Production of hydrogen- and methane-rich gas by stepped pyrolysis of biomass and its utilization in IC engines

Abstract

Automobile industries primarily use petroleum-based fuels like petrol and diesel, creating environmental hazards, a high carbon footprint, and severe health issues. The world focuses on compressed natural gas (CNG)-based energy solutions and developing CNG infrastructures to minimize environmental concerns from fossil fuel. The current focus to introduce a fraction of hydrogen with CNG in the existing fuel system is initiated here. Therefore, biomass utilization is taken into account to produce high hydrogen-containing fuel to cut down the carbon footprint and environmental issues. Biomass residues such as sun hemp, pigeon pea, mustard stem, wheat straw, dhaincha, and vantulasi were slowly pyrolyzed in a stepped manner to produce a hydrogen-rich clean fuel. The yield of product gas (hydrogen-rich CNG; HCNG) obtained by the pyrolysis process (21–29%) contains a volumetric composition of 40–55% hydrogen and 10–25% methane balanced with oxides of carbon depending on different biomass feedstocks. This study also focused on utilizing obtained HCNG in IC engine (2KVA Honda Genset) in terms of its running duration and efficiency. The maximum running time observed in sun hemp is 30 min, followed by the mustard stem is 28 min, the lowest in vantulasi is 16 min. However, the highest process efficiency is 87% for dhaincha which is 3.6 times more effective, and the lowest is 74% for Sun hemp, which is 3 times more effective than petrol in Genset for power production. A correlation is developed between ultimate analysis and product gas composition for running time estimation.