This Small Business Innovation Research Phase I project proposes a fundamentally new means for biogas (landfill gas) desulfurization that produces less waste, allows recycle of recovered sulfur, and provides annualized operating costs a fraction of current practice. Inexpensive biogas cleanup is required for subsequent combustion, fuel cell usage, or conversion to liquid fuels. The costs of gas clean up and spent sorbent disposal currently dictate the cost of biogas conversion to clean energy. The proposed two-stage process is a synergistic combination of: a novel Oxidative Sulfur Removal (OSR) catalyst formulation producing elemental sulfur; a wide temperature range regenerable downstream polishing sorbent; and a unique in situ sensor permitting optimal adsorbent bed operation and cycling. Current technology produces 125 tons of spent adsorbent for a 500kWe biogas combustor. Ironically, this adsorbent must be landfilled. The proposed process could reduce adsorbent waste 7-20 times and yields elemental sulfur that can be recycled into the fertilizer industry. The OSR catalyst is anticipated to be contaminant-tolerant in practice. Major innovations of the proposed approach include: long-life OSR catalyst, high selectivity to elemental sulfur, high activity and low-cost catalyst, real-time in situ adsorbent capacity monitoring to maximize material utilization and further reduce costs.
The broader impact/commercial potential of this project includes the greatly enhanced ability to utilize biogas for alternative and renewable energy production facilities with significantly reduced carbon and waste footprints and process costs. The proposed process is thermodynamically efficient and readily scalable to a variety of locations and capacities. The proposed process has the ability to remove sulfur contaminants to very low levels thereby enabling catalytic conversion of biogas to higher value liquid fuels and chemicals. Recovered elemental sulfur can be utilized directly as a fertilizer additive. In short, the proposed innovation permits biogas desulfurization and subsequent usage in a more economic and environmentally friendly manner than current approaches. The proposed process is also capable of cleaning biogas and other gas sources with high sulfur contents (ca. 1-3%) without a significant increase in process costs. Besides biogas, other gas streams including natural gas, frac gas, petroleum gas, and syngas from a variety of sources can be desulfurized. Therefore, BTL, CTL, GTL, and renewable electric power generation can be impacted by the success of this innovation.
Normal 0 false false false EN-US ZH-CN X-NONE IntraMicron has completed the SBIR Phase I Project on the desulfurization technology suite (IM-TDS) for biogas and landfill gas. The technology suite includes oxidative sulfur removal (OSR) and bed life sensor (BLS). During Phase I period, the selected OSR catalyst demonstrated high oxidation activity, high elemental sulfur selectivity and high tolerance to contaminates such as halides and ammonia. It had been tested continuously for more than 1 month without obvious deactivation. BLS was tested for various types of sulfur sorbents. The signals obtained from BLS preciously predicted the breakthrough of the adsorbent beds. On the successful development of this technology suite, IntraMicron believes that this groundbreaking technology suite will lead to the following outcomes: (1) Sorbent-free desulfurization approach for high sulfur tolerance applications Some applications such as pipeline gas production, CHP and SOFC based power generation can work well with relatively high sulfur contents. For example, CHP can take a few hundred ppm of sulfur and most recent SOFC, especially those high temperature ones, can tolerate 20-50 ppm of sulfur. For these types of applications, a single OSR reactor can reduce the sulfur concentration to desire levels. There may not be any need for adsorbent bed. As a result, the gigantic adsorbent beds with labor and chemical intensive operation will be replaced by much smaller OSR reactors, and the desulfurization cost be reduced by 15-65 percent. (2) Gauged sulfur capacity for streams with significant sulfur concentration variation. The bed life sensor technology, for the first time, adds sulfur capacity meters for various adsorbent beds. A series of bed life sensors placed along the sorbent bed can clearly indicate the adsorption frontier and the remaining sulfur capacity so that the adsorbent bed can be replaced or regenerated at the point of capacity depletion. This will provide significant convenience to adsorbent bed operations (e.g. sorbent changes) and maximize adsorbent utilization. This benefit of using BLS cannot be overemphasized, especially for the desulfurization system with significant fluctuation in the sulfur concentrations (e.g. the daily and seasonal sulfur concentration changes in biogas and landfill gas). (3) Optimal desulfurization technology suite for low-sulfur-tolerance applications IntraMicron’s Desulfurization Technology Suite, the integration of OSR and BLS, provides an optimal solution for applications or processes with very low sulfur tolerance such as various BTL, CTL, GTL processes. For these applications, an OSR reactor is followed by an adsorbent bed assisted with BLS. OSR removes a majority of the sulfur from gas-phase streams with significant reductions in reactor size, material consumption, and solid waste generation; an adsorbent bed monitored with a BLS can further reduce the sulfur to desired levels with improved adsorbent utilization. It is estimated that the combination provides a 11-31 fold reduction in reactor size, a 25-85 fold reduction in solid waste generation, and a 15-65 percent reduction in desulfurization cost, compared with traditional adsorbent only approach. (4) Feasibility to utilize resources with high sulfur resources Due to the high desulfurization cost, high sulfur-laden resources such as biogas/landfill gas, sour gas, associated gas, etc. cannot be utilized economically. IM-DTS provides low-cost desulfurization solution compared with current state-of-the art approaches. It enables the use of these resources and turns them into valuable fuel sources, which will certainly improve the energy security of the United States.
