Source: OKLAHOMA STATE UNIVERSITY submitted to NRP
IMPROVING GASIFICATION CONVERSION SYSTEMS IN THE PRODUCTION OF BIOENERGY, BIOFUELS AND BIOPRODUCTS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
1003832
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Oct 2, 2014
Project End Date
Sep 30, 2019
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
OKLAHOMA STATE UNIVERSITY
(N/A)
STILLWATER,OK 74078
Performing Department
Biosystems & Ag Engineering
Non Technical Summary
Recent initiatives at the national level have demonstrated a strong commitment to developing energy sources and industrial products from biomass. Oklahoma has a great potential in supplying significant quantities of biomass in the form of dedicated energy crops, crop residues and municipal solid wastes. One of the more recognized bioconversion pathways in utilizing biomass is gasification which produces a gas that can be injected into an internal combustion engine for the production of power or further processed via fermentation to produce fuels and chemicals.The overall goal of this research is to address key issues limiting the commercial application of OSU developed biomass gasification technologies. The primary issues are gasifier scale-up, materials handling and producer gas cleaning. Initial emphasis will be on the scale-up of OSU's patented downdraft gasifier that will be used as a component of a self-contained renewable electricity generation system. A materials handling system will be developed that is capable of delivering a variety of feedstocks and a specified particle size to the gasifier. An oil based wet scrubbing system will be developed capable of reducing producer gas contaminant loading to a level specified by the downstream application.
Animal Health Component
50%
Research Effort Categories
Basic
(N/A)
Applied
50%
Developmental
50%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
5111629202050%
5111630202050%
Knowledge Area
511 - New and Improved Non-Food Products and Processes;

Subject Of Investigation
1629 - Perennial grasses, other; 1630 - Summer annual grasses;

Field Of Science
2020 - Engineering;
Goals / Objectives
The overall goal in the proposed research is to address key issues limiting the commercial application of OSU developed biomass gasification technologies. The primary issues are gasifier scale-up, materials handling and producer gas cleaning. Specific objectives for this study are:Objective 1: Design and evaluate performance of small-scale gasifiers.Objective 2: Develop a materials processing system capable of delivering a variety of feedstocks to a gasifier.Objective 3: Develop an oil based wet scrubbing system capable of reducing contaminant loading allowed by the downstream application.
Project Methods
Research will be conducted at various laboratories within Biosystems and Agricultural Engineering (BAE) Department, Oklahoma State University. The fabrication of the scaled-up downdraft gasifier will occur in the BAE Laboratory. Gasifier testing will occur in the OSU Gasification Laboratory. Quality of feedstocks and producer gases will be analyzed using equipment at the Bioenergy Laboratory. These equipment include bomb calorimeter to measure energy content of biomass, gas chromatography (GC) connected with Mass Spectrometer (MS) for measurement of gas and volatiles composition, and a tar sampling system to sample and quantify tars in the producer gas. It is important to note that the scaled-up downdraft gasifier research results will be applicable to other gasifier types and sizes.Research plan for each objectiveObjective 1: Initial emphasis will be on the scale-up of OSU's patented downdraft gasifier. This gasifier will be used as a component of a self-contained renewable electricity generation system. The gasifier design will be based on a combination of simple thermochemical models and personal experience. The design and development will be an iterative process followed by extensive testing. Once satisfactory gasifier performance is achieved, as determined through several parameters including carbon conversion efficiency, the unit will be automated to allow continuous input and output monitoring. During design and development process, the gasifier will be modeled using Aspen Plus to better understand how changes in feedstocks and gasifier operation impact producer gas quantity and quality. Experience gained during the scale-up process will be used in the design of other gasifier reactors, including a significantly larger version of the OSU patented downdraft unit.Objective 2: The existing downdraft gasifier has the ability of accepting low bulk density feedstocks that are processed to less than 2.5 cm in length. The scaled-up gasifier developed as part of Objective 1 should be able to efficiently use larger particle size material. As such, the materials handling system will be modified to produce and deliver larger particle sizes. The system will be designed to allow several feedstock streams, including MSW. Testing will be conducted to determine the acceptable range of selected feedstocks and feedstock mixture particle sizes that can be supplied to and converted in the gasifier. Materials handling study results will be applied to other gasifier types and sizes.Objective 3: The recently completed study on using vegetable oils to remove producer gas tars provided proof of concept. This study was performed using two oils, i.e., soybean and canola. Using the existing bench scale wet scrubbing system, other oils will be tested to determine their effectiveness in removing tar compounds. The bench scale scrubber was operated as a batch system; whereas, in commercial applications, the waste solvent stream is regenerated using a stripping column before being routed back to the absorption column. Therefore, a stripping column will be designed and tested at bench scale. The results of the studies on other oils and the addition of the stripping column will be used to enhance the current process model. Ultimately, the oil based wet scrubbing system will be designed, fabricated and tested at pilot scale.

