The Experts below are selected from a list of 189 Experts worldwide ranked by ideXlab platform
Lawrence M. Pratt - One of the best experts on this subject based on the ideXlab platform.
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Brown Grease pyrolysis under pressure: Extending the range of reaction conditions and hydrocarbon product distributions
Fuel, 2021Co-Authors: Lawrence M. Pratt, Jihyun Kim, Dequan XiaoAbstract:Abstract Pyrolysis of Brown Grease to hydrocarbon products was performed in a pressure reactor. Compared to our previous work at atmospheric pressure, higher reaction temperatures could be achieved. These resulted in shorter reaction times, reduced formation of undesirable ketone byproducts, and a higher percentage of the most valuable light hydrocarbon products. Higher temperatures did, however, increase the percentage of gas products at the expense of liquid products. The major liquid products are alkanes ranging from heptane to heptadecane, with smaller amounts of cycloalkanes, and in some cases, aromatic compounds.
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Mechanistic Investigation of the Pyrolysis of Brown Grease
Journal of Chemistry, 2020Co-Authors: Mansour H. Almatarneh, Imarat Y. Alnemrat, Reema A. Omeir, Lawrence M. Pratt, Thi Xuan Thi Luu, Minh Bui, Dickens Saint HilaireAbstract:The conversion of Brown Grease using pyrolysis reactions represents a very promising option for the production of renewable fuels and chemicals. Brown Grease forms a mixture of alkanes, alkenes, and ketones at a temperature above 300°C at atmospheric pressure. This work is a computational study of the detailed reaction mechanisms of Brown Grease pyrolysis using DFT methodology. Prior experimental investigations confirmed product formation consistent with a set of radical reactions with CO2 elimination, as well as ketone by product formation, CO forming reactions, and formation of alcohols and aldehydes as minor byproducts. In this work, computational quantum chemistry was used to explore these reactions in greater detail. Particularly, a nonradical pathway formed ketone byproducts via the ketene, which we refer to as Pathways A1 and A2. Radical formation by thermal decomposition of unsaturated fatty acids initiates a set of reactions which eliminate CO2, regenerating alkyl radicals leading to hydrocarbon products (Pathway B). A third pathway (Pathway C) is an alternative set of radical reactions, resulting in decarbonylation and formation of minor byproducts. The results of the calculations are in good agreement with recent experimental studies.
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Thermal Transformation of Palm Waste to High-Quality Hydrocarbon Fuel
Fuels, 2020Co-Authors: Chai Yu Kuan, Yoke-leng Sim, Joel Strothers, Mark Low Yoong Neng, Yu-bin Chan, Lawrence M. PrattAbstract:Empty fruit bunches (EFB) are waste products in the palm oil industry. Upon pressing of EFB, a liquor is produced which contains low grade fats, oils, and Greases (FOG). These are the least valuable products of palm oil production, and are often discarded as waste. It is shown here that the EFB pressed liquor can be thermally transformed at or below 350 °C to produce a series of hydrocarbons in the range of kerosene and diesel fuel. This is distinctly different from other studies of biofuels from palm oil, which were based entirely on biodiesel (fatty acid methyl ester (FAME)) and biogas production. Furthermore, this transformation takes place without addition of an external catalyst, as was shown by comparison to reactions with the potential Lewis acid catalysts, ferric sulfate, and molecular sieves. The product distribution is similar to that obtained from Brown Grease, another waste FOG stream obtained from the sewage treatment industry, although the products from palm oil waste are less sensitive to reaction conditions.
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Biodiesel fuel production from Brown Grease produced by wastewater treatment plant: Optimization of acid catalyzed reaction conditions
Journal of Environmental Chemical Engineering, 2020Co-Authors: Mohammed J.k. Bashir, Dickens St. Hilaire, Lai Peng Wong, Jihyun Kim, Oluwaseun Salako, Mith Jennifer Jean, Remi Adeyemi, Serena James, Tia Foster, Lawrence M. PrattAbstract:Abstract Periodic spikes in crude oil prices have led to a need in alternative energy sources. A major potential source of biodiesel feedstocks is Brown Grease, a byproduct of wastewater treatment. A recent Brown Grease sample from this contained 60 % FOG (fats, oils, and Greases), 25 % water, and 15 % biosolids by mass. This study is focused optimizing the reaction conditions (i.e., quantities of Methanol, Sulfuric Acid, Fe2(SO4)3, and time) to maximize the yield of esters, with minimal residual free fatty acid (FFA), in the shortest residence time. Response Surface Methodology (RSM) was used to evaluate the correlation between the process variable and the response. The significance of quadratic model of each response was determined by analysis of variance, where all models indicated sufficient significance with p-value
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Hydrocarbon fuels from Brown Grease: Moving from the research laboratory toward an industrial process
2017Co-Authors: Lawrence M. Pratt, Travis Pinnock, Beatrice Bacolod, Zhuo Biao Cai, Dickens Saint Hilaire, Joel Strothers, Yoke-leng SimAbstract:Brown Grease is a generic term for the oily solids and semi-solids that accumulate in the sewer system and in sewage treatment plants. It has previously been shown that Brown Grease undergoes pyrolysis to form a homologous series of alkanes and 1-alkenes between 7 and 17 carbon atoms, with smaller amounts of higher hydrocarbons and ketones up to about 30 carbon atoms. The initial study was performed in batch mode on a scale of up to 50 grams of starting material. However, continuous processes are usually more efficient for large scale production of fuels and commodity chemicals. This work describes the research and development of a continuous process. The first step was to determine the required reactor temperature. Brown Grease consists largely of saturated and unsaturated fatty acids, and they react at different rates, and produce different products and intermediates. Intermediates include ketones, alcohols, and aldehydes, and Fe(III) ion catalyzes at least some of the reactions. By monitoring the pyrol...
