemápolis, no Estado de São Paulo. No período de setembro a março de 2014, foram geradas, em média, 4.928,32t/mês de Resíduo da Shredder. Pelas características apresentadas, os Resíduos da Shredder são divididos em Fluf da Shredder e em Terra da Shredder. A Terra da Shredder apresentou características para potencial aplicação na construção civil, e o Fluf para recuperação energética, principalmente devido ao alto poder calorífico. O poder calorífico médio encontrado para o Fluf foi de 4.527,48 Kcal/Kg (PCI E PCS). Este valor é equivalente a combustíveis consolidados, como o carvão mineral brasileiro. Entretanto, devem ser tomadas precauções no gerenciamento desses resíduos para mantê-los classificados como não perigosos, bem como deve ser estudada tecnologia para remoção de organoclorados. / The waste management in Brazil and Worldwide is becoming a priority in any management system either private or public. Considering the triple bottom line (social, environmental and economical), the industry has adopted the transformation of wastes into byproducts as a strategic business. An example is the steel industry. Mini-mill process uses at least 70% of iron and steel scrap as its raw material. Iron and steel scrap post-consumer is the most widely used due to greater availability in the market. However, this kind of scrap contains high levels of impurities. The removal of these impurities is usually done in a device called Shredder. The nonferrous metals removed are commercialized because of high market value and the non-metallic remains are called the Shredder Residue. The focus of this work was the physicochemical characterization and the classification of hazards these wastes poses in order to identify possible applications. This work was performed in a Shredder located in Iracemápolis City, State of São Paulo. In the period of this work were generated in average 4.928, 32t/month of Shredder Residue. Due to the characteristic found this waste was divided in Fluff of Shredder and Sand of Shredder. The Sand of Shredder showed features for potential application in civil construction and Fluff for energetic recovery mainly because of its high heat value. The average heat value found was 4.527,48 Kcal/Kg (between HHV and LHV). This heat value is equivalent to consolidated fuel such as Brazilian mineral coal. But, precautions should be taken in the management of such wastes to keep them classified as non-hazardous as well as studies should be performed on ways of removing organochlorine compounds.

Research was conducted using algal biomass obtained from the surface of a secondary clarifier at Bridge City Wastewater Treatment Plant and subsequently sent through an electrochemical (EC) batch reactor at various concentrations. The first objective was to achieve maximum cell wall destruction electrochemically using the EC batch reactor and determine the optimal detention time and voltage/current relationship at which this occurred. The second objective was to subject two algal mediums to anaerobic digestion: the algal medium without electrochemical disinfection and the algal medium after disinfection. Every three days, for 12 days, total solids were measured from each apparatus to determine if cell destruction increased, decreased or did not change the consumption rate of algae by anaerobic bacteria. The consumption rate of algae is directly proportional to the production of methane, which can be used as a source of biofuel.

In this thesis, heat and moisture transfer between supply and exhaust air streams are investigated for a run-around system in which the coupling material is a desiccant coated solid that is transported between two exchangers. The finite difference method is used to solve the governing partial differential equations of the cross-flow heat exchangers in the supply and exhaust ducts. The outlet air properties are calculated for several inlet air operating conditions and desiccant properties. The accuracy of the heat transfer model is verified by comparing the simulations with well-known theoretical solutions for a single cross flow heat exchanger and a liquid coupled run-around system. The difference between the analytical predictions and the numerical model for sensible effectiveness for each exchanger and the run-around system were found to be less than 1% over a range of operating conditions. The model is also verified by modifying the boundary conditions to represent a counter flow energy wheel and comparing the calculated sensible, latent, and total effectiveness values with correlations in the literature. <p>Using the verified model for energy exchangers and the run-around energy recovery system, the sensible, latent and overall effectiveness are investigated in each exchanger and the run-around system during simultaneous heat and moisture transfer. The overall effectiveness of the run-around energy recovery system is dependent on the air flow rate, the solid desiccant flow rate, the desiccant properties, specific surface area, the size of each exchanger, and the inlet air operating conditions. The run-around system can achieve a high overall effectiveness when the flow rates and exchangers properties are properly chosen. Comparisons between the solid desiccant and salt solution run-around system effectiveness (Fan, 2005 and Fan et al, 2006) shows they are in good agreement. In a sensitivity study, the thickness of desiccant on the fibre is investigated in the solid run-around system. It was found that good performance is obtained with very thin desiccant coatings (1 or 2 micron). During the practical use of this system, a desiccant coated fibre could be inserted into very porous balls or cages that protect the desiccant coated fiber from mechanical wear. The performance sensitivity for this kind of run-around system is demonstrated.

In this thesis, several possible liquid desiccants (aqueous solutions of LiCl, LiBr, MgCl2 and CaCl2) are investigated to find the most appropriate working fluid to be used in a run-around membrane energy exchanger (RAMEE). The liquid desiccant is one of the main components of the RAMEE and indirectly conditions the outdoor ventilation air by using the energy of the exhaust air, significantly reducing the building energy consumption.<p> Numerical simulations, in this thesis, show that the total effectiveness of the RAMEE changes less than 0.5% when different salt solutions are used. However, the capital and operational costs of the RAMEE are significantly different for different desiccants. MgCl2 is the most inexpensive among the selected salt solutions and is followed by CaCl2, LiBr and LiCl. The price of a LiCl solution in the RAMEE is almost 20 times more than the price of MgCl2 solution. Different thermo-physical properties of the salt solutions result in different pumping energy consumptions for each specific salt solution. For example, the pumping energy consumption for a MgCl2 solution is 3.5 times more than for a LiBr solution in the RAMEE. The change in the volume of the liquid desiccant throughout a year is another characteristic which depends on the thermo-physical properties of the salt solution. Solutions with larger volume expansion require larger storage tanks and will experience longer transient delays. The difference between the volume expansions of different salt solutions is less than 5% of the total solution volume. MgCl2 solution expands more than 17% throughout a yearly operation of the system in Saskatoon.<p> Crystallization of the salt solution is another important parameter in the selection of the liquid desiccant. Simulations show that, for a specific indoor and outdoor operating condition the risk of crystallization is greatest for MgCl2, followed by CaCl2, LiCl and LiBr. The risk increases as the supply or exhaust airstreams become dryer. For a cross flow RAMEE with a total effectiveness of 55% (NTU=10 and Cr*=3) operating in a building with indoor RH of 50%, the critical outdoor humidity below which crystallization will begin to occur is 28% RH for MgCl2, 20% for CaCl2 and 0%RH for LiCl and LiBr. According to the simulations, all four investigated salt solutions can be used in North America (except the states of Nevada, Arizona, New Mexico and parts of Texas) with no risk of crystallization when the indoor humidity is 50% RH. However, with indoor humidity of 30% MgCl2 and CaCl2 solutions will have risk of crystallization for a large number of hours in a year in most of the central western United States. A mixture of 50% LiCl and 50% MgCl2 solution is suggested to be used when the cost-effective MgCl2 solution cannot be used due to crystallization issues. The price of this newly suggested mixture is 30% less than that of a pure LiCl solution and can be used in all North American climates with very small risk of crystallization.