Progress 10/02/14 to 09/30/19

Outputs
Target Audience:Scientists, engineers, graduate students, postdoctoral fellows, product developers, and the public. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Training and professional development were provided to an undergraduate and graduate student. How have the results been disseminated to communities of interest?Gasifier system and engine performance data were shared with potential investors who could commercialize this technology. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Modeling plasma gasification Plasma gasification is a promising technology in converting municipal solid waste (MSW) into high-quality producer gas. However, plasma gasification typically requires high-energy input and temperature that has hindered adoption. A modeling study was performed to evaluate the performance of a low-temperature (below 2,500oC) plasma gasification system in converting MSW into producer gas. The model was employed at reactor temperatures of 1,500, 2,000, and 2,500oC to assess effects on producer gas composition and system performance with air as the plasma medium. At plasma temperatures of 1,500, 2,000, and 2,500oC, the model generated producer gas lower heating values of 5.41, 6.02, and 6.45 MJ/Nm3, respectively, with energy inputs of 2,358, 2,775, and 3,245 kW per kg/s of MSW, respectively, and plasma gasification efficiencies of 49.6, 49.2, and 48.9%, respectively. In comparison to conventional non-plasma air gasification of MSW, producer gas generated from low-temperature plasma gasification contained higher concentrations of hydrogen and carbon monoxide, resulting in higher heating values of the producer gas. Tar reduction in producer gas Reducing tar concentrates in producer gas is a major challenge. A heat exchanger and vegetable oil bubbling system was designed and tested for biomass-generated producer gas cooling and cleaning. The fully enclosed heat exchanger contained water at 15oC. Producer gas flow rate was set at 35 m3/s. Using canola oil, the bubbler was tested at 70 and 100 mm oil depths and 5 and 10 mm producer gas bubble sizes to determine the effect of tar removal. The results showed that tar removal efficiency was significantly affected by oil depth and bubble size; however, the interaction between bubble size and oil depth was not significant. About 60% of tars were removed by the heat exchanger, while 96% of the remaining tars were removed by the oil bubbler when used in series with the heat exchanger. Overall, tar reduction efficiency of 98.5% was achieved with the heat exchanger plus oil bubbler having oil depth of 100 mm and producer gas bubble size of 5 mm.

Publications

  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Indrawan, N., S. Mohammad, A. Kumar, R. L. Huhnke. 2019. Modeling low temperature plasma gasification of municipal solid waste. Environmental Technology & Innovation. 15:1-12.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Thapa, S., N. Indrawan, P. R. Bhoi, A. Kumar, R. L. Huhnke. 2019. Tar reduction in biomass syngas using heat exchanger and vegetable oil bubbler. Energy. 175:402-409.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Kumar, A., S. Thapa, N. Indrawan, R.L. Huhnke. Non-thermal plasma (NTP) for syngas clean-up and reforming. S-1075: Multistate Committee Annual Meeting and Symposium on Science and Technology Driving Bioeconomy. Golden, CO. Jul 29-30, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Indrawan, N., P. R. Bhoi, A. Kumar, R. L. Huhnke. Mobile-scale power generation from MSW and switchgrass: Gasification, engine power generation and engine emission performance. 2018 Thermal & Catalytic Sciences Symposium (TCS), Auburn, AL Oct 8-10, 2018.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Tshikesho, R. S., A. Kumar, R. L. Huhnke, A. Apblett. 2019. Catalytic Co-Pyrolysis of Red Cedar with Methane to Produce Upgraded Bio-oil. Bioresource Technology. 285:1-8.


