VALORIZATION OF BIOCHAR: APPLICATIONS IN ANAEROBIC DIGESTION, LIVESTOCK ODOR CONTROL AND PLANT GROWTH

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: TERMINATED
• Funding Source: OTHER GRANTS
• Reporting Frequency: Annual
• Accession No.: 1016836
• Grant No.: 2018-10008-28616
• Project No.: IOWW-2018-03697
• Proposal No.: 2018-03697
• Program Code: BRDI
• Project Start Date: Sep 1, 2018
• Project End Date: May 31, 2022
• Grant Year: 2018

Project Director
Brown, R. C.

Recipient Organization
IOWA STATE UNIVERSITY
2229 Lincoln Way
AMES,IA 50011

Performing Department
Department of Mechanical Engineering

Non Technical Summary
The goal of this project is to advance the economic prospects for pyrolysis-based biofuels by developing value-added applications for the co-product biochar. Researchers at Iowa State University (ISU) have developed a new approach to providing energy to pyrolyzers based on autothermal processing, which simplifies the design and operation of pyrolyzers and preserves biochar for applications other than heating the pyrolyzer. The high ash content and high porosity of biochar produced by autothermal pyrolysis of herbaceous biomass compared to biochar from conventional (oxygen-free) pyrolysis of woody biomass suggest its use in two immediate markets: enhancing anaerobic digestion (AD) of grassy feedstocks and livestock odor control (LOC). The mixture of digestate and spent biochar or composted manure and spent biochar from these two applications has potential as fertilizer. Specific objectives of the project include: (1) Produce high alkalinity/porosity (HAP) biochar through autothermal pyrolysis of herbaceous feedstocks such as perennial grasses; (2) Assess the utility of HAP biochar in improving the quality of biogas from AD of herbaceous biomass; (3) Assess the utility of HAP biochar for LOC; (4) Assess the utility of HAP biochar to improve performance of AD digestate and composted manure as a fertilizer and to lower NH3 discharge from animal feeding operations; and (5) Determine how valorizing biochar affects the economic, environmental and societal impacts of pyrolysis-based biofuels. The objectives will be pursued through a combination of bench-scale and pilot-scale pyrolysis, AD and LOC experiments and technoeconomic and life cycle analyses over two years. The project will be managed and administered by ISU's Bioeconomy Institute (BEI), which has extensive experience in managing collaborative, multi-investigator federally funded projects. Collaborating organizations include Argonne National Laboratory and Roeslein Alternative Energy.

Animal Health Component

0%

Research Effort Categories

Basic

(N/A)

Applied

100%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
402	1799	2020	100%

Knowledge Area
402 - Engineering Systems and Equipment;

Subject Of Investigation
1799 - Fiber crops, general/other;

Field Of Science
2020 - Engineering;

Keywords

biofuels

biochar

pyrolysis

anaerobic digestion

biogas

livestock odor control

Goals / Objectives
The goal of this project is to advance the economic prospects for advanced biofuels from the pyrolysis of herbaceous biomass by creating high-value markets for biochar (a co-product of pyrolysis) for: 1) livestock odor control; 2) improved performance of anaerobic digestion and composted manure fertilizers from anaerobic digestion; and, 3) minimized NH3 discharge from animal feeding operations. Specific objectives include:Produce biochar with high alkalinity and porosity through autothermal pyrolysis of herbaceous feedstocks such as perennial grasses;Assess the utility of the biochar in improving the quality of biogas from anaerobic digestion of herbaceous biomass;Assess the utility of the biochar for livestock odor control;Assess the utility of the biochar to improve performance of digestate from anaerobic digestion and composted manure as a fertilizer and to lower NH3 discharge from animal feeding operations;Determine how increasing the market value of biochar affects the economic, environmental and societal impacts of pyrolysis-based biofuels.

Project Methods
Task 1. Production of HAP biochar via autothermal pyrolysis: Biochar will be produced from bales of prairie grass provided by Roeslein Alternative Energy (RAE). Two autothermal pyrolyzers will be used. The 8 kg/h system will produce kilogram quantities of biochar for bench-scale studies with the goal of optimizing HAP biochar for the three applications being investigated. The 45 kg/h system will produce hundreds of kilogram quantities of biochar for pilot-scale studies. Milestones: Produce HAP biochar with alkalinity and porosity suitable for AD and LOC applications (Qtr 3); Produce sufficient quantities of HAP biochar for field-scale trials (Qtr 7).Task 2. Characterization of HAP biochar: Particle size distribution of the biochar samples will be determined by sieving the pre-weighed (10 g) biochar using a micro sieve set (Scienceware, Wayne, NJ). Surface morphology and textural properties of the biochar will be characterized with an FEI Quanta 400F environmental scanning electron microscope (SEM) (FEI, Hillsboro, OR) operated at high vacuum mode at ambient temperature. Brunauer-Emmet-Teller (BET) surface area, total pore volume and pore size will be determined utilizing argon or nitrogen gas adsorption analysis at 77.35 K. The pH value of the biochar will be measured by mixing 5 g of biochar sample in 100 mL deionized water (Milli-Q, Millipore) stirred at 180 rpm for 24 h at room temperature. Proximate, ultimate and ash elemental analyses will be conducted in triplicate using ASTM methods. Milestones: Complete characterization of HAP biochar synthesized in Task 1 (Qtr 8); determine 2-3 HAP biochar candidates for evaluation in Task 3 (Qtr 2).Task 3. Laboratory-scale anaerobic digestion experiments with HAP biochar: Lab scale AD tests will be conducted in 500 milliliters digesters to evaluate the effects of biochar on AD process including: 1) different