Browsing by Subject "syngas"
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Item A Systematic Approach for the Design of Integrated Energy and Chemicals Production(2014-12-02) Noureldin, Mohamed MahmoudWith the tightening of the crude oil supply-demand gap, interest in energy independence, and global climate change concerns, attention has been directed to finding alternatives to crude oil. In particular, efforts have focused on alternative feedstock for liquid transportation fuels and chemicals production. The purpose of this work is to investigate the potential use of biomass and natural gas as alternative options to petroleum for liquid transportation fuels and chemicals production. From a broader perspective, this work explores the synthesis of integrated industrial complexes that can lead to various benefits including conservation of material and energy resources, reduction of environmental impact, improvement in capital productivity, increase in material utilization, and enhancement in natural-resource monetization. The fundamental research approach is a process systems approach. First the system is defined and investigated. This investigation is used to determine if the system is feasible through various criteria (economic, environmental, and social). Targeting techniques are used to reduce the number of options investigated. If it is determined that the system is feasible, opportunities for improvement are identified. If the system is not feasible, major issues are identified and potential prospects to achieve feasibility are investigated. Focus is directed to the major issues with the greatest impact on system feasibility. In this work, initial focus is directed to the production of synthetic liquid transportation fuels from biomass. This is followed by focus on intermediates which would facilitate the integration of multiple processing facilities. This understanding is used to synthesis an intra-process resource management framework. Finally the potential to use natural gas to mitigate CO2 emissions by chemically fixating the CO2 is investigated and results presented.Item Cyclone Performance for Reducing Biochar Concentrations in Syngas(2013-05-28) Saucier, David ShaneCotton gins have a readily available supply of biomass that is a by-product of cotton ginning. A 40 bph - cotton gin processing stripped cotton must manage 2,600 to 20,000 tonnes of cotton gin trash (CGT) annually. CGT contains approximately 16.3 MJ/kg (7000 Btu/lb.). CGT has the potential to serve as a renewable energy source. Gasification of biomasses such as CGT can offer processing facilities the opportunity to transform their waste biomass into electricity. The gasification of CGT yields 80% synthesis gas (syngas) and 20% biochar. The concentration of biochar in the syngas needs to be reduced prior to the direct fueling of an internal combustion engine driving a generator for electricity production. It was estimated that direct fueling of an internal combustion engine with syngas to drive the generator to produce electricity would cost $1M per megawatt (MW). In contrast, a 1MW system that consists of a boiler and steam turbine would cost $2M/MW. The current provisional patent for the TAMU fluidized bed gasification (FBG) unit uses a 1D2D and 1D3D cyclone for the removal of biochar. A cyclone test stand was designed and constructed to evaluate cyclone capture efficiencies of biochar. A statistical experiment design was used to evaluate cyclone performances for varying concentrations of biochar. A total of 24 tests for the 1D2D and 36 tests for the 1D3D cyclone were conducted at ambient conditions. Average collection efficiency for the 1D2D cyclone was 96.6% and 96.9% for the 1D3D cyclone. An analysis on the cyclone?s pressure drop was performed to compare the change in pressure drop from air only passing through the cyclone and when the cyclones are loaded with biochar. The average change in pressure drop for the 1D2D cyclone was a decrease of 74%, and the average change in pressure drop for the 1D3D cyclone was a decrease of 36%. An economic feasibility study was conducted to determine the price per kWh to produce electricity for a CGT fueled internal combustion engine power plant (ICPP) and a boiler and steam turbine power plant (SPP). The simulated cotton gin is a 40 bph rated facility operating for 2,000 hours a season (200% utilization) processing stripped cotton that yields approximately 180 kg/bale (400 lbs/bale) of CGT. Revenues consist of the electricity and natural gas expenses incurred during the ginning season, along with the extra electricity produced and sold back to the utility company at the whole price. Loan payments and operating costs include labor, maintenance, taxes, and insurance. Labor costs, the selling price of electricity and biochar are varied in the economic model. The ICPP has a NPV of $1,480,000, and the SPP has a NPV of -$160,000, under the base assumptions. The sensitivity analysis resulted in the selling price of electricity as having the largest change on the NPV for both of the power plants. The average predicted purchase price of electricity is $0.10/kWh for the twenty year simulation. The average price to produce electricity, with no source of revenue generation for the ICPP is $0.20/kWh and $0.26/kWh for the SPP.Item Measurement of Turbulent Flame Speeds of Hydrogen and Natural Gas Blends (C1-C5 Alkanes) using a Newly Developed Fan-Stirred Vessel(2014-05-06) Ravi, SankaranarayanaA fan-stirred flame speed vessel was developed at Texas A&M University to conduct turbulent combustion studies. Four high-speed impellers were installed in a central-symmetric pattern at the central circumference of an existing cylindrical laminar flame bomb. The fans generated homogeneous and isotropic turbulence with negligible mean flow (< 10% u?) at the vessel center, and flames up to 12.7 cm in diameter can be measured. The fan designs were optimized using particle image velocimetry inside a Plexiglas model of the vessel. The uniformity of the flow fields was verified using spatial uniformity maps, two-point correlations, and the energy spectra. Additionally, the capability to independently vary the intensity level and the integral length scale was developed. Where the former changed with fan speeds, increasing the blade pitch angle of the impeller decreased the integral length scale. Turbulent flame speeds of fuels that are of topical interest to gas turbines were measured in the fan-stirred bomb. Schlieren photography was used to visualize the flame growth under constant-pressure conditions, and the captured images were processed using an edge-detection code developed in-house. The equivalent-circle-area method was used to determine the flame radii. The shot-to-shot variability was minimal, which resulted in a low experimental scatter close to 10 cm/s. The flame speeds increased with radius due to flame acceleration. Effective turbulent intensity levels were estimated which increased progressively with flame radius. A systematic approach was followed to determine the effects of hydrogen addition on the turbulent displacement speeds of alkanes (C1-C3). Particularly, a natural gas surrogate (NG2) containing large amounts of C2+ hydrocarbons (>20%) was studied. Turbulent displacements were higher for alkane mixtures with Lewis number below unity than those with Le>1. NG2 and methane gave near-identical turbulent displacement speeds consistent with the laminar flame speed trends. Similar trends in displacement speeds were observed for blends of NG2/H_(2) and CH_(4)/H_(2), thus validating the newly established experimental technique. Additionally, turbulent flame speeds of hydrogen and a generic, high-hydrogen-content syngas blend (50:50 H_(2):CO) were studied. The wide range of laminar flame speeds explored herein revealed significantly different flame surface features between the various regimes of turbulent combustion.