Evaluation of the Sustainability of Integrated Hydrothermal Synthesis of Zeolites Obtained from Waste

Ferrarini, Suzana F.; Cardoso, Ariela M.; Alban, Luisa; Pires, Marçal J. R.

doi:10.21577/0103-5053.20180017

Acessibilidade / Reportar erro

Brasil

Journal of the Brazilian Chemical Society

Español English

Brasil

Español English

sumário « anterior atual seguinte »

Sumário

Articles • J. Braz. Chem. Soc. 29 (7) • July 2018 • https://doi.org/10.21577/0103-5053.20180017 copy

Evaluation of the Sustainability of Integrated Hydrothermal Synthesis of Zeolites Obtained from Waste

Authorship SCIMAGO INSTITUTIONS RANKINGS

The high Si and Al contents in the amorphous phase of coal fly ash have been used for its conversion into zeolites. This process converts a toxic low-value by-product into a product used in a number of environmental applications, but has the disadvantage of introducing contaminants. Despite the large number of studies on the conversion of fly ash into zeolites, few report this drawback or discuss the efficiency of the proposed processes from a technical or ecological perspective. In this respect, the present study conducts a detailed assessment of two routes for integrated hydrothermal synthesis of zeolites 4A and Na-P1 obtained from coal fly ash. The processes are evaluated and compared in relation to the presence of undesirable metals and elements in the different steps of synthesis, as well as the feedstock and final product. Different performance parameters are presented and applied in the assessment of both processes and the most sustainable is recommended.

Keywords:
coal fly ash; zeolite; contaminant; efficiency; sustainability

Test	Fly ash	Extract (IA)							Zeolitic product (IIA, NaP1)
	Fly ash	Volume	Element mass		Si recovery		Al recovery		mP / g	mZ / g	CEC	Purity
	m_FA / g	V_Ex / mL	m_{Si Ext.} / g	m_{Al Ext.} / g	Total / %	Amorphous / %	Total / %	Amorphous / %	mP / g	mZ / g	NH₄⁺ / (meq g^-1)	PZ / %
1	15.04	73	1.66	0.02	35	44	1.1	1.4	12.6	6.9	2.5	54
2	15.00	72	1.68	0.01	36	45	0.5	0.7	13.6	7.7	2.6	57
3	15.01	80	1.53	0.01	33	40	0.7	0.8	13.3	6.3	2.2	48
4	15.09	72	1.52	0.01	32	40	0.5	0.7	13.0	11.0	3.9	85
5	15.05	76	1.12	0.05	24	30	2.7	3.4	12.4	7.8	2.9	63
6	15.00	77	1.46	0.01	31	39	0.7	0.9	13.0	8.2	2.9	63
7	15.00	70	1.30	0.02	28	35	0.9	1.1	13.2	9.5	3.3	72
8	15.03	75	1.46	0.02	31	39	0.9	1.2	13.0	12.4	4.4	96
9	15.01	82	1.45	0.01	31	38	0.5	0.6	13.2	8.6	3.0	65
10	15.00	74	1.30	0.01	28	35	0.7	0.9	13.6	9.5	3.2	70
11	14.97	59	1.26	0.01	27	34	0.3	0.4	13.7	8.6	2.9	63
12	14.99	65	1.31	0.00	28	35	0.2	0.3	13.5	7.9	2.7	59
13	15.03	80	1.61	0.03	35	43	1.5	1.9	13.6	7.7	2.6	57
14	15.08	74	1.20	0.03	26	32	1.5	1.9	13.0	7.9	2.8	61
15	15.06	80	1.60	0.04	34	42	2.5	3.1	13.8	8.7	2.9	63
Average	15.02	74	1.43	0.02	31	38	1.0	1.3	13.2	8.6	3.0	65
SD	0.03	6	0.17	0.01	4	5	0.7	0.9	0.4	1.5	0.6	12
RSD / %	0.2	8	12	73	12	12	73	73	3	18	19	19

