Isobutane (R600A) Thermodynamic properties

Saturation tables by temperature and by pressure, superheated vapor table, p–h and T–s diagrams and constants of Isobutane (C₄H₁₀), computed with CoolProp. Any other state of Isobutane, from any two properties, in the State Explorer or the Worksheet.

Calculate a state of Isobutane Open it in the Worksheet

Constants

Formula: C₄H₁₀
Also known as: isobutane, Isobutane, ISOBUTANE, R600A, R600a, ISOBUTAN
CAS: 75-28-5
Molar mass: 58.122 g/mol
Normal boiling point (1 atm): -11.749 °C (261.4 K)
Critical temperature: 134.66 °C (407.81 K)
Critical pressure: 3.629 MPa
Critical density: 225.5 kg/m³
Triple point: -159.42 °C, 0.000022891 kPa
Acentric factor: 0.18353
Valid up to: 301.85 °C, 35 MPa

Saturation table

By temperature: saturated liquid (f) and saturated vapor (g).

Saturated Isobutane, by temperature
T °C	Psat kPa	vf m³/kg	vg m³/kg	hf kJ/kg	hfg kJ/kg	hg kJ/kg	sf kJ/(kg·K)	sg kJ/(kg·K)
-140	0.0015941	0.001385	11948	-78.98	465.24	386.26	-0.40886	3.0853
-120	0.036795	0.0014224	595.37	-43.322	449.75	406.43	-0.15946	2.7772
-100	0.37947	0.0014622	65.235	-6.395	434.59	428.19	0.067079	2.5769
-80	2.2705	0.001505	12.14	31.823	419.57	451.39	0.27588	2.4481
-60	9.2684	0.0015514	3.2662	71.413	404.44	475.86	0.47081	2.3683
-40	28.703	0.0016022	1.1427	112.51	388.84	501.35	0.65491	2.3227
-20	72.477	0.0016587	0.48339	155.3	372.31	527.61	0.83064	2.3013
0	156.96	0.0017224	0.23491	200	354.34	554.34	1	2.2972
20	302.22	0.0017958	0.12637	246.88	334.33	581.21	1.1647	2.3052
40	531.21	0.0018826	0.073174	296.28	311.52	607.8	1.3263	2.3211
60	869.16	0.0019892	0.044591	348.66	284.87	633.53	1.4863	2.3414
80	1343.8	0.002128	0.027994	404.73	252.58	657.31	1.6469	2.3621
100	1986.5	0.0023275	0.017638	465.9	211.03	676.94	1.8114	2.3769
120	2836.6	0.0026884	0.010555	536.26	150.2	686.46	1.9894	2.3714

Saturation table by pressure

By pressure: saturated liquid (f) and saturated vapor (g).

Saturated Isobutane, by pressure
P kPa	Tsat °C	vf m³/kg	vg m³/kg	hf kJ/kg	hfg kJ/kg	hg kJ/kg	sf kJ/(kg·K)	sg kJ/(kg·K)
1	-89.795	0.0014836	26.195	12.941	426.92	439.86	0.17557	2.5039
2	-81.594	0.0015015	13.671	28.728	420.77	449.49	0.25979	2.4564
3	-76.388	0.0015131	9.3538	38.867	416.85	455.72	0.312	2.4306
5	-69.342	0.0015292	5.8048	52.742	411.54	464.29	0.38127	2.4005
10	-58.78	0.0015544	3.0433	73.875	403.51	477.38	0.48232	2.3646
20	-46.853	0.0015843	1.598	98.249	394.26	492.51	0.59288	2.3351
30	-39.128	0.0016046	1.0967	114.34	388.14	502.48	0.66273	2.3213
50	-28.475	0.001634	0.68258	136.95	379.46	516.41	0.75706	2.3079
100	-12.085	0.001683	0.35815	172.75	365.4	538.15	0.89833	2.298
200	7.035	0.001747	0.187	216.23	347.57	563.79	1.0584	2.2989
300	19.757	0.0017948	0.12726	246.3	334.58	580.88	1.1627	2.305
500	37.713	0.0018718	0.07766	290.49	314.3	604.79	1.3079	2.3189
1000	66.186	0.0020279	0.038529	365.56	275.61	641.17	1.5358	2.348
2000	100.36	0.0023321	0.017486	467.08	210.15	677.23	1.8144	2.3771
3000	123.29	0.0027893	0.0095444	549.64	136.09	685.73	2.0221	2.3654

Diagrams

p–h diagram of Isobutane, with isotherms

T–s diagram of Isobutane, with isobars

Superheated vapor table

At each pressure, from its saturated vapor (Sat.) to higher temperatures.

