Fossilfri Kexchoklad : En undersökning om möjligheter till utökad biogasanvändning i livsmedelsindustrin, utifrån en fallstudie om potentiell biogaskonvertering av gasoldrivna wafer-ugnar

The need to substitute fossil fuels for renewables increases dramatically as the climate crisis continues. The Swedish industry sector uses 4,5 TWh petroleum gas per year, which generates greenhouse gas emissions equaling 600 000 cars. A renewable energy source that is often overshadowed is biomethane, which could replace conventional fossil fuels like petroleum gas. Substitution of petroleum gas for biomethane could reduce the climate impact of the Swedish industry sector considerably. This study examines the transition from fossil fuels to biofuels in the food industry, through a case study of candy manufacturer Cloetta's factory in Ljungsbro, Sweden. The study focuses on aspects related to engineering, economy, energy and climate regarding a potential conversion of wafer ovens from petroleum gas to biomethane. The production of wafers is the last process that is dependent on fossil fuels in the Ljungsbro factory. The empirical data was gathered using interviews with relevant actors linked to the conversion, and calculations related to energy, economy and climate. The study found that converting Cloetta's wafer ovens to use biomethane is possible, and should be applicable in similar processes in other industries as well. Since bio methane has a lower volumetric energy density than petroleum gas the fuel supply needs to be increased. The study found that this can be achieved either by increasing the pressure in the piping, or by adding more burner nozzles in the ovens, to increase the velocity of the gas flow. Furthermore, biomethane can be delivered in compressed or liquified form by lorry, alternatively directly by pipeline. The study found that the infrastructure necessary for storage and receipt of biomethane varies considerably in cost depending on the method of delivery. In Cloetta's case, compressed biogas is viewed as the best alternative, mostly for economic reasons. A transition from petroleum gas to biomethane would lead to a large decrease in greenho