Formaldehyde removal

Before the actual distillation could be carried out, the flask was heated to approximately 95° and the residual formaldehyde removed at the aspirator. Only after the formaldehyde was removed could the pressure be reduced to that required for the distillation. 

Reactor Tested HCHO (mg/L) Limiting Dose (mg HCHO/L) Formaldehyde Removal Efficiency (%) Reference... 

Garrido, J.M., Mendez, R., and Lema, J.M., Simultaneous urea hydrolysis, formaldehyde removal and denitrification in a multifed upflow filter under anoxic and anaerobic conditions, Water Res., 35, 691-698, 2001. 

Applying fins coated with titania is an effective way to enhance the formaldehyde removal performance (Mo et al., 2008b). In order to compare the formaldehyde removal performance of annular photocatalytic reactors with and without the aforementioned fins, the PCO reactors without and with the fins operated in a sealed stainless steel chamber with formaldehyde in its air, respectively. Figure 4.15 shows the chamber formaldehyde concentration decay curves (a) an annular PCO reactor without fins, (b) an annular PCO reactor with six fins. It can be seen that the reactor with fins is more efficient than that without. The reason and the analysis are presented by Mo et al. (2008b) in detail. 

Mo, J.H., Zhang, Y.P., Yang, R. et al. (2008b) Influence of fins on formaldehyde removal in annular photocatalytic reactors. Building and Environment, 43, 238-45. 

There is no certain value for D(G - H) in formaldehyde. Long and Norrish3i8 point out that atomic hydrogen reacts very readily with formaldehyde, removing a hydrogen atom, but does not react with methane. They consider that this shows that the dissociation energy of the first GH bond has a smaller value in formaldehyde than in methane. 

For simple amino acids, and Ki, are generally so small that their determination by direct neutralization is impossible. Addition of formaldehyde removes the amine functional group, however, and leaves the carboxylic acid available for titration with a standard base. For example, with glycine,... 

To shed additional light on the emission mechanism and the contribution of resin hydrolysis to formaldehyde emission, my recent experiments have examined the liberation or extraction of formaldehyde from particleboards, from wood containing sorbed formaldehyde, and from cured resins. Here, I present results from particleboard and formaldehyde-sorbed wood experiments in which rates of formaldehyde removal were measured by three different procedures (see Appendix 1 for experimental details). 

Formaldehyde Removal By Gas Elution. These experiments involve the continuous collection of formaldehyde removed by a controlled flow of gas over the wood samples. Variables studied include time, gas flow rate, sample comminution, gas type, humidity, and adhesive type. 

Interpretation for Comminuted Systems. The similarities and differences noted for the kinetics of formaldehyde removal from UF and PF particleboards and from formaldehyde-sorbed wood are brought out more clearly by plotting relative formaldehyde losses versus time. Loss ratios, i.e., formaldehyde loss by any material divided by the UF board loss at the same time, are shown in Figures 10 and 11 included in Figure 10 are analogous ratios for resin data from formaldehyde liberation (weighing bottle test) and formaldehyde elution by toluene experiments (10). Examination of the data leads to the following additional comments ... 

Figure 10. Formaldehyde loss ratios at 20 percent relative humidity for various materials. (Formaldehyde removed from a material divided by that removed from urea-formaldehyde particleboard. Board elution by nitrogen. Resin liberation by weighing bottle test. PF = phenol-formaldehyde) (ML85 5437)...

Dimethyl hydantoin-formaldehyde polymer formaldehyde testing 2,4-Diaminophenol hydrochloride formaldehyde, removal Hydrogen peroxide... 

Mesoporous manganese oxide eatalysts for formaldehyde removal influenee of the eerium ineorporation... 

Mesoporous manganese oxide catalyst for formaldehyde removal... 

Other variantr of thLs type of pi cedine employ aodium bisulfite and sulfanilic aeid in place of ammonia to facilitate formaldehyde removal. 

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