raw materials for the digestion (swine manure, fescue grass, prairie grass, mixed manure and fescue grass, and mixed manure with prairie grass); 2) different types of anaerobic digesters (CSTR vs plug flow); 3) water content of the digestion system (liquid AD vs solid AD) and 4) AD temperature (mesophilic, thermophilic, and temperature-phased). Milestones: Bench-scale AD produces biogas with CH4 content exceeding 90 vol% when digested in the presence of HAP biochar (Qtr 4); in the presence of HAP biochar, bench-scale AD achieves 20% reduction in H2S, NH3, and selected odorous VOCs when treating manure and manure-grass mixtures; and 50% reduction when treating grass samples, without a significant increase in GHGs emissions, at a cost that is less than 0.5% of market price of targeted livestock (Qtr 6).Task 4. Pilot-scale anaerobic digestion experiments with HAP biochar: Laboratory results will be scaled-up by Roeslein Alternative Energy (RAE) in a 500-gallon mesophilic AD pilot plant at its Ruckman Farm facility in northern Missouri. The manure substrate at 2% TS is fed into the first stage reactor which has a capacity of 120 gallons resulting in a hydraulic retention time (HRT) of seven days. The substrate is then fed from the first stage reactor to both second stage reactors in equal proportions, with one second stage reactor being used to evaluate the effects of adding biochar, and the other reactor used as a reference. The second stage reactors have a capacity of 275 gallons each, and an HRT of fourteen days. All reactors are submerged in a heated water bath that is temperature controlled at the mesophilic range. Biogas production rate and composition are measured by flow meter totalizers and gas analyzers. Milestones: Establish baseline performance for digestion of grassy feedstock (Qtr 5); Establish optimal operating conditions for AD with HAP biochar (Qtr 8).Task 5. Odor control experiments with HAP biochar: Laboratory scale odor control: A lab-scale apparatus will be used for testing the effects of HAP biochar dose and time on odor, NH3, H2S, key odorous VOCs responsible for downwind swine barn odor, and GHGs (CO2, CH4, N2O) on emissions from simulated swine manure storage treated surficially with HAP biochar. At least three doses and three trials will be conducted using the recent work with conventional biochar as an initial dose. Pilot-scale odor control: An existing pilot-scale setup will be used for testing the effects of surficial HAP biochar treatments on odor and gaseous emissions from simulated (100 L) swine manure storage as functions of dose and time. Milestone: 50% reduction in odor, H2S, NH3, and selected odorous VOCs from the use of HAP biochar without a significant increase in GHGs emissions, at a cost that is less than 0.5% of market price of targeted livestock (swine) (Qtr 8).Task 6. Nutrient recycling with spent biochar: Composting trials will be conducted at the labs-scale in a series of three runs using a randomized complete block design. Twenty-five pounds of compost mixture without biochar and then two mixtures with biochar (at rates of 5, based on dry mass, and 10%) will be created. Generated materials will be mixed, subsampled (analyzed for C, N, and P), and then mixtures placed into forced air, temperature controlled composting vessels. Airflow and CO2 content into and from each composter will be monitored continuously. Ammonia in the air stream will be monitored daily during initial phases of composting (1-2 weeks), two times per week thereafter. Compost will be turned as necessary at which time the mass, moisture content, and pH will be monitored. Chemical analysis and mass balance will be conducted to determine impact on composting kinetics, N loss, and value as a certified compost. Soil incubation and leaching studies will be conducted to evaluate how biochar addition rates to manures impacts N and P leaching as well as how it influences nutrient loss from composted digestate solids. Milestones: Achieve 50% reduction in NH3 loss during poultry composting and 30% reduction in volume of composted material (Qtr 8); Achieve a 70% separation of P and 40% separation of N from manure onto biochar with biochar recovery > 80% (Qtr 7); NO3-N losses reduced by 15% during first two weeks of incubation and by 5% after two months (Qtr 8).Task 7. LCA and TEA evaluations of biochar valorization: A baseline scenario, where biochar is marketed as low-value boiler fuel ($20/tonne), will be compared to an enterprise based on value-added applications of HAP biochar. Process profitability, environmental footprint, and social impacts will form the basis of the comparison. Process profitability will be measured in terms of its payback period, and 20-year net present value. Environmental impacts will be characterized by several midpoint categories including: climate change, human toxicity, ecotoxicity, land use, energy use (efficiency and petroleum displacement), particulate matter/respiratory inorganics and others. Social impacts will be evaluated in terms of job creation, labor income, value added, and economic output. Milestone: Design of an integrated HAP biochar and AD system with a 7-year payback period, net reduction in GHG emissions, and net increase in rural economic impacts developed (Qtr 8).Evaluation: Benchmarks will be established for each metric upon which milestones are based. Metrics by task are: 1) Yield of HAP biochar from autothermal pyrolysis of grassy biomass; 2) Alkaline content and porosity of HAP biochar; 3) Concentration of CH4 and H2S in raw biogas from laboratory-scale AD tests; 4) Concentration of CH4 and H2S in raw biogas from pilot-scale AD tests; 5) Gas concentrations (ppm) and emissions rates for H2S, NH3, and selected odorous VOCs; 6) N loss from biochar amended compost; economic value of compost; N loss from soil applied compost; 7) Costs of renewable natural gas ($/MMBtu) and livestock odor mitigation (% market price of livestock).

