Obtaining of Acetic Acid from Birch Wood upon Its Complex Processing
2010
Nikolajs Vederņikovs, Māris Puķe, Irēna Krūma, Prans Brazdausks

Technical acetic acid is produced worldwide by 165 companies in quantities of 8.2 million t per year practically only from petroleum refining products. It is forecasted that the annual volume of production of technical acetic acid will increase up to 11.8 million t by 2015, and it will be necessary to produce its additional quantities from the renewable raw material, including from deciduous wood. According to the data of the department of Forestry of the Forest Service of Latvia, the birch wood resources in Latvia make up more than 150 million m3. Only the processing wastes of this wood make up more than 1 million m3 per year, from which environmental friendly and economically efficient production of 25 000 t of acetic acid is possible. Therefore, the aim of the present work was to develop theoretical principles of the technology for obtaining acetic acid from birch wood, using as the catalyst sulphuric acid, which is commonly used in furfural production. When compiling the program of the studies, technical ideas were employed, described in two new patents. Experiments were performed on an original pilot unit, enabling the modelling of the production process. All this enabled, for the first time in the world’s research practice, to investigate the deacetylation of hemicellulose polysaccharides of birch wood, and to find the basic regularities of the acetic acid formation process. It has been shown that the main parameters of the given process are the catalyst concentration as well as the temperature and duration of the process, which have a favourable effect on the formation dynamics and yield of acetic acid. With increasing catalyst concentration and temperature from 3 % to 9 % and from 410 K to 440 K, respectively, the acetic acid formation curves have maxima in the range 10- 30 min from the beginning of the process. With increasing these parameters in the specified ranges, the time of reaching the maximum decreases. With increasing these parameters in the specified ranges and the process duration from 10 to 120 min, the yield of acetic acid increases from 1.6 % to 95.4 %, while, upon decreasing the process duration to 40 min, its yield makes up 86.8 % from the theoretically possible one. Because the export of chemical products is economically much more profitable than the use of waste wood as the fuel, the obtained results may become the basis for the development of a new technology with the aim of organising the production of acetic acid in Latvia.


Keywords
bērza koksne, hemicelulozes, acetilgrupas, hemiceluložu deacetilēšana, etiķskābes iegūšana

Vederņikovs, N., Puķe, M., Krūma, I., Brazdausks, P. Obtaining of Acetic Acid from Birch Wood upon Its Complex Processing. Materials Sciences and Applied Chemistry. Vol.22, 2010, pp.57-63. ISSN 1407-7353.

Publication language
Latvian (lv)
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