Progress 10/01/17 to 09/30/18

Outputs
Target Audience:Scientists, engineers, graduate students, postdoctoral fellows, product developers, and the public. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Training and professional development were provided to graduate students, who presented their works at local seminars. How have the results been disseminated to communities of interest?Gasifier and engine performance data were shared with potential investors, who expressed interest in moving this technology to market. What do you plan to do during the next reporting period to accomplish the goals?Testing of the scaled-up downdraft gasifier will continue using municipal solid waste and other biomass resources to further enhance performance and operation reliability. Modifications will be incorporated as funding permits. Research will continue on the development of a low-technology syngas cleaning system.

Impacts
What was accomplished under these goals? Syngas Generated from Co-gasification Municipal solid waste (MSW) was mixed with switchgrass and co-gasified using Oklahoma State University's patented 60-kW downdraft gasifier. The general composition of the MSW was: food (14.6%), paper (27%), yard trimmings (13.5%), plastics (12.8%), metals (9.1%), rubber, leather and textiles (9%), wood (6.2%), and other (7.8%). Proximate analysis (weight %, dry basis) showed that MSW consisted of 77.5% volatile matter, 8.7% fixed carbon and 13.7% ash, and had 4% moisture content (wet basis). Switchgrass consisted of 78.6% volatile matter, 17.5% fixed carbon and 3.9% ash, and had 8% moisture content. Ultimate analysis (weight %, dry basis) showed carbon, hydrogen, oxygen, and nitrogen to be 50.7%, 6.1%, 29.1%, and 0.14%, respectively, for MSW, while switchgrass was 49.6%, 5.7%, 40.4% and 0.30%, respectively. Feedstock was gasified at 0, 20 and 40% co-gasification ratios (CGRs), which is the ratio of MSW content in the feedstock mixture. Maximum temperatures in the reactor's combustion zone ranged from 700-900oC with an average temperature of 800oC. Syngas was cleaned using a cyclone separator and wet-scrubbed using an acetone-water mixture. The maximum heating value of syngas were 6.91, 7.74, and 6.78 MJ/Nm3 for CGRs of 0, 20, and 40%, respectively. Engine Performance A 10-kWe natural gas-fired internal combustion engine was modified so that generated syngas could be used as the fuel. Power de-rating of about 28% was observed when the engine operated on syngas as compared to natural gas. The engine achieved a maximum load of 5 kW on syngas; whereas, a maximum load of 7 kW was measured on natural gas. Type of gaseous fuel (syngas generated from the different CGRs) and loads had significant effects on electrical efficiency. However, the interaction between fuel type and load variation was not significantly different. The electrical efficiency increased with increasing loads. At the maximum load (5 kW), electrical efficiencies of 22, 20, and 19.5 were achieved when the engine operated on CGRs of 0, 20, and 40%, respectively. Engine Emissions CO, NOx, SO2 and CO2 emissions decreased with increasing load, while hydrocarbon (HC) emission increased with increasing load. CO, NOx, and CO2 emissions decreased, while HC and SO2 emissions increased with increasing CGR. For example, at CGRs of 0, 20, and 40%, the CO emissions decreased from 20,000, 16,500, and 16,000 ppm, respectively, at the initial load to 5,500, 4,800, and 2,900 ppm, respectively, at the maximum load. At the 40% CGR, CO, NOx, SO2, CO2, and HC emissions were 2,900, 4, 34, 33,800 and 88 ppm, respectively, at the maximum load.