Progress 09/01/18 to 05/31/22

Outputs
Target Audience: Livestock farmers looking to utilize composting as their mortality management method where introduction of biochar may help with ammonia and odor retention. Regulators and legislators looking to address air and water quality issues associated with livestock production Researcher Scientists and engineers working in renewable energy, biomass utilization, soil science, nutrient management and water quality Agricultural engineers, environmental scientist, and technical service provides involved in helping livestock production facilities make manure management and application decisions. Anaerobic digestion researchers and scientists looking for ways to enhance their system performance or at alternative gas clean up systems. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Graduate students supported on the project that have graduated: PhD in Food Science, now working at a company developing specialty proteins Masters of Science in Agricultural and Biosystems Engineering, now working for a food sustainability company Graduate students supported on the project still at Iowa State University: PhD student in Mechanical Engineering currently at an internship at the National Renewable Energy Laboratory PhD in Agricultural and Biosystems Engineering, has passed preliminary PhD exam with research on livestock odor control utilizing biochar PhD in Food Science, currently studying anaerobic digestion of grassy biomass PhD in Mechanical Engineering, completing techno-economic and life cycle analyses of biorefineries and integrated anaerobic digestion operations How have the results been disseminated to communities of interest? 10 peer reviewed manuscripts have been published 2 graduate dissertations have been published 5 presentations were given at National and International technical conferences The information on biochar addition to manure has been presented as part of manure applicator training to Iowa livestock producers and will be again as more data is collected to help promote behavior change and experimentation What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Significant accomplishments during the project include evaluating high alkalinity/porosity (HAP) biochar N and P sorption characteristics. We have engineered HAP biochar further for enhanced P sorption affinity. The engineering process includes the pretreatment of the corn stover biochar with iron sulfate (FeSO4). The Fe-impregnated HAP biochar has been shown to have 11-12 times more P sorption capacity, while the P desorption rate was ~1/3 relative to the pristine HAP biochar. The studied Fe-impregnated HAP biochar's high adsorption and low desorption capacity of P suggest the use of this as an effective adsorbent to remove P from livestock manure and can potentially be used as a slow-release P fertilizer. We have also engineered autothermal high porosity wood biochar (yellow pine) to introduce nitrogen-enriched slow-release fertilizer. The engineering process includes post-treatment of low-ash pine biochar with H3PO4 followed by the impregnation with urea and a mixer of calcium lignosulfonate and paraffin wax binder. The produced N slow-release fertilizer has been shown toreduce NH3 volatilization by 5-8 times, reduce urea solubilization by 5-8 times, and reduce NH4+ to NO3- conversion by several times. The H3PO4 inclusion in the slow-release fertilizer can also provide 1.9-12.3 g kg-1 elemental P, adding P fertility. The effect of biochar on anaerobic digestion(AD) was investigated using starch-based food waste. The daily and cumulative biogas and methane yields were shown in Fig 1A. With addition of biochar, the biogas production lasted approximately 80 days, indicating adding biochar can enhance AD performance. After the first 3 days of high biogas yield, digesters with 2% biochar and 4% biochar both had a low daily biogas yield period. The digester with 4% biochar resumed the biogas production from 23th day, while 2% biochar restarted until 40th day. These results suggested the differences between buffering capacity of 2% and 4% biochar. Cumulative biogas yield was also recorded (Fig 1B). Adding starch (starch+sludge) reduced the biogas yield by 53.0% compared to sludge-only, indicating inhibition of organic fraction conversion caused byacidification. Adding biochar greatly increased biogas yield. Compared to the starch+sludge group, 2% biochar and 4% biochar increased biogas yield by 234.4% and 314.1%, respectively.As shown in Fig 1C, daily methane peak appeared at the first day with sludge+starch while it appeared at the 8th day for sludge only. Although the daily biogas yield was extremely high the first day (Fig 1A), CO2 was the major componentin the biogas, and acidogenesis and acetogenesis were too fast, resulting inlow daily methane yield (Fig 1C). Similar tobiogas production, methane yield of starch+sludge gradually reduced and even stopped after the 5th day, resulting in low methane yield (Fig 1D). The sludge-only group steadily produced methane for 28 days, with a high methane content (average 60.7%) and a cumulative methane yield of 92.7mL/g TS. The group of 2% biochar hada cumulative methane yield 9.5% higher than the sludge only, and 619% higher than starch+sludge. Methane yield improved by 4% in the biochar group, which is 32.8% higher than sludge-only group and 772.5% higher than starch+sludge group. Figure 1. Time-course profiles of batch AD experiments with biochar addition: (A) Daily biogas yield; (B) cumulative biogass yield; (C) daily CH4 yield; (D) cumulative CH4 yield. Biochar treatments were topically applied to manure and tested on a pilot-scale setup, simulating deep pit storage. Each setup experienced 3-min of agitation.Concentrations of NH3 and H2S were taken in real-time and measured until the concentration stabilized after the sharp increase due to agitation. Maximum and total emissions of NH3 and H2S were reduced upon addition prior to agitation, as well as during agitation. Table 1. The mean of total emission and maximum concentration for HAP biochar treatments with its standard deviation during the 3 min of agitation process. Percent reduction is statistically significant when P < 0.05 Table 2. Emissions after applying RO biochar to manure surface and before manure agitation Table 3. The mean of total emissions and maximum emissions with its standard deviation for RO biochar treatment during the 3-min of agitation process. Percent reduction is significant when P < 0.05 The effect of biochar on nitrogen loss from swine manure was investigated.For eight weeks, soil columns were leached to determine total NO3-N loss of soil alone, biochar amended soil, swine manure, and a combination of biochar and swine manure. In this study, it was determined that swine manure increased the amount of nitrogen lost from the soil, the addition of biochar to swine manure treated soil decreased total nitrate loss. It is suggested that biochar has the ability to increase water and nutrient retention, reducing the risk of nitrogen loss.A follow-up experiment was used to evaluate the effect of biochar application rate (all lower than in the previous study) with two different manure types, poultry litter and swine manure. Results again showed that biochar application reduced nitrate loss from the biochar amended soils. Figure 2. Progressive nitrate loss by treatment (shared letters show no significant difference). We conducted techno-economic (TEAs) and lifecycle analyses (LCA) of biochar valorization through an integrated pyrolysis, fermentation, and anaerobic digestion biorefinery as shown in Figure 6. The integrated biorefinery produces biochar for co-digestion with animal manure to enhance power production and reduce emissions and animal odors in agriculture. The biorefinery generates additional revenue through the sale of gasoline via bio-oil hydroprocessing or from producing ethanol via pyrolytic sugar fermentation. The biorefinery was designed to process 2000 metric tonnes per day (MTPD) of corn stover and 430 MTPD of cow manure into either gasoline (scenario 1) or ethanol (scenario 2), and power and digestate. The gasoline scenario produces 60.5 million gallons per year of gasoline, and the ethanol scenario generates 11.5 million gallons per year and 7.13 million gallons (16 gallons of gasoline equivalent (GGE)) of phenolic oil - a boiler fuel. Electricity generation for both scenario is 105,000 MWh/year, and the total digestate output is 0.114 million tonnes per year. We estimated the minimum fuel-selling price (MFSP) for biofuels from each scenario. The gasoline MFSP estimate was $2.77 per gallon, and the ethanol MFSP was $1.20 per gallon ($1.41 per GGE). Feedstock and capital (ROI) csosts are the main contributors to the gasoline MFSP. The ethanol scenario has a lower capital cost of $288 million compared to $643 million for the gasoline scenario. This corresponds with a lower annualized capital cost of $21 million for the ethanol scenarios versus $46 million for the gasoline scenario. Power generation from the digester lowers the annual operating costs by $7 million for both scenarios. These results suggest that pyrolytic sugar fermentation to ethanol offers a lower capital investment pathway for valorizing biochar via anaerobic digestion. However, both pathways seem commercially competitive given current fuel prices. The LCA results indicate that greenhouse gas (GHG) emissions are net negative for both scenarios. The gasoline scenario has emissions of -9.6 gm of CO2/MJ, and the ethanol scenario emissions are -16.6 gm of CO2/MJ. The largest source of positive emissions for both scenarios is the corn stover production emissions of 4 and 9.48 gm of CO2/MJ for gasoline and ethanol. Biochar removes 6.46 and 11.11 gm CO2 per MJ of gasoline and ethanol, respectively. Electricity offsets 7.76 and 16 gm CO2 per MJ from the grid. Additionally, the anaerobic digestion of cow manure avoids 6.46 and 3.49 gm CO2 per MJ from the business-as-usual practice of leaving manure on the field.

