available, a capital expense for additional compression should be included. • The Divi-H membrane life is estimated at five years. All analysis of ROI and cost/kg separated was conducted over a five-year cycle. Longer time windows improve the eco - nomics. The fibre replacement that would occur in year five is cheaper than the original capital expenditure, as cartridge housings and ancillary equipment are not included. • Module cost for a 10in diameter, 3m length membrane module was assumed to be $80,000. This is a rough con - servative estimate based on current manufacturing costs and projected savings with scale-up. Ancillary equipment, including piping, valving, and pressure control, was esti - mated to be 50% of total module and housing costs. • A rate of $0.08/kWh was assumed when converting compressor duty to cost. This is the current average indus - trial electricity cost in the US. Below are definitions that may be useful for understand - ing the simulation data: • Permeate : The gas stream that permeates through the membrane surface, in this case hydrogen. • Retentate : The gas stream that does not permeate through the membrane surface. • Permeance : How much gas permeates the membrane per unit surface area. • Selectivity : How many molecules of one gas will pass through the membrane per one molecule of a different gas. • Purity : Mol% hydrogen in the stream. • Recovery : The percentage of feed hydrogen that ends up in the permeate.
• Single-stage: Membrane separation conducted with a single-pass through membrane modules set up in parallel flow configuration. • Two-stage : Membrane separation conducted with two passes through membrane modules in series. • High-throughput fibre : Designed by Divigas to prioritise permeance (gas throughput) over selectivity (purity). • Balanced fibre : Designed by Divigas to balance perme - ance and selectivity. • High-purity fibre : Designed by Divigas to prioritise selec - tivity over permeance. ROG streams will be a crucial source of hydrogen in refiner - ies as product regulations and crude processing requirements drive increased hydrogen demands. The need will further increase as energy companies look to limit heavy sources of carbon within their operations to meet net zero goals by 2050. As refiners shift from SMR produced grey hydrogen to green or blue, costs will increase, lowering the economic barrier to downstream hydrogen recovery and purification. Part 2 in the Q3 issue of PTQ will review sample ROG streams produced from several hydrotreaters, a hydroc - racker, an isomerisation unit, and a catalytic reformer for their potential separation and purification via Divi-H, References will be included in Part 2. Zach Foss is Director of Business Development for Divigas, responsi - ble for sales, marketing, strategic initiatives, and project management. He has 10 years of experience in the manufacturing and sale of down - stream petrochemical and specialty products. He holds a BS in chemical engineering from University of Texas. Email: Zach.foss@divigas.com
ac24_Decarbonisation Technology Magazine_178x125.indd 1
23.10.2023 07:52:37
35
Gas 2024
www.digitalrefining.com
Powered by FlippingBook