Acids, industrial

Liquid Effluents. Recycling of acid, soda, and zinc have long been necessary economically, and the acid—soda reaction product, sodium sulfate, is extracted and sold into other sectors of the chemical industry. Acid recovery usually involves the degassing, filtering, and evaporative concentration of the spent acid leaving the spinning machines. Excess sodium sulfate is removed by crystallization and then dehydrated before sale. Traces of zinc that escape recovery are removable from the main Hquid effluent stream to the extent that practically all the zinc can now be retained in the process. 

Many substituted, ie, branched, fatty acids, particularly methacryUc, 2-ethylhexanoic, and ricinoleic acids, are commercially significant. Several substituted fatty acids exist naturally (Table 5). Fatty acids with a methyl group in the penultimate position are called iso acids, and those with a methyl group in the antepenultimate position are called anteiso acids (1) (see Carboxylic acids, branched-CHAIN acids). However, the term iso is often used in a broader sense to mean branched or mixtures of branched-chain industrial acids. 

The EPA defines corrosivity in terms of pH (i.e., wastes with pH <2 or >2.5) or in terms of ability to corrode steel (SAE 20) at a rate of >6.35 mm (0.250 in.) per year at a temperature of 55 C (13°F). This discussion will address corrosivity as it applies to acids and caustics. Acids are compounds that yield H ions (actually HjO ions) when dissolved in water. Common industrial acids include acetic, nitric, hydrochloric, and sulfuric acids. The terms concentrated and dilute refer to the concentrations in solution. Mixing a concentrated acid with enough water will produce a dilute acid. For example, a bottle of concentrated HCl direct from the manufacturer is approximately 12 N in HCl, while a solution of HCl used in a titration may be only 0.5 N. The latter is a dilute acid solution. 

Acid reuse, recycle, and recovery systems are extensively used in the acid pickling industry. Typical industrial acid reuse and recovery systems include the following ... 

Acid-base catalysis is important for reactions of hydrocarbons in the petrochemical industry. Acids, either as solids or in solution, react with hydrocarbons to form reactive... 

Nitric acid (HNO ) is an important industrial acid used to alter or produce many products such as fertilizers and explosives. It reacts with ammonia to produce ammonium nitrate, an important commercial chemical. 

Driving the Fischer esterification toward a favorable equilibrium is rarely difficult, so this is a common method for making esters, both in the laboratory and in industry. Acid chlorides also react with alcohols to give esters (Section 20-15), but acid chlorides are more expensive, and they are more likely to promote side reactions such as dehydration of the alcohol. 

Table 13.10 gives some critical threshold values of NH3 in the environment. In-stream standards in many states allow a maximum concentration of 0.02 mg L-1 unionized ammonia in trout waters and 0.50 mg L 1 in all other waters. No limits are set in drinking water standards. Ammonia is often used to neutralize acid mine drainages (AMD) as well as other industrial acid- or metal-rich drainages (e.g., woodpulp and electronics). Many states have banned or discourage the use of ammonia for such purposes unless extensive monitoring is carried out. 

Most industrial acid plants have three flows of sulfuric acid - one gas-dehydration flow and two H2S04-making flows. These flows are connected through automatic control... 

Table 6.2. Equilibrium H20(g) pressures over sulfuric acid at temperatures around those of industrial acid plant gas dehydration (Perry and Green, 1997). The pressures are translated into volume% H20(g) in gas and milligrams H20(g) per Nm3 of gas. An industrial dehydration target of 50 milligrams H20(g) per Nm3 of gas is chosen to avoid downstream corrosion.

Section 9.4 s industrial acid compositions strike a balance between these opposing effects. 

This is the basis of all industrial acid plant designs. 

It would, however, tend to give catalyst overheating and degradation in the 1st catalyst bed, Section 12.11. For this reason, 12 volume% S02 is about the maximum strength used in industrial acid plants. 

Most industrial acid plants have 4 catalyst beds. The arrangements of these beds in order of decreasing industrial use are ... 

Fig. 24.7. Schematic of acid heat to steam energy recovery system, after Puricelli et al., 1998. It is for intermediate H2S04 making, Fig. 9.6. Note (i) the double packed bed H2S04 making tower and (ii) boiler. Industrial acid heat recovery H2S04 making towers are 25m high and 10 m diameter. They produce 2000 to 4000 tonnes of H2S04 per day. For photographs see Sulfur, 2004.--------- large flows. small flows.

The book begins with a 9 chapter description of sulfuric acid manufacture. These chapters introduce the reader to industrial acidmaking and give reasons for each process step. They also present considerable industrial acid plant operating data. We thank our industrial colleagues profusely for so graciously providing this information. 

Fig. 2. Scheme of molybdenum recovery from industrial acid pickling effluents. 

Lot of good, basic chemicals used in this industry. Acids such as sulfuric, nitric, chromic and HCL. There are also bases, solvents, and many metal compounds including the palladium and platinum kind. I wasn t gonna include a section on this because I had no local sources and was not going to search elsewhere because I was really getting sick of researching for this damn book. 

Corrosive industrial acids and bases nitric acid, sulfuric acid... 

As soon as one comes across a green copper roof , one should attempt to remove the green layer until one reaches the pure red-brown copper metal. If one dissolves the green substance in diluted hydrochloric acid, bubbles form. The addition of limewater helps to prove the existence of carbon dioxide. The green substance must be a type of copper carbonate, a completely different substance than the red-brown metal. The formation of green carbonate can be explained by reactions of copper with the solution of carbon dioxide in rainwater, or the formation of blue copper sulfate by the reaction of copper with industrial acidic rain . 

O B Hibit. [O Brien Industries] Acid coiosion irihibitors. 

FOLLOW-UP PROBLEM 3.2 Tetraphosphorus decaoxide reacts with water to form phosphoric acid, a major industrial acid. In the laboratory, the oxide is used as a drying agent. 

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