Progress 05/01/24 to 04/30/25
Outputs
Target Audience:The target audiences for this project include upstream stakeholders who produce olive and grape pomaces and downstream users who eventually consume olive and grape pomaces in transportation sectors. In this reporting period, the team reached out to UC Davis Experimental Winery in CA to collect red grape pomace from the winery's production. Dr. Kun Zhang and his team presented the outcomes from this project at the 2024 Association of Asphalt Paving Technologists (AAPT) conference with audiences from the asphalt industry. Dr. Shi presented the research results of lowering salt usage for winter maintenance during the Transportation Summer Camp at Washington State University. Dr. Selina Wang shared the project goals and up-to-date activities with the Olive Oil Commission of California, California Olive Oil Council, American Olive Oil Producers Associations as well as through conversations with olive growers and processors. Dr. Liv Haselbach from Lamar University introduced the use of olive and grape pomace as thebase-cases and example problems in CVEN 6334 Environmental Life Cycle Assessment classwith 25 graduate students. Dr. Liv Haselbach also presented the "Incorporation of pomace waste into asphalt pavements" atthe SMU Carbon Capture Workshop with Monika U. Ehrman, Professor of Law and Professor of Civil & Environmental Engineering (by Courtesy). Changes/Problems:Dr. Xianming Shi left Washington State University and joined the University of Miami on August 15, 2024. Dr. Shi leads Objective 3 of this project. The subaward contract was changed from Washington State University to the University of Miami on November 1st, 2024, to continue the Objective 3. What opportunities for training and professional development has the project provided?In this reporting period, one graduate student and one undergraduate student from UC-Davis were trained to characterize antioxidant activities and mass spectra analysis of processed pomaces and their extracts to achieve Objective 1. The graduate student was supported to attend the California State University (CSU) Agriculture Research Institute (ARI) annual meeting on November 7, 2024. One graduate student from the UC Davis was trained to use LC-MS-QTOF for unknown compound analysis. This included acquiring the data with the instrument and data analysis. Three undergraduate students and one postdoc at Chico State were trained to conduct state-of-practice performance tests to evaluate pomace-modified asphalt binders and mixtures. The PD, one undergraduate student, and one postdoc researcher from Chico State were supported to attend the 2024 AAPT Centennial Annual Meeting from September 9 to 12, 2024. The PD also attended the 2ndInternational Workshop on the Use of Biomaterials in Pavements from September 23 to 24, 2024, virtually. These professional developmentactivities helped the PD and his team members to stay with the latest knowledge on the development and evaluation of bio-based antioxidants in asphalt paving materials. One graduate student and one undergraduate student from the University of Miami were trained to work on the pomace-derived green extracts for roadway winter maintenance of anti-icing applications. One graduate student from Lamar University was trained to perform process modeling analysis and life cycle assessment for pomace transportation, processing, and conversion. Dr. Liv Haselbach from Lamar University introduced the use of olive and grape pomace as thebase-cases and example problems in CVEN 6334 Environmental Life Cycle Assessment classwith 25 graduate students. How have the results been disseminated to communities of interest?The PD, Dr. Kun Zhang, and one undergraduate student from Chico State presented a poster presentation based on the outcomes from this project at the 2024 Association of Asphalt Paving Technologists (AAPT) conference. The poster presentation title was "Recycling of olive and grape byproducts as renewable antioxidant additives for asphalt binders". The targeted audiences wereconference attendees from the asphalt industry, who were potential downstream users of consuming olive and grape pomaces. Dr. Xianming Shi presented the research results of lowering salt usage for winter maintenance during the Transportation Summer Camp at Washington State University.Dr. Selina Wang shared the project goals and up-to-date activities with the Olive Oil Commission of California, California Olive Oil Council, American Olive Oil Producers Associations as well as through conversations with olive growers and processors.Dr. Liv Haselbach also presented the "Incorporation of pomace waste into asphalt pavements" atthe SMU Carbon Capture Workshop with Monika U. Ehrman, Professor of Law and Professor of Civil & Environmental Engineering (by Courtesy). What do you plan to do during the next reporting period to accomplish the goals?In the next reporting period, the UC-Davis team plans to continue enzymatic treatments of GP and OP. Compounds with anti-icing properties will be analyzed via targeted analysis as