Grantee Research Project Results
Single-Stage Process for Biogas Purification
EPA Grant Number: SV840418Title: Single-Stage Process for Biogas Purification
Investigators: Lashaki, Masoud Jahandar , Meeroff, Daniel , Bloetscher, Frederick , Ayub, Ali , Ahsan, Sara , Thomas, Ryan , Guirard, Mitch , Lam, Dung , Deshommes, Julie , McFadden, Megan , Owen., Tyler , Li, Diego
Current Investigators: Lashaki, Masoud Jahandar , Meeroff, Daniel , Bloetscher, Frederick , Hosseini, Amirjavad , Nutter, Brandyn , Rojas, Laura , Smith, Jalyn , Cowart, Jason , Mugan, Sierra
Institution: Florida Atlantic University - Boca Raton
EPA Project Officer: Page, Angela
Phase: II
Project Period: November 1, 2022 through October 31, 2024
Project Amount: $100,000
RFA: 17th Annual P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet - Phase 2 (2022) Recipients Lists
Research Category: P3 Awards
Description:
Biogas is a cleaner source of renewable energy that may be produced in farming communities or commercial facilities by anaerobic digestion of agricultural and municipal organic waste or dedicated crops. Similarly, landfill gas is a natural by-product of anaerobic decomposition of organic waste in landfills. Biogas and landfill gas have similar composition and primarily consist of methane and carbon dioxide, in addition to ubiquitous compounds such as water vapor, hydrogen sulfide, and siloxanes. If not properly managed, the decomposition of organic waste on farms and in municipal landfills generate uncontrolled emissions of hydrogen sulfide, carbon dioxide, and methane, the last two being potent greenhouse gases. Hydrogen sulfide is not only a well-known air pollutant with adverse human health impacts, but also causes severe odor issues in the communities adjacent to landfills and farms. It is, therefore, prudent to produce biogas from agricultural waste on farms and collect landfill gas to minimize such adverse environmental, health and societal impacts. Biogas and landfill gas are typically used locally for heat and power cogeneration. However, added benefits are generated by upgrading biogas and landfill gas into high-purity biomethane, also known as renewable natural gas, which can be injected into natural gas pipelines for use as a carbon-neutral fuel. Current technologies for biogas and landfill gas purification are often costly, multi-stage processes because they require multiple separate upstream units for desulfurization, drying, and compression or cooling of the feed gas before carbon dioxide removal.
Objective:
The overarching goal of this research, therefore, is to develop an alternative upgrading technique capable of integrating (i.e., reducing the number of treatment units) and intensifying (i.e., decreasing power consumption) the purification process.
Approach:
Adsorption remains one of the most competitive gas separation techniques because of its simplicity of operation, low energy requirements, and the availability of a large array of adsorbents. We propose that a cyclic adsorption-desorption process using amine-modified silica materials, also known as aminosilicas, can integrate and intensify the biogas and landfill gas upgrading process. This technique consists of an adsorption step in which all impurities are simultaneously removed from biogas and landfill gas to produce high-purity biomethane. Once saturated with the impurities, the adsorbents are regenerated at elevated temperatures in the presence of air to recover their adsorption affinity for the subsequent cycle. Aminosilica properties, however, should be tailored to fulfil the cost, performance, and stability requirements of this process. Explicitly, the materials should be (i) capable of simultaneous and reversible removal of all impurities, while letting methane through, (ii) compatible with ultra-rapid adsorption-desorption cycling to maximize biomethane production, (iii) stable in the presence of hot air, and (iv) inexpensive.
Expected Results:
During “Phase I”, over 100 aminosilicas were synthesized using commercial mesoporous silica supports with various particle sizes, and different amounts of water and amine. All materials were assessed in terms of organic content, amine content, equilibrium carbon dioxide uptake in the presence of dry feed gas, and amine efficiency. Sixteen aminosilicas with equilibrium uptake greater than 6 wt.% were chosen for further analysis in terms of adsorption kinetics. Three aminosilicas with the fastest kinetics were selected for additional investigation in terms of thermal and oxidation stability. Considering all the above results, one final candidate was chosen for column-breakthrough experiments in the presence of dry and humid carbon dioxide and hydrogen sulfide. The results indicated that the final candidate can effectively and concurrently remove all the major target impurities, namely water vapor, carbon dioxide, and hydrogen sulfide. The final aminosilica was also studied in the presence of synthetic landfill gas samples to conclude “Phase I” research. For “Phase II”, the research will build on “Phase I” findings, particularly investigating aminosilicas capability to remove other landfill gas and biogas impurities (e.g. siloxanes) and further improving the long-term stability of aminosilicas.
Publications and Presentations:
Publications have been submitted on this project: View all 3 publications for this projectSupplemental Keywords:
green chemistry; treatment and emission control technologies; waste to energy; chemicals; toxics; clean technologies; sustainable development; global climate; southeast; Florida; FL; Atlantic coast; EPA Region 4Progress and Final Reports:
P3 Phase I:
Single-Stage Process for Biogas Purification | 2021 Progress Report | Final ReportThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.