Progress 02/01/07 to 09/30/11
Outputs
OUTPUTS: This study explores the potential of integrating three processes; biodrying, gasification and gas conditioning to produce medium heating value gas from a dairy manure-wheat straw mixture. Three aeration levels; 0.05, 0.80 and 1.50 liter/minute/kilogramvolatile-matter were tested. Moisture content dropped from 55.94% to 27.94, 34.50, and 34.80% wet-basis under high, medium and low aeration rates, respectively. A comparison of energy consumption between biodrying and conventional drying showed the biodrying process to demand less energy than conventional drying, 2.0 Mega Joule/kilogram compared to 2.1 Mega Joule/kilogram. Three air gasification trials were carried out under different equivalence ratios; 0.25, 0.30 and 0.35. Gas yield and higher heating value ranged between 1.61 - 1.74 cubic meter/kilogrambiomass and 4.55 - 4.86 Mega Joule/cubic meter with highest yield and heating value occurring under an equivalence ratio of 0.25. Values of cold gas efficiency ranged between 64.17% - 65.38%. Results of this study showed that the use of the biodried mixture as gasification fuel is a valid thermochemical conversion feedstock. PARTICIPANTS: A graduate student finished his MSC Thesis on this project. TARGET AUDIENCES: Arkansas Farmers. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Average moisture decreased in all reactors but with varying degrees. Maximum reduction occurred under high-aeration, with moisture content decreasing from 55.94% to 27.94%. Medium and low-aeration reactors had similar final moisture content, 34.53% and 34.85%, respectively. The gas heating value reached 4.68 Mega Joule/cubic meter, 5.60 Mega Joule/cubic meter and 6.20 Mega Joule/cubic meter, after air-steam gasification, steam reformation and carbon dioxide capture, respectively. Mass balance was performed on the gasification system. For instance, at equivalence ratio of 0.25, the input biomass and air represented 59.09 kilogram/hour however; the output gas and char represented 48.87 kilogram/hour. Tar and water content in the producer gas were calculated by difference due to the difficulties of handling tar throughout this study. Therefore, the gasification mass balance represents 100%. Energy balance in the input feedstock represents 75.89 kilowatt. The output energy balance represents 58.7 kilowatt. Tar and heat losses represent 17.18 kilowatt of the total energy at the same equivalence ratio. Based on the assumption that the number of heads per farm is 1000 head and manure moisture content is 70%, the amount of bulking material will be 21,980 kilogram at moisture content of 10%. The daily biodried manure-straw mixture will be 51,616 kilogram at moisture content of 27%. This amount can be converted to producer gas contain 480,000 Mega Joule. In other words, it can replace about 12,000 cubic meters (420,000 cubic feet) of natural gas. The prolonged conversion of biodried dairy manure - wheat straw mixture to medium heating value gas and replacement of natural gas will supply cheap energy from an abundant byproduct source. The development of gasification-steam reforming or producer gas/syngas cleaning system will increase the usage of these byproducts. Assuming that 50% of dairy cow manure (750,000 tons/year) produced in a State such as California can be utilized via the novel technique; vast reduction of natural gas used could be observed. Based on 1.5 cubic meter of producer gas can be produced by gasifying 1 kilogram of dried manure, and the energy content can reach 6 Mega joule per cubic meter of producer gas, about 6.1 billion cubic feet of natural gas equivalent could be produced. This vast amount of producer gas can reward dairy producer by $24 million annually based on natural gas price of $4 per cubic foot. Successful medium heating value gas production will benefit the United States in several ways. These include: a.Decrease the dependency on foreign energy sources, b.Utilize dairy and agricultural byproducts particularly dairy manure and wheat straw which are otherwise considered wastes in an environmentally friendly, economical profitable and efficient way, c.Improve the environmental impact of energy production, d.Reduce the natural gas consumption which potentially decreases the cost of power generation, e.Supply cheaper gas to many rural areas, and f.Produce medium heating value gas that has potential to replace natural gas.
Publications
- No publications reported this period
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: Three 900 liter batch reactors were used to evaluate the biodrying process of three types of manure namely beef, swine and poultry manure mixed with corn stalks. Biodrying process was investigated as a pretreatment for thermochemical conversion processes. The results indicated that the highest temperature achieved in the three manure types was 71C in the poultry manure-corn stalks mixture at day 5. Moisture contents of the three manure types were reduced to levels suitable for gasification after 2 to 4 weeks. Biodried manure weight reduced significantly which, in turn, will reduce manure transportation cost if transportation is charged on a cost per ton basis. Insignificant reduction of manure-corn stalks heating value were observed for the three manure types. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Swing, poultry and beef producers are the target audience of this project. PROJECT MODIFICATIONS: This project is present a significant step towards converting animal wastes to biofuels source. The project results will enhance the quality of the fuel produced for thermochemical conversion processes. Biodrying could enables reduced transportation costs of animal manure on a cost per ton basis since biodried manure is less in weight compared to fresh animal manure.