Superheated Isobutane at 20 kPa (Tsat -46.853 °C)
T °C	v m³/kg	u kJ/kg	h kJ/kg	s kJ/(kg·K)
Sat.	1.598	460.55	492.51	2.3351
0	1.9405	521.88	560.69	2.6083
50	2.3022	598.07	644.12	2.8883
100	2.6623	685.97	739.22	3.1615
150	3.0216	785.49	845.92	3.4296
200	3.3804	896.06	963.67	3.6924
250	3.7388	1016.9	1091.7	3.9494
300	4.0971	1147.3	1229.2	4.2004

Superheated Isobutane at 50 kPa (Tsat -28.475 °C)
T °C	v m³/kg	u kJ/kg	h kJ/kg	s kJ/(kg·K)
Sat.	0.68258	482.28	516.41	2.3079
0	0.76807	520.96	559.37	2.4739
50	0.91537	597.47	643.24	2.7553
100	1.0609	685.53	738.58	3.0293
150	1.2056	785.14	845.43	3.2977
200	1.3498	895.78	963.28	3.5607
250	1.4937	1016.7	1091.4	3.8179
300	1.6374	1147.1	1229	4.069

Superheated Isobutane at 100 kPa (Tsat -12.085 °C)
T °C	v m³/kg	u kJ/kg	h kJ/kg	s kJ/(kg·K)
Sat.	0.35815	502.33	538.15	2.298
0	0.37704	519.38	557.08	2.3689
50	0.45302	596.44	641.74	2.653
100	0.5271	684.79	737.5	2.9281
150	0.60029	784.57	844.6	3.1972
200	0.67297	895.32	962.62	3.4606
250	0.74535	1016.3	1090.9	3.718
300	0.81753	1146.8	1228.5	3.9692

Superheated Isobutane at 200 kPa (Tsat 7.035 °C)
T °C	v m³/kg	u kJ/kg	h kJ/kg	s kJ/(kg·K)
Sat.	0.187	526.39	563.79	2.2989
50	0.22169	594.3	638.64	2.5471
100	0.26014	683.27	735.3	2.8249
150	0.2976	783.41	842.93	3.0953
200	0.33454	894.39	961.3	3.3594
250	0.37116	1015.5	1089.8	3.6174
300	0.40758	1146.1	1227.6	3.8689

Superheated Isobutane at 500 kPa (Tsat 37.713 °C)
T °C	v m³/kg	u kJ/kg	h kJ/kg	s kJ/(kg·K)
Sat.	0.07766	565.96	604.79	2.3189
50	0.082333	587.11	628.28	2.3931
100	0.099767	678.44	728.33	2.6806
150	0.11592	779.81	837.77	2.9556
200	0.13145	891.53	957.26	3.2223
250	0.14664	1013.2	1086.5	3.4818
300	0.16161	1144.1	1224.9	3.7344

Superheated Isobutane at 1 MPa (Tsat 66.186 °C)
T °C	v m³/kg	u kJ/kg	h kJ/kg	s kJ/(kg·K)
Sat.	0.038529	602.64	641.17	2.348
100	0.045913	669.24	715.15	2.5558
150	0.05522	773.36	828.58	2.8409
200	0.063709	886.56	950.27	3.1126
250	0.071789	1009.2	1080.9	3.3749
300	0.079627	1140.7	1220.4	3.6293

Superheated Isobutane at 2 MPa (Tsat 100.36 °C)
T °C	v m³/kg	u kJ/kg	h kJ/kg	s kJ/(kg·K)
Sat.	0.017486	642.26	677.23	2.3771
150	0.024545	758.18	807.27	2.7044
200	0.029745	875.7	935.19	2.9901
250	0.034348	1000.6	1069.3	3.2594
300	0.038651	1133.7	1211	3.518

Enthalpy and entropy are measured from Isobutane's own reference state (CoolProp's default). The textbooks' refrigerant tables use ASHRAE's: in the Worksheet, write reference ASHRAE.