In this ppt we have studied what is lactic acid and how it produce

1. DEPARTMENT OF CHEMICAL
ENGINEERING [2018]
SUBMITTED TO:
Engr. Zubair Hashmi
SUBMITTED BY:-
Wahab Baloch
[D-18-CH-52]
BE 8th Semester

2. Introduction: Lactic Acid
 Widely occurring organic acid
 Applications in industry, food , textile,
pharmaceutical
 White in solid
 Extremely
 DISCOVERY:-
 In 1780 discovered by a Swedish chemist
SCHEELE by sour milk.
 1839, FERMY from sugar , milk , starch ,
dextrin.
 1857, PASTEUR, discovered that it is not a
component of milk , but a metabolite that
certain microorganisms produced by
fermentation.

3. Property of Lactic Acid
 IUPAC NAME: 2- Hydroxy Propanoic Acid.
 CHEMICAL FORMULA: C3H6O3 or
CH3CHOHCOOH.
 MOLAR MASS: 90.08 g·mol−1
 MELTING POINT:
 L: 53 °C
 D: 53 °C
 D/L: 16.8 °C
 BOILING POINT: 122 °C.
 DENSITY: 1.206 g/ml at 25 °C

4. Structure of D(-) and L(+) Lactic Acid
Lactic acid is chiral, consist of 2 optical isomers.
When both added in equal quantity to form a
mixture is known as DL-lactic acid,
or racemic lactic acid.

5. Production of Lactic Acid

6. Synthesis of Lactic Acid
CHEMICAL SYNTHESIS:
:- used to produce racemic
mixture(DL -lactic acid).
:- LACTONITRILE is hydrolysed by
conc. Sulphuric acid to get lactic
acid and ammonium salt.
MICROBIAL SYNTHESIS:
:- used to produce pure L(+)
and D(-) lactic acid.
:- mainly CARBOHYDRATE
is a substrate for LAB’S
(LACTIC ACID BACTERIA)
& Rhizopus oryzae.

7. Lactic Acid Bacteria
LAB are an order of gram +ve,
acid tolerant, non sporulating ,
nonrespiring , rod / spherical
shaped share common
metabolic & physiological
characteristics.
Found in decomposing plants ,
milk products,
Produce lactic acid as major
metabolic end product of
carbs fermentation.

9. Classifications

10. Process
 Widely used method for the production of lactic acid is Batch
fermentation.
 In batch fermentation process the culture is first grown in a series of
inoculums vessels and after that transferred to the fermenter.
 The size of inoculum is usually 5–10% of the liquid volume in this
fermenter.
 The fermentation is usually kept at 35–45 °C and at pH 5–6.5 by
adding a suitable base, such as ammonium hydroxide.
 The acid synthesized is neutralized by calcium hydroxide or calcium
carbonate fermentation takes 1–2 days under optimal conditions.
 The yield of lactic acid after the fermentation stage is 90–95 wt%
 based on the initial sugar or starch concentration.
 Rate of fermentation depends mainly on the parameters such as pH,
temperature, initial substrate concentration and concentration of
nitrogenous nutrients.

11. Product recovery
 ION EXCHANGE CHROMATOGRAPHY.
 NEW MEMBRANE INTEGRATED
 TECHNOLOGY(NANOFILTERATION)
 Strong acid Cation Exchange Resin (Sulfonic
acid on Polyesterene).
 Foam separation technique.