I am a pathologist and would like to know just how hard it would be to convert the used formalin (10% formaldehyde in water) to a solution of methanol. It seems to me that I just need a long column and bubble hydrogen gas through it. When the hydrogen gas is able to make it all the way to the top of the column all the formalin should have been converted (I think) Is there more to it?
I own a band distillation unit and I'm hoping I then could distill the methanol to power my flex fuel truck.© BrainMass Inc. brainmass.com October 16, 2018, 7:32 pm ad1c9bdddf
As per your assumption, formaldehyde can be reduced to passing hydrogen gas.
However I'll mark your assumption as partially correct. Since formalin is usually 35-40% formaldehyde and ...
This solution explains how to concert formalin to formaldehyde in water. When the hydrogen gas is able to make it all the way to the top of the column all the formalin should be converted is determined.
Chemical Engineering: Stoichiometry and Mass Balance
Please see the attached file for the fully formatted problems. Just do A3 and A4, please.
A3. Solid calcium fluoride (CaF2) reacts with sulphuric acid to form solid calcium sulphate (CaSO4) and gaseous hydrogen fluoride (HF). The HF is then dissolved in water to form hydrofluoric acid. A source of calcium fluoride is fluorite ore containing 96% w/w CaF2 and 4% w/w SiO2.
In a typical hydrofluoric acid manufacturing process, fluorite ore is reacted with 93% w/w aqueous sulphuric acid, supplied in 15% excess of the stoichiometric amount. Ninety five percent (95%) of the CaF2 reacts with the acid. Some of the HF formed reacts with the dissolved silica (SiO2) in the reaction. The unreacted HF gas exiting from the reactor is subsequently dissolved in enough water to produce 60% w/w aqueous hydro fluoric acid.
(a) Determine the mass of 93%w/w acid in the feed.
(b) Calculate the quantity of fluorite ore needed to produce 2500 kg of 60% w/w acid. Assume all the SiO2 present in the ore reacts with HF. The reaction equations are:
CaF2 (s) + H2SO4(aq) ---> CaSO4(s) + 2 HF(g)
6 HF(g) + SiO2(aq) ---> H2SiF6(s) + 2 H2O(l)
Ca = 40, F = 19, H = 1, S = 32, O = 16, Si = 28
A4. Formaldehyde (CH2O) is manufactured by the catalytic oxidation of methanol using an excess of air. Formic acid (HCOOH) is also formed if conditions are not properly controlled. The reaction equations are as follows:
CH3OH + ½ O2 → CH2O + H2O --------- (1)
CH2O + ½ O2 → HCOOH --------- (2)
The product gases in a test run have the following composition:
Component Mol %
Determine the following:
(a) The molar ratio of feed air to feed methanol
(b) The per cent excess air based on the main reaction
(c) The conversion of methanol
(d) The yield of formaldehyde
(e) The selectivity of formaldehydeView Full Posting Details