well as untargeted analysis. The phenolic profiles and quantification for processed GP and OP will be continued to determine the specific phenolic makeup of the samples. This information will then be compared with the relative antioxidant capacity of each phenolic compound. Additional correlation analyses will be conducted to establish the relationship between the chemical compositions of processed GP and OP and engineering performance for pomace-derived additives for antioxidation and anti-icing applications. The OP and GP will be further bioprocessed and biorefined to increase their antioxidant effectiveness for asphalt binder modifications. The long-term aging tests will be performed for pomace-modified asphalt mixtures and control mixtures. The cracking performance tests will be conducted and compared for long-term aged asphalt mixtures with pomaces and commonly-used antioxidant additives. The design and production guidance will be developed for pomace-modified asphalt mixtures with balanced engineering performance, economic cost, and environmental benefit. We also plan outreach to stakeholders for the field trial using pomace-modified asphalt mixtures. The University of Miami(UM) team (transferred from Washington State University) will complete ice melting capacity tests with additional pomace-derived formulations. COD tests will be conducted for all treatment stages. The steel corrosion performance of solutions with pomace extracts will be evaluated. The UM team will work with the UC-Davis team to analyze the chemical composition of the OP and GP extracts (via LC-MS, FTIR, etc.) and establish the relationship between the chemical composition of the extracts and ice-melting and corrosion performance. Field tests will be conducted to evaluate various anti-icer formulations during the winter season. The Lamar University team will work with the UM team on the process model, energy consumption, and life cycle assessment for GP and OP processes for anti-icing applications. Sensitivity analysis and optimization analysis will be conducted to optimize the processes of GP and OP for pomace-derived additives for roadways with balanced engineering performance, economic costs, and environmental footprints.
Impacts
What was accomplished under these goals?
The UC-Davis (UCD) team optimized the enzyme digestion conditions using tannase, cellulase, and pectinase to treat GP and improve its antioxidant activities for Objective 1. The pH and temperature had effects on the extraction of phenolic compounds. However, the reproducibility of the extraction using enzymes was inconsistent, and improvement is needed. The UCD team also characterized the active ingredients in GP and OP that contribute to antioxidant and anti-icing performances. The tests included total oil content, total phenolic content (Folin-Ciocalteu method), and 2,2-diphenyl-1-picrylhydrazyl Inhibition (DPPH) and ferric reducing antioxidant power (FRAP) assays for newly processed OP and red GP. These results were correlated with the performance of pomace-modified asphalt. The results of the several assays used to measure phenolic compounds correlated with each other. This will further guide the mechanical and bio-processing of pomace to improve antioxidant performance. The individual phenolic profiles of the red GP were completed, and the most abundant phenolics were catechin, epicatechin, gallic acid, and quercetin. The UCD team also performed untargeted analysis of the extraction samples from task 3 for anti-icing application. An LC-MS-QTOF (liquid chromatography - quadrupole time of flight mass spectrometer) was used to find compounds with elements of interest (oxygen, nitrogen, phosphorus, and/or sulfur). This instrument had a high mass resolution, allowing the prediction of the molecular formula of the unknown compounds. The targeted experiments were performed on the compounds of interest to fragment them and then measure their masses, which were used to determine the functional groups, such as amines, thiols, carboxylic acids, and phosphates. A further curated compound list was made, which will be quantified on the LC-MS-QQQ (liquid chromatography- triple quadrupole mass spectrometer). The results will be used to correlate with anti-icing performance and steel corrosion reduction for Objective 3. The Chico State team led objective 2 to achieve zero-waste recycling of GP and OP as antioxidants in asphalt. The team standardized two processing methods for OP, namely dry and wet processes. The dry process was to dry wet OP first and then separate the stone-rich and pulp-rich fractions. This method could process OP in bulk, but the stone and pulp fractions could not be separated completely. The wet process was to separate pulp and stone fractions first before drying. Although this approach had a longer processing time, the collected olive pulp had better antioxidant effectiveness among processed OP. The red GP was collected and processed as an antioxidant additive for asphalt binder. The results of red GP-modified asphalt confirmed that the grape seed fraction