Element	Test - concentration / (mg L^-1)															Mean ± SD / (mg L^-1)	RSD / %	Recovery / %
Element	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	Mean ± SD / (mg L^-1)	RSD / %	Recovery / %
Ag	0.06	0.04	0.05	0.06	0.05	0.05	0.06	0.04	0.06	0.06	0.06	0.07	0.06	0.16	0.05	0.06 ± 0.03	50	35
As	2.3	2.1	2.3	2.3	1.8	2.1	2.0	2.0	2.3	2.4	2.4	2.6	2.0	2.1	2.3	2.2 ± 0.2	10	54
Ba	2.3	2.4	1.6	1.4	1.0	0.2	4.1	0.2	2.0	0.2	1.8	0.2	1.1	0.2	1.4	1.3 ± 1.1	83	2
Cr	0.1	0.1	0.1	0.2	0.0	0.1	0.5	0.1	0.1	0.1	0.1	0.2	0.1	0.1	0.1	0.1 ± 0.1	92	0.9
Cs	0.4	0.4	0.4	0.5	0.8	0.4	0.5	0.5	0.5	0.4	0.4	0.7	0.6	1.1	0.3	0.5 ± 0.2	36	14
Cu	0.05	0.06	0.06	0.06	0.07	0.07	0.07	0.09	0.1	0.05	0.12	0.09	0.1	0.1	0.07	0.08 ± 0.02	25	1.5
Fe	14	11	10	10	10	9	10	10	10	10	10	10	17	13	11	11 ± 2	18	0.2
Ga	1.6	1.3	1.7	1.4	1.5	1.5	1.5	1.5	1.4	1.7	1.5	1.6	1.6	1.6	1.7	1.5 ± 0.1	8	20
Li	0.4	0.2	0.3	0.1	0.7	0.3	0.3	0.7	0.3	0.4	0.3	0.3	0.8	0.9	0.5	0.4 ± 0.2	56	4
Mg	0.9	0.7	1.3	0.9	0.6	0.8	0.8	1.0	1.1	0.9	1.9	1.0	0.9	1.2	1.2	1.0 ± 0.3	32	0.4
Mn	0.09	0.06	0.08	0.07	0.05	0.05	0.05	0.06	0.08	0.06	0.09	0.06	0.07	0.06	0.06	0.07 ± 0.01	14	0.1
Ni	0.16	0.15	0.16	0.15	0.15	0.17	0.23	0.17	0.16	0.13	0.22	0.17	0.21	0.21	0.15	0.17 ± 0.03	18	4
Pb	0.4	0.1	0.2	0.2	0.7	0.2	0.7	0.4	0.4	0.3	0.3	0.6	1.1	0.9	0.4	0.5 ± 0.3	65	6
Rb	6.4	5.7	5.7	6.2	7.4	5.7	6.1	6.4	6.6	6.6	6.0	7.6	7.5	8.6	6.0	6.6 ± 0.8	13	34
Se	0.21	0.23	0.16	0.31	0.19	0.22	0.28	0.26	0.31	0.24	0.28	0.3	0.28	0.31	0.24	0.25 ± 0.05	20	8
Sr	0.13	0.09	0.11	0.1	0.07	0.09	0.15	0.1	0.13	0.1	0.18	0.1	0.13	0.1	0.13	0.11 ± 0.03	27	0.7
V	10	10	11	10	7	9	9	9	11	11	11	12	8	7	10	10 ± 1	14	51
Zn	1.8	1.3	1.8	1.5	2.1	1.7	2.2	2.7	2.4	1.7	4.8	3.2	7.5	4.4	2.3	3 ± 2	60	19
Al	153	228	222	110	165	87	53	335	370	550	269	138	154	126	627	239 ± 167	70	1.0
Si / (g L^-1)	18.9	18.7	19.6	17.9	17.7	21.6	20.3	20.1	16.1	19.9	23.0	23.7	19.1	21.2	14.7	19 ± 2	12	30