Impacts
Biodrying technique is a valid method of reducing manure moisture content from the range of 60% to the range of 30% and producing a product suitable for gasification technology. With no external heat provided to beef, poultry and swine manures-corn stalks mixtures, 30% of their moisture content was reduced after biodrying time of 2-4 weeks. Poultry manure-corn stalks mixture showed the fastest reduction of moisture content compared to beef and swine manure-corn stalks mixtures. Thermophilic temperatures, 60 oC, were achieved after 19 days for the beef manure, 4 days for swine manure, and 3 days for poultry manure. Biodrying did not greatly affect the biodegradability of the animal manure-corn stalks mixture as measured by volatile solids and heating value reduction. These results will enhance the quality of the fuel produced for thermochemical conversion processes. Biodrying could enables reduced transportation costs of animal manure on a cost per ton basis since biodried manure is less in weight compared to fresh animal manure. Energy consumption to biodry beef manure, swine manure and poultry manure were 0.18 kJ/kg water removed, 0.12 kJ/kg water removed and 0.09 kJ/kg water removed, respectively.
Publications
- No publications reported this period
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: Thermophilic temperatures, 60C, were achieved after 19 days for the beef manure, 4 days for swine manure, and 3 days for poultry manure. The highest temperature achieved in the three manure types was 71C in the poultry manure at day 5. It was visually observed that the mixture height decreased with increase in biodrying time. The decrease in the mixture height exposed the upper thermocouple sensor to the headspace and, gradually, the recorded temperatures at L3 became the same as at L4. Initial MC were 59%, 60% and 61% for the beef, poultry, and swine manure, respectively. MC of all the samples was decreased continuously during biodrying. Water evaporation caused a continuous heat removal in forced and natural aeration and dried the compost material progressively. The continuous decrease in moisture content during composting is an indication of organic matter decomposition. Initially, beef manure didn't exhibit any moisture removal for 14 days. Then a significant reduction in moisture content, 59%, was achieved between days 15 and 29, followed by another plateau which lasted until the end of the experiment. Both swine and poultry exhibited similar moisture removal profile with a rapid decrease in moisture content in the first 10 days of about 58% and 53% of the initial moisture, respectively. Beef manure mixture exhibited the highest increase in pH, 60% compared to its initial pH, during 36 days of biodrying, followed by poultry manure which showed a gradual increase in pH from 7.6 to 8.9. Swine manure, however, showed no significant change in pH. The initial C:N ratios for the beef, swine and poultry manure were 16.1, 16 and 15.7 respectively. The three manure types exhibited similar C:N profiles. They showed an initial increase, with varying degrees, followed by increase-decrease cycles. Poultry manure showed the highest increase, 32%, by day 7 then again by day 15 reaching a C:N ratio of 21.7. Both swine and beef manure showed similar profiles but the beef manure was lagging behind the swine manure. However, the in initial C:N. ratios were less than the recommended C:N ratio for optimum composting, Oxygen concentration in the exit air was monitored continously for the three manure types, along with the ambient air oxygen levels. As expected, oxygen levels at exit were less than those of ambient air due to the microbial activities inside the reactors. In beef manure, no difference was observed between ambient and exit oxygen levels for the first 5 days. Starting from day 6 till day 25, the difference was almost constant, 1.3%. However, both swine and poultry manure showed noticeble difference between exit air oxygen concentration and ambient air oxygen. The turning regime may have effect on the microbial activities that fluctuate O2 concentration levels. Poultry manure showed the highest O2 consumption at day 9 with the O2 level falling 2.5% below ambient air level. After day 15, the O2 consumption was reduced in both swine and poultry manure. The heating value of the three types of manure-corn stalks decreased slightly with increase in biodrying time. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Poultry, swine and beef producers as well as energy personal will be interested with the project findings. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Biodrying technique is a valid method of reducing manure moisture content from the range of 60% to the range of 30% and producing a product suitable for gasification technology. With no external heat provided to beef, poultry and swine manures-corn stalks mixtures, 30% of thier moisture content was reduced after biodrying time of 2-4 weeks. Poultry manure-corn stlaks mixture showed the fastest reduction of moistture content from compared to beef and swine manure-corn stalks mixturs. Thermophilic temperatures, 60 oC, were achieved after 19 days for the beef manure, 4 days for swine manure, and 3 days for poultry manure. Biodrying did not greatly affect the biodegradability of the animal manure-corn stalks mixture as measured by volatile solids and heating value reduction. These results will enhance the quality of the fuel produced for thermochemical conversion processes. Biodrying could enables reduced transportation costs of animal manure on a cost per ton basis since bioried manure is less in weight compared to fresh animal manure.
Publications
- No publications reported this period
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Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: The main objective of this project is to explore the bio-drying process of animal manure in a forced-air reactor. Specific objectives include: (a) to design three identical bioreactors using forced air technique, (b) investigate the bio-drying technique of three different manure types including swine manure, beef manure and poultry manure mixed with corn stalks as a bulking agent, (c) to monitor manure temperatures, moisture content, volatile solids and pH as affected by and (d) to explore potential production of bio oil from manure. Swine, beef and poultry manures were collected for bio drying experiments. Chopped corn stalks were added to adjust manure initial moisture content to about 60%. Three units (0.900 m3 each) were used to test forced air manure bio-drying technique. Forced air was applied to the reactors. Reactor temperature, CO2, O2 and relative humidity were recorded using CR10X Campbell Scientific data loggers. Bio dried manure was pyrolyzed in a 25 kW
pyrolysis system.
PARTICIPANTS: HeeKown Ahn Vetress Thompson Mahmoud Sharara
TARGET AUDIENCES: Public,farmers
Impacts
Thermophellic temperatures were obtained within the first week for swine and poultry manure and within the third week for beef manure. Bio drying technique is a valid method of reducing manure moisture content from the range of 60% to the range of 30%. Bio Dried manure could be pyrolyzed to produce bio oil.
Publications
- No publications reported this period
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