Reference

Minimizing fouling of heat exchangers

Minimizing fouling of heat exchangers. Miller, Richard F.; Go, Ting S. L. (Atlantic Richfield Co., USA). U.S. US 4456526 A 26 Jun 1984, 4 pp. (English). (United States of America). CODEN: USXXAM. CLASS: IC: C10G009-16. NCL: 208048000AA. APPLICATION: US 82-423408 24 Sep 1982. DOCUMENT TYPE: Patent CA Section: 51 (Fossil Fuels, Derivatives, and Related Products) Hydrocarbon process equipment is protected against fouling by incorporating into the hydrocarbon being processed small amts. of a compn. comprised of a dialkylhydroxylamine and a tertiary alkylcathechol. Thus, a 50 ppm addn. of a 50/50 mixt. of tert-butylcatechol [98-29-3] and N,N-diethylhydroxylamine [3710-84-7] to depentanizer bottoms at low rate 240 mL/h and 600°F resulted in superior antifouling properties as shown by the final pressure drop of only 10 mm.

Pickling of boiler steels

Pickling of boiler steels. (Tokai Electro-Chemical Co., Ltd.; Nitto Chemical Industry Co., Ltd., Japan). Jpn. Kokai Tokkyo Koho JP 59043884 A2 12 Mar 1984 Showa, 5 pp. (Japanese). (Japan). CODEN: JKXXAF. CLASS: IC: C23G001-06. APPLICATION: JP 82-152678 3 Sep 1982. DOCUMENT TYPE: Patent CA Section: 55 (Ferrous Metals and Alloys) Inorg. acid solns. contg. N,N-dialkyl hydroxylamine given by a general formula (R1(R2)NOH, where R1 and R2 are alkyl radicals having ￡4 C atoms are used for pickling steels. Thus, an acid soln. contg. HCl 5, Fe3+ 0.1, corrosion inhibitor (Rescol A-804 [91729-16-7]) 0.5, and N,N-diethyl hydroxylamine [3710-84-7] 0.1-0.2% was contacted with a rolled steel for boilers (JIS G3103, SB42) [39371-38-5] for 5 h. The corrosion rate was 0.04-0.06, compared to 0.06-0.15 mg/cm2-h for a conventional pickling soln.