had better antioxidant effectiveness than the grape skin fraction and whole GP. The Chico State team also evaluated the cracking resistance of pomace-modified asphalt mixtures. The control baseline mix is the mixture with 25% reclaimed asphalt pavement (RAP) and 5.4% binder content (BC). This mix had a low cracking resistance. Asphalt mixtures with pomaces were produced using wet and dry mixing methods. It was found that when pomace was used as the binder replacement at 15%, the mixture became stiffer, and cracking resistance was reduced. When the pomace was used as the binder extender to keep the effective binder content the same, the cracking resistance was improved. The dry mixing method was used to replace the aggregate filler finer than 0.075mm with processed pomace. The strength of asphalt mixtures with pomace using the dry mixing method was significantly reduced. These findings will guide the production of asphalt mixtures with pomaces. The Chico team also collaborated with the Lamar Team on the life cycle analysis (LCA) for pomace-modified asphalt mixtures. Objective 3, led by the WSU team (transferred to the University of Miami (UM) team on 11/01/ 2024), is to maximize the yield of pomace to green chemicals for the anti-icing application during the winter maintenance. The UM team investigated various sequential treatments on biomass conversion, including water treatment, alkali treatment, and enzymatic treatment, to maximize the weight loss of biomass for use as deicers. The findings revealed that water treatment significantly affected biomass weight loss, and the optimum sample showed a weight loss of 25.0%. Alkali pre-treatment with sodium hydroxide (NaOH) could remove lignin from biomass and improve the accessibility of cellulose and hemicellulose for enzymatic processing. The results indicated that NaOH treatment significantly enhanced biomass decomposition, leading to weight losses between 20% and 66%. Enzymatic decomposition experiments were conducted using different enzymes, including Cellulase, Hemicellulose, Xylanase, Mannanase, Galactosidase, and Pectinase. The results showed that cellulase treatment at 50°C for 168 hours yielded the highest conversion rate of 33.7%. The chemical oxygen demand (COD) experiments were conducted to assess the organic load of biomass leachate after water, enzymatic, and alkaline pretreatments. Alkali-treated biomass extracts (e.g., Alkali-GP and Alkali-OP) exhibited the highest COD values, indicating that the alkaline treatment was the most effective to break down complex components like lignin and hemicellulose into soluble, oxidizable organics. Water-treated extracts before the alkali treatment showed moderate COD, reflecting the release of readily soluble sugars and low-molecular-weight compounds. Enzymatic-treated extracts after water and alkali treatments had the lowest COD, suggesting that most oxidizable organics had already been extracted in the previous steps. Enzymes primarily targeted structural carbohydrates that did not significantly raise COD. This trend (Alkali > Water > Enzyme) confirmed that alkaline treatment is important to solubilize oxidizable organic matter. Ice melting tests were performed to evaluate the effectiveness of treated biomass extracts compared to conventional salt-based deicers. Ice melting tests were conducted using NaCl 23% (30 mL) and modified formulations with water-, alkali-, and enzymatic-treated biomass extracts. Replacing part of NaCl with water reduced the melting capacity. Adding GP or OP helped recover performance, and alkali pretreatment further improved effectiveness. Alkali-GP reached 83% of the control's capacity. Further tests will be conducted to optimize the ice melting capacity with biomass extracts. The University of Lamar team started objective 4 as planned. The team used a process flow diagram (PFD) simulation software package (SuperPro Designer) and chemical process simulator (ASPEN Plus) to estimate energy consumption and LCA for GP and OP transportation and processing. AnASPEN Plus modeling simulation was used to calculate the global warming potential (GWP) based on Open LCA and Sphera (GaBi) databases for four processing scenarios, including whole GP, GP seed, olive pulp (dry process), and olive pulp (wet process). It was found that the drying process accounted for more than 90% energy consumption and GWP. Based on the sensitivity analysis, reducing the initial moisture content from 60% to 20% using renewable energy sources can lower the carbon footprint by more than 70%. The energy demand for GP seed is significantly higher than for whole GP due to a lower yield, as GP skin was separated. However, the GP seed exhibited better antioxidant effectiveness than whole GP. Thus, optimization will be done to balance engineering performance, energy consumption, and environmental benefits of using pomaces in roadways. In addition, the PFD and ASPEN were used to explore the alternative uses and conversion of pomaces into polyphenol antioxidants, bio-oil, biochar, and syngas for the zero-waste recycling of GP and OP.