Publications

• Type: Journal Articles Status: Published Year Published: 2020 Citation: Chen, B.; Koziel, J.A.; Bia?owiec, A.; Lee, M.; Ma, H.; Li, P.; Meiirkhanuly, Z.; Brown, R.C. (2020). The Impact of Surficial Biochar Treatment on Acute H2S Emissions during Swine Manure Agitation before Pump-Out: Proof-of-the-Concept. Catalysts, 10, 940. https://doi.org/10.3390/catal10080940.
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Meiirkhanuly, Z.; Koziel, J.A.; Chen, B.; Bia?owiec, A.; Lee, M.; Wi, J.; Banik, C.; Brown, R.C.; Bakshi (2020) S. Mitigation of Gaseous Emissions from Swine Manure with the Surficial Application of Biochars. Atmosphere, 11, 1179. https://doi.org/10.3390/atmos11111179.
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Zhou H, Brown R, Wen Z. (2020). Biochar as an additive in anaerobic digestion of municipal sludge - biochar properties and their effects on the digestion performance. ACS Sustainable Chemistry & Engineering. 8: 6391-6401.
• Type: Journal Articles Status: Published Year Published: 2021 Citation: Bakshi, S.; Banik, C.; Laird, D. A.; Smith, R. G.; Brown, R. C. Enhancing biochar as scaffolding for slow release of nitrogen fertilizer. ACS Sustainable Chemistry & Engineering. 2021, 9, 24, 8222-8231.
• Type: Journal Articles Status: Published Year Published: 2021 Citation: Bakshi, S.; Laird, D. A.; Smith, R. G.; Brown, R. C. Capture and release of orthophosphate by Fe-modified biochars: Mechanisms and environmental applications. ACS Sustainable Chemistry & Engineering. 2021, 9, 2, 658-668.
• Type: Journal Articles Status: Other Year Published: 2022 Citation: " Banik, C.; Bakshi, S.; Andersen, D.; Laird, D.; Smith, R. G.; Brown, R. C. The role of biochar and zeolite in enhancing nitrogen and phosphorus recovery: A sustainable manure management technology. In preparation.
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Ganguly, Arna, Irene M. Martin, Robert C. Brown, and Mark M. Wright. "Application of hydroprocessing, fermentation, and anaerobic digestion in a carbon-negative pyrolysis refinery." ACS Sustainable Chemistry & Engineering 8, no. 44 (2020): 16413-16421.
• Type: Journal Articles Status: Published Year Published: 2022 Citation: Ganguly, Arna, Robert C. Brown, and Mark Mba Wright. "Investigating the Impacts of Feedstock Variability on a Carbon-Negative Autothermal Pyrolysis System Using Machine Learning." Frontiers in Climate 4 (2022): 842650.
• Type: Journal Articles Status: Published Year Published: 2019 Citation: Meiirkhanuly, Z.; Koziel, J.A.; Bia?owiec, A.; Banik, C.; Brown, R.C. (2019). The-Proof-of-Concept of Biochar Floating Cover Influence on Water pH. Water 11, 1802, doi:10.3390/w11091802.
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Meiirkhanuly, Z.; Koziel, J.A.; Bia?owiec, A.; Banik, C.; Brown, R.C. (2020). The proof-of-the concept of biochar floating cover influence on swine manure pH: Implications for mitigation of gaseous emissions from area sources. Front. Chem. 8, 656, doi: 10.3389/fchem.2020.00656.
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Aui, Alvina, Arna Ganguly, Irene Mas-Martin, and Mark Mba Wright. "Carbon Negative Biofuel and Power Systems Via Hybrid Pyrolysis and Anaerobic Digestion Biorefineries." In 2019 AIChE Annual Meeting. AIChE, 2019.
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Bakshi, S.; Smith, R.G.; Brown, R.C. (2019) Phosphate sorption onto modified biochar surfaces. Biochar and Bioenergy Ineternational Meeting, International Biochar Initiative, June 30-July 3, 2019, Fort Collins, CO (oral presentation).
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Steenhoek, Alyvia. Andersen, Daniel. 2019. Effect of biochar and animal manure on nitrogen loss from soil. 2019 Annual Meeting of American Society of Agricultural and Biological Engineers. St. Joseph, Michigan.
• Type: Theses/Dissertations Status: Published Year Published: 2020 Citation: Zhou H. (2020). Strategies to enhance anaerobic digestion of biomass waste to produce renewable biofuel. PhD Dissertation. Iowa State University.
• Type: Theses/Dissertations Status: Published Year Published: 2019 Citation: Steenhoek, Alyvia. Cover Crop, Manure Application Timing, Nitrification Inhibitors, and Biochar Impact Nitrogen Loss in Midwestern Soils (2019) Thesis to the Graduate Collage @ Iowa State University. Ames, Iowa.
• Type: Book Chapters Status: Published Year Published: 2022 Citation: Ganguly, Arna, and Mark Mba Wright. "Techno-economic analysis of biochar in wastewater treatment." In Sustainable Biochar for Water and Wastewater Treatment, pp. 205-231. Elsevier, 2022.
• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Chen, B., J.A. Koziel, M. Lee, H. Ma, Z. Meiirkhanuly, P. Li, A. Bia?owiec, R.C. Brown. The Impact of Biochar Treatment on H2S and NH3 Emissions During Manure Agitation prior to Pump-Out. ASABE Paper No. 2000873. St. Joseph, MI.: ASABE. 2020 ASABE Annual International Meeting, Omaha, NE, July 2020.
• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Meiirkhanuly, Z., J.A. Koziel, A. Bialowiec, C. Banik, B. Chen, M. Lee, J. Wi, R.C. Brown, S. Bakshi. Mitigation of gaseous emissions from swine manure with biochar. ASABE Paper No. 2000863. St. Joseph, MI.: ASABE.2020 ASABE Annual International Meeting, Omaha, NE, July 2020.

Progress 09/01/20 to 08/31/21

Outputs
Target Audience: Livestock farmers looking to utilize composting as their mortality management method where introduction of biochar may help with ammonia and odor retention. Regulators and legislators looking to address air and water quality issues associated with livestock production Researcher Scientists and engineers working in renewable energy, biomass utilization, soil science, nutrient management and water quality Agricultural engineers, environmental scientist, and technical service provides involved in helping livestock production facilities make manure management and application decisions. Anaerobic digestion researchers and scientists looking for ways to enhance their system performance or at alternative gas clean up systems. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Graduate students supported on the project that have graduated PhD in Food Science, now working at a company developing specialty proteins Masters of Science in Agricultural and Biosystems Engineering, now working for a food sustainability company Graduate students supported on the project still at Iowa State University PhD in Agricultural and Biosystems Engineering, has passed preliminary PhD exam with research on livestock odor control utilizing biochar PhD in Food Science, currently studying anaerobic digestion of grassy biomass PhD in Mechanical Engineering, completing techno-economic and life cycle analyses of biorefineries and integrated anaerobic digestion operations A graduate student presented at the 2020 American Institute of Chemical Engineers fall meeting. Six undergraduate students have been involved in various aspects of the experiments with data collection and analysis. They have had opportunities to attend technical presentations and enhance their school work though applied learning opportunities. Through work on this project, a postdoctoral associate authored a published manuscript, has another submitted for publication, and has presented at a conference hosted by the International Biochar Initiative. The postdoc was promoted to a Research Scientist at Iowa State University. How have the results been disseminated to communities of interest? Nine peer reviewed manuscripts have been published Two graduate dissertations have been published Six presentations were given at National and International technical conferences The information on biochar addition to manure has been presented as part of manure applicator training to Iowa livestock producers and will be again as more data is collected to help promote behavior change and experimentation What do you plan to do during the next reporting period to accomplish the goals? Complete manuscript on biochar-based slow-release Nitrogen fertilizers

Impacts
What was accomplished under these goals? Pilot scale anaerobic digestion was conducted in two reactor systems operated by Roeslein Alternative Energy. These tests were used to compare prior pilot studies done at ISU that compared methane production and concentration in anaerobic digestion with and without biochar addition. The ISU pilot studies showed when digesting swine manure, methane production and concentration increased with the addition of biochar. The pilot studies using the Roeslein digesters involved tests with rye grass and sorghum. Rye digestion occurred over 19 days, and sorghum digestion occurred over 42 days. Each feedstock was digested with and without biochar to compare methane concentration. The rye digestions with and without biochar addition resulted in methane concentrations of 56% and 62%, respectively. The sorghum digestions with and without biochar addition resulted in methane concentrations of 50% and 58%, respectively. In both cases higher methane production occurred in the treatment without biochar This is in contrast to the lab studies and the swine manure only studies. In part, this may be due to reactor 1 (no biochar) consistently being 3-degrees warmer due to issues with the control system. This also may be due to low ammonia concentrations, which minimizes a primary benefit of biochar in anaerobic digestion. Figure 1. Performance of anaerobic digestion of rye grass with (Flow2 - red) and without (Flow1 - green) biochar addition. Methane concentration with biochar was 56%. Methane concentration without biochar was 62%. Figure 2. Performance of anaerobic digestion of sorghum with (Flow2 - red) and without (Flow1 - green) biochar addition. Methane concentration with biochar was 50%. Methane concentration without biochar was 58%.

