Lean gas

Adsorption. Adsorption processes have been used to recover hydrocarbons that are heavier than ethane from natural gas. Although the adsorption process has appHcations for the recovery of pentane and heavier hydrocarbons from lean gas, the percentage recovery of LPG components in these plants usually is low compared to the normal recovery of LPG in modem turboexpander or oil-absorption plants. 

Convergence was achieved rapidly in five iterations by using Eq. (13-88) as the criterion. Computed compositions for lean gas and rich oil are ... 

A typical diagram for the complete absorption of pentane and heavier components from a lean gas mixture is own in Fig. 14-9. The oil used as solvent for this case was assumed to be solute-free (i.e., Xo = 0), and the key component, butane, was identified as that component absorbed in appreciable amounts whose equiUbrium line is most... 

Schwachgas, n. poor gas, lean gas. schwachlegiert, a. Metal.) low-alloy, schwachlich, a. weak, feeble, frail, schwacb-sauer, -stiuerlicb, a. weakly acid. 

Vj = Mols/hr lean gas leaving absorber Vi = Gas leaving tray i, mols/hr Vj + i = Gas leaving tray, i + 1, mols/hr Vn = Vapor leaving bottom absorber tray, mols/hr Vn + 1 = Mols/hr rich gas entering absorber... 

The lean sponge oil enters the absorber on the top tray. The gas from the presaturator or from the primary absorber enters below the bottom tray. The rich sponge oil from the bottom is then returned to the main fractionator. The lean gas leaves the top of the absorber to an amine unit for H,S removal prior to entering the refinery fuel... 

Dry (lean) gas is natural gas containing insufficient quantities of hydrocarbons heavier than methane to allow their commercial extraction. 

Rich gas entering at bottom Gas absorbed Lean gas leaving absorber Gas leaving bottom tray Gas leaving tray 2 from top Lean oil... 

Models and Correlations. A multitude of different models and correlations have been proposed for prediction of the heat transfer coefficient at vertical surfaces in fast fluidized beds. To organize the various models in some context, it is helpful to consider the total heat transfer coefficient as comprised of convective contributions from the lean-gas... 

The lean/gas phase convection contribution has received the least attention in the literature. Many models in fact assume it to be negligible in comparison to dense phase convection and set hl to be zero. Compared to experimental data, such an approach appears to be approximately valid for fast fluidized beds where average solid concentration is above 8% by volume. Measurements obtained by Ebert, Glicksman and Lints (1993) indicate that the lean phase convection can contribute up to 20% of total... 

GRH A process for increasing the calorific value of a lean gas to make it suitable for use as a town gas, by thermal hydrogasification. Developed by British Gas. 

Checking for surge conditions and suitability of gas turbine units because of excess flow in case of syngas on account of it being a lean gas... 

Chemometric evaluation methods can be applied to the signal from a single sensor by feeding the whole data set into an evaluation program [133,135]. Both principle component analysis (PCA) and partial least square (PLS) models were used to evaluate the data. These are chemometric methods that may be used for extracting information from a multivariate data set (e.g., from sensor arrays) [135]. The PCA analysis shows that the MISiC-FET sensor differentiates very well between different lambda values in both lean gas mixtures (excess air) and rich gas mixtures (excess fuel). The MISiC-FET sensor is seen to behave as a linear lambda sensor [133]. It... 

If composition of absorbate is to be reduced below 100 ppm in lean gas product, consider following by chemical absorption or possibly adsorption. 

Fig. 24. Fitting of kinetic parameters to isothermal adsorption experiment—comparison of measured (meas) and calculated (calc) outlet NOx concentrations. Fresh catalyst, SV = 60,000 lU1, =200° , lean gas composition 145ppm NOx, 4% C02, 4% H20, 18% 02 (Giithenke et al, 2007a).

The calorific value of this gas is too high for direct use as town gas (470-500 Btu/standard cubic foot in the United Kingdom) and too low for SNG, However, by removing the CO> the calorific value is increased to about 870 Btu/standard cubic foot, which is useful for enriching lean gas (e.g. from an Imperial Chemical Industries (IC1) naphtha reformer) to town gas quality. Long has suggested that by enriching this gas with LPG (liquefied petroleum gas) a satisfactory SNG may be obtained. 

The flow diagram for a rich gas plant producing gas with a calorific value of 710 Biu/slandard cubic foot is shown in Fig. 1. The product is used to enrich lean gas from an IC1 (Imperial Chemical Industries) naphtha reformer which has a calorific value of about 320 Btu/standard cubic foot to the town gas standard of 500 Btu/standard cubic foot (56 Calories/cubic meter). Typical gas analyses arc given in Table 1. 

Hydrate Lean gas and rich gas with methanol Reference Ng et al. (1987b)... 

Offshore gas is supplied to consumers either treated or untreated, depending upon its landing point. Higher-pressure gas, about 60% of the total gas supply, is forwarded to the Gas Processing Plant at Karadagh. Lean gas from the GPP is supplied either to ... 

Further, the treated gas outlet pressure is limited by the allowable operating pressure (typically 11-15 bar) of the twin transmission lines, which supply Baku from the Karadagh Gas Distribution Station. This station is supplied by pipeline with treated lean gas from the Gas Plant. Gas from this station can also be directed to the storage facilities of Karadag and Kalmas. 

Lean gas the residual gas from the absorber after the condensable gasoline has been removed from the wet gas. 

Wet gas gas containing a relatively high proportion of hydrocarbons that are recoverable as liquids see also Lean gas. 

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