Indirect gasification production of biomethane for use in heavy-duty state-of-the-art gas engines

• The climate targets set for the European transport sector have stimulated intensiveresearch by groups in academia, the energy industry, and vehicle manufacturing in theGothenburg region into biomethane production via indirect gasification of lignocellulosebiomass and the development of advanced gas engine technologies.This work presents the results of a comprehensive study of biomethane production andutilization in heavy duty engines. The different steps in the biomethane chain (biomassdrying, gasification process, and combustion) are assessed, and opportunities forimproving the efficiency of utilization of biomass resources are evaluated. The biomethanechain is investigated through a well-to-wheel (WtW) analysis of the newly built GoBiGasplant (Gothenburg, Sweden), in combination with three state-of-the-art gas enginestechnologies: spark-ignited (SI); dual fuel (DF); and high-pressure direct injection (HPDI).Opportunities for improving the biomethane process are focused on the drying system andon the dual fluidized bed gasifier. An advanced drying system for the dual fluidized bedgasifier, which uses low-temperature steam as the drying medium and recovers theevaporated moisture as a gasification agent, is evaluated. A method for simulating theprocess that occurs in the dual fluidized bed gasifier using experimental data is introduced,with the aim of exploiting the extensive body of information derived from pilot anddemonstration gasifiers in relation to process optimization and techno-economic analyses.The uncertainty that arises from the measurements is assessed stochastically andtransferred to process parameters.The WtW analysis shows that emissions from biomethane are reduced by 73%, 46%, and68% when used in the SI, DF, and HPDI engines, respectively, as compared to using NG andLNG. The evaluation of the drying process reveals a theoretical energy efficiency of 95%when combined with a DFB gasifier and an exergy efficiency of 53%, values that areconsiderably higher than those obtained with other drying systems. Through interpolationiiand extrapolation of the experimental data, the proposed modeling method isdemonstrated to be a flexible tool for simulating the gasifier under several operationalconditions Comparisons of the data from different measurement set-ups demonstrate thata detection rate of ≥95% for the carbon in the produced gas is necessary to keep theuncertainty at

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Energiteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Energy Engineering (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Farkostteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Vehicle Engineering (hsv//eng)

Nyckelord

well-to-wheel

biomethane

gas engines

SNG

DFB gasifier

process simulation

dual fuel

Biomass gasification

Publikations- och innehållstyp

lic (ämneskategori)

vet (ämneskategori)