Recipient Organization
PENNSYLVANIA STATE UNIVERSITY
408 Old Main
UNIVERSITY PARK,PA 16802-1505
Performing Department
(N/A)
Non Technical Summary
Biochar is an important biorefinery product with a large potential market and growing interest in its use as a soil amendment, biomaterial, and for carbon sequestration. However, biochar may contain harmful compounds, especially toxic organics such as Benzene, Hexane, Toluene, and other compounds that are produced as part of the biochar manufacturing process in a biorefinery. As a result, workers can be exposed to harmful conditions and the biochar can be a source of contamination, reducing its applicability and acceptability for widespread use.This project will characterize the emission of harmful organic compounds from biomass during conversion to biochar in a biorefinery, and its redeposition on the biochar (Task 1). Experiments will utilize model compounds and acutal biomass feedstocks, and will assess emission and redeposition processes (Task 2), and evaluate engineered treatment processes for contaminant removal and utilization (Tasks 3 and 4). Drawing on those foundational and applied findings, biorefinery TEA and LCA models will be employed to assess overall performance, and strategies will be developed for design and optimization of biorefineries that include biochar in their product mix (Task 5).The impact of this project will be that it enables biorefinery owners and biochar end users to minimize risk of harm from biochar production and utilization, and maximize the value and positive impact of their activities. This will enhance sustainability and circularity of biorefineries through improved engineering design and operation of these facilities. The project team is uniquely positioned to carry out this project, having significant expertise and ongoing experience in this topic area.
Animal Health Component
50%
Research Effort Categories
Basic
50%
Applied
50%
Developmental
(N/A)
Goals / Objectives
The foundational research goal for this project is to characterize the emission of harmful organic compounds from biomass, during conversion to biochar, and its redeposition on the biochar. The applied research goal, drawing on the foundational research findings, is to identify and test strategies for design and optimization of biorefineries that produce biochar that does not contain harmful levels of dangerous organic compounds. The anticipated overall impact of the project will come from developing recommendations that allow biorefineries to minimize risk of harm and maximize the value and positive impact of their operations.Five project objectives have been identified, addressing key foundational and applied research needs:Objective 1: Determine relationships between process conditions and organics emission and redeposition.Objective 2: Develop a data-driven model of organics generation and redepositionObjective 3: Assess the quantities and characteristics of recoverable compounds obtained by treating the pyrolytic gasses and biocharObjective 4: Measure the performance of bench scale biochar production and treatment strategies on emission and redeposition performanceObjective 5: Assess the life cycle and technoeconomic performance of a biorefinery that optimizes economic returns while excluding harmful compounds from biochar produced at the biorefinery.
Project Methods
The five project tasks for this research effort (Figure 1) correspond to the five research objectives listed above with each objective synergistically linked to the others to form a cohesive body of knowledge that will empower biorefiners and biochar users to avoid the potential problems associated with harmful compound production. The methodology for each task is described in the following sections, listing the team members who will lead that effort, procedures to be followed, and anticipated results. Potential pitfalls for each task are also discussed, along with strategies for mitigating potential problems.Task 1: Measure relationships between process conditions and organics emission and redeposition. In this task, experiments will be carried out to quantify the processes by which harmful organic compounds are produced by and redeposited on biochar during the manufacturing process. These experiments will be based on the established experience of the project team, utilizing methodologies and equipment that have been proven effective and achievable. This research task is split into three subtasks, as follows:Subtask 1.1 - Classify compounds emitted during pyrolysis of idealized biomass samples. Subtask 1.2 - Measure temperature-dependent redeposition of compounds during cooling of pyrolitic gases (Bialowic). Subtask 1.3 - Measure compounds retained on biochar during the pyrolysis process. Task 2: Create and validate an empirical model of organics generation and redeposition In this task, the results of Task 1 will be used to create an empirical, data-driven model of organics generation and redeposition, which will be validated with experiments conducted on biomass samples. The procedure will consist of the following subtasks:Subtask 2.1 - Selection and construction of modelSubtask 2.2 - Collection of experimental validation dataSubtask 2.3 - Validation of modelsTask 3: Measure response of contaminated biochar to different mitigation/cleanup strategies (Bialowic, Causer, Ciolkosz, DeVallance)In this task, contaminated biochar samples and gases will be exposed to different mitigation processes, and the impact on contaminant level will be measured. For each method, 10g batches of biochar will be produced under conditions identified in Task 1 to result in contaminated biochar and gases. The biochar samples will then be subjected to treatment as follows:Aqueous solvent extraction:Organic solvent extraction:Gas samples will be subjected to treatment by two methods:Condensation and recovery.Scrubbing for later microbial degradation:The above measurements will be compared to the gas composition of untreated pyrolysis gas, determined by GCMS. Wastewater from the scrubber will be subjected to an anaerobic processing bioassay to determine its applicability for utilization/cleanup.Data analysis will consist of ANOVA with Tukey's HSD as a post-hoc test to describe the impact of the cleanup methods on organics concentration. These results will be used as inputs into the biorefinery TEA and LCA models that will be developed in Task 5.Task 4: Quantify bench-scale performance of thermal treatment performance processes (Ciolkosz, Causer)For this task, biochar production will be carried out in bench scale pyrolysis devices utilizing two system designs: batch and continuous flow. Process conditions (temperature and time profiles) will be varied, and measurements made of the contaminant levels on the resulting biochar samples along with energy and mass flow characteristics. Existing pyrolysis devices will be adapted for this experiment, allowing for control of temperature, duration, ventilation rate, and sample type. Treatment equipment will be assembled for the experiment and designed to integrate with the pyrolysis devices. The treatment processes will be carried out simultaneously with manufacture of the char, and their performance assessed by subsequent analysis of the gas and char products. Gas products will be analyzed using the same procedures outlined in Task 3.1, while char products will be analyzed using the same procedures outlined in Task 3.2. Measured data of organics treatment will be used to calculate treatment efficiency for each process. Data analysis will consist of ANOVA with Tukey's HSD as a post-hoc assessment of differences in organics concentration. The resource utilization rate (water, energy, etc.) will be recorded and used in the TEA and LCA models.Task 5: Quantify whole-system impacts of treatment/removal of harmful organic compounds from biorefinery produced biochar (Vasco, Ciolkosz, Bialowic)This task will develop a TEA and LCA model of a commercial biorefinery that includes biochar production and contaminant mitigation strategies, utilizing inputs generated in Tasks 1-4. The biorefinery will consist of a series of processes including storage, commutation, thermal treatment, hydrolysis, fermentation, fractionation, chemical treatment, electricity production, and waste treatment. Each unit operation will be linked to all other units and will include both input and output streams, allowing for selection and optimization of flows between units based on material inputs and economic constraints. Three to 5 specific configurations will be tested, corresponding to the treatment approaches analyzed in Task 4, and adapted based on input from the project advisory committee. These configurations are expected to include:Biomass pyrolysis, condensable gas and non-condensable gas recoveryBiomass treatment - extractives removal, then pyrolysisBiomass AD then pyrolysisOutputs of the TEA model will include mass and energy balances, discounted cash flows, and overall economic performance of the biorefinery. Outputs of the LCA model will include life-cycle inventory analysis, net carbon performance, and environmental performance across a range of indicators.