FRANKFURT (Reuters) - Russia's demand that some buyers pay for its gas in roubles has raised concerns in Germany, which relies on Russian fuel, that the payment dispute could escalate and disrupt supplies. Russia accounted for 55% of Germany's gas imports in 2021. Although that figure fell to 40% in the first quarter of 2022, Economy Minister Robert Habeck has said Germany will not achieve full independence from Russian supplies before mid-2024. If Germany does not secure enough gas, industry will be hit first. It accounts for a quarter of German gas demand. "This means that industrial production gets lost,...