Test	Fly ash	Zeolitic product (IVA, 4A)
	m_FA / g	mP / g	mZ / g	CEC			Purity PZ / %
	m_FA / g	mP / g	mZ / g	Ca²⁺ /(meq g^-1)	Na⁺ /(meq g^-1)	Na/Ca	Purity PZ / %
1	15.04	8.1	7.8	5.6	5.7	1.0	97
2	15.00	8.2	6.2	4.4	6.0	1.4	76
3	15.01	7.4	6.4	5.0	6.2	1.2	86
4	15.09	7.6	6.3	4.8	6.0	1.3	83
5	15.05	5.3	4.0	4.4	6.9	1.6	76
6	15.00	7.1	5.4	4.4	6.3	1.4	76
7	15.00	6.3	5.8	5.4	6.9	1.3	93
8	15.03	7.0	5.8	4.8	6.3	1.3	83
9	15.01	7.3	6.0	4.8	7.5	1.6	83
10	15.00	6.4	5.6	5.1	6.2	1.2	88
11	14.97	6.2	4.3	4.0	6.5	1.6	69
12	14.99	6.3	5.3	4.9	7.6	1.6	84
13	15.03	7.9	7.6	5.6	7.5	1.3	97
14	15.08	6.0	4.3	4.2	7.1	1.7	72
15	15.06	7.9	7.0	5.1	6.6	1.3	88
Mean	15.02	7.0	5.9	4.8	6.6	1.4	83
SD	0.03	0.9	1.1	0.5	0.6	0.2	8
RSD / %	0.2	12	19	10	9	13	10

Test	Flyash	Residual ash	Extract							Zeolitic product
			(IB)							Na-P1 (VB)				4A (IVB)
			Volume	Element mass		Si recovery		Al recovery		mP / g	mZ / g	CEC	Purity	mP / g	mZ / g	CEC	Purity
	m_FA / g	mRA / g	V_Ex / mL	m_{Si Ext.} / g	m_{Al Ext.} / g	Total / %	Amorphous / %	Total / %	Amorphous / %	mP / g	mZ / g	NH₄⁺ / (meq g^-1)	PZ / %	mP / g	mZ / g	Ca²⁺ / (meq g^-1)	PZ / %
1	30.00	24.1	253	1.90	0.137	20.0	25	3.9	4.9	24.8	15.1	2.8	61	7.6	5.6	4.3	74
2	30.00	24.7	263	1.91	0.138	20.1	25	3.9	5.0	24.5	14.4	2.7	59	7.6	5.5	4.2	72
3	30.00	25.6	258	1.77	0.135	18.6	23	3.8	4.9	25.1	15.9	2.9	63	7.1	5.5	4.5	78
Mean	30.00	24.8	258	1.86	0.137	19.5	24	3.9	4.9	24.8	15.1	2.8	61	7.4	5.5	4.3	75
SD	0.01	0.8	5	0.08	0.002	0.8	1	0.0	0.1	0.3	0.7	0.1	2	0.3	0.1	0.2	3
RSD	0.03	3	2	4.2	1.1	4.2	4.2	1.1	1.1	1	5	4	4	4	1	4	4

Element	Effluent (III) and ratios / (mg L^-1)			Discharge limits and ratios / (mg L^-1)
Element	Process A	Process B	B/A	MPL^a a Brazilian wastewater discharge standards.37,54 nd: not determined.	A/MPL	B/MPL
Ag	0.03	1.22	40.7	0.1	0.3	12
Al	698	695	1.0	10	70	70
As	0.56	0.95	1.7	0.5	1	2
Ba	0.33	0.21	0.6	5	0.1	0.04
Be		0.02
Ca		1.67
Cd		0.03		0.2		0.2
Co		0.03
Cr	0.13	0.05	0.4	0.1	1.3	0.5
Cs	0.11	0.3	2.7
Cu	0.08	0.06	0.8	1	0.1	0.1
Fe	2.22	1.75	0.8	15	0.1	0.1
Ga	1.01	1.56	1.5
In		0.02
K		175
Li	0.1	0.19	1.9	10	0.01	0.02
Mg	0.41	0.68	1.7
Mn	0.04	0.01	0.3	1	0.04	0.01
Na	75,000	81,000	1.1
Ni	0.07	0.01	0.1	2	0.04	0.01
Pb	0.13	0.09	0.7	0.5	0.3	0.2
Rb	1.55	3.1	2.0
Se	0.14	0.18	1.3	0.3	0.5	0.6
Si	1.05	1,21
Si	1.05	1.21
Sr	0.03	0.04	1.3
Tl	nd	0.03
U	nd	0.03
V	2.43	5.5	2.3	1	2	6
Zn	1.66	0.77	0.5	5	0.3	0.2