Steven O. Salley - One of the best experts on this subject based on the ideXlab platform.
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Catalytic Conversion of Brown Grease to Green Diesel via Decarboxylation over Activated Carbon Supported Palladium Catalyst
Industrial & Engineering Chemistry Research, 2013Co-Authors: Elvan Sari, Craig Dimaggio, Manhoe Kim, Steven O. SalleyAbstract:The decarboxylation of Brown Grease (BG) to green diesel hydrocarbons over a 5 wt % Pd/C catalyst was investigated in semibatch and batch reactors. Catalytic deoxygenation of BG under H2–Ar occurs ...
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performance of heterogeneous zro2 supported metaloxide catalysts for Brown Grease esterification and sulfur removal
Bioresource Technology, 2011Co-Authors: Manhoe Kim, Craig Dimaggio, Huali Wang, Shuli Yan, Steven O. SalleyAbstract:In order to achieve a viable biodiesel industry, new catalyst technology is needed which can process a variety of less expensive waste oils, such as yellow Grease and Brown Grease. However, for these catalysts to be effective for biodiesel production using these feedstocks, they must be able to tolerate higher concentrations of free fatty acids (FFA), water, and sulfur. We have developed a class of zirconia supported metaloxide catalysts that achieve high FAME yields through esterification of FFAs while simultaneously performing desulfurization and de-metallization functions. In fact, methanolysis, with the zirconia supported catalysts, was more effective for desulfurization than an acid washing process. In addition, using zirconia supported catalysts to convert waste Grease, high in sulfur content, resulted in a FAME product that could meet the in-use ASTM diesel fuel sulfur specification (<500 ppm). Possible mechanisms of desulfurization and de-metallization by methanolysis were proposed to explain this activity.
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Performance of heterogeneous ZrO2 supported metaloxide catalysts for Brown Grease esterification and sulfur removal.
Bioresource Technology, 2010Co-Authors: Craig Dimaggio, Steven O. Salley, Huali Wang, K. Y. Simon NgAbstract:In order to achieve a viable biodiesel industry, new catalyst technology is needed which can process a variety of less expensive waste oils, such as yellow Grease and Brown Grease. However, for these catalysts to be effective for biodiesel production using these feedstocks, they must be able to tolerate higher concentrations of free fatty acids (FFA), water, and sulfur. We have developed a class of zirconia supported metaloxide catalysts that achieve high FAME yields through esterification of FFAs while simultaneously performing desulfurization and de-metallization functions. In fact, methanolysis, with the zirconia supported catalysts, was more effective for desulfurization than an acid washing process. In addition, using zirconia supported catalysts to convert waste Grease, high in sulfur content, resulted in a FAME product that could meet the in-use ASTM diesel fuel sulfur specification (
Peter W. Hart - One of the best experts on this subject based on the ideXlab platform.
