Environmental protection awareness in the hottest

2022-09-23
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Environmental awareness in packaging and printing

in recent years, due to the rapid rise and development of food, beverage, cigarette, medicine, health care products, cosmetics, hardware, home appliances, clothing, toys and other industries, especially with the expansion of foreign trade, the market demand for packaging and printing products is increasing day by day; According to statistics, the annual demand of the American Printing Market in 2003 was as high as 162.4 billion US dollars, while the total output value of nearly 21000 packaging and printing enterprises in China in 2002 was only 75billion yuan

according to a preliminary survey, nearly 670 cities across the country have various types of printing machines, and the inks used are mainly divided into organic solvent inks, water-soluble inks, high solid inks and benzene free inks. Organic solvent based inks use toluene, xylene, acetone, butanol, ethyl acetate and other low boiling point volatile organic compounds as solvents, which have high printing speed, good print quality and low cost, so they are widely used. In the process of use, due to the volatilization of organic solvents, a large number of toxic and harmful organic waste gases will be produced, which will cause serious local pollution. If human beings are exposed for a long time, it will bring serious harm to the nervous system and hematopoietic function

most of the existing domestic or imported printing machines are not equipped with the corresponding purification device when leaving the factory. If the corresponding purification device is not set up separately, a large number of toxic and harmful waste gases (such as "triphenyl", acetone, etc.) will be directly discharged into the atmosphere during the production process, seriously polluting the urban atmospheric environment, which will cause non negligible harm to the urban environment and human survival. For example, in July last year, when the six ministries, commissions and bureaus of the state launched a nationwide clean-up and rectification of the environmental protection market, a color printing company in Huli Industrial Zone, Xiamen City, Fujian Province, has been ordered by the local environmental protection department to stop production for rectification because it produced without any environmental purification facilities, and the organic waste gas emitted made the surrounding people dizzy and vomit

according to the "China environmental situation bulletin" released by the State Environmental Protection Administration, the proportion of people in cities with air quality up to standard in the first transmission mode is only 26.3% of the urban population. Among them, the air pollution in super large and super large cities is significantly heavier than that in small and medium-sized cities. If it is not controlled in time, the urban air environment will further deteriorate. Therefore, the state and various places have successively formulated some comprehensive , Such as the integrated emission standard of air pollutants (GB), which clearly stipulates the emission limits of various organic waste gases; At the same time, it is required that the environmental protection facilities of new or expanded projects must strictly implement the "three Simultaneities" examination and approval (i.e. simultaneous design, simultaneous construction, simultaneous operation and use), and the national unified certification system will also be established and fully launched. In the future, when enterprises apply for various quality management system certifications such as environmental management system ISO14000), quality management system (OHSMS), environmental protection and emission standards will become one of the important conditions

in order to comply with the relevant national and local laws and regulations, ensure the sustainable development of the enterprise itself, and improve the surrounding and staff working environment, some printing enterprises have invested (some even invested a huge amount of money) to equip the printing machine of the enterprise with corresponding purification facilities, but due to a variety of reasons, most of them are still unable to meet the emission standards or are listed in the list of rectification within a time limit, causing varying degrees of losses to the enterprise, The main reasons are as follows:

(1) due to the late start of the environmental relative humidity protection industry in China, the treatment process is relatively backward, and the lack of pertinence to relevant pollutants, so the purification effect cannot be achieved

(2) the treatment process or equipment is too complex, resulting in high equipment operation costs

(3) the equipment has potential safety hazards, and improper control is easy to cause safety accidents

concave has high failure rate, unstable operation, troublesome maintenance, which makes the environmental protection equipment unable to operate normally, etc

due to the manufacturers' little understanding of environmental protection purification equipment, coupled with the above-mentioned reasons, some enterprises have doubts about investing in the construction of environmental protection purification equipment, lest the above problems occur and fall into a dilemma

with the development of environmental protection industry in recent years, aiming at the characteristics of a wide variety of organic waste gas pollutants and different physical properties, at present, China often adopts the following methods for the treatment of organic waste gas:

1. Condensation recovery method: the organic waste gas is directly introduced into the condenser, and valuable organic matter can be recovered through adsorption, absorption, decomposition and separation. This method is applicable to the working conditions of high concentration, low temperature and small air volume of organic waste gas, It requires auxiliary refrigeration equipment, which is mainly used in pharmaceutical and chemical industries, and less used by printing enterprises

2. Absorption method: generally, the physical absorption of phenanthrene is adopted, that is, the waste gas is introduced into the absorption liquid for purification, and after the absorption liquid is saturated, it is heated, analyzed, condensed and recycled; This method is applicable to waste gas with large volume, low temperature and low concentration, but it needs to be equipped with heating, analysis and recovery device, which has large volume and high investment

3. Direct combustion method: use auxiliary fuels such as gas or oil to burn, heat the mixed gas, and decompose harmful substances into harmless substances under the action of high temperature; This method is simple in process and small in investment. It is suitable for waste gas with high concentration and small air volume, but it has high requirements for safety technology and operation

4. Catalytic combustion method: heat the exhaust gas and convert it into harmless and odorless carbon dioxide and water through catalytic combustion; This method has the advantages of low ignition temperature, energy saving, high purification rate, convenient operation, small floor area and large investment. It is suitable for high temperature or high concentration organic waste gas

5. Adsorption method:

(1) direct adsorption method: organic waste gas is adsorbed by activated carbon, and the purification rate can reach more than 95%. The equipment is simple and the investment is small, but the activated carbon is replaced frequently, which increases the working procedures such as loading and unloading, transportation and replacement, resulting in increased operating costs

(2) adsorption recovery method: use fiber activated carbon to adsorb organic waste gas, and use superheated steam to blow back after it is close to saturation for desorption regeneration; This law requires the provision of the necessary amount of steam

(3) new adsorption catalytic combustion method: this method combines the advantages of the adsorption method and catalytic combustion method that can make the mechanical arm slide around the model. New adsorption materials (honeycomb activated carbon) are used for adsorption, and hot air is introduced after approaching the drinking water for desorption and analysis. After desorption, waste gas is introduced into the catalytic combustion bed for flameless combustion, which is completely purified. Hot gas is recycled in the system, greatly reducing energy consumption. This method has the characteristics of stable and reliable operation, low investment, low operation cost and convenient maintenance. It is suitable for the treatment of large air volume and low concentration waste gas. It is a mature and practical method for the treatment of organic waste gas in China at present

with the enhancement of environmental protection awareness in the whole society, environmental protection departments at all levels have increased environmental protection supervision and punishment on all walks of life

the printing industry has always been one of the most active industrial fields in China's technological transformation. The elimination of old equipment, the continuous renewal and introduction of new and high technologies and equipment have formed some new characteristics and development trends in the industry. How to solve the problems of development and environmental protection has always been an important topic that all insiders need to think about to maintain the sustainable development of their enterprises

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