Publications
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Progress 05/01/23 to 04/30/24
Outputs
Target Audience:The target audiences for this project are stakeholders from the olive and grape food industries (e.g. California Olive Ranch and Welch's), and pavement and anti-icing industries, including but not limited to, practitioners in the state Department of Transportation, city public agencies, winter road maintenance, and producers of deicer and asphalt. The team reached out to stakeholders who provided letters of support for this project when the project was awarded, including Olive Oil Commission of California (OOCC), City of Chico, City of Kirkland/WA, WSU Facilities Services, Massachusetts DOT, County of El Dorado/CA, and Idaho Asphalt Supply. The team also reached out to Welch's in WA and UC Davis Experimental Winery in CA to collect grapepomace and California Olive Ranch to collect olive pomace used in this project. Dr. Kun Zhang at California State University Chico hosted engineers from FHWA and Caltrans to visit Chico State Labs on November 6th, 2023. Dr. Zhang discussed this USDA-funded research project and potential field trials. The UC-Davis team shared the most recent project results with the Olive Oil Commission of California in April 2024. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?In this project, one postdoc, one graduate student, and three undergraduate students at UC Davis were trained to conduct experiments for Objective 1. Four undergraduate research students at Chico State were trained to conduct experiments for objective 2 with a total number of 430 hours of working. One postdoc and twoundergraduate research students at WSU were trained to work on this project for objective 3. The PD attended the 2023 Association of Asphalt Paving Technologies (AAPT) annual conference to learn the latest additives and methods to evaluate the antioxidant and ani-aging performance of asphalt paving materials. How have the results been disseminated to communities of interest?The UC-Davis team shared the most recent project results with the Olive Oil Commission of California in April 2024. The PD of this project delivered a poster presentation titled "Utilization of Agricultural Waste (Olive and Grape Pomaces) to Improve the Service Life and Sustainability of Roadways" at the Chico State Enterprises Sponsored Program Showcase on April 15th, 2024. This poster presentation aims to connectthe local community onagricultural and food byproducts recycling. What do you plan to do during the next reporting period to accomplish the goals?In the next reporting period, the planned activities to achieve Objective 1 include continuing enzyme experiments along with developing GP and OP methods for the LC-MS for targeted quantification for all samples of interest. Compounds with anti-icing properties and antioxidant performance will be analyzed via targeted analysis as well as untargeted analysis. More correlation analyses will be conducted to establish the relationship among bioprocessing, chemical compositions, and engineering performance for pomace-derived additives for antioxidation and anti-icing implementation. The processed pomaces via the enzymatic treatments will be used to modify asphalt binder and compare the antioxidant performance with the modified asphalt binders in this reporting period. In addition, the engineering performance of asphalt mixtures that blend aggregates and pomace-modified asphalt binders will be evaluated. The performance data will be used as inputs to conduct life cycle analysis and life cycle cost analysis in Objective 4 with the Lamar Team. The WSU team plans to complete the analysis of testing results of blends incorporating the Welch Company grape pomace extract, California grape pomace extract, and the California olive pomace extract and potentially modify the experimental program for them accordingly and then design and execute a design of experiments (DOE), which aimed to explore how to enhance the parameters of the chemical and microbial digestion process to maximize the yield and efficacy of the green chemicals (including organic phosphates). Furthermore, the WSU team will work with the UC Davis team to analyze the chemical composition of the 18 California grape pomace extracts (via LC-MS, FITR, etc.). Field tests will be conducted to evaluate anti-icer formulations during the 2024-2025 winter season. The Lamar team will start working on this project as planned. The process model of conversion of raw olive and pomaces to antioxidant and anti-icing additives will be established. The life cycle methodologies will be conducted to determine the environmental and economic benefits of using pomace-derived additives for roadways.