Publications

• Type: Journal Articles Status: Published Year Published: 2021 Citation: Bakshi, S.; Banik, C.; Laird, D. A.; Smith, R. G.; Brown, R. C. (2021) Enhancing biochar as scaffolding for slow release of nitrogen fertilizer. ACS Sustainable Chemistry & Engineering. 9, 24, 8222-8231.
• Type: Journal Articles Status: Published Year Published: 2021 Citation: Bakshi, S.; Laird, D. A.; Smith, R. G.; Brown, R. C. (2021) Capture and release of orthophosphate by Fe-modified biochars: Mechanisms and environmental applications. ACS Sustainable Chemistry & Engineering. 9, 2, 658-668.
• Type: Journal Articles Status: Published Year Published: 2021 Citation: Chen, B.; Koziel, J.A.; Bia?owiec, A.; Lee, M.; Ma, H.; OBrien, S.; Li, P.; Meiirkhanuly, Z.; Brown, R.C. (2021) Mitigation of Acute Ammonia Emissions During Swine Manure Agitation Before Pump-Out with Biochar: Proof-of-the-Concept. Frontiers in Environmental Science, 9:613614.
• Type: Journal Articles Status: Published Year Published: 2021 Citation: Chen, B.; Koziel, J.A.; Banik, C.; Ma, H.; Lee, M.; OBrien, S.C.; Li, P.; Andersen, D.S.; Bialowiec, A.; Brown, R.C. (2021) Mitigation of Gaseous Emissions from Stored Swine Manure with Biochar: Effect of Dose and Reapplication on a Pilot-Scale. Atmosphere, 12, 96.
• Type: Journal Articles Status: Published Year Published: 2021 Citation: Chen, B.; Koziel, J.A.; Lee, M.; OBrien, S.; Li, P.; Brown, R.C. (2021) Mitigation of Acute Hydrogen Sulfide and Ammonia Emissions from Swine Manure during Three-Hour Agitation Using Pelletized Biochar. Atmosphere, 12(7), 825.
• Type: Journal Articles Status: Published Year Published: 2021 Citation: Bakshi, S.; Laird, D.A.; Smith R.G.; Brown, R.C.; (2021) Capture and release of orthophosphate by Fe2 modified biochars: Mechanisms and environmental applications. ACS Sustainable Chemistry & Engineering. 9,2,658-668.
• Type: Journal Articles Status: Published Year Published: 2021 Citation: Meiirkhanuly, Z.; Koziel, J. A.; Chen, B.; Bialowiec, A.; Lee, M.; Wi, J.; Banik, C.; Brown, R. C.; Bakshi, S. (2021) Mitigation of gaseous emissions from swine manure with the surficial application of biochars. Atmosphere. 11 (11), 1179.
• Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: Bakshi, S.; Banik, C.; Laird, D. A.; Smith, R. G.; Brown, R. C. Biochar supported slow-release nitrogen fertilizer for sustainable agriculture. American Chemical Society Fall 2021 National and International Meeting & Exposition, August 22-26, Atlanta, GA, USA (Paper ID # 3589212; oral).
• Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: Bakshi, S.; Laird, D. A.; Smith, R. G.; Brown, R. C. Recycling phosphate using Fe-modified biochar for environmental applications. American Chemical Society Fall 2021 National and International Meeting & Exposition, August 22-26, Atlanta, GA, USA (Paper ID # 3589217; oral).

Progress 09/01/19 to 08/31/20

Outputs
Target Audience: Livestock farmers looking to utilize composting as their mortality management method where introduction of biochar may help with ammonia and odor retention. Regulators and legislators looking to address air and water quality issues associated with livestock production Researcher Scientists and engineers working in renewable energy, biomass utilization, soil science, nutrient management and water quality Agricultural engineers, environmental scientist, and technical service provides involved in helping livestock production facilities make manure management and application decisions. Anaerobic digestion researchers and scientists looking for ways to enhance their system performance or at alternative gas clean up systems. Changes/Problems:Field pilot testing of the anaerobic digestion system was delayed as COVID-19 impacted availability of the pumps we were hoping to use. Different pumps were purchased. Original gas flow have been replaced by ones more tuned to the gas production levels anticipated. What opportunities for training and professional development has the project provided?Graduate students supported on the project that have graduated PhD in Food Science, now working at a company developing specialty proteins Masters of Science in Agricultural and Biosystems Engineering, now working for a food sustainability company Graduate students supported on the project still at Iowa State University PhD in Agricultural and Biosystems Engineering, has passed preliminary PhD exam with research on livestock odor control utilizing biochar PhD in Food Science, currently studying anaerobic digestion of grassy biomass PhD in Mechanical Engineering, completing techno-economic and life cycle analyses of biorefineries and integrated anaerobic digestion operations Graduate students have completed three conference presentations at the American Society of Agricultural and Biological Engineers annual meeting. Another graduate student has a presentation accepted at the 2020 American Institute of Chemical Engineers fall meeting. Four undergraduate students have been involved in various aspects of the experiments with data collection and analysis. They have had opportunities to attend technical presentations and enhance their school work though applied learning opportunities. Through work on this project, a postdoctoral associate authored a published manuscript, has another submitted for publication, and has presented at a conference hosted by the International Biochar Initiative. The postdoc was promoted to a Research Scientist at Iowa State University. How have the results been disseminated to communities of interest? Six peer reviewed manuscripts have been published Two graduate dissertations have been published Four presentations were given at National and International technical conferences One presentation has been accepted and will be given November, 2020 at the AIChE Fall conference The information on biochar addition to manure has been presented as part of manure applicator training to Iowa livestock producers and will be again as more data is collected to help promote behavior change and experimentation We are also working with two livestock producers who are interested utilizing biochar in their composting process Results from this project were presented at a virtual forum, "Why are we missing the boat on biogas?" hosted by Iowa State University's Consortium for Cultivating Human and Naturally reGenerative Enterprises (C-Change). Attendees and presenters included researchers from Universities, NGOs, Companies, State of Iowa Economic Development leaders and State of Iowa legislators. What do you plan to do during the next reporting period to accomplish the goals? Lab testing and verification of biomass and Anaerobic digestion equipment so system is deployable next spring. All components are assembled and final decisions on recipes will be made. Continue to test biomethane production from AD with biochar addition from mixed grasses in both serum bottle system and Continuously Stirred Tank Reactor Completion of both the lab-scale manure composting and the field-scale mortality composting with and without biochar amendment is in progress and will be completed. Data processing will also occur. Test methods for nutrient separation and biochar recovery from livestock manures. Commence lab column studies and greenhouse studies to scale-up trials of biochar derived slow-release nitrogen fertilizer

