Water, acid technological

Jeffries, D. S., Lam, D. C. L. (1993). Assessment of the effect of acidic deposition on Canadian lakes determination of critical loads for sulfate deposition. Water Science Technology, 28, 183-187. 

Roensch, L. F. (2005) Steam and boiler water treatment for the modem sulfuric acid plant, paper presented at 29th Annual Clearwater Conference (AIChE), Clearwater, Florida, June 3, 2005 www.chemtreat.com Also, Fahrer, N.D. and Roensch, L.F. (2005) Steam and boiler water treatment technologies for the modem sulfuric acid plant, paper distributed at 29th Annual Clearwater Conference (AIChE), Clearwater, Florida, June 3 and 4, 2005. www.chemtreat.com... 

Hoechst Celanese Low-Water Acid Optimization (AO) Technology... 

In the 1990s, BP re-examined the iridium-catalyzed methanol carbonylation chemistry first discovered by Paulik and Roth and later defined in more detail by Forster [20]. The thrust of this research was to identify an improved methanol carbonylation process using Ir as an alternative to Rh. This re-examination by BP led to the development of a low-water iridium-catalyzed process called Cativa [20]. Several advantages were identified in this process over the Rh-catalyzed high-water Monsanto technology. In particular, the Ir catalyst provides high carbonylation rates at low water concentrations with excellent catalyst stability (less prone to precipitation). The catalyst system does not require high levels of iodide salts to stabilize the catalyst. Fewer by-products are formed, such as propionic acid and acetaldehyde condensation products which can lead to low levels of unsaturated aldehydes and heavy alkyl iodides. Also, CO efficiency is improved. 

Since the development of Cativa , BP has converted three world-scale acetic acid plants from the old Rh-based high-water Monsanto technology to the Ir-based low-water process. Significant capital and operating cost savings were achieved from the conversion of a Rh-based process to an Ir-based process. Also, the start-up in 2000 of a 500 X 10 metric ton per year acetic acid plant in Malaysia uses the Cativa process [20d]. 

R. A. Sierka, S. P. Cooper, and P. S. Pagoria, Ultrafiltration and reverse osmosis treatment of an acid stage wastewater. Water Science Technology 35, 155-161 (1997). 

A variant of this process, studied by DuPont and DSM [32c], includes the hydrocarboxylation (hydroxycarbonylation) of butadiene with carbon monoxide and water this technology offers potential savings in raw material costs. The reaction primarily yields 3-pentenoic acid using a palladium/crotyl chloride catalyst system, with a selectivity of 92%. Further conversion of pentenoic acids by reaction with carbon monoxide and methanol and a palladium/ferrocene/phosphorous ligand catalyst has demonstrated a selectivity to dimethyl adipate of 85% the latter is finally hydrolyzed to AA. The main problem in this reaction is the propensity of pentenoic acid to undergo acid-catalyzed cyclization to y-valerolactone one way to circumvent the problem is to carry out the hydrocarboxylation of pentenoic acid using the y-valerolactone as the solvent. 

Antifreeze contains corrosion-inhibiting compounds and dye for identification purposes. Dilution is 1 1 glycol to water mixture, which gives protection down to -40°C. Newer developments have seen the advent of organic acid technology (OAT) antifreezes such as Dex-cool. OAT antifreezes have extended service lives of up to 150,000 miles. The properties of OAT coolant are shown in Table 7.7. OATs can mix with non-OATs however, the change interval will decrease to 2 years or 30,000 miles. OATs work by a mechanism different from that of traditional antifreeze mechanisms. As can be seen from Table 7.7, the additive package of the OAT contains... 

Baker, J.P. et al. (1990) Biological effects of changes in surface water acid-base chemistry. State of Science and Technology Report 9, National Acid Precipitation Assessment Program, Washington, DC, USA. 

Solubilizable Dispersions (19). The chemistry of solubilizable acrylic dispersions is a hybrid of emulsion and water-reducible technology. These polymers are synthesized by emulsion techniques but contain acidic or basic functionality that renders them water soluble upon neutralization with an appropriate titrant. For example, if the solubilizing functionality is acidic, the polymer will behave like an emulsion below a certain critical pH range, like a highly swollen emulsion within the critical pH range, and like a true water-soluble polymer at sufficiently high pH values. Such polymers offer a favorable balance of properties for many coating applications. 

Kastelan-Macan M., Petrovic M. (1996), The role of fulvic acids in phosphorus sorption and release from mineral particles. Water Science Technology, 34, 7-8, 259-265. 

The highlight of the cold process proposed is the higher efficiency of recovering the energy of conversion of SO3 to sulfuric acid with water. Conventional technology cannot fully recover the exothermic heat generated in this process. 

Additional safety considerations apply to the use of microwave technology. First, the equipment should be operated in strict accordance with instructions to ensure that no detectable amounts of microwave radiation will escape. Leak tests should be conducted on a regular basis by a trained technician. Vessels or other objects made of metal should never be placed in the oven chamber. Microwave equipment must also never be operated empty (i.e.. in the absence of a sample solution, water, acid, etc.), since the magnetron might be destroyed by reflected radiation. The behavior of unknown samples should be tested on a small scale (see above). 

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