Impacts
What was accomplished under these goals?
This project aims to repurpose olive and grape pomaces as agricultural and food wastes to pavement antioxidants and anti-icing additives through bioprocessing and biorefining technology. The main accomplishments to achieve the first three objectives of this study are discussed below. The work was completed as planned. Objective 4 will start in Year 2 of this project. To achieve objective 1, the UC-Davis team determined total phenolic content (TPC), limited specific phenolics content, oil content, and moisture content of grape pomace (GP) and olive pomace (OP)-derived antioxidants. The GP was processed to GP-whole, GP-Seed-rich, and GP-Skin-rich. The OP was processed to OP-whole, OP-Pulp-rich, OP<0.3mm, and OP>0.3mm fractions. These additives were also heated at 160 °C for 1 hour to further dry additives before adding to asphalt binders. It was found that GP-Seed-rich had the highest TPC among the GP additives. The OP-pulp had the highest oil contents among the OP additives. These chemical composition test results were correlated with engineering performance and discussed in Objective 2. For specific phenolics in the GP samples, epicatechin was found to be the most abundant and procyanidin-B3 was second. More accurate quantification for Grape Pomace and Olive Pomace will be analyzed. For the moisture content, as expected, samples that were heated for 1 hour at 160 °C had lower percent moisture than their unheated counterparts. Furthermore, the GP samples had a higher percent moisture than the OP samples. The bioprocessing experiments using enzymes, including Cellulase, Pectinase, and Tannas, were conducted to increase the TPC of grape and olive pomace. In this reporting period, the GP-Seed-rich fraction was selected and conducted at various pH conditions and buffer solvents. There was little to no increase in TPC based on the preliminary results, but the team will explore new enzymes and optimal conditions to increase TPC of grape and olive pomace as antioxidant additives. The Chico State team leads objective 2 for the zero-waste recycling of GP and OP as antioxidant additives in asphalt paving materials. Two commonly used antioxidant additives (Zinc diethyldithiocarbamate (ZDC) and Kraft Lignin) were used as reference antioxidant additives to compare with pomace-derived antioxidant additives. The dosages for these two additives are 3% and 5% based on wt% of asphalt binders, which had performance grade (PG) of PG58-22 and PG64-22. It was found that ZDC exhibited antioxidant effectiveness to retard asphalt aging rate after long-term aging test. The ZDC-modified asphalt binders have better low-temperature thermal cracking resistance and resistance to aging-induced cracking. However, kraft lignin did not provide antioxidant effectiveness after the long-term aging. The GP of white grape (Sauvignon blanc) was collected from the UC Davis Experimental Winery in California. Grape Pomace was processed by drying and grinding. The PG 64-22 binder was modified by GP-whole at 10%, 15%, and 20% by wt% of asphalt binder. In addition, the GP-Seed-rich fraction and GP Skin-rich fraction were separated using No.8 sieve and also used to modify asphalt binders at the 15% by wt% of asphalt binder. It was found that the GP-Seed-rich fraction could help improve the low-temperature cracking resistance and resistance to aging-induced cracking after the long-term aging. The GP-Skin-rich fraction could stiffen the binder due to the existence of wax in grape skin. The OP-whole, OP-Pulp-rich, and OP<0.3mm was processed and blended with asphalt binder at 15%. It was found that the OP-Pulp-rich has better antioxidant effectiveness than the OP-whole and OP<0.3mm. Correlation analysis was conducted to establish chemical composition analysis results, including total phenolic content (TPC) and oil content with