Impacts
What was accomplished under these goals? ???Biochar Production and characterization Autothermal (air-blown) pyrolysis of ferrous sulfate treated corn stover was carried out to produce the FeSO4 impregnated biochar. Autothermal pyrolysis of untreated corn stover was also conducted to produce control biochar (CS-control). We have assessed the phosphate sorption efficacy of the FeSO4 impregnated biochar in presence of competing ions by conducting the laboratory simulated column leaching studies using simulated agricultural effluent water. The columns with the simulated agricultural runoff water (phosphate concentrations were 10 and 80 mg/L and biochar amount was 2 g/ column) demonstrate prominent effect of FeSO4 impregnation on phosphate sorption. The cumulative phosphate sorption increases, and sorption efficiency decreases with increasing leaching volume for all cases, however, the FeSO4 impregnated biochars were substantially more effective for removing phosphate than the CS-control biochar. The FeSO4 impregnated biochar columns were ~3-4 times and 5-6 times more effective, respectively, for low and high phosphate ion concentrations than the CS-control biochar for removing phosphates in presence of other competing ions. Biochar amended anaerobic digestion The effect of biochar on anaerobic digestions (AD) was investigated by adding biochar to (1) sludge as the substrate (2) sludge+starch mixture as the substrate, respectively. The digester fed with sludge only had steady biogas production in the first 23 days with the maximum daily biogas appeared at the 8th day. Other conditions with starch had the maximum daily biogas at the first day, which was 34.7, 38.0 and 35.3 mL/g TS for starch+sludge, 2% biochar, and 4% biochar, respectively. For the starch+sludge, the biogas production was nearly 0 after the first 5 days. With addition of biochar, the biogas production lasted for approximately 80 days, indicating adding biochar can enhance the AD performance. After the first 3 days of high biogas yield, digesters with 2% biochar and 4% biochar both had a low daily biogas yield period. The digester with 4% biochar resumed the biogas production from 23th day, while 2% biochar restarted until 40th day. These results suggested the differences between buffering capacity of 2% and 4% biochar. Adding starch into the digesters (starch+sludge) reduced the biogas yield by 53.0% compared to the sludge-only, indicating the inhibition of organic fraction conversion caused by the acidification. Adding biochar greatly increased the biogas yield, which was 223.3mL/g TS for 2% biochar and 276.6 mL/g TS for 4% biochar. Compared to the starch+sludge group, 2% biochar and 4% biochar increased the biogas yield by 234.4% and 314.1%, respectively. Livestock odor control Two kinds of biochar were tested, highly alkaline, and porous (HAP, pH 9.2) biochar made from corn stover and red oak biochar (RO, pH 7.5). Two scenarios of (6 mm) 0.25" and (12 mm) 0.5" thick layers of biochar treatments were topically applied to the manure and tested on a pilot-scale setup, simulating deep pit storage. Each setup experienced 3-min of agitation using a transfer pump, and measurements of the concentrations of NH3 and H2S were taken in real-time and measured until the concentration stabilized. The results were compared with the control in 3 situations: 1. The maximum (peak) flux 2. Total emission from the start of agitation until the concentration stabilized, and 3. The total emission during the 3-min of agitation. For NH3, 0.5" HAP biochar treatment significantly (p<0.05) reduced maximum flux by 63.3%, overall total emission by 70%, and total emissions during the 3-min agitation by 85.2%; 0.25" HAP biochar treatment significantly (p<0.05) reduced maximum flux by 75.7%, overall, total emissions by 74.5%, and total emissions during the 3-min agitation by 77.8%. The 0.5" RO biochar treatment significantly reduced max by 8.8%, overall total emissions by 52.9%, and total emissions during 3-min agitation by 56.8%; 0.25" RO biochar treatment significantly reduced max by 61.3%, overall total emission by 86.1%, and total emission during 3-min agitation by 62.7%. For H2S, 0.5" HAP biochar treatment reduced the max by 42.5% (p=0.125), overall total emissions by 17.9% (p=0.290), and significantly reduced the total emissions during 3-min agitation by 70.4%; 0.25" HAP treatment reduced max by 60.6% (p=0.058), and significantly reduced overall and 3-min agitation's total emissions by 64.4% and 66.6%, respectively. 0.5" RO biochar treatment reduced the max flux by 23.6% (p=0.145), and significantly reduced overall and 3-min total emissions by 39.3% and 62.4%, respectively; 0.25" RO treatment significantly reduced the max flux by 63%, overall total emissions by 84.7%, and total emissions during 3-min agitation by 67.4%. Biochar amended digestate and manure composting The relationship between biochar and nitrogen loss in liquid swine manure application was investigated. For eight weeks, soil columns were leached to determine total NO3-N loss of soil alone, biochar amended soil, swine manure, and a combination of biochar and swine manure. In this study, it was determined that swine manure increased the amount of nitrogen lost from the soil, the addition of biochar to swine manure treated soil decreased total nitrate loss. It is suggested that biochar has the ability to increase water and nutrient retention, reducing the risk of nitrogen loss. A follow-up experiment was used to evaluate the effect of biochar application rate (all lower than in the previous study) with two different manure types, poultry litter and swine manure. Results again showed that biochar application reduced nitrate loss from the biochar amended soils. Techno-economic analysis and life-cycle assessment Two Aspen PlusTM process models were developed simulating gasoline and power production via pyrolysis-hydroprocessing-anaerobic digestion, and ethanol and power production via pyrolysis-fermentation-anaerobic digestion. Both process models simulate the conversion of 2000 metric tonnes per day of corn stover and 430 dry tonnes per day of manure. Techno-economic analysis was conducted for the two scenarios and compared based on the annual operating cost and fixed capital investment (FCI). Total capital costs were estimated at $643 and $288 million for the hydroprocessing and fractionation scenario, respectively. The minimum fuel selling prices for the two scenarios are $2.77 per gallon and $1.21 per gallon (or $1.41 per gallons of gasoline equivalent). Corn stover and return on investment (ROI) contribute the most towards the annual operating costs in both the scenarios. For both the scenarios, electricity and the biochar rich solid and liquid digestates from anaerobic digestion generates similar credits as observed. Life cycle analysis of both the scenarios is conducted in GREET. The results show negative greenhouse gas emissions for both the scenarios. Life cycle emissions were estimated at -9.6 gm CO2,eqv. /MJ for scenario I and -16.6 gm CO2,eqv. /MJ for scenario II (Figure 14). Corn stover is the primary source of emissions in both cases with contributions of 4 and 9.48 gm of CO2, eqv per MJ of gasoline and ethanol, respectively. Electricity is the primary GHG emission avoidance factor with 7.8 and 16.2 gm of CO2, eqv per MJ of gasoline and ethanol and phenolic oils displaced from the U.S. grid. Biochar contributes greenhouse gas emission credits of -6.5 and -11.1 gm CO2,eqv. /MJ for the scenario I and II, respectively.

