The cold high-pressure approach to hydrogen delivery

Abstract

In view of the very expensive and wasteful nature of today's approaches to H2 delivery, we explore the possibility of transporting cold (200 K) high pressure (875 bar) H2 in thermally insulated trailers and dispensing H2 directly from the trailer, with the potential to eliminate station compressor, cascade, and refrigerator, leading to major reductions in station complexity, maintenance, electricity consumption, and cost, while improving functionality by enabling essentially unlimited back to back refuels, and improving safety due to reduced H2 expansion energy at low temperature.Detailed techno-economic analysis shows promise for substantial delivery cost reductions through cold high pressure H2 dispensed directly from the trailer. Results indicate that: (1) Terminal operations for cold high pressure H2 delivery are $0.32/kg H2 more expensive than for 350 bar compressed gas delivery (today's lowest cost H2 delivery technology) due to higher level of pressurization (to 1000 bar) and chilling needs (to 165 K). (2) Trailer cost drops slightly ($0.73 vs. $0.81/kg H2 for a 350 bar trailer) due to increased capacity (1035 kg H2 delivered vs. 700 kg) compensating for increased capital cost ($906,900 for cold high pressure H2 vs. $634,000 for 350 bar trailer). (3) Cold hydrogen delivery presents major advantages in fueling station cost, reduced from $1.27 to $0.46/kg H2 due to elimination of major system components: compressor, cascade, and chiller. (4) Total compression cost (terminal + station) drops from $0.92/kg H2 ($0.32 terminal and $0.60 station) for 350 bar trailers to $0.55/kg H2 (all at the terminal) for cold high pressure H2. (5) Elimination of small-scale station compressors is the main contributor to reduced delivery cost due to their inefficiency, capital expense, and maintenance needs. In summary, total delivery cost reduction vs. 350 bar trailer equals $0.58/kg H2 (from $2.96 to 2.38/kg H2), equivalent to 24% of the total delivery cost. This large cost advantage will improve the economics of H2 vehicles facilitating the transition to a future of zero emission transportation.