Organic waste of the food industry
Waste in the food industry mainly includes organic residues of the raw material after processing.
Disposal and utilization of organic waste is a challenging task due to its poor biological stability, high water activity, poor oxidative stability, pathogenicity and optimum enzymatic activity. Unlawful disposal and utilization of untreated or poorly treated waste without following the relevant regulations of handling, transport and disposal of waste material causes serious threats to the environment, reduces profits of the enterprise, and also increases the cost of the disposal.
In the meat industry, when processing livestock materials, a large amount of waste such as bones, offal, horns, hooves, skin, etc., is generated. For example, the meat industry in Russia annually produces about 1 million tons of organic waste. In addition, the sanitary-veterinary plants face the problem of disposing fallen stock that cannot be further used.
Established practice of organic waste recycling with further use of its residues to feed cattle is increasingly suppressed in Europe at the legislative level, as there is an expert opinion that the epizooty of mad cow disease (bovine spongiform encephalopathy (BSE)) and other diseases are caused by the use of meat and bone meal infected by prions due to insufficient processing.
However, on the other hand, waste of the food industry is products with high biological value that, being properly disposed, may increase the income of the enterprise.
Therefore, the development and implementation of systems for thermal recycling of waste products of the meat industry on the territory of enterprises, slaughterhouses, sanitary-veterinary plants, where the waste can be used as fuel to generate heat and electricity, become even more urgent.
Municipal solid waste
The problem of municipal solid waste (MSW) is very pressing, as it is associated with the need to ensure the normal life of the population, sanitary cleaning of cities, environmental protection and resource saving.
In world practice, to date the vast amount of MSW is still disposed of to landfills. The disadvantages of the storage of solid waste in landfills are:
– a large land area required;
– the complexity of establishing new landfills due to the lack of available land;
– high cost of solid waste transportation;
– the loss of valuable components of solid waste;
– environmental hazard.
In connection with the global trend of rising energy prices, MSW is referred to renewable energy. Average calorific value of unsorted MSW varies within the range of 1200-1700 kcal/kg, after selective sorting – increases to 2800-2900 kcal/kg.
In global practice, the most common method is the thermal treatment of waste with recuperation of electric and thermal energy. However, the existing technologies are either technically complex or environmentally hazardous. Therefore, the development of new methods of MSW thermal utilization is important.