Publications

  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Thapa, S., P.R. Bhoi, A. Kumar, and R.L. Huhnke. 2017. Effects of syngas cooling and biomass filter medium on tar removal. Energies. 10(3), 349; doi:10.3390/en10030349.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Bhoi, P.R., R.L. Huhnke, A. Kumar, N. Indrawan and S. Thapa. 2018. Co-gasification of municipal solid waste and biomass in a commercial scale downdraft gasifier. Energy. 163:513-518; https://doi.org/10.1016/j.energy.2018.08.151.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Bhoi, P.R., R.L. Huhnke, A. Kumar, S. Thapa and N. Indrawan. 2018. Scale-up of a downdraft gasifier system for commercial scale mobile power generation. Renewable Energy. 118:25-33; doi.org/10.1016/j.renene.2017.11.002.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Indrawan, N., S. Thapa, P.R. Bhoi, R.L. Huhnke and A. Kumar. 2018. Electricity power generation from co-gasification of municipal solid wastes and biomass: Generation and emission performance. Energy 162:764-775.


Progress 10/01/16 to 09/30/17

Outputs
Target Audience:Scientists, engineers, graduate students, postdoctoral associates, product developers, and the general public. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Training plus professional development were provided to graduate students and postdoctoral researcher. Graduate students and postdoctoral researcher presented their works at local seminars and an international conference. How have the results been disseminated to communities of interest?Gasifier performance was shared with potential investors, who expressed an interestin moving this technology to market. What do you plan to do during the next reporting period to accomplish the goals?Testing of the scaled-up downdraft gasifier will continue using municipal solid waste and other biomass resources to further enhance performance and to identify additional modifications aimed at enhancing operation reliability plus improving syngas quality and quantity. Modifications will be incorporated as funding permits. Research will continue on the development of a low-technology syngas cleaning system,

Impacts
What was accomplished under these goals? Scaled-up Gasifier Performance A feasibility study using municipal solid waste (MSW) as a co-gasification feedstock with switchgrass was carried out using OSU's downdraft gasifier (100 kg biomass per hour). MSW was in pellet form and had a higher heating value (HHV) of 19MJ/kg, while chopped switchgrass had a HHV of 15MJ/kg. The effect of the feedstock on syngas quality and quantity by varying the content of MSWwas studied at 0, 20, and 40% co-gasification ratios (CGR); this ratio is the MSW content in the MSW and switchgrass mixture. At a CGR of 60%, agglomeration of ash was observed during gasification, resulting in the 60% CGR not being included in the study. Results showed that performance of CGR of 20 and 40% are comparable to switchgrass gasification (0% CGR). At CGR of 20 and 40%, CO and H2 generated were 12.6 and 14.1%, and 8.6 and 10.0%, respectively. The calorific value of the syngas varied from 6.5 to 7.0 MJ/Nm3 and hot and cold gas efficiencies varied from 51 to 60% and 55 to 64%, respectively, at an average equivalence ratio of 0.20. Engine Performance A 10-kWe natural gas fired internal combustion engine was modified so that syngas could be used as the fuel. A slipstream of syngas from the scaled-up gasifier was routed through a gas cleaning system before introducing to the engine. Switchgrass was used as the gasified feedstock. The produced syngas measured about 6.5 MJ/Nm3 lower heat value and contained about 11% H2, 21% CO, 5% CH4, and 1% C2H6 Using syngas, the engine's net electrical efficiency was 21% with a specific fuel consumption (SFC) of 1.9 kg/kWh when the engine was producing 5 kW electricity. Using natural gas as the reference fuel, the engine reached 23% electrical efficiency with a SFC of 0.3 kg/kWh. Major exhaust emissions did not exceed federal emissions limits. CO2 emissions from syngas fuel decreased with increasing load, generating about 149,000 ppm at 0 kW to 7,900 ppm at 5 kW. At all loads, CO emissions from syngas fuel (4,400 to 17,050 ppm) was lower than natural gas fuel (9,850 to 17,250 ppm). NOX emissions generated from syngas fuel (21to 32ppm) was lower than natural gas fuel (21to 177 ppm), with the lowest of 21 ppm at 5 kW from syngas fuel. Hydrocarbon emissions from syngas fuel (0 to 260 ppm with 0 ppm at the maximum load) was lower than natural gas fuel (1 to 1,840 ppm). SO2 emissions from syngas fuel (430 to 770 ppm) was consistently lower than natural gas fuel (520 to 880 ppm).

