Hydrogen exploration: a review of global hydrogen accumulations and implications for prospective areas in NW Europe

Abstract

From a geological perspective, hydrogen has been neglected. It is not as common as biogenic or thermogenic methane, which are ubiquitous in hydrocarbon basins, or carbon dioxide, which is common in geologically-active areas of the world. Nevertheless, small flows of hydrogen naturally reach the Earth's surface, occur in some metal mines and emerge beneath the oceans in a number of places worldwide. These occurrences of hydrogen are associated with abiogenic and biogenic methane, Further research should aim to identify the extent of the hydrogen flux and its probable dominant role in the abiogenic production of hydrocarbons in Precambrian times, a natural process now largely replaced by biogenic participation. A similar industrial process replicates serpentinization, producing hydrogen and ultimately liquid hydrocarbons on a commercial scale in some countries. It remains to be proved whether a contribution from exploration can be made to any future Hydrogen Economy.

Abiotic Methane on Earth

“…Serpentinization, that is hydration of olivine and/or pyroxene, produces H 2 which then may react with C-gases (CO 2 or CO) forming CH 4 . The FTT synthesis, however, may be independent of serpentinization, whereby H 2 in many rocks can derive from other processes, such as radiolysis, cataclasis of silicates in fault zones, or magmatic degassing [Smith et al, 2005;Onstott et al, 2006].…”

Methane Seepage on Mars: Where to Look and Why

“…The H 2 necessary for FTT-Sabatier reaction can derive from different sources: serpentinization, radiolysis, cataclasis of silicates in fault zones, or magmatic degassing (Smith et al, 2005 ). Serpentinization, in particular, is widely invoked as a source of CH 4 on Mars ( e.g., Oze and Sharma, 2005 ; Atreya et al, 2007 ).…”

Global rate and distribution of H2 gas produced by serpentinization within oceanic lithosphere

“…An increasing number of discoveries in both continental and oceanic lithosphere suggest that free H 2 is not as rare as once thought [Apps and van de Kamp, 1993;Smith et al, 2013]. A quantitative understanding of H 2 production by serpentinization, as well as other known abiotic and biotic sources, represents a challenging but important research frontier that bears on many open questions across the geosciences [e.g., Apps and van de Kamp, 1993;Hoehler et al, 2001;Bach and Edwards, 2003;Sherwood Lollar et al, 2014;Telling et al, 2015].…”

“…Of the various processes that can generate free hydrogen gas (H 2 ) in the lithosphere, field evidence suggests that one of the principal mechanisms is the hydration of ferrous iron minerals or “serpentinization” reactions [ Apps and van de Kamp , ]. The H 2 produced by serpentinization in turn figures prominently in theories regarding (1) the origin and early evolution of life on Earth [e.g., Canfield et al , ; Sleep and Bird , ], (2) the basal fuel‐source sustaining the subsurface biosphere [e.g., Charlou et al , ; Kelley et al , ; Menez et al , ], (3) the formation of abiogenic hydrocarbons [ McCollom and Seewald , ; Sherwood Lollar et al , ; Proskurowski et al , ] as well as (4) native metal alloys [ Dekov , ; McCollom and Bach , ], (5) the biogeochemical cycling of elements such as sulfur and carbon [ Alt et al , ], and (6) the potential use of H 2 as a substitute for fossil fuels [ Smith et al , ].…”