anti-aging performance of pomace-modified asphalt binders. It was found that for grape pomace, the TPCs in GP-Skin-rich, GP-whole, and GP-Seed-rich have a strong correlation with the rheological aging index (Glover-Rowe (GR) parameter) of laboratory long-term aged asphalt binders. The phenolic compounds work as free radical scavengers to retard asphalt aging. The oil contents in OPs have a strong correlation with GR of long-term aged binders. These preliminary results indicate that grape pomace and olive pomace may have different modification mechanisms to interact with asphalt binders. The Fourier Transform Infrared Spectroscopy (FTIR) tests for ZDC, Kraft Lignin, Pomace-derived antioxidant additives, and modified asphalt binders were tested. The Carbonyl Index (Ic) was calculated as the chemical aging index to characterize the asphalt aging evolution. The preliminary analysis showed that pomace-modified asphalt binders had higher Ic than the control binder, but they had a lower increase rate of Ic. The objective 3 led by WSU team is to maximize the yield of pomace to green chemicals used as anti-icing additives for pavement infrastructure. In this reporting period, the team secured two grape pomace samples from UC Davis via Chico State and Welch Company in the State of Washington, and olive pomace from California Olive Ranch via Chico State. The Welch grape pomace exhibited signs of natural fermentation and thus looked different than the Davis pomace. The WSU team has focused on further development of the WSU technology in the laboratory to derive "green chemicals" from pomaces. Our approach is to develop anti-icing liquids consisting of cost-competitive chemicals (extracts from grape and olive pomaces), rock salt, and other additives with minimal toxicity (low in N and P and without heavy metals). The optimized addition of renewable additives to salt brine will enhance its anti-icing performance at cold temperatures at reasonable costs, while producing substantial savings through reduced application rates, reduced corrosion to metals, and reduced impact on concrete or asphalt materials, etc. We have tested the properties of "green chemicals" extracts using the grape pomace sample from Welch Company's inventory in the State of Washington or using the olive pomace sample from the State of California. For these two feedstocks, we followed our previously reported process to derive the extracts. The results of corrosion inhibition and ice melting using the blend of each extract, NaCl brine, sodium metasilicate, etc. are being analyzed. The WSU team has also executed a statistical design of experiments (DoE) using the grape pomace sample from the State of California, aimed to explore how to enhance the parameters of the chemical and microbial digestion process to maximize the yield and efficacy of the green chemicals (including organic phosphates). The multi-objective experimental design and optimization explored the following process parameters: fermentation time (14 vs. 21 days), fermentation temperature (38 vs. 25C), pomace/urea mass ratio (15%, 20%, vs. 25%), cultured bacteria dosage (50, 150, vs. 100 ml), initial pH value for bacteria growth (8.0, 9.0, vs. 8.5), and phosphate/pomace mass ratio (0.7%, 1.4%, vs. 2.1%). The three main objectives are yield of green chemicals, degradation degree, and corrosion inhibition efficiency of the extract. The statistical DoE is an orthogonal (Taguchi) design, with 6 factors (quasi-horizontal method), and 16 runs each with triplicates. The 18 runs for the use of California-sourced grape pomace as the feedstock was completed and the extract (liquid) samples were shipped to UC Davis for chemical composition. In summary, all stated goals and tasks of the project are carried out as planned. There is no changes for this project.
Publications
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