Chemical consumption

Stannic and stannous chloride are best prepared by the reaction of chlorine with tin metal. Stannous salts are generally prepared by double decomposition reactions of stannous chloride, stannous oxide, or stannous hydroxide with the appropriate reagents. MetaUic stannates are prepared either by direct double decomposition or by fusion of stannic oxide with the desired metal hydroxide or carbonate. Approximately 80% of inorganic tin chemicals consumption is accounted for by tin chlorides and tin oxides. 

Formaldehyde is an important chemical in the plastics industry, being a vital intermediate in the manufacture of phenolic and amino resins. It was also used by Reppe during World War II as an important starting point for the preparation of a wide range of organic chemicals. Consumption of formaldehyde in acetal resins is still a minor outlet for the material but exceptionally pure material is required for this purpose. 

Chemical consumption Chemical consumption will be associated with boiler feed make-up water-treatment plant, dosing systems for feedwater and boiler system, treatment of cooling water circuits and effluent treatment. Typical chemical requirements for a thermal power plant are given in Table 15.9. 

Researchers at AECI s Research and development Department have developed a novel microwave depolymerisation process for the thermal decomposition of polymethyl methacrylate and the recovery of the monomer methyl methacrylate. This comprehensive article supplies a detailed explanation and examination of the process which has been patented in South Afriea. The microwave technology provides a purer produet which will simplify downstream processing and reduee effluent volume and chemical consumption. 

Coinjection of a low-concentration surfactant and a biopolymer, followed by a polymer buffer for mobility control, leads to reduced chemical consumption and high oil recovery. There may be synergistic effects between the surfactant and the polymer in a dynamic flood situation. The chromatographic separation of surfactant and polymer is important to obtain good oil recovery and low surfactant retention [1721],... 

The amount of chemicals used varies significantly with the specification of the final product, the types of hides and skins that are treated and the process chosen. Figures for the consumption of chemicals can therefore only be given within a broad range. The water content must also be taken into account when comparing consumption figures. An example of a brief overview of the chemical consumption is given in Table 1 [2],... 

Around 10-40% of the chemical consumption in a tannery is organic chemicals. Examples of standard organic chemicals used are organic acids and their salts. 

Batch operations are usually performed in a similar vessel without liquid and gas outlet. In such a set-up (batch) the hydrogen is still fed to the tank, at a flow rate corresponding to the chemical consumption, and possibly to heat removal capability. 

Low running cost. The RNDS requires no brine purge and less chemical dosing. As the RNDS uses dechlorinated brine at pH2, additional HC1 is unnecessary, achieving minimal chemical consumption and loss of NaCl. The RNDS consumes a small quantity of caustic soda at desorption. However, compared with former processes, the consumption is almost the same, since the amount of caustic soda needed for neutralising depleted brine is decreased. 

An economic benefit can occur through the retrofitting of a catalytic reactor, designed to perform partial destruction of the hypochlorite, into a plant already equipped with a chemical treatment system. The savings in chemicals consumption can more than offset the capital investment associated with the catalytic reactor and purchase of the initial catalyst charge. At high feed concentrations, say above a few weight per cent, the payback time can in fact be less than six months. 

The activities described in this section intend to minimize or avoid the release of chemicals into the stream wastewater by substitution, optimization, reuse, and recycling. Besides a lowering of the costs for following up general wastewater treatment, benefits due to minimization of chemical consumption are intended. As there are various specific problems arising from the particular treatment steps applied for different fibers, this section concentrates on the most important problems. Table 2 gives an overview of the annual production of textile fibers [10]. 

A key feature of the DeCaF technology is the recovery and recycling of reagent chemicals, thereby reducing overall chemical consumption and operating costs. 

TABLE 1 Chemical Consumption and Operating Costs—King of Prussia Site... 

TABLE 2 Chemical Consumption and Operating Costs—South Carolina Site ... 

Installation costs were 12,000. Operating costs included an estimated 0.25 per 1000 gal for electrical power and 0.02/gal for chemical consumption (D11314U, p. 44). 

Economic analysis of costs based on pilot-scale demonstration results gave an estimated cost of 98 to 206 per ton of waste treated. 85 to 90% of these costs are for raw materials (cement and Chloranan) and labor. The lowest value ( 98 per ton) is based upon the vendor s expectation of reducing chemical consumption by 33%, attaining an on-stream factor of 90%, and using a new 2300-lb/min batch processing unit. These costs do not include profits of the... 

Promoting Chemical Leasing based on the preventive Cleaner Production concept provides practical solutions for industry to become more efficient and at the same time reduce unnecessary hazardous chemicals consumption and protect human health and the environment. In this way, environmental and economic policy matters as well as international cooperation objectives can be addressed. In his article, T. Jakl excellently highlights Chemical Leasing and regulatory approaches in Chemical Policy. 

Chemical Leasing suggests new forms of payments for chemicals that direct the economic interests of all partners towards process optimisation and reduction of chemicals consumption. 

In addition to the economic advantages ChL also has obvious environmental advantages. Process optimisation not only leads to a reduced chemical consumption but very often also to a reduction in the consumption of other resources like energy or water. As a result the waste load as well as air and water pollution will decrease, reducing the total environmental impact of the production process. 

Since chemical products provide a broad variety of services such as "cleaning", "coating", "colouring" and "greasing" the ChL model is applicable in a multitude of industry sectors. In addition ChL is applicable to large companies just as to small and medium enterprises. Based on the experiences obtained to date, ChL business models have the greatest success when applied to processes that are not yet optimised with regard to chemicals consumption. 

As provider of Chemical Leasing services PERO Innovative Services was able to include in the project all peripheral devices necessary for the supply, reconditioning, recovery and maintenance of the chemicals. The equipment was engineered based on the principle of cost reduction with regard to chemicals consumption, energy consumption, supply of spare parts and service. The solvent and the stabilisers used were adapted to the specific cleaning needs of Automobiltechnik Blau. 

Economic benefits More than 50% decrease of wastewater purification cost and required chemicals consumption mutually profitable for participating companies. 

What were the key benefits expected leading to your participation in the project 1. implementation of new equipment, chemicals and process for the purification of glue production wastewater 2. more than 50% decrease of wastewater purification cost and required chemicals consumption mutually profitable for participating companies ... 

Reasons The application of Chemical Leasing business model provided more than 50% decrease of wastewater purification costand required chemicals consumption thus providing a mutual profit for both participating companies. Small enterprises also can collect wastes for cyclic purification (for example once per week). ... 

Check of industrial sectors (based on the existing supplier structures) using a set of specific selection criteria (e.g., rate of chemicals consumption within sectors, economical criteria, opportunity of a sector for growing etc.) — short list of industrial sectors. 

Please assess if reduction of chemicals consumption by process optimisation can be expected ... 

Surplus application costs - due to probably higher chemical consumption because of information asymmetries regarding the proper application of the chemical ... 

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