Life-cycle greenhouse gas emissions of biomethane and hydrogen pathways in the European Union

A caller life-cycle investigation of perchance low-greenhouse-gas options for producing hydrogen successful Europe finds that lone hydrogen produced utilizing renewable energy tin beryllium efficaciously zero-emission, and that hydrogen pathways involving fossil fuels, adjacent with c seizure and storage, person greenhouse-gas (GHG) strength precocious capable to marque it improbable they tin lend to gathering the European Union's clime targets. The study, from the International Council connected Clean Transportation (ICCT), besides recovered that waste-based biomethane accumulation pathways mostly person antagonistic GHG intensity, but are taxable to important uncertainties.

The investigation appears arsenic the European Union is revising its Renewable Energy Directive (REDII), which governs improvement of renewable vigor crossed each sectors of the system successful Europe. The revision is portion of the EU's "Fit for 55" bundle of measures to present connected the European Green Deal, the EU's wide-ranging connection to thrust nett GHG emissions down 55% by 2030 and scope c neutrality by 2050.

"Hydrogen made from electrolysis powered by renewable energy is fundamentally 'climate-clean' from accumulation to use," noted ICCT researcher Yuanrong Zhou. "And it's the lone efficaciously zero-carbon hydrogen enactment that could beryllium brought to standard successful Europe."

The investigation recovered wide saltation successful the GHG strength of 8 hydrogen accumulation methods successful the EU, each of which utilized antithetic feedstocks oregon processes. Some of the hydrogen pathways impact archetypal producing biomethane and past converting it to hydrogen. The modeled pathways, from lowest to highest successful GHG intensity, are wastewater sludge biomethane, renewable electricity, biomass gasification, natural gas combined with carbon capture and retention (CCS), LFG biomethane, manure biomethane, 2030 EU grid electricity, and ember with CCS. GHG strength is measured arsenic GHGs emitted per portion of vigor produced.

Only 3 of these pathways conscionable the 70% GHG simplification threshold (compared to petroleum) required for hydrogen successful the REDII: Wastewater sludge, renewable electricity, and wood biomass residue (see figure). The highest GHG intensities among the 8 pathways modeled were hydrogen produced from ember positive CCS and hydrogen from 2030 EU grid electricity. These bash not conscionable the 70% GHG simplification requirement.

The interaction of accumulation processes connected GHG strength is wide successful the study: hydrogen produced from electrolysis powered by star and upwind vigor has a overmuch little GHG strength than erstwhile the energy for electrolysis comes from the projected EU 2030 vigor mix.

The survey recovered that accumulation based connected wastewater sludge scored debased successful GHG intensity. But sludge is not a reliably low-GHG enactment for hydrogen accumulation due to the fact that of the hazard of methane leakage implicit its beingness cycle. Because methane is simply a almighty greenhouse state with a important effect connected climate, adjacent tiny leakages successful the accumulation signifier tin offset the imaginable clime benefits of utilizing hydrogen. In fact, the survey highlights the precocious clime hazard of immoderate hydrogen accumulation enactment that relies connected methane (the earthy state and biomethane pathways), owed to the hazard of leakage.

In summation to hydrogen production, the survey examined biomethane produced from 4 feedstocks: wastewater sludge, landfill gas, manure, and silage maize. Biomethane could perchance present important emissions reductions, but similar hydrogen derived from methane, the assorted options for producing it besides carries a hazard of methane leakages.

"Policymakers should look cautiously astatine the greenhouse state profiles of options for producing and utilizing hydrogen," said Zhou. "Some options that look promising whitethorn really harm the clime unless processes crossed their beingness rhythm enactment perfectly—which is seldom the case."

The survey urges EU argumentation makers not to adhd fossil-based hydrogen arsenic an eligible pathway successful the RED II revision oregon incentivize it successful immoderate different policies. Instead, EU policymakers should follow rules for the RED II requiring that electrolysis hydrogen beryllium produced from genuinely further renewable electricity. It besides recommends that policymakers usage rigorous and transparent life-cycle investigation for evaluating hydrogen accumulation pathways. These recommendations volition assistance guarantee that EC argumentation lone supports state pathways accordant with a imaginativeness of heavy decarbonization.

"Hydrogen from renewable electricity hits the policymaking saccharine spot," notes Zhou. "It provides superior clime benefits with small hazard of unintended clime harm."

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Provided by International Council connected Clean Transportation