Publications

  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Thapa, S., P.R. Bhoi, A. Kumar, and R.L. Huhnke. 2017. Effects of syngas cooling and biomass filter medium on tar removal. Energies. 10(3):349.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Indrawan N., S. Thapa, P. Bhoi, A. Kumar, and R.L. Huhnke. 2017. Mobile power generation unit from co-gasification of municipal solid wastes and biomass. ASABE 1700917. Presented at the Annual International Meeting of ASABE, Spokane, WA.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Thapa, S., P. R. Bhoi, A. Kumar, and R. L. Huhnke. 2017. Development of a low-cost syngas cleaning technology using heat exchanger and vegetable oil bubbler. ASABE 1700564. Presented at the Annual International Meeting of ASABE, Spokane, WA.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Indrawan, N., S. Thapa, P. R. Bhoi, R. L. Huhnke, and A. Kumar. 2017. Engine power generation and emission performance of syngas generated from low-density biomass. Energy Conversion and Management. 148:593-603.


Progress 10/01/15 to 09/30/16

Outputs
Target Audience:Scientists, engineers, graduate students, postdoctoral associates, product developers, and the general public. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Training plus professional development were provided to graduate students and postdoctoral researcher. Graduate students and postdoctoral researcher had the opportunity to present their work at national and international conferences. How have the results been disseminated to communities of interest?During this year, a demonstration was held for potential developers and investors, interested in commercializing this technology. What do you plan to do during the next reporting period to accomplish the goals?Testing of the scaled-up downdraft gasifier will continue using a wide variety of biomass resources to further enhance performance and to identify additional modifications aimed at enhancing operation reliability plus improving syngas quality and quantity. Modifications will be incorporated as funding permits. Research will continue on the development of a biomass-based dry syngas cleaning system.