Publications

• Type: Journal Articles Status: Published Year Published: 2019 Citation: 1. Meiirkhanuly, Z.; Koziel, J.A.; Bia?owiec, A.; Banik, C.; Brown, R.C. (2019). The-Proof-of-Concept of Biochar Floating Cover Influence on Water pH. Water 11, 1802, doi:10.3390/w11091802.
• Type: Journal Articles Status: Published Year Published: 2020 Citation: 2. Meiirkhanuly, Z.; Koziel, J.A.; Bia?owiec, A.; Banik, C.; Brown, R.C. (2020b). The proof-of-the concept of biochar floating cover influence on swine manure pH: Implications for mitigation of gaseous emissions from area sources. Front. Chem. 8, 656, doi: 10.3389/fchem.2020.00656.
• Type: Journal Articles Status: Published Year Published: 2020 Citation: 3. Chen, B.; Koziel, J.A.; Bia?owiec, A.; Lee, M.; Ma, H.; Li, P.; Meiirkhanuly, Z.; Brown, R.C. (2020b). The Impact of Surficial Biochar Treatment on Acute H2S Emissions during Swine Manure Agitation before Pump-Out: Proof-of-the-Concept. Catalysts, 10, 940. https://doi.org/10.3390/catal10080940.
• Type: Journal Articles Status: Published Year Published: 2020 Citation: 4. Meiirkhanuly, Z.; Koziel, J.A.; Chen, B.; Bia?owiec, A.; Lee, M.; Wi, J.; Banik, C.; Brown, R.C.; Bakshi (2020) S. Mitigation of Gaseous Emissions from Swine Manure with the Surficial Application of Biochars. Atmosphere, 11, 1179. https://doi.org/10.3390/atmos11111179.
• Type: Journal Articles Status: Published Year Published: 2020 Citation: 5. Bakshi, S., Banik, C. & Laird, D.A. Estimating the organic oxygen content of biochar. Sci Rep 10, 13082 (2020). https://doi.org/10.1038/s41598-020-69798-y
• Type: Journal Articles Status: Published Year Published: 2020 Citation: 6. Zhou H, Brown R, Wen Z. (2020). Biochar as an additive in anaerobic digestion of municipal sludge - biochar properties and their effects on the digestion performance. ACS Sustainable Chemistry & Engineering. 8: 6391-6401.
• Type: Theses/Dissertations Status: Published Year Published: 2020 Citation: Zhou H. (2020). Strategies to enhance anaerobic digestion of biomass waste to produce renewable biofuel. PhD Dissertation. Iowa State University.
• Type: Theses/Dissertations Status: Published Year Published: 2019 Citation: Steenhoek, Alyvia. Cover Crop, Manure Application Timing, Nitrification Inhibitors, and Biochar Impact Nitrogen Loss in Midwestern Soils (2019) Thesis to the Graduate Collage @ Iowa State University. Ames, Iowa.
• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Chen, B., J.A. Koziel, M. Lee, H. Ma, Z. Meiirkhanuly, P. Li, A. Bia?owiec, R.C. Brown. The Impact of Biochar Treatment on H2S and NH3 Emissions During Manure Agitation prior to Pump-Out. ASABE Paper No. 2000873. St. Joseph, MI.: ASABE. 2020 ASABE Annual International Meeting, Omaha, NE, July 2020.
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Bakshi, S.; Smith, R.G.; Brown, R.C. (2019) Phosphate sorption onto modified biochar surfaces. Biochar and Bioenergy Ineternational Meeting, International Biochar Initiative, June 30-July 3, 2019, Fort Collins, CO (oral presentation).
• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Meiirkhanuly, Z., J.A. Koziel, A. Bialowiec, C. Banik, B. Chen, M. Lee, J. Wi, R.C. Brown, S. Bakshi. Mitigation of gaseous emissions from swine manure with biochar. ASABE Paper No. 2000863. St. Joseph, MI.: ASABE.2020 ASABE Annual International Meeting, Omaha, NE, July 2020.
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Steenhoek, Alyvia. Andersen, Daniel. 2019. Effect of biochar and animal manure on nitrogen loss from soil. 2019 Annual Meeting of American Society of Agricultural and Biological Engineers. St. Joseph, Michigan.
• Type: Other Status: Published Year Published: 2020 Citation: Chen, B.; Koziel, J.A.; Lee, M.; Ma, H.; Meiirkhanuly, Z.; Li, P.; Bia?owiec, A.; Brown, R.C. Can Biochar Save Lives? The Impact of Surficial Biochar Treatment on Acute H2S and NH3 Emissions During Swine Manure Agitation Before Pump-out. .Preprints 2020, 2020060104; doi: 10.20944/preprints202006.0104.v1?
• Type: Other Status: Published Year Published: 2020 Citation: Meiirkhanuly, Z.; Koziel, J.A.; Chen, B.; Bia?owiec, A.; Lee, M.; Wi, J.; Banik, C.; Brown, R.C.; Bakshi, S. Mitigation of Gaseous Emissions from Swine Manure with the Surficial Application of Biochars. Preprints 2020, 2020090614 (doi: 10.20944/preprints202009.0614.v1).

Progress 09/01/18 to 08/31/19

Outputs
Target Audience:Audiences at technical conferences, including the International Biochar Initative in Ft. Collins, CO. The technical conference audiences include USDA technical and administrative representatives, researchers from universities and non-profits, company R&D and business development personnel, farmers and agricultural trade and commodity groups. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project provides graduate and undergraduate students an opportunity to work in the area of chemical, agricultural and biological engineering. Graduate students are expected to conduct experiments and present results in written reports and oral presentation. They receive training on experimental design, data collection and analysis, as well as environmental monitoring. Graduate students and post docs will also have opportunities to prepare manuscripts for technical journals and present at technical conferences attended by universities, federal agencies including the USDA, and companies. Undergraduate students were involved in data collection and utilization and received training on measurement methods, soil analysis, and water analysis. An international student (Zhanibek Meiirkhanuly) was trained to work in this project, graduated and received his M.S. degree Environmental Science at Iowa State University in August 2019. How have the results been disseminated to communities of interest?Objective 1. An oral presentation has been presented at the Biochar & Bioenergy annual conference in 2019. Another oral presentation will be presented at the American Chemical Society Spring meeting in 2020. A scientific journal publication is under preparation for submission in early 2020. Objective 2. A manuscript was published in Water. Additional manuscripts focused on the effect of biochar addition on pH in the air-manure interface is in preparation. Objective 3. A manuscript is being completed and is nearly ready for submission. Objective 4. A manuscript is in preparation for Transactions of the ASABE. Objective 5. A scientific journal publication is under preparation for submission in 2019. A poster and oral presentation are planned for delivery in 2020. What do you plan to do during the next reporting period to accomplish the goals?Objective 1. Efficacy of the FeSO4 impregnated biochar towards phosphate recycling using both agricultural and industrial effluents by performing benchtop leaching trials. Objective 2. Year 2 pilot-scale evaluation of the effects of HAP biochar dose and time on odor, NH3, H2S, key odorous VOCs responsible for downwind swine barn odor, and GHGs (CO2, CH4, N2O) on emissions from simulated swine manure storage treated with a surficial application of biochar. Objective 3. AD of the fibrous feedstock materials (grasses): The fescue grass, prairie grass, and mixtures of manure and these grasses will be used as feedstock for AD. A CSTR will be used for digesting grasses, while a plug flow reactor (PFR) will be used to digest the manure/grass mixtures due to the difficulty of processing these heterogeneous mixtures in CSTRs. AD will be performed in both liquid (>85% moisture content) and solid (<85% moisture content) phases to accommodate the nature of grassy biomass. In addition to mesophilic AD, we will also use a temperature-phase method, i.e., thermophilic stage first to hydrolyze the recalcitrant fiber and produce volatile fatty acid, followed by the mesophilic stage for the CH4 production, to treat the materials with efficient raw material degradation and process stability. Objective 4. A follow up experiment is being conducted to evaluate the impact of biochar addition rate to both swine manure and poultry manure. We developed and refined our methodology for composting analysis and plan to evaluate how adding biochar to compost impacts both compost processes and ammonia loss of bedded pack cattle manure and herbaceous material separated from anaerobic digesters. Objective 5. Process models will be updated with experimental data gathered from the project. Economic assumptions will be updated when the model is modified to account for new performance metrics. Process design will be optimized to minimize costs. Lifecycle analysis results will be updated when the model is modified to account for new performance metrics. Process design will be optimized to minimize environmental impacts.

