Waste-free and low-waste technologies

SHARE WITH FRIENDS:

Waste-free and low-waste technologies.

For the first time in the 50s of the last century, Russian scientists Acad. NN Semyonov and IVPetryanov introduced the term "waste-free technology" into science. Currently, instead of the terms "zero-waste and low-waste technologies", the terms "clean or somewhat clean technologies" are also used.

Waste-free technology is the practical application of knowledge, methods and tools in order to satisfy human needs, ensure effective use of natural resources and energy, and protect the environment.

Waste-free technology is such an effective method of product production, in which raw materials and energy are efficiently and comprehensively used in the cycle of "raw materials - production - consumption - secondary raw materials resources" and every amount delivered to the natural environment what kind of influence can't take it out of its normal state.

There are 3 scarves in this description:

1. The basis of waste-free production is the man-made cycle of materials consciously organized and adjusted by man.

2. Obligation of effective use of all components contained in raw materials and full use of potential of energy resources.

3. Non-impact of waste-free technology on the natural environment and its normal operation.

It is known from the "Physics" course that based on the second law of thermodynamics, the useful work coefficient (FIK) of periodic machines can be calculated using the following formulas:

So, the amount of heat removed from the refrigerator is Q₂ = 0 or the temperature of the refrigerant T₂ = 0, the FIK of a periodic machine can be equal to 100%. But as Nerist showed, it is impossible to get absolute zero temperature. Therefore, it is impossible to make a machine with FIK equal to 100% of periodic machines, or Q from the heater₁ taking the amount of heat, this heat fully represents the second law of thermodynamics. This law can be described as follows: you cannot make a machine that works with only one heat source.

Machines with FIK equal to 100% are called the second type of perpetium mobile, and the second law of thermodynamics is defined as that it is impossible to make the second type of perpetium mobile.

Based on the second law of thermodynamics, it is theoretically possible to create a 100% waste-free technology. But in practice (in real life) there is a waste of energy in production processes, that is, a certain amount of energy can heat up the machine. Therefore, the term "waste-free technology" is conditional, and the terms "environmentally friendly technology" or "environmentally friendly technology" are used instead.

Low-waste technology is a method of product production in which any impact on the natural environment does not exceed the permitted sanitary-hygienic standards. Due to organizational, technical and economic reasons, a certain small amount of raw materials can become waste.

The main condition for the organization of low-waste production is the existence of a system for neutralization of unusable waste, in particular, toxic substances. In this case, the impact of waste on the natural environment should not exceed their permitted limit concentrations.

It should be noted separately that the terms "zero-waste and low-waste technologies" include "natural resources", "complex processing of raw materials", "efficient use of resources", "by-products", "production waste", "unusable waste ", "secondary material resources", "secondary energy resources", "economic damage" are inextricably linked.

Natural resources. Water, land, mineral resources, animal and plant resources, solar energy, energy obtained from the earth (for example, mineralized hot water energy) and others are called natural resources.

Mineral resources. This is the source of underground mineral resources (coal, oil, gas, mineral and non-mineral minerals).

Complex use of raw materials. This means the full use of useful components contained in raw materials and production waste.

It should be noted separately that the level of extraction of valuable components in raw materials and their effective use depends on the development of technology and the need of society for them. Comprehensive and integrated use of raw materials increases production efficiency, ensures an increase in product types and sizes, reduces the price of the obtained products, reduces the costs of creating raw material reserves and, most importantly, helps to prevent environmental pollution. will give.

It should also be remembered that in practice, during the physical and chemical processing of raw materials, the main production product, along with additional intermediate or fine products (for example, dusts, fumes, mixtures of gases, effluents, steam, short fibers, powders, stones, sediments and others) may appear. For example, during the extraction of cotton fiber, dust, short fibers, lint and fluff with different chemical composition appear. Or, during the extraction of copper, nickel, zinc, cobalt and other precious metals from ores in metallurgical enterprises, gold matches are separated. Gold match is also found in oil and natural gas. But there are also elements such as magnesium, tellurium, and selenium in the gold match. Or fluorine compounds that pollute the natural environment are released during aluminum production. If fiber, copper, nickel, zinc, cobalt, aluminum, oil and gas are the main products, then the dust, short fibers, lint and lint, sulfur, margium, tellurium, selenium and fluorine compounds formed during their production are additional intermediate or fine products. is counted. Their appearance is not the main purpose of the production process, but they can be used as raw materials or finished products. For example, 1 ton of sulfur produces 3 tons of sulfuric acid, sulfur dioxide (SO2) and other products. In addition, sulfur is an extremely valuable raw material in the production of mineral spirits (as sulfuric acid), coir (as SO2), rubber products, washing powders, and construction materials. Tellurium and selenium are the main raw materials in the production of semiconductors. Fluorine compounds are the main raw materials in the production of hydrofluoric acid.

In production enterprises, there are state standards (DAVANs), network standards, technical norms and approved prices for such additional intermediate or small products. If the separation or recycling of additional intermediates or by-products is not economically feasible, then they can be used as fuel.

Production waste. These are scraps of raw materials, partially or completely degraded materials and semi-finished products (semi-finished products) that do not meet state standards. Such waste can be used in recycling without treatment or after preliminary treatment. For example, if the quality indicators of plastic products (pots, pipes, films, household items, etc.), dyed colors, patterns, disposable products (glasses) do not meet the state standards, they can be considered production waste.

Unusable waste. These are materials that cannot be restored to their original properties, materials that have passed their useful life, or various obsolete items.

Resource of secondary materials. This is a set of production waste and unusable waste, and additional intermediate or waste products can also be included in this group. They can be used as the main raw material or as an auxiliary material in the production of products. Such waste is considered a potential reserve of material resources for industrial enterprises. For example, the use of old or obsolete materials - films, containers, and similar materials in production is a guarantee of great economic benefits.

Secondary energy resources. This is the energy potential of products, wastes, additional intermediates or substances released during the technological process. In them, two units are partially used to supply energy to consumers inside the enterprise or outside the enterprise.

Secondary energy resources can be of 3 types:

1. Secondary energy resources that are used as energy.

2. Secondary energy resources used as heat.

3. Mechanical secondary energy resources.

            The group of fuel secondary energy resources includes such wastes, wastes, garbage or additional intermediate products that can only be used as fuel. For example, for the purpose of neutralizing garbage, waste and garbage, they are often burned in special incinerators. The energy produced in this process is included in the fuel secondary energy resources.

            The group of thermal secondary energy resources includes the physical heat of fumes, gases and their mechanical mixtures, the heat of the flow of substances, the heat of water and others. For example, high-temperature vapors generated during the production process can be used to heat the premises of the enterprise or meet the needs of consumers outside the enterprise. Or it is possible to cool the equipment and facilities with the help of waste water produced in the enterprise. This not only brings great economic benefits, but also greatly helps in maintaining the natural environment.

            Mechanical secondary energy resources. The group includes heat generated from technological processes or the energy of compressed gases and others.

   It should be mentioned separately that among the industrial enterprises, aluminum production plants consume the most electricity. 15-16 thousand kW to produce one ton of aluminum. hours of electricity is consumed. Therefore, the sole purpose of introducing zero-waste production is not only the efficient use of household goods and waste, but also the efficient use of energy types and secondary energy resources, as well as the creation of energy-saving technologies.