Recycling design

About half of the wodd production comes from methanol carbonylation and about one-third from acetaldehyde oxidation. Another tenth of the wodd capacity can be attributed to butane—naphtha Hquid-phase oxidation. Appreciable quantities of acetic acid are recovered from reactions involving peracetic acid. Precise statistics on acetic acid production are compHcated by recycling of acid from cellulose acetate and poly(vinyl alcohol) production. Acetic acid that is by-product from peracetic acid [79-21-0] is normally designated as virgin acid, yet acid from hydrolysis of cellulose acetate or poly(vinyl acetate) is designated recycle acid. Indeterrninate quantities of acetic acid are coproduced with acetic anhydride from coal-based carbon monoxide and unknown amounts are bartered or exchanged between corporations as a device to lessen transport costs. 

In run 19, where considerable carbon monoxide conversion was obtained in both stages, the recycle ratio was 1.48 scf recycle gas per scf feed gas. Recycle ratios in the other tests varied from 1.14 to 1.30. The design recycle ratio is 1.67 for lignite coal feed with hydrogen/steam synthesis gas. 

Theoretical treatments on recycling chromatography have been published by Chizhkov [67], Martin [68], and Coq [69]. Seidel-Morgenstern and Guiochon [70] developed a mathematical model to design recycling and... 

The carbon dioxide from (3.63) is in most designs recycled as input to (3.62) together with the hydrogen fuel. It has been suggested that CO2 emissions from fossil power plants could be used as input as a way of reducing greenhouse gas emissions from the current system. However, then the output CO2... 

Recycle structure, designing. See Process design, recycle structure. 

---