Impacts
What was accomplished under these goals? Objective 1. Biochar Production Autothermal (air-blown) pyrolysis of ferrous sulfate treated corn stover was carried out to produce FeSO4 impregnated biochar. Autothermal pyrolysis of untreated corn stover was conducted to produce control biochar (CS-control). Characteristics of these biochars are shown in Table 1. Phosphate sorption tests in solution with 0, 100, 400, 1000 and 4000 mg L-1 phosphate concentration at 48 hours with solid loading of 5 g/L and pH 7.5-8.2 were conducted. Phosphate sorption capacity of CS-FeSO4 biochar was 88.7 mg of phosphate per g biochar. Phosphate sorption capacity of CS-control biochar was only 59.8 mg of phosphate per g biochar. Desorption isotherms with three washings of water and Mehlich-III solution were done to test release of phosphate from the biochar. Desorption rates for CS-control biochar in water and Mehlich-III solution were 52.28% and 69.48%, respectively. Desorption rates for ferrous sulfate treated corn stover biochar were 15.15% and 26.19% in water and Mehlich-III solution, respectively. The combination of autothermal pyrolysis and ferrous sulfate treatment dramatically increases phosphate sorption capacity, and dramatically decreases desorption rates. Table 1: Biochar properties Figure 1: Phosphate sorption and desorption data of (a) biochar from untreated corn stover and (b) biochar from ferrous sulfate treated corn stover. Blue - water desorption; Gray - Mehlich-III desorption. Numbers in the dark portion of each bar represent the % phosphate desorbed. The number below each bar (PO43- aq mg L-1) is the phospate concentration remaining in the aqueous phase. The number above each bar (PO43- ads mg g-1) indicates indicates concentration of adsorbed phosphate. The four pairs of bars in each chart from L-R are results from 0, 100, 400, 1000 and 4000 mg L-1 phosphate-concentrated solutions. Objective 2. Biochar amended anaerobic digestion Anaerobic digestions (AD) experiments were conducted using municipal sludge. A control group (A0) without biochar addition and groups amended with biochar from untreated corn stover (A1), and biochar from sulfuric acid treated corn stover (A2) at three different dosages (L, M, and H) were investigated. The three dosages of biochar from low to high included 3.6g/g TSsludge (L), 7.2 g/g TSsludge (M) and 15 g/g TSsludge (H). Each digester contained inoculum (0.44g TS), sludge (0.36g TS), biochar (varies) and deionized (DI) water to total 80mL. Each condition was conducted in duplicate. Fig. 2 shows the time course of cumulative biogas production, cumulative methane production and daily methane content. Untreated corn stover biochar addition increased cumulative biogas and methane production proportional to biochar dosages. Sulfuric acid treated corn stover biochar increased the biogas production (Fig. 2B) but only significantly (p<0.05) with high dosage (A2-H). All of the three dosages resulted in significant higher methane production than that of the control group A0 (p<0.05). Contrary to the trend of biogas production in Fig. 2B, addition of sulfuric acid treated corn stover biochar decreased the methane production. Figure 2. Time-course profiles of AD experiments. Cumulative biogas production with: (A) untreated corn stover biochar; (B) sulfuric acid treated corn stover biochar. Cumulative methane production with: (C) untreated corn stover biochar; (D) sulfuric acid treated corn stover biochar. Methane content with: (E) untreated corn stover biochar; (F) sulfuric acid treated corn stover biochar. Objective 3. Livestock odor control Experiments to study biochar pH impact on the liquid-air interface were completed. Small doses of biochar were surficially-applied on water and swine manure to study the temporal and spatial (with depth) changes that regulate emissions of pH-sensitive odorous compounds from liquid to air. The impact of HAP corn stover biochar (pH 9.2) was compared with red oak (RO) biochar (pH 7.5). Both experiments showed OH- ions from biochar gradual movement from the surface into the water and manure. Both experiments support the hypothesis that biochar pH can be used to control the odorous compound emissions by buffering the H+/OH- ion concentrations. Table 2. Physicochemical properties of two manures sourced from a lagoon and pit used in this experiment. Lab-scale experiments were completed to evaluate the impact of HAP and RO biochar surficial application on mitigation of NH3, H2S, odorous VOCs and GHGs (CO2, CH4, N2O) emissions from swine manure. Both biochars showed the highest reduction of NH3 emissions on the day after application. Surficial biochar addition to manure reduced odorous VOCs emission up to 90% depending on the type of manure. Biochar application reduced the CH4 emission for the first two weeks after the surficial application then enhanced the CH4 emissions compared to untreated manure. High ash content and porosity is likely reducing the biochar floatability and therefore its ability to control the odorous compounds and their emissions in the long term. Green font represents significant reduction vs. control. Red font represents significant increase vs. control. Table 3. Efficacy of surficially-applied HAP biochar in mitigating NH3 emissions (mg/h/m2) from swine manure (lab-scale trials). Table 4. Efficacy of surficially-applied HAP biochar in mitigating H2S emission emissions (mg/h/m2) from swine manure (lab-scale trials). Table 5. Efficacy of HAP biochar in mitigating CH4 emission flux (mg/h/m2) from swine manure (lab-scale trials). Table 6. Efficacy of HAP biochar in mitigating odor emission (OUe.m-3) from swine manure Table 7. Efficacy of HAP biochar in mitigating odorous VOC emissions from manure over three lab-scale trials. Objective 4. Biochar amended digestate and manure composting The relationship between biochar and liquid swine manure application and its effect on total nitrogen loss was investigated. For eight weeks, soil columns were leached to determine total NO3-N loss of soil alone, biochar amended soil, swine manure, and a combination of biochar and swine manure. In this study, it was determined that swine manure increased the amount of nitrogen lost from the soil, the addition of biochar to swine manure treated soil decreased total nitrate loss. It is suggested that biochar has the ability to increase water and nutrient retention, reducing the risk of nitrogen loss. Figure 3: Cumulative Nitrate Loss by Treatment; Shared letters show no significant difference. Figure 4: Progressive Nitrate Loss by Treatment; Shared letters show no significant difference. Objective 5. Economic analysis and life cycle assessment Aspen PlusTM process models have been developed simulating gasoline and power production via pyrolysis-hydroprocessing-anaerobic digestion (Scenario I), and ethanol and power production via pyrolysis-fermentation-anaerobic digestion (Scenario II). Both scenarios assume conversion of 2000 metric tonnes per day of corn stover and 430 dry tonnes per day of manure to liquid transportation fuels, electricity, phenolic compounds, and biochar products. Total capital costs were estimated at $642 and $719 million for the gasoline and ethanol production scenarios, respectively. Preliminary minimum fuel selling prices for scenarios I and II were $2.71 per gallon and $2.31 per gallon (or $3.46 per gallons of gasoline equivalent). Corn stover and return on investment (ROI) contributed the most towards the MFSP in both scenarios. Preliminary life cycle analysis results showed negative greenhouse gas emissions for both scenarios. Life cycle emissions were estimated at -9.6 gm CO2,eqv. /MJ for scenario I and -80 gm CO2,eqv. /MJ for scenario II. Figure5. Cornstoverfast pyrolysis to gasoline or ethanol and manure anaerobic digestion to power Table 8:Comparison of gasoline and ethanol production scenario costs, fuel yield, minimum fuel-selling price, and greenhouse gas emissions GGE: gallons of gasoline equivalent

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Bakshi, S.; Gable, P.; Brown, R. C., 2018. Phosphate sorption onto modified biochar surface. Biochar & Bioenergy, International Biochar Initiative, Fort Collins, CO, June 30-July 3, 2019 (Oral presentation).
• Type: Journal Articles Status: Published Year Published: 2019 Citation: Meiirkhanuly, Z., J.A. Koziel, C. Banik, A. Bialowiec, R. Brown. 2019, The-proof-of-concept of biochar floating cover influence on water pH. Water, 11(9), 1802; doi: 10.3390/w11091802.