Acid hydrolysis is one of the most universal and widely-used methods for phytowaste pretreatment. The most widely-used method of phytowaste processing is its anaerobic fermentation for biogas production. This is due to the relatively low purchase cost, proven technology and also often due to the subsidized prices for the produced electricity. Compost is a stabilised and sanitised product obtained from the composting of organic substances derived from urban and agro-industrial, biodegradable solid wastes with a pH value around 8 and is subjected to partial microbial fermentation. An excessive proportion of biowaste from the food industry is being routinely landfilled or combusted. In addition, about 30–40% of the mass of the municipal solid waste produced is represented by voluminous biowaste, whereas developed countries are well above the global average, the USA far ahead of others. Pretreatment plays an important step in processing the lignocellulosic phytomass by modifying the recalcitrant material to be more amenable for further processes or reactions.