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biogas production from Brown Grease using a pilot scale high rate anaerobic digester
Renewable Energy, 2014Co-Authors: Simon A. Evers, Pengchong Zhang, Chejen Lin, James Liu, Pruek Pongprueksa, Peter W. HartAbstract:Food wastes are typically disposed of in landfills for convenience and economic reasons. However, landfilling food wastes increases the organic content of leachate and the risk of soil contamination. A sound alternative for managing food wastes is anaerobic digestion, which reduces organic pollution and produces biogas for energy recovery. In this study, anaerobic digestion of a common food waste, Brown Grease, was investigated using a pilot-scale, high-rate, completely-mixed digester (5.8 m3). The digestibility, biogas production and the impact of blending of liquid waste streams from a nearby pulp and paper mill were assessed. The 343-day evaluation was divided into 5 intensive evaluation stages. The organic removal efficiency was found to be 58 ± 9% in terms of COD and 55 ± 8% in terms of VS at a hydraulic retention time (HRT) of 11.6 ± 3.8 days. The removal was comparable to those found in organic solid digesters (45–60%), but at a much shorter HRT. Methane yield was estimated to be 0.40–0.77 m3-CH4@STP kg-VSremoved−1, higher than the typical range of other food wastes (0.11–0.42 m3-CH4@STP kg-VSremoved−1), with a mean methane content of 75% and <200 ppm of hydrogen sulfide in the biogas. The blending of selected liquid wastes from a paper mill at 10 vol% of Brown Grease slurry did not cause significant reduction in digester performance. Using a pseudo-first-order rate law, the observed degradation constant was estimated to be 0.10–0.19 d−1 compared to 0.03–0.40 d−1 for other organic solids. These results demonstrate that Brown Grease is a readily digestible substrate that has excellent potential for energy recovery through anaerobic digestion.
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Biogas production from Brown Grease using a pilot-scale high-rate anaerobic digester
Renewable Energy, 2014Co-Authors: Pengchong Zhang, Simon A. Evers, Chejen Lin, James Liu, Pruek Pongprueksa, Peter W. HartAbstract:Abstract Food wastes are typically disposed of in landfills for convenience and economic reasons. However, landfilling food wastes increases the organic content of leachate and the risk of soil contamination. A sound alternative for managing food wastes is anaerobic digestion, which reduces organic pollution and produces biogas for energy recovery. In this study, anaerobic digestion of a common food waste, Brown Grease, was investigated using a pilot-scale, high-rate, completely-mixed digester (5.8 m3). The digestibility, biogas production and the impact of blending of liquid waste streams from a nearby pulp and paper mill were assessed. The 343-day evaluation was divided into 5 intensive evaluation stages. The organic removal efficiency was found to be 58 ± 9% in terms of COD and 55 ± 8% in terms of VS at a hydraulic retention time (HRT) of 11.6 ± 3.8 days. The removal was comparable to those found in organic solid digesters (45–60%), but at a much shorter HRT. Methane yield was estimated to be 0.40–0.77 m3-CH4@STP kg-VSremoved−1, higher than the typical range of other food wastes (0.11–0.42 m3-CH4@STP kg-VSremoved−1), with a mean methane content of 75% and
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Commissioning of a biogas pilot plant: From Brown Grease to paper mill-generated organic wastes
April 2012, 2012Co-Authors: Ricardo B. Santos, Peter W. Hart, Gary W. Colson, Simon A. Evers, Dennis EversAbstract:The MeadWestvaco mill in Evadale, TX, USA, in conjunction with VOW Resources LLC, has constructed and commissioned a green biogas skid-mounted pilot plant to evaluate the potential of various organic waste streams to produce high-quality biogas. It is the fourth plant in the world incorporating this technical approach to biogas production. At initial startup, the plant used cow manure as organic feedstock. To commission the plant for verifying the VOW bioaugmentation process, the transition was made to using Brown Grease. After the Brown Grease commissioning trials are completed, the plant will be transitioned to a number of paper mill-generated organic wastes to acquire the design parameters and engineering data that will aid in construction of a full-scale biogas facility.
Pengchong Zhang - One of the best experts on this subject based on the ideXlab platform.
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biogas production from Brown Grease using a pilot scale high rate anaerobic digester
Renewable Energy, 2014Co-Authors: Simon A. Evers, Pengchong Zhang, Chejen Lin, James Liu, Pruek Pongprueksa, Peter W. HartAbstract:Food wastes are typically disposed of in landfills for convenience and economic reasons. However, landfilling food wastes increases the organic content of leachate and the risk of soil contamination. A sound alternative for managing food wastes is anaerobic digestion, which reduces organic pollution and produces biogas for energy recovery. In this study, anaerobic digestion of a common food waste, Brown Grease, was investigated using a pilot-scale, high-rate, completely-mixed digester (5.8 m3). The digestibility, biogas production and the impact of blending of liquid waste streams from a nearby pulp and paper mill were assessed. The 343-day evaluation was divided into 5 intensive evaluation stages. The organic removal efficiency was found to be 58 ± 9% in terms of COD and 55 ± 8% in terms of VS at a hydraulic retention time (HRT) of 11.6 ± 3.8 days. The removal was comparable to those found in organic solid digesters (45–60%), but at a much shorter HRT. Methane yield was estimated to be 0.40–0.77 m3-CH4@STP kg-VSremoved−1, higher than the typical range of other food wastes (0.11–0.42 m3-CH4@STP kg-VSremoved−1), with a mean methane content of 75% and <200 ppm of hydrogen sulfide in the biogas. The blending of selected liquid wastes from a paper mill at 10 vol% of Brown Grease slurry did not cause significant reduction in digester performance. Using a pseudo-first-order rate law, the observed degradation constant was estimated to be 0.10–0.19 d−1 compared to 0.03–0.40 d−1 for other organic solids. These results demonstrate that Brown Grease is a readily digestible substrate that has excellent potential for energy recovery through anaerobic digestion.
