The agricultural land requirements for biomass-based hydrogen production depend on the type of feedstock, yield per hectare, and conversion efficiency. Biomass gasification and fermentation are two primary pathways, each with distinct land use implications. Feedstocks include energy crops like miscanthus, switchgrass, and sugarcane, as well as agricultural residues such as straw and corn stover.

Energy crops typically require dedicated land, raising concerns over competition with food production. For example, miscanthus yields range between 10-20 dry tonnes per hectare annually in temperate regions, while tropical sugarcane can produce 30-80 wet tonnes per hectare. Assuming a hydrogen yield of 100 kg per dry tonne of biomass via gasification, one hectare of miscanthus could generate 1,000-2,000 kg of hydrogen per year. In contrast, sugarcane residues might yield 3,000-8,000 kg of hydrogen per hectare, depending on processing efficiency.

Agricultural residues avoid direct land competition but are limited by availability. Straw from wheat or rice production yields 2-5 dry tonnes per hectare. Collecting more than 30-50% of residues risks soil degradation, reducing the effective hydrogen output to 200-500 kg per hectare annually.

Indirect land use change (ILUC) is a critical risk when expanding energy crop cultivation. If biomass production displaces food crops, new land must be cleared elsewhere, potentially increasing deforestation and carbon emissions. Studies suggest ILUC emissions could negate the carbon benefits of biomass hydrogen if not managed carefully.

Regional variations in feedstock yields significantly impact land efficiency. In the EU, wheat straw yields average 3-4 dry tonnes per hectare, while in the US Midwest, corn stover reaches 4-6 dry tonnes. Brazil’s high sugarcane productivity gives it an advantage, with bagasse residues offering substantial hydrogen potential without additional land use.

Sustainable feedstock certification schemes, such as the Roundtable on Sustainable Biomaterials (RSB) or ISCC, aim to mitigate environmental and social risks. These programs enforce criteria like minimal biodiversity impact, no deforestation, and fair labor practices. Certified feedstocks ensure hydrogen production aligns with sustainability goals but may increase costs by 10-20%.

Comparing land use efficiency, biomass-based hydrogen is less efficient than solar or wind-powered electrolysis. Producing 1,000 kg of hydrogen via biomass may require 0.5-2 hectares, while solar electrolysis needs just 0.1-0.3 hectares for equivalent output. However, biomass offers dispatchable hydrogen production, unlike intermittent renewables.

Balancing biomass hydrogen with food security requires prioritizing marginal or degraded lands for energy crops and maximizing residue utilization. Integrated systems, such as agroforestry or dual-purpose crops, can reduce land conflicts. Policy frameworks must incentivize sustainable practices to prevent ILUC and ensure long-term viability.

The future of biomass hydrogen hinges on improving feedstock yields, conversion technologies, and land-use policies. Advances in high-yield energy crops and efficient gasification can reduce land demands, while robust certification schemes will be essential to maintain sustainability. Without careful management, scaling biomass hydrogen risks exacerbating land-use conflicts and undermining climate goals.

In summary, biomass-based hydrogen production presents a trade-off between land use and renewable fuel potential. While it offers a pathway to low-carbon hydrogen, its scalability depends on minimizing agricultural competition, mitigating ILUC risks, and adopting stringent sustainability standards. Regional strategies must optimize feedstock selection and land productivity to ensure biomass hydrogen contributes effectively to the energy transition.