The Use of Waste Material from the Food and Agricultural Industries (Press Cake) as an Alternative, Renewable Solid Fuel

The research utilised by-products from the food and agricultural industry, which offer a promising, eco-friendly approach to waste utilisation and solid fuel production. With the growing global energy demand and the depletion of fossil fuel resources, renewable energy sources like biomass have gained significant importance. This study focused on investigating the pyrolysis of various press cakes from oil crops, such as rapeseed, flaxseed, apricot, and camelina. The pyrolysis process involves the conversion of biomass into biochar and volatile fractions, with potential applications in energy generation and other industries. The results showed that pyrolysis at 500 °C produced satisfactory char yields comparable to wood pyrolysis. As a result of pyrolysis, a solid fraction of 27 to 28 % was obtained. The primary challenge lies in the high ash content of press cake chars, which originates from the conversion of the entire mineral fraction into char. Nonetheless, press cake pyrolysis demonstrates promise as an eco-friendly waste utilisation method and a means to generate solid fuels. The char obtained from pyrolysis can be used directly as a substitute for solid fuels or as an additive during the formation of fuels, such as straw pellets. The second option seems more favourable due to the high ash content in the char. The main advantage of waste pyrolysis is that the waste is not sufficiently microbiologically stable without thermal treatment.