Impacts
What was accomplished under these goals? Scaled-up Gasifier Performance The performance of a scaled-up downdraft gasifier system (100 kg biomass per hour) was evaluated at varied equivalence ratios (ERs) using switchgrass and redcedar as feedstocks. Maximum particle size for switchgrass was 2.5 cm, while redcedar was 10.0 cm. The scaled-up gasifier performance was comparable to our laboratory-scaled gasifier system for redcedar while the performance was lower for switchgrass. Moreover, the performance of the scaled-up unit was superior in terms of syngas quality. The major results are: ER has a significant effect on the yield, compositionand calorific value of syngas, gasification efficiency, and syngas tar content. Optimum ER for switchgrass gasification is within the range of 0.22 to 0.28 based on the highest gasification efficiencies of 60 to 64%. Maximum carbon monoxide (CO) and hydrogen (H2) content of 18 and 9.7%, respectively, calorific value of 5.8 MJ/Nm3, and hot and cold gas efficiencies of 64 and 57%, respectively, were achieved at an ER of 0.22 for switchgrass gasification. Recommended ER for redcedar gasification is 0.24 due to the fact that at higher ERs the pressure drop across the reactor significantly increases while there is marginal improvement in gasification performance. Maximum CO and H2 content of 18.2 and 15%, respectively, calorific value of 6.0 MJ/Nm3, and hot and cold gas efficiencies of 81 and 75%, respectively, were achieved at an ER of 0.24 for redcedar gasification. Gasification performance using redcedar was superior, in part, because of higher carbon content in redcedar (54.4% biomass dry basis) than switchgrass (49.6%). Engine Performance A 10-kWe natural gas fired internal combustion engine was modified, allowing syngas to be used as fuel. A slipstream of syngas from the scaled-up gasifier was routed through a gas cleaning system before introducing to the engine. The engine was tested using syngas produced from both switchgrass and redcedar feedstocks. Major exhaust emissions, such as nitrogen oxide and hydrocarbons, were measured and did not exceed federal emissions limits. Syngas Cleaning System Three different types of syngas cleaning systems consisting of wood shavings as filter medium were developed and evaluated. It was determined that tar removal efficiencies of the wood shavings filter, wood shavings filter with a heat exchanger and wood shavings filter with an oil bubbler were 10.3, 60.3 and 97.0%, respectively. Using a heat exchanger prior to the wood shavings filter reduced syngas temperature and increased the condensation of tars. Using a vegetable oil bubbler prior to wood shavings filter significantly reduced syngas tars. Based on these results, a prototype indirect contact type heat exchanger was designed and constructed for the removal of tars. The total surface area of the heat exchanger exposed to 35 Nm3/hour syngas was 6.6 m2. Water was used as the cooling fluid. Testing was performed using syngas supplied by the lab-scale downdraft gasifier. Three different cooling temperatures (5, 15 and 25°C) were used. The tar removal efficiencies of the heat exchanger were 76, 65 and 51% with water at 5, 15 and 25°C, respectively. These results suggest that a heat exchanger with high cooling effects (in the range of 5°C) could be used an alternative to the existing water-based wet syngas cleaning systems. In addition, a vegetable oil based scrubbing system could be used as a final syngas cleaning system to meet the engine requirements.

Publications

  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Qian, K., A. Kumar, H. Zhang, D. Bellmer and R. Huhnke. 2015. Recent advances in utilization of biochar. Renewable & Sustainable Energy Reviews 42:1055-1064.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Yang, Z., A. Kumar and R.L. Huhnke. 2015. Review of recent developments to improve storage and transportation stability of bio-oil. Renewable and Sustainable Energy Reviews 50:859-870.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Kumar, A., Z. Yang, R.L. Huhnke, M. Buser and S. Capareda. 2016. Pyrolysis of eastern redcedar in PY-GC-MS and batch reactors. Journal of Analytical and Applied Pyrolysis 166:157-165.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Yang, Z., A. Kumar, R.L. Huhnke, M.D. Buser, and S. Capareda. 2016. Pyrolysis of eastern red cedar: distribution and characteristics of fast and slow pyrolysis products. Fuel 166:157-165.
  • Type: Journal Articles Status: Submitted Year Published: 2016 Citation: Bhoi, P.R., R.L. Huhnke, A. Kumar, S. Thapa and N. Indrawan. Scale-up of a downdraft gasifier system for commercial scale mobile power generation. Renewable Energy. (In review.)
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: Tshikesho, R.S., A. Kumar, R.L. Huhnke, and P. Bhoi. 2016. Catalytic pyrolysis of municipal solid wastes (MSW) in pyroprobe and a lab scale pyrolyzer. ASABE 162461552. Presented at the Annual International Meeting of ASABE, Orlando, FL.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2015 Citation: Indrawan, N., P. Bhoi, A. Kumar, and R.L. Huhnke. 2015. Bio-Power Generation Characteristics of a Spark-Ignited Engine Operated on Syngas Derived from Biomass Downdraft Gasification. Presented at the AIChE Annual Meeting, Salt Lake City, UT.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: Bhoi, P., S. Thapa, N. Indrawan, A. Kumar, and R.L. Huhnke. 2016. Performance of a unique downdraft gasifier for a mobile power generation. ASABE 162459829. Presented at the Annual International Meeting of ASABE, Orlando, FL.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: Indrawan, N., P. Bhoi, A. Kumar, and R.L. Huhnke. 2016. Emission characteristics of a spark-ignited engine operated on syngas derived from biomass downdraft gasification. ASABE 162459921. Presented at the Annual International Meeting of ASABE, Orlando, FL.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: Thapa, S., P. Bhoi, A. Kumar, and R.L. Huhnke. 2016. Effectiveness of biomass and biochar filters to remove tars from syngas. ASABE 162461546. Presented at the Annual International Meeting of ASABE, Orlando, FL.


Progress 10/02/14 to 09/30/15

Outputs
Target Audience:Scientists, biofuel engineers, graduate students, postdoctoral associates, product developers,and the general public Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Training plus professional development were provided to graduate students and postdoctoral researcher. Graduate students and postdoctoral researcherhad the opportunity to present their work at national and international conferences. How have the results been disseminated to communities of interest?In August 2015, the research team successfully demonstrated the operation of the scaled-up downdraft gasifier to many interest groups, including representatives of the military, congressional staffers, and potential investors of the mobile electricity generation technology. What do you plan to do during the next reporting period to accomplish the goals?The scaled-up downdraft gasifier will be extensively tested to measure overall range of performance and to identify potential modifications aimed at enhancing operation reliability plus improving syngas quality and quantity. Modifications will be incorporated as funding permits. Several different types of carbonaceous feedstocks will be evaluated, including eastern redcedar and municipal solid waste. Research will continue on the development of a biomass-based dry syngas cleaning system.

Impacts
What was accomplished under these goals? The overall goal of this research is to address key issues limiting the commercial application of Oklahoma State University (OSU) developed biomass gasification technologies. The primary issues are gasifier scale-up, materials handling and producer gas cleaning. Initial emphasis is currently on the scale-up of OSU's patented downdraft gasifier that will be used as a component of a self-contained renewable electricity generation system. Objective 1:The patented downdraft gasifier was scaled-up to approximately 100 kg/h biomass input. Using switchgrass as the biomass feedstock and operating the reactorat equivalence ratios (ER) of 0.25 and 0.3, preliminary gasifier performance was stable and consistent throughout initial experiments. Producer gas' heating value was 5-6 MJ/Nm3, while syngas yield ranged from 1.7 to 1.8 Nm3/kg of switchgrass. Fuel (biomass) consumption rate was 80 and 97 kg/h for ER of 0.25 and 0.3, respectively, while cold gas efficiency was 60%. During several preliminary tests, a slipstream of syngas was routed through a gas cleaning system before introducing to a 10-kWinternal combustion engine. Major exhaust emissions such as nitrogen oxide and hydrocarbons were well below the federal emissions limits. Objective 2: Preliminary tests were conducted to determine the feasibility of using biomass (e.g.switchgrass) as a media to remove tars from the syngas stream. As expected, media temperature is a major factor in tar deposition. Objective 3: No progress.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Bhoi, P.R., A. Kumar, and R.L. Huhnke. 2015. Comparative performance of internal combustion engine using biomass producer gas and natural gas as fuels. ASABE 152190696. Presented at the Annual International Meeting of ASABE, New Orleans, LA.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Qian, K., A. Sharma, A. Kumar, and R. Huhnke. 2014. Conditioning of biomass-generated syngas using biochar and biochar-based catalyst. ASABE 141830177. Poster presented at the Annual International Meeting of ASABE, Montreal, CN.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Indrawana, N., S. Thapa, P. Bhoi, A. Kumar, and R.L. Huhnke. 2015. Performance and emissions of a spark ignited engine operated on syngas derived from biomass downdraft gasifier. Poster presented at the 2015 Gasification Technologies Conference. Colorado Springs, CO.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Qian, K., A. Kumar, R.L. Huhnke, and D.D. Bellmer. 2015. Reforming of lignin-derived tars over char supported catalysts. ASABE 152189925. Presented at the Annual International Meeting of ASABE, New Orleans, LA.