Today about 98% of 70 million tonnes of H 2 comes from carbon-intensive sources. Carbon- neutral energy is receiving unprecedented attention. While green H 2 is the ultimate goal of the H 2 economy, blue H 2 is viewed as the first step to this goal. Proven technologies combined with anticipated greater demand for H 2 and government incentives like 45Q in the US are making blue H 2 projects economically attractive and bankable. Wabash Valley Resources project The idle Wabash River gasification facility will be redeveloped by Wabash Valley Resources to produce electricity to be transferred to the network grid and provide opportunities for H 2 offtakes to transportation or be used as chemical feedstock. It is anticipated to use waste products like petroleum coke and locally available biomass to generate up to 285 MW of electricity with net-zero CO 2 emissions by 2024. The project will capture, liquefy and sequester the produced CO 2 near the plant site in suitable underground formations of the Illinois Basin. Retrofitting the existing gasification facility reduces the technical risk and capital costs associated with the project. The Wabash gasification plant has successfully produced syngas for over 20 years, utilising petcoke as the feedstock, and the configuration selected maintains the existing plant as is with minimal modifications. Several processes are combined in the integrated facility to produce H 2 and power. Byproducts produced at the facility include CO 2 , sulphur and vitrified slag. The solid feedstock and biomass
are milled with recycled water to produce a slurry solids concentration that varies depending on the feedstock selected. In the gasifier, the slurry is injected with a high-purity oxygen stream generated by the air separation unit. Raw syngas exiting the gasification process consists mostly of carbon monoxide, H 2 , CO 2 , water and hydrogen sulphide (H 2 S). The slag produced in the gasifier is quenched, crushed and removed from the unit through a continuous slag removal system. The syngas from the gasifier is cooled in a high- temperature heat recovery unit (HTHRU) that produces high-pressure saturated steam, which will be utilised in the steam turbine to produce power. The syngas from the outlet of the HTHRU is sent to a particulate removal system, where the remaining particulates consisting mostly of carbon will be recycled to the gasifier. The syngas will be directed through the existing sulphur removal process, where the H 2 S will be removed. The sour gas containing H 2 S from the sulphur removal process will be sent to the existing sulphur recovery unit (SRU). The SRU converts the H 2 S to elemental sulphur, a valuable byproduct of the facility. The syngas will be routed to the new water gas shift (WGS) process to shift the syngas to maximise H 2 production. Syngas will then be routed through a new CO 2 recovery system to be designed and licensed by Honeywell UOP. A dehydration unit is included to produce an anhydrous gas suitable to be sent to the new CO 2 fractionation unit. The CO 2 fractionation unit will then separate the CO 2 from the H 2 , producing a high-purity liquid
CO 2 stream. The liquid CO 2 stream will be pumped to the battery limits for permanent underground sequestration. The H 2 gas stream will then be sent to a PolyBed pressure swing absorption unit (PSA) for purification. The product H 2 stream from the PSA will be sent to a H 2 turbine to produce electricity. The CO 2 from the PSA unit will then be recycled to the CO 2 fractionation unit to ensure minimal emissions of greenhouse gases (GHG). Since Wabash Valley Resources is investigating blending in biomass feedstocks,
12% Biomass
88% Solid waste
CO
CO atmospheric draw down
Hydrogen
UOP technology Capture & liquefy CO
CO
Capture
Storage- Deep geologic formations
Transport
Figure 1 Overall flow scheme
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