Substantiation of the conditions of obtaining porous carbon materials from pyrolyzed wood wastes by chemical activation of H3PO4

Abstract

Introduction. The purpose of this publication is to search for alternative materials -food industry wastes; valuation of it's use in the production of porous carbon materials (PCM) for use in water treatment systems.Materials and methods. Pyrolyzed wood waste (PWW) of the meat processing industry as raw material for the production of sorbents. Chemical activation of PWW by orthophosphoric acid. Using the adsorption-desorption methods of nitrogen, the porous structure was determined at 77 K; mesopore distribution by size and mesopore's volume -by BJH-method; distribution of micropores by size -using QSDFT-method; volume of micropores -by Dubinin-Radushkevich method; subnanopor's volume -by QSDFT-method.Results and discussion. The microporous structure has the following characteristics: pore diameters are in the range of D mi =0,60-2,5 nm, mostly represented by pores with a diameter of 0,87; 1,56 nm; volume of micropores -V mi =0,091 cm Conclusion. An energy-saving method is proposed for the production of PCM from secondary «renewable» resources -PWW, for use in water treatment systems. ─── Food Technology─── ───

Study of internal mechanisms for establishment of the equilibrium state of water-alcohol mixtures in vodka technology

“…The ECA process leads to an increase in the water temperature to T1.1-1.2=310 K, which is unacceptable for the manufacture of WAMs, so the water flows (1.1, 1.2) are additionally cooled using a chiller (14).…”

“…Drinking water (0.0) through the open tap (9) enters the line for preparation of technological water, which consists of the following elements: − mechanical filter (1) of polypropylene fiber with a filtration rating of 5 μm, which removes mechanical impurities of more than 5 μm from the water; − carbon filter (2) with porous carbon materials (PCM), which is prepared from alternative materials -food industry wastes by method of chemical activation using H3PO4 (Kuzmin O., Shendrik T., Zubkova V., 2017) [14], which provides clearing of active chlorine, iron; − a mechanical filter (3) with a filtration rating of 1 μm which removes mechanical impurities from the water, which are in the form of weighted particles of varying degrees of dispersion sized by more than 1 μm; − a filter with ion exchange resin cationic type granules (4). The installation is equipped with mechanisms of automatic regeneration of ion exchange resin NaCl (6.0) and a drain of water concentrate from CaCl2 and MgCl2 (7.0); − a barrier filter (5), which is designed for control softened water filtration before supplying reverse osmosis with a particle lag rating of 1 μm.…”

Production of active coal from pyrolyzed wood wastes by alkaline activation of KOH

“…The received AC cleaned from activating agent with a usage of water for τ 4 =300-600 s and dried at a temperature T 7 =373-383 K up to a level of humidity W 4 =4-8% with the yield of AC Y 1 =70-80%, followed by fractioning with the help of MP residue on sieves with holes: d≥3,6•10 >d≥1,0•10 -3 [9]. Figure 1 shows the stages of AC production; Figure 2 -general scheme of AC obtaining as per experimental data at Table 1.…”

“…Benefits of chemical activation are one-step process; low activation temperature; short activation time; large yield; high surface; welldeveloped controlled microporosity [28]. Chemical activation involves usage of activating agent (ZnCl 2 [4], H 3 PO 4 [9,11,12,16,23,26], NaOH [28], KOH [27,28], et al), entered by impregnation, followed by carbonization of raw materials in the atmosphere of inert gases and activation [1].…”

“…This kind of raw material has a gigantic range of precursors (natural coal, peat, wood, carbonaceous wastes of various origins, etc.) [1][2][3][4][5][6][7][8][9][10][11][12]. Therefore, there is an urgent need to obtain AC from an alternative material.…”