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Biogas production from Brown Grease using a pilot-scale high-rate anaerobic digester
Renewable Energy, 2014Co-Authors: Pengchong Zhang, Simon A. Evers, Chejen Lin, James Liu, Pruek Pongprueksa, Peter W. HartAbstract:Abstract Food wastes are typically disposed of in landfills for convenience and economic reasons. However, landfilling food wastes increases the organic content of leachate and the risk of soil contamination. A sound alternative for managing food wastes is anaerobic digestion, which reduces organic pollution and produces biogas for energy recovery. In this study, anaerobic digestion of a common food waste, Brown Grease, was investigated using a pilot-scale, high-rate, completely-mixed digester (5.8 m3). The digestibility, biogas production and the impact of blending of liquid waste streams from a nearby pulp and paper mill were assessed. The 343-day evaluation was divided into 5 intensive evaluation stages. The organic removal efficiency was found to be 58 ± 9% in terms of COD and 55 ± 8% in terms of VS at a hydraulic retention time (HRT) of 11.6 ± 3.8 days. The removal was comparable to those found in organic solid digesters (45–60%), but at a much shorter HRT. Methane yield was estimated to be 0.40–0.77 m3-CH4@STP kg-VSremoved−1, higher than the typical range of other food wastes (0.11–0.42 m3-CH4@STP kg-VSremoved−1), with a mean methane content of 75% and
Craig Dimaggio - One of the best experts on this subject based on the ideXlab platform.
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Catalytic Conversion of Brown Grease to Green Diesel via Decarboxylation over Activated Carbon Supported Palladium Catalyst
Industrial & Engineering Chemistry Research, 2013Co-Authors: Elvan Sari, Craig Dimaggio, Manhoe Kim, Steven O. SalleyAbstract:The decarboxylation of Brown Grease (BG) to green diesel hydrocarbons over a 5 wt % Pd/C catalyst was investigated in semibatch and batch reactors. Catalytic deoxygenation of BG under H2–Ar occurs ...
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performance of heterogeneous zro2 supported metaloxide catalysts for Brown Grease esterification and sulfur removal
Bioresource Technology, 2011Co-Authors: Manhoe Kim, Craig Dimaggio, Huali Wang, Shuli Yan, Steven O. SalleyAbstract:In order to achieve a viable biodiesel industry, new catalyst technology is needed which can process a variety of less expensive waste oils, such as yellow Grease and Brown Grease. However, for these catalysts to be effective for biodiesel production using these feedstocks, they must be able to tolerate higher concentrations of free fatty acids (FFA), water, and sulfur. We have developed a class of zirconia supported metaloxide catalysts that achieve high FAME yields through esterification of FFAs while simultaneously performing desulfurization and de-metallization functions. In fact, methanolysis, with the zirconia supported catalysts, was more effective for desulfurization than an acid washing process. In addition, using zirconia supported catalysts to convert waste Grease, high in sulfur content, resulted in a FAME product that could meet the in-use ASTM diesel fuel sulfur specification (<500 ppm). Possible mechanisms of desulfurization and de-metallization by methanolysis were proposed to explain this activity.
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Performance of heterogeneous ZrO2 supported metaloxide catalysts for Brown Grease esterification and sulfur removal.
Bioresource Technology, 2010Co-Authors: Craig Dimaggio, Steven O. Salley, Huali Wang, K. Y. Simon NgAbstract:In order to achieve a viable biodiesel industry, new catalyst technology is needed which can process a variety of less expensive waste oils, such as yellow Grease and Brown Grease. However, for these catalysts to be effective for biodiesel production using these feedstocks, they must be able to tolerate higher concentrations of free fatty acids (FFA), water, and sulfur. We have developed a class of zirconia supported metaloxide catalysts that achieve high FAME yields through esterification of FFAs while simultaneously performing desulfurization and de-metallization functions. In fact, methanolysis, with the zirconia supported catalysts, was more effective for desulfurization than an acid washing process. In addition, using zirconia supported catalysts to convert waste Grease, high in sulfur content, resulted in a FAME product that could meet the in-use ASTM diesel fuel sulfur specification (