Parameter		Integrated processes (this study)				A³³		B¹⁸
Parameter		A		B		A³³		B¹⁸
Fly ash		Candiota UB (Brazil)		Candiota UB (Brazil)		Puertollano (Spain)		un (Netherlands)
Total mass	m_FA / g	15.023 ± 0.03		30.001 ± 0.002		1,000		500
Silicon	m_{Si FA} / g	4.668 ± 0.01		9.321 ± 0.002		274		220
Aluminum	m_{Al FA} / g	1.785 ± 0.004		3.565 ± 0.002		145		132
Solvent	NaOH / (mol L^-1)	3		2		2		2
	m_{Na Ext} / g	6.21		13.8		138		99
Extract
Time	time / h	24		2		9		6
Temperature	T / ^oC	100		85		90		90
Liq/Solid ratio	L/S / (mL g^-1)	6.0		10.0		3		3
Volume	V_Ex / mL	74 ± 6		258 ± 3		3,000		1,250
Concentration	C_{si Ext} / (mL g^-1)	19,493 ± 2,391		7,235 ± 330		21,814		10,000
	C_{Al Ext} / (mL g^-1)	239 ± 167		531 ± 11		53		200
Recovery	Y_{si ext} / %	31		20		24		6
	Y_{Al ext} / %	1.0		4		0.1		0.2
Al source		powder Al		aluminate		Al effluent		aluminate
Al added	m _{Al ad} / g	1.4 ± 0.18		3.4 ± 0.2		63		8
Parameter		Integrated processes (this study)				A³³		B¹⁸
Parameter		A		B		A³³		B¹⁸
Zeolite		Na-P1	4A	Na-P1	4A	Na-P1	4A	Na-P1	4A
Mass	mP / g	13.2 ± 0.4	7.0 ± 0.9	24.8 ± 0.3	7.4 ± 0.1	817	425	515	40
						267	176
	Y_P / %	37 ± 4		25. ± 0.4		87		80
Silicon	m_Si.Z / g	1.8 ± 0.3	0.9 ± 0.2	2.3 ± 0.2	0.9 ± 1.4	86	63	44	5
	Sm_Si.Z / g	2.7		3.2		193		49
	I_Si / %	59 ± 8		44 ± 2		54		22
Aluminum	m_Al.Z / g	0.2 ± 0.2	0.9 ± 0.2	2 ± 3	0.82 ± 0.04	49	61	25	5
	Sm_Al.Z / g	1.9		2.7		135		30
	I_Al / %	60 ± 2		39 ± 1		53		21
CEC	Ca²⁺ / (meq L^-1)		4.8 ± 0.5		4.3 ± 1.6		5		4
	NH₄⁺ / (meq L^-1)	3.0 ± 0.6		2.8 ± 0.1
Effluent	V_Ef / mL	113 ± 9		447 ± 5		4,020		1,360
Ratio effluent/zeolite	R_{Ef. Z} / (mL g^-1)	8 ± 1		22 ± 1		5		6

Sociedade Brasileira de Química Instituto de Química - UNICAMP, Caixa Postal 6154, 13083-970 Campinas SP - Brazil, Tel./FAX.: +55 19 3521-3151 - São Paulo - SP - Brazil
E-mail: office@jbcs.sbq.org.br

Acompanhe os números deste periódico no seu leitor de RSS

[1] *e-mail: suzana.ferrarini@gmail.com