RESEARCHING OIL CAPACITY OF MOSS FUSCUM PEAT TO THE COMMERCIAL OIL AND STABLE GAS CONDENSATE

RESEARCHING OIL CAPACITY OF MOSS FUSCUM PEAT TO THE COMMERCIAL OIL AND STABLE GAS CONDENSATE

Research article

Чухарева Н.В.¹, Рожкова Д.С.², Хадкевич И.А.³

₁К.х.н., доцент, кафедра транспортировки и хранения нефти и газа, Национальный исследовательский Томский политехнический университет;

₂Студент, 4 курс, Национальный исследовательский Томский политехнический университет;

₃Студент, 4 курс, Национальный исследовательский Томский политехнический университет

Abstract

The articles talks about influence of  fractional composition of moss fuscum peat on its oil capacity. The technique for determining oil capacity of peat are discribed. The experiments were carried out for hydrocarbons with different density (ρ =880 kg/m3 and ρ =770 kg/m3.

Key words: oil capacity (нефтеемкость), moss fuscum peat (верховой фускум торф), fraction (фракция).

At present the region of the Russian Federation characterized by having significant peat deposits start facing the problem of their development or water flooding. Primarily, it is connected with the increasing of incidence of peat autogenous ignition.

Complex processing of peat is conducted successfully in many countries. Previously, techniques of peat deposit development and methods of obtaining valuable products of the economy were implemented in our country too. Therefore, the Russian Federation has a considerable experience of work with such unique natural raw materials, which will be put into a new Complex Program of Rational environmental management.

One of the directions to realize the above mentioned Program can be getting the sorbents based on peat for oil spill and oil products removing. Therefore, the research aimed on studying sorbent properties of peats from different deposits is an important task.

The goal: studying  the sorbent capacity of peat.

The object of studying: the moss fuscum peat taken at “Temnoye” deposit. Research object features are given in Table 1.

Table 1. Features of studying object

Deposit	Type, kind of peat	Rate of peat decay, %	Code	Technical analysis, %			Elemental content, per % del
				Analitic humidity	Ash-content per dry fuel	Volatile content per dry fuel	C	H	O+N+S
Temnoye	highbog, fuscum	20	933-2	7,90	2,10	76,00	49,19	5,10	45,71

Experiment: peat was dried up to air-dry condition, crushed and divided into fractions, then we measured the humidity and ash-content using the method described in technique [1]. The data of fractions are given in Table 2.    

Table 2. Dependence of humidity and ash-content of moss fuscum peat on its fractional composition

Fraction № of moss peat	Fraction, mm	Analytic humidity, %	Ash-content per dry-fuel, %
1	0,25…0,5	7,4	5,0
2	0,5…1	8,0	4,5
3	1…2	8,5	4,6
4	2…3	9,2	4,6
5	3…4	11,4	5,0

Then the samples were studied to determine oil capacity . As a sorbtive, the commercial oil and stable gas condensate were used. Sorbtive features are shown in Table 3.

Table 3. Features of hydrocarbon

Code of hydrocarbons	Deposit	Some parameters of hydrocarbon quality GOST 51858-2002
		Density at 20 0C, kg/m3	Mass content, %	Mass content of chloride salts, mg/dm3	Mass content of sulfur, %	Fractional output (%) at 200 0C	Saturated vapor pressure, kPa
1	Vankorskoye (Krasnoyarsk region)	880,0	0,03	12,0	0,15	14,0	28,5
2	Myldzhinskoe gas-condensate (Tomsk region)	700,0	0,03	0,79	0,01	93,0	59,0

  Method of determining oil capacity of peat:

1. We found the mass of hydrocarbon which could be kept by grating trap. To do this, we weighed it (m₁) using the scales of 2^nd class of accuracy. 200 ml of oil or stable gas condensate was poured into a glass bowl. Grating trap was put into sorbtive for 10 minutes. The bowl with the grating trap was covered with watch glass. Then the grating trap was taken out of the bowl and put into the glass and let hydrocarbon flow for 10 minutes. The glass was covered too. After 10 minutes we weighed the mass of grating trap with hydrocarbon (m₂). The difference in masses (between m₁ and m₂) is the mass of hydrocarbon kept by grating trap.

m₁ – mass of grating trap, g;

m₂ – mass of grating trap with hydrocarbon, g;

m₃ – mass of hydrocarbon kept by grating trap, g.  

The room temperature was within +18 ⁰C while the experiment.

2. We determined the oil capacity of peat using the following technique. 3 g of one fraction of peat sample was put in the grating trap in an even layer. Then the grating trap was put into in hydrocarbon and the experiment was conducted according to abovementioned one. The hydrocarbon mass kept by the grating trap was found by:

N_e – oil capacity, 1 g of hydrocarbon/1 g of peat;

m₅ – mass of grating trap, peat and kept hydrocarbon, g;

m₄ – mass of grating trap and peat, g;

m_т – mass of peat sample, g.  

3. The obtained oil capacity N_e was counted per dry peat by the following:

m_тс – mass of absolute dry peat, g;

W^a_i – analytic hymidity of i peat sample, %.

N_ec – oil capacity per dry peat, 1 g of hydrocarbon/1 g of peat.

The experiments were carried out to achieve the result convergence: P=0,95, n=5, the range of oil capacity results was taken within the interval  ±2,5%.

The results obtained during the experiment are presented in Table 4.

Table 4. Influence of  fractional composition of moss fuscum peat on its oil capacity.  

Type of peat	Fraction	Code of hydrocarbons
		1	2
		Nе(Nес), 1 g of hydrocarbon/1 f of peat
Moss	1	1,98 (2,15) 2,08 (2,26) 2,59 (2,82) 2,19 (2,42) 1,25 (1,40)	1,87 (2,02)
	2		1,78 (1,93)
	3		1,71 (1,86)
	4		1,46 (1,61)
	5		1,13 (1,27)

The obtained results showed that fraction 3 and 4 have the largest oil capacity in the commercial oil, and the increasing of fraction size leads to decreasing oil capacity in stable gas condensate (Fig. 1).

Fig. 1. Influence of fraction composition of moss fuscum peat on oil capacity:

1 – the commercial oil of Vankorskoe deposit ρ =880 kg/m³;

2- stable gas condensate of Myldyzhanskoe deposit, ρ =700 kg/m³  

Thus, it can be concluded that the increasing of hydrocarbon density of small size fraction, according to [2], can be a barrio for penetration of hydrocarbon molecules into the particle as a small size fraction has a very compact structure.

It should be noted, that the oil capacity is influenced on not only by fraction size, but also it can be the porous structure, nature of the surface and, probably, the group composition of peat.

Conclusions:

1. Moss fuscum peat fractions having the sizes 1 to 2 mm and 2 to 3 mm sorbite the commercial oil (ρ=880 kg/m³) better.
2. The increasing of peat fraction size leads to the decreasing of oil capacity in stable gas condensate.
3. To increase oil capacity of peat, it should be dried to change its hydropath.

References

1. Lishtvan I.I., Korol N.T. Basic properties of peat and methods of their determination. Minsk: Science and technology, 1975. 320 pg.
2. Lych A. M. Peat hydrophilicity. – Minsk: Science and technology, 1991. – 256 pg.
3. Gamayunov N. I., Gamayunov S. N. Sorbtion in hydrophilic materials. – Tver: TSTU, 1997. – 160 pg.
4. Larionov N. S., Bogolitsyn K. G., Bogdanov M. V. and others. Features of sorbtion properties of moss peat to d- and p-metals // Chemistry of plant raw materials. – 2008